NIR-activated quercetin-based nanogels embedded with CuS nanoclusters for the treatment of drug-resistant biofilms and accelerated chronic wound healing

We have developed multifunctional nanogels with antimicrobial, antioxidant, and anti-inflammatory properties, facilitating rapid wound healing. To prepare the multifunctional nanogels, we utilized quercetin (Qu) and a mild carbonization process to form carbonized nanogels (CNGs). These CNGs possess excellent antioxidative and bacterial targeting properties. Subsequently, we utilized the Qu-CNGs as templates to prepare nanogels incorporating copper sulfide (CuS) nanoclusters, further enhancing their functionality. Notably, the CuS/Qu-CNGs nanocomposites demonstrated an exceptional minimum inhibitory concentration against tested bacteria, approximately 125-fold lower than monomeric Qu or Qu-CNGs. This enhanced antimicrobial effect was achieved by leveraging near-infrared II (NIR-II) light irradiation. Additionally, the CuS/Qu-CNGs exhibited efficient penetration into the extracellular biofilm matrix, eradicating methicillin-resistant Staphylococcus aureus-associated biofilms in diabetic mice wounds. Furthermore, the nanocomposites were found to suppress proinflammatory cytokines, such as IL-1β, at the wound sites while regulating the expression of anti-inflammatory factors, including IL-10 and TGF-β1, throughout the recovery process. The presence of CuS/Qu-CNGs promoted angiogenesis, epithelialization, and collagen synthesis, thereby accelerating wound healing. Our developed CuS/Qu-CNGs nanocomposites have great potential in addressing the challenges associated with delayed wound healing caused by microbial pathogenesis.

Trace identification of cysteine enantiomers based on an electrochemical sensor assembled from CuxS@SOD zeolite

The nonchiral sensor concept based on a sodalite (SOD) zeolite loaded CuxS (CuxS@SOD) catalyst is proposed as a sensing platform for chiral cysteine (Cys) determination. Chiral Cys is analyzed by the difference of binding capacity between CuxS catalysts. The observed current in amperometric i-t curve (A i-t C) is always positive for the L-cysteine (L-Cys), while it is negative for the D-cysteine (D-Cys). Under differential pulse voltammetry (DPV) method, the characteristic current peak for the CuxS@SOD moves to right (positive potential position) with the addition of L-Cys while it moves to left (negative potential direction) with the addition of D-Cys, respectively. Cyclic voltammetry (CV) is consistent with DPV and discusses the diffusion control mechanism. In this work, the ultra-trace determination of cysteine enantiomers reaches the limit of detection (LOD) of 0.70 fM and 0.60 fM by the highly efficient CuxS catalyst restrained in the nanosized SOD zeolite cages of the opening window pores, respectively. The sensor opens up a novel potential prospect for achiral composite in the field of chiral recognition through electrochemical methods with extra-low concentration.

Photothermal and Acid-Responsive Fucoidan-CuS Bubble Pump Microneedles for Combined CDT/PTT/CT Treatment of Melanoma

Transdermal cancer therapy faces great challenges in clinical practice due to the low drug transdermal efficiency and the unsatisfactory effect of monotherapy. Herein, we develop a novel bubble pump microneedle system (BPMN-CuS/DOX) by embedding sodium bicarbonate (NaHCO3) into hyaluronic acid microneedles (MNs) loaded with fucoidan-based copper sulfide nanoparticles (Fuc-CuS NPs) and doxorubicin (DOX). BPMN-CuS/DOX can generate CO2 bubbles triggered by an acidic tumor microenvironment for deep and rapid intradermal drug delivery. Fuc-CuS NPs exhibit excellent photothermal effect and Fenton-like catalytic activity, producing more reactive oxygen species (ROS) by photothermal therapy (PTT) and chemodynamic therapy (CDT), which enhances the antitumor efficacy of DOX and reduces the dosage of its chemotherapy (CT). Simultaneously, DOX increases intracellular hydrogen peroxide (H2O2) supplementation and promotes the sustained production of ROS. BPMN-CuS/DOX significantly inhibits melanoma both in vitro and in vivo by the combination of CDT, PTT, and CT. In short, our study significantly enhances the effectiveness of transdermal drug delivery by constructing BPMNs and provides a promising novel strategy for transdermal cancer treatment with multiple therapies.

Guided screen for synergistic three-drug combinations

Combinations of three or more drugs are routinely used in various medical fields such as clinical oncology and infectious diseases to prevent resistance or to achieve synergistic therapeutic benefits. The very large number of possible high-order drug combinations presents a formidable challenge for discovering synergistic drug combinations. Here, we establish a guided screen to discover synergistic three-drug combinations. Using traditional checkerboard and recently developed diagonal methods, we experimentally measured all pairwise interactions among eight compounds in Erwinia amylovora, the causative agent of fire blight. Showing that synergy measurements of these two methods agree, we predicted synergy/antagonism scores for all possible three-drug combinations by averaging the synergy scores of pairwise interactions. We validated these predictions by experimentally measuring 35 three-drug interactions. Therefore, our guided screen for discovering three-drug synergies is (i) experimental screen of all pairwise interactions using diagonal method, (ii) averaging pairwise scores among components to predict three-drug interaction scores, (iii) experimental testing of top predictions. In our study, this strategy resulted in a five-fold reduction in screen size to find the most synergistic three-drug combinations.

Clearable Black Phosphorus Nanoconjugate for Targeted Cancer Phototheranostics

Therapeutic efficacy of synergistic photodynamic therapy (PDT) and photothermal therapy (PTT) is limited by complex conjugation chemistry, absorption wavelength mismatch, and inadequate biodegradability of the PDT-PTT agents. Herein, we designed biocompatible copper sulfide nanodot anchored folic acid-modified black phosphorus nanosheets (BP-CuS-FA) to overcome these limitations, consequently enhancing the therapeutic efficiency of PDT-PTT. In vitro and in vivo assays reveal good biocompatibility and commendable tumor inhibition efficacy of the BP-CuS-FA nanoconjugate because of the synergistic PTT-PDT mediated by near-infrared laser irradiation. Importantly, folic acid unit could target folate receptor overexpressed cancer cells, leading to enhanced cellular uptake of BP-CuS-FA. BP-CuS-FA also exhibits significant contrast effect for photoacoustic imaging, permitting its in vivo tracking. The photodegradable character of BP-CuS-FA is associated with better renal clearance after the antitumor therapy in vivo. The present research may facilitate further development on straightforward approaches for targeted and imaging-guided synergistic PDT-PTT of cancer.

Using 3D gastrointestinal tract in vitro models with microfold cells and mucus secreting ability to assess the hazard of copper oxide nanomaterials

BACKGROUND

Copper oxide nanomaterials (CuO NMs) are exploited in many products including inks, cosmetics, textiles, wood preservatives and food contact materials. Their incorporation into these products may enhance oral exposure in consumer, environmental and occupational settings. Undifferentiated and differentiated monocultures of Caco-2 cells are commonly used to assess NM toxicity to the intestine in vitro. However, the integration of other cell types into Caco-2 in vitro models increases their physiological relevance. Therefore, the aim of this study is to evaluate the toxicity of CuO NMs and copper sulphate (CuSO4) to intestinal microfold (M) cell (Caco-2/Raji B) and mucus secreting (Caco-2/HT29-MTX) co-culture in vitro models via assessment of their impact on barrier integrity, viability and interleukin (IL)-8 secretion. The translocation of CuO NMs and CuSO4 across the intestinal barrier was also investigated in vitro.

RESULTS

CuO NMs and CuSO4 impaired the function of the intestinal barrier in the co-culture models [as indicated by a reduction in transepithelial electrical resistance (TEER) and Zonular occludens (ZO-1) staining intensity]. Cu translocation was observed in both models but was greatest in the Caco-2/Raji B co-culture. CuO NMs and CuSO4 stimulated an increase in IL-8 secretion, which was greatest in the Caco-2/HT29-MTX co-culture model. CuO NMs and CuSO4 did not stimulate a loss of cell viability, when assessed using light microscopy, nuclei counts and scanning electron microscopy. CuO NMs demonstrated a relatively similar level of toxicity to CuO4 in both Caco-2/Raji B and Caco-2/HT29-MTX co- culture models.

CONCLUSIONS

The Caco-2/Raji B co-culture model was more sensitive to CuO NM and CuSO4 toxicity than the Caco-2/HT29-MTX co-culture model. However, both co-culture models were less sensitive to CuO NM and CuSO4 toxicity than simple monocultures of undifferentiated and differentiated Caco-2 cells, which are more routinely used to investigate NM toxicity to the intestine. Obtained data can therefore feed into the design of future studies which assess the toxicity of substances (e.g. NMs) and pathogens to the intestine (e.g. by informing model and endpoint selection). However, more testing with a wider panel of NMs would be beneficial in order to help select which in vitro models and endpoints to prioritise when screening the safety of ingested NMs. Comparisons with in vivo findings will also be essential to identify the most suitable in vitro model to screen the safety of ingested NMs.

Arsenic trioxide and/or copper sulfate induced apoptosis and autophagy associated with oxidative stress and perturbation of mitochondrial dynamics in the thymus of Gallus gallus

Arsenic (As) and copper (Cu) are ubiquitous environmental contaminants that are hazardous to the immune system. Our objective was to investigate the toxicity and potential mechanisms of thymus exposure to As and/or Cu. A chicken model was established by adding arsenic trioxide (As₂O₃; 30 mg/kg), copper sulfate (CuSO₄; 300 mg/kg), and simultaneously both elements in the basal diet. After the chickens were fed for 12 weeks, a significant reduction in antioxidant enzyme levels or production of malondialdehyde (MDA) emphasized the occurrence of oxidative stress. Furthermore, an imbalance in mitochondrial dynamics along with its abnormal structure certified mitochondrial dysfunction. Additionally, elevated levels of pro-apoptotic and autophagy genes and decreased levels of antiapoptotic genes were found in treated groups. Karyopyknosis and chromatin peripheral condensation were accompanied by an increased apoptosis ratio, as well as accumulation of autophagosomes, thus indicating that apoptosis and autophagy are involved in immune cell death. All of the above thymus lesions and index abnormalities occurred in a time-dependent manner, and the Cu and As co-administered groups showed more deteriorating effects than the Cu and As groups alone. Moreover, in the As or Cu group, the thymus tissue suffered different susceptibilities in oxidative toxicity, which needs further study. Collectively, our results manifested that co-exposure to As and Cu increased the oxidative burden and exacerbated mitochondrial dysfunction on the thymus. Additionally, apoptosis and autophagy may act as partners in inducing cell death in a cooperative manner in chicken thymus after As and/or Cu exposure.

Photodegradation of 17β-estradiol on silica gel and natural soil by UV treatment

This paper evaluates the UV photodegradation of 17β-estradiol (E2) on silica gel and in natural soil with different soil components. Silica gel was chosen as a stable and pure support to simulate the photochemical behavior of E2 on the surface of natural soil. Ultraviolet light, rather than visible light, was confirmed to play a decisive role in the photodegradation of E2 on silica gel. The effect of three soil components, including humic acid (HA), inorganic salts, and relative humidity (RH), on the photochemical behavior of E2 on silica gel or soil under UV irradiation was then evaluated. Two HA concentrations (10 and 20 mg g^-1) and three salts (ferric sulfate, copper sulfate and sodium carbonate) were observed to obviously inhibit the degradation of E2 on silica gel. Interestingly, nitrate was found to obviously improve the removal efficiency of E2. Both too-dry and too-wet conditions obviously reduced the removal rate of E2, and the optimum relative humidity (RH) value was found to be approximately about 35% (30 °C). Furthermore, twenty intermediate products and two major pathways were proposed to describe the transformation processes of E2 treated by UV irradiation, among which oligomers were found to be the major intermediate products before complete mineralization. The efficient UV removal of E2 on silica gel and natural soil suggested a feasible strategy to remediate E2 contaminated soil.

Characterization of Carboxylated Cellulose Nanocrytals Isolated through Catalyst-Assisted H2O2 Oxidation in a One-Step Procedure

A green and facile method was designed to isolate a type of cellulose nanocrystal (CNC) with carboxylated surfaces from native cellulose materials. Because isolation and modification processes of cellulosic particles are generally performed separately using harmful chemicals and multiple steps, the one-pot approach employed in this work is interesting from both an economical and ecological point of view. The reaction is carried out by adding hydrogen peroxide as an oxidant and copper(II) sulfate as a catalyst in acidic medium under mild thermal conditions. The charge content of the carboxylated CNC is about 1.0 mmol g^-1, measured by a conductometric titration. Fourier transform infrared spectroscopy also proved the presence of carboxyl groups on the CNC particles. Atomic force microscopy along with optical polarized microscopy readily showed a rod shape morphology for the cellulosic particles. An average length of 263 nm and width of 23 nm were estimated by transmission electron microscopy. Dynamic laser scattering on carboxylated CNC suspensions by adding salt confirmed that nanoparticles are electrostatically stable. Carboxylated CNCs were furthermore characterized by solid carbon-13 nuclear magnetic resonance and X-ray spectroscopy.

Degradation reaction of Diazo reactive black 5 dye with copper (II) sulfate catalyst in thermolysis treatment

The theme of present research demonstrates performance of copper (II) sulfate (CuSO₄) as catalyst in thermolysis process to treat reactive black 5 (RB 5) dye. During thermolysis without presence of catalyst, heat was converted to thermal energy to break the enthalpy of chemical structure bonding and only 31.62% of color removal. With CuSO₄ support as auxiliary agent, the thermally cleaved molecular structure was further destabilized and reacted with CuSO₄. Copper ions functioned to delocalize the coordination of π of the lone paired electron in azo bond, C=C bond of the sp² carbon to form C-C of the sp³ amorphous carbon in benzene and naphthalene. Further, the radicals of unpaired electrons were stabilized and RB 5 was thermally decomposed to methyl group. Zeta potential measurement was carried out to analyze the mechanism of RB 5 degradation and measurement at 0 mV verified the critical chemical concentration (CCC) (0.7 g/L copper (II) sulfate), as the maximum 92.30% color removal. The presence of copper (II) sulfate catalyst has remarkably increase the RB 5 dye degradation as the degradation rate constant without catalyst, k₁ is 6.5224 whereas the degradation rate constant with catalyst, k₂ is 25.6810. This revealed the correlation of conversion of thermal energy from heat to break the chemical bond strength, subsequent fragmentation of RB 5 dye molecular mediated by copper (II) sulfate catalyst. The novel framework on thermolysis degradation of molecular structure of RB 5 with respect to the bond enthalpy and interfacial intermediates decomposition with catalyst reaction were determined.

Sub-lethal effects of waterborne exposure to copper nanoparticles compared to copper sulphate on the shore crab (Carcinus maenas)

The toxicity of soluble copper (Cu) to marine organisms is reasonably well described. However, the hazard of Cu engineered nanomaterial (ENMs) is poorly understood. The aim of the present study was to compare the toxicity of Cu ENMs to Cu as CuSO₄ in the shore crab, Carcinus maenas. The crabs were exposed via the water using a semi-static approach to 0.2 or 1mgL^-1 of Cu ENMs or 1mgL^-1 of Cu as CuSO₄. Gills, hepatopancreas, chela muscle and haemolymph were collected at days 0, 4 and 7 for the body burden of Cu, histology and biochemical analysis [thiobarbituric acid reactive substances (TBARS) and total glutathione (GSH)]. Nominal exposure concentrations of both the ENMs and the metal salt were maintained at over 80% in each treatment throughout the experiment. By day 7, 54% mortality was recorded in the 1mgL^-1 CuSO₄ treatment, compared to just 21% in the 1mgL^-1 Cu ENM-exposed crabs. The target organs for Cu accumulation were similar for both forms of Cu with highest concentrations in the gills, particularly the posterior gills; followed by the hepatopancreas, and with the lowest concentrations in the chela muscle. No changes were observed in the osmolarity of the haemolymph (ANOVA, P>0.05). TBARS were measured as an indicator of lipid peroxidation and showed the greatest change in the anterior and posterior gills and hepatopancreas of animals exposed to 1mgL^-1 Cu ENMs (ANOVA or Kruskal-Wallis, P<0.05). No statistically significant changes in total GSH were observed (ANOVA, P>0.05; n=6 crabs per treatment). Histological analysis revealed organ injuries in all treatments. The types of pathologies observed in the Cu ENM treatments were broadly similar to those of the Cu as CuSO₄ treatment. Overall, the target organs and Cu accumulation from Cu ENMs were comparable to that following exposure to Cu as CuSO₄, and although there were some differences in the sub-lethal effects, the metal salt was more acutely toxic.

Impact of copper oxide nanomaterials on differentiated and undifferentiated Caco-2 intestinal epithelial cells; assessment of cytotoxicity, barrier integrity, cytokine production and nanomaterial penetration

BACKGROUND

Copper oxide nanomaterials (CuO NMs) are exploited in a diverse array of products including antimicrobials, inks, cosmetics, textiles and food contact materials. There is therefore a need to assess the toxicity of CuO NMs to the gastrointestinal (GI) tract since exposure could occur via direct oral ingestion, mucocillary clearance (following inhalation) or hand to mouth contact.

METHODS

Undifferentiated Caco-2 intestinal cells were exposed to CuO NMs (10 nm) at concentrations ranging from 0.37 to 78.13 μg/cm2 Cu (equivalent to 1.95 to 250 μg/ml) and cell viability assessed 24 h post exposure using the alamar blue assay. The benchmark dose (BMD 20), determined using PROAST software, was identified as 4.44 μg/cm2 for CuO NMs, and 4.25 μg/cm2 for copper sulphate (CuSO4), which informed the selection of concentrations for further studies. The differentiation status of cells and the impact of CuO NMs and CuSO4 on the integrity of the differentiated Caco-2 cell monolayer were assessed by measurement of trans-epithelial electrical resistance (TEER), staining for Zonula occludens-1 (ZO-1) and imaging of cell morphology using scanning electron microscopy (SEM). The impact of CuO NMs and CuSO4 on the viability of differentiated cells was performed via assessment of cell number (DAPI staining), and visualisation of cell morphology (light microscopy). Interleukin-8 (IL-8) production by undifferentiated and differentiated Caco-2 cells following exposure to CuO NMs and CuSO4 was determined using an ELISA. The copper concentration in the cell lysate, apical and basolateral compartments were measured with Inductive Coupled Plasma Optical Emission Spectrometry (ICP-OES) and used to calculate the apparent permeability coefficient (Papp); a measure of barrier permeability to CuO NMs. For all experiments, CuSO4 was used as an ionic control.

RESULTS

CuO NMs and CuSO4 caused a concentration dependent decrease in cell viability in undifferentiated cells. CuO NMs and CuSO4 translocated across the differentiated Caco-2 cell monolayer. CuO NM mediated IL-8 production was over 2-fold higher in undifferentiated cells. A reduction in cell viability in differentiated cells was not responsible for the lower level of cytokine production observed. Both CuO NMs and CuSO4 decreased TEER values to a similar extent, and caused tight junction dysfunction (ZO-1 staining), suggesting that barrier integrity was disrupted.

CONCLUSIONS

CuO NMs and CuSO4 stimulated IL-8 production by Caco-2 cells, decreased barrier integrity and thereby increased the Papp and translocation of Cu. There was no significant enhancement in potency of the CuO NMs compared to CuSO4. Differentiated Caco-2 cells were identified as a powerful model to assess the impacts of ingested NMs on the GI tract.

Quantitative methylene blue decolourisation assays as rapid screening tools for assessing the efficiency of catalytic reactions

Identifying the most efficient oxidation process to achieve maximum removal of a target pollutant compound forms the subject of much research. There exists a need to develop rapid screening tools to support research in this area. In this work we report on the development of a quantitative assay as a means for identifying catalysts capable of decolourising methylene blue through the generation of oxidising species from hydrogen peroxide. Here, a previously described methylene blue test strip method was repurposed as a quantitative, aqueous-based spectrophotometric assay. From amongst a selection of metal salts and metallophthalocyanine complexes, monitoring of the decolourisation of the cationic dye methylene blue (via Fenton-like and non-Fenton oxidation reactions) by the assay identified the following to be suitable oxidation catalysts: CuSO₄ (a Fenton-like catalyst), iron(II)phthalocyanine (a non-Fenton oxidation catalyst), as well as manganese(II) phthalocyanine. The applicability of the method was examined for the removal of bisphenol A (BPA), as measured by HPLC, during parallel oxidation experiments. The order of catalytic activity was identified as FePc > MnPc > CuSO₄ for both BPA and MB. The quantitative MB decolourisation assay may offer a rapid method for screening a wide range of potential catalysts for oxidation processes.

CuSO4/H2O2-Triggered Polydopamine/Poly(sulfobetaine methacrylate) Coatings for Antifouling Membrane Surfaces

Mussel-inspired polydopamine (PDA) coatings have been broadly exploited for constructing functional membrane surfaces. One-step codeposition of PDA with antifouling polymers, especially zwitterionic polymers, has been regarded as a promising strategy for fabricating antifouling membrane surfaces. However, one challenge is that the codeposition is usually a slow process over 10 h or even several days. Herein, we report that CuSO₄/H₂O₂ is able to notably accelerate the codeposition process of PDA with poly(sulfobetaine methacrylate) (PSBMA). In our case, PSBMA is facilely anchored to the polypropylene microporous membrane (PPMM) surfaces within 1 h with the assistance of PDA because of its strong interfacial adhesion. The PDA/PSBMA-coated PPMMs show excellent surface hydrophilicity, high water permeation flux (7506 ± 528 L/m²·h at 0.1 MPa), and an outstanding antifouling property. Moreover, the antifouling property is maintained after the membranes are treated with acid and alkali solutions as well as organic solvents. To recap, it provides a facile, universal, and time-saving strategy for exploiting high-efficiency and durable antifouling membrane surfaces.

Copper oxide nanoparticles and copper sulphate act as antigenotoxic agents in drosophila melanogaster

The biological reactivity of metal and metal oxide nanomaterials is attributed to their redox properties, which would explain their pro- or anti-cancer properties depending on exposure circumstances. In this sense, copper oxide nanoparticles (CuONP) have been proposed as a potential anti-tumoral agent. The aim of this study was to assess if CuONP can exert antigenotoxic effects using Drosophila melanogaster as an in vivo model. Genotoxicity was induced by two well-known genotoxic compounds, namely potassium dichromate (PD) and ethyl methanesulfonate (EMS). The wing-spot assay and the comet assay were used as biomarkers of genotoxic effects. In addition, changes in the expression of Ogg1 and Sod genes were determined. The effects of CuONP cotreatment were compared with those induced by copper sulfate (CS), an agent releasing copper ions. Using the wing-spot assay, CuONP and CS were not able to reduce the genotoxic effects of EMS exposure, but had the ability to decrease the effects induced by PD, reducing the frequency of mutant twin-spots that arise from mitotic recombination. In addition, CuONP and CS were able to reduce the DNA damage induced by PD as determined by the comet assay. In general, similar qualitative antigenotoxic effects were obtained with both copper compounds. The antigenotoxic effects of environmentally relevant and non-toxic doses of CuONP and CS may be explained by their ability to partially restore the expression levels of the repair gene Ogg1 and the antioxidant gene Cu,ZnSod, both of which are inhibited by PD treatment. Environ. Mol. Mutagen. 58:46-55, 2017. © 2016 Wiley Periodicals, Inc.

In ovo administration of copper nanoparticles and copper sulfate positively influences chicken performance

BACKGROUND

Copper (Cu) is a key trace mineral involved in a variety of physiological processes, and is commonly used in poultry production. However, regardless of the inclusion level the majority of Cu is excreted with poultry faeces. We hypothesise that in ovo administration will allow for better utilisation of Cu during embryo development than when supplied post-natally with feed to growing chickens. Thus, the objective of this study was to evaluate effects of in ovo administration of NanoCu and copper sulfate (CuSO4 ) on broiler chicken performance.

RESULTS

The study showed the positive influences of Cu nanoparticles and CuSO4 on broiler chickens performance. Body weight, at the end of the rearing period (day 42) was significantly higher in NanoCu (2206 g) and CuSO4 (2402 g) groups compared to the control group (2000 g). Both treatment groups had significantly lower feed conversion rate and mortality, and higher percentage of breast and leg muscles in the carcass versus control.

CONCLUSION

The in ovo application of Cu colloids may ensure an efficient penetration of Cu into the embryonic tissue with long lasting effects on postnatal growth. The method may provide a successful alternative to using Cu as a feed additive. © 2015 Society of Chemical Industry.

Template-Free 3D Microprinting of Metals Using a Force-Controlled Nanopipette for Layer-by-Layer Electrodeposition

A novel 3D printing method for voxel-by-voxel metal printing is presented. Hollow atomic force microscopy (AFM) cantilevers are used to locally supply metal ions in an electrochemical cell, enabling a localized electroplating reaction. By exploiting the deflection feedback of these probes, electrochemical 3D metal printing is, for the first time, demonstrated in a layer-by-layer fashion, enabling the fabrication of arbitrary-shaped geometries.

Catalytic thermolysis in treating Cibacron Blue in aqueous solution: Kinetics and degradation pathway

A thermal degradation pathway of the decolourisation of Reactive Cibacron Blue F3GA (RCB) in aqueous solution through catalytic thermolysis is established. Catalytic thermolysis is suitable for the removal of dyes from wastewater as it breaks down the complex dye molecules instead of only transferring them into another phase. RCB is a reactive dye that consists of three main groups, namely anthraquinone, benzene and triazine groups. Through catalytic thermolysis, the bonds that hold the three groups together were effectively broken and at the same time, the complex molecules degraded to form simple molecules of lower molecular weight. The degradation pathway and products were characterized and determined through UV-Vis, FT-IR and GCMS analysis. RCB dye molecule was successfully broken down into simpler molecules, namely, benzene derivatives, amines and triazine. The addition of copper sulphate, CuSO4, as a catalyst, hastens the thermal degradation of RCB by aiding in the breakdown of large, complex molecules. At pH 2 and catalyst mass loading of 5 g/L, an optimum colour removal of 66.14% was observed. The degradation rate of RCB is well explained by first order kinetics model.

Copper Nanoparticles and Copper Sulphate Induced Cytotoxicity in Hepatocyte Primary Cultures of Epinephelus coioides

Copper nanoparticles (Cu-NPs) were widely used in various industrial and commercial applications. The aim of this study was to analyze the cytotoxicity of Cu-NPs on primary hepatocytes of E.coioides compared with copper sulphate (CuSO₄). Cultured cells were exposed to 0 or 2.4 mg Cu L^-1 as CuSO₄or Cu-NPs for 24-h. Results showed either form of Cu caused a dramatic loss in cell viability, more so in the CuSO₄ than Cu-NPs treatment. Compared to control, either CuSO₄ or Cu-NPs significantly increased reactive oxygen species(ROS) and malondialdehyde(MDA) concentration in hepatocytes by overwhelming total superoxide dismutase (T-SOD) activity, catalase(CAT) activity and glutathione(GSH) concentration. In addition, the antioxidative-related genes [SOD (Cu/Zn), SOD (Mn), CAT, GPx4] were also down-regulated. The apoptosis and necrosis percentage was significantly higher after the CuSO₄ or Cu-NPs treatment than the control. The apoptosis was induced by the increased cytochrome c concentration in the cytosol and elevated caspase-3, caspase-8 and caspase-9 activities. Additionally, the apoptosis-related genes (p53, p38β and TNF-α) and protein (p53 protein) were up-regulated after the CuSO₄ or Cu-NPs treatment, with CuSO₄ exposure having a greater effect than Cu-NPs. In conclusion, Cu-NPs had similar types of toxic effects as CuSO₄ on primary hepatocytes of E.coioides, but toxicity of CuSO₄ was more severe than that of Cu-NPs.

Overmodulation of projections as signal-to-noise enhancement method in EPR imaging

A study concerning the image quality in electron paramagnetic resonance imaging in two-dimensional spatial experiments is presented. The aim of the measurements was to improve the signal-to-noise ratio (SNR) of the projections and the reconstructed image by applying modulation amplitude higher than the radical electron paramagnetic resonance linewidth. Data were gathered by applying four constant modulation amplitudes, where one was below 1/3 (Amod  = 0.04 mT) of the radical linewidth (ΔBpp  = 0.14 mT). Three other modulation amplitude values were used in this experiment, leading to undermodulated (Amod  < 1/3 ΔBpp), partially overmodulated (Amod  ~ 1/3 ΔBpp) and fully overmodulated (Amod  > > 1/3 ΔBpp) projections. The advantages of an applied overmodulation condition were demonstrated in the study performed on a phantom containing four shapes of 1.25 mM water solution of 2, 2, 6, 6-tetramethyl-1-piperidinyloxyl. It was shown that even when the overmodulated reference spectrum was used in the deconvolution procedure, as well as the projection itself, the phantom shapes reconstructed as images directly correspond to those obtained in undermodulation conditions. It was shown that the best SNR of the reconstructed images is expected for the modulation amplitude close to 1/3 of the projection linewidth, which is defined as the distance from the first maximum to the last minimum of the gradient-broadened spectrum. For higher modulation amplitude, the SNR of the reconstructed image is decreased, even if the SNR of the measured projection is increased.

Catalysis of CuSO4 for total organic carbon detection based on supercritical water oxidation

The catalytic effects of CuSO4 in total organic carbon (TOC) detecting processes based on supercritical water oxidation have been investigated. Using benzoic acid as a model pollutant, the presence of a CuSO4 catalyst can significantly decrease the reaction temperature and H2O2 multiple during the TOC detection processes. A better TOC conversion efficiency was obtained at a much lower temperature in the catalytic system compared with the non-catalytic condition. The use of the catalyst effectively lowered the necessary H2O2 multiple from 20.0 without catalyst to 3.0 in the catalytic system. The established device could detect the TOC concentration precisely in model wastewater without inorganic carbon (IC). Moreover, the detection of the practical wastewater was studied. Detection results were total carbon of wastewater rather than TOC of practical wastewater. A detection or removal unit of IC is necessary before it can be practically utilized.

Lethal and sublethal endpoints observed for Artemia exposed to two reference toxicants and an ecotoxicological concern organic compound

Swimming speed alteration and mortality assays with the marine crustacean Artemia franciscana were carried out. EC50 and LC50 values after 24-48h exposures were calculated for two reference toxicants, copper sulphate pentahydrate (CuSO4·5H2O) and Sodium Dodecyl Sulphate (SDS), and an ecotoxicological concern organic compound, Diethylene Glycol (DEG). Different end-points have been evaluated, in order to point out their sensitivity levels. The swimming speed alteration (SSA) was compared to mortality values and also to the hatching rate inhibition (literature data). SSA resulted to be more sensitive than the mortality and with a sensitivity comparable to (or even higher than) the hatching rate endpoint.

Assessment of the Polychlorinated Biphenyl (PCB) Occurrence in Copper Sulfates and the Influential Role of PCB Levels on Grapes

Copper sulfates (CuSO₄) are widely used as the primary component of fungicides in the grape industry. The agricultural-grade CuSO₄ that we collected from Chinese nationwide markets were found to be contaminated by polychlorinated dibenzo-p-dioxins and dibenzofurans and high levels of polychlorinated biphenyls (Σ₁₉PCBs: 0.32~9.51 ng/g). In the following research, we studied the impact of CuSO₄ application on PCB levels in grape products through a field experiment, and conducted a national survey to speculate the role that CuSO₄ played on the occurrence of PCB in grapes. In the field experiment, an obvious increase of PCBs in grape leaves (from 174 to 250 pg/g fw) was observed after Bordeaux mixture (the main component of which is CuSO₄) application. As to the main PCB congener in CuSO₄, the most toxic CB 126 (toxic equivalency factor = 0.1) also increased in grape peels (from 1.66 to 2.93 pg/g fw) after pesticide spray. Both the correlation study and the principal component analysis indicated that environmental factors were dominant PCB contributors to grapes, and grapes from e-waste dismantling area containing the highest PCBs also proved the notion. It is worth noting that this report describes the first research examining PCBs in CuSO₄ and its influence on agricultural products to date.

Micron-scale magnetic resonance imaging of both liquids and solids

We describe and demonstrate a novel apparatus for magnetic resonance imaging (MRI), suitable for imaging of both liquid and solid samples with micron-scale isotropic resolution. The apparatus includes a solenoidal radio-frequency microcoil with 170 μm inner diameter and a set of planar gradient coils, all wound by hand and supported on a series of stacked sapphire plates. The design ensures efficient heat dissipation during gradient pulses and also facilitates disassembly, sample changes, and reassembly. To demonstrate liquid state (1)H MRI, we present an image of polystyrene beads within CuSO4-doped water, contained within a capillary tube with 100 μm inner diameter, with 5.0 μm isotropic resolution. To demonstrate solid state (1)H MRI, we present an image of NH4Cl particles within the capillary tube, with 8.0 μm isotropic resolution. High-resolution solid state MRI is enabled by frequency-switched Lee-Goldburg decoupling, with an effective rotating frame field amplitude of 289 kHz. At room temperature, pulsed gradients of 4 T/m (i.e., 170 Hz/μm for (1)H MRI) are achievable in all three directions with currents of 10 A or less. The apparatus is contained within a variable-temperature liquid helium cryostat, which will allow future efforts to obtain MRI images at low temperatures with signal enhancement by dynamic nuclear polarization.

Effect of Copper Sulfate on Expression of Endogenous L1 Retrotransposons in HepG2 Cells (Hepatocellular Carcinoma)

The long interspersed element-1 (LINE-1 or L1) constitutes approximately 17% of human genome. The expression of these elements is deregulated upon exposure to environmental exposures resulting to genomic instability and cancer promotion. The effect of copper as essential elements in regulation of L1 expression remained to be elucidated. Using non-cytotoxic concentrations of the copper, the expression of endogenous L1 was analyzed by qPCR after 6 days of copper pretreatment in human hepatocellular carcinoma cells (HepG2). The results indicated that the expression of active L1 elements are significantly downregulated at concentrations of 12.5, 25, and 50 μM (p < 0.005). Our data imply that low-level copper exposure may have a protective effect to suppress the induction of L1 activity and decrease incidence of cancer-associated L1 mutagenesis. If this achievement is confirmed by further studies, it can be applied in the long-term goals of cancer prevention.

Optimization and validation of a method for the determination of the refractive index of milk serum based on the reaction between milk and copper(II) sulfate to detect milk dilutions

We report the use of a method to determine the refractive index of copper(II) serum (RICS) in milk as a tool to detect the fraudulent addition of water. This practice is highly profitable, unlawful, and difficult to deter. The method was optimized and validated and is simple, fast and robust. The optimized method yielded statistically equivalent results compared to the reference method with an accuracy of 0.4% and quadrupled analytical throughput. Trueness, precision (repeatability and intermediate precision) and ruggedness are determined to be satisfactory at a 95.45% confidence level. The expanded uncertainty of the measurement was ±0.38°Zeiss at the 95.45% confidence level (k=3.30), corresponding to 1.03% of the minimum measurement expected in adequate samples (>37.00°Zeiss).

A novel method for comparison of biocidal properties of nanomaterials to bacteria, yeasts and algae

Toxicity testing of nanomaterials (NMs) is experimentally challenging because NMs may interfere with test environment and assay components. In this work we propose a simple and reliable method--a 'spot test' to compare biocidal potency of NMs to unicellular microorganisms such as bacteria, yeasts and algae. The assay is straightforward: cells are incubated in deionized water suspensions of NMs for up to 24h and then pipetted as a 'spot' on agarized medium. Altogether seven bacterial strains, yeast and a microalga were tested. CuO, TiO2 and two different Ag NPs, multi-wall C-nanotubes (MWCNTs), AgNO3, CuSO4, 3,5-dichlorophenol, triclosan and H2O2 were analyzed. The biocidal potency of tested substances ranged from 0.1mg/L to >1000 mg/L; whereas, the least potent NMs toward all test species were TiO2 NPs and MWCNTs and most potent Ag and CuO NPs. Based on the similar toxicity pattern of the tested chemicals on the nine unicellular organisms in deionized water we conclude that toxicity mechanism of biocidal chemicals seems to be similar, whatever the organism (bacteria, yeast, alga). Therefore, when the organisms are not 'protected' by their environment that usually includes various organic and inorganic supplements their tolerance to toxicants is chemical- rather than organism-dependent.

Determination of low methylmercury concentrations in peat soil samples by isotope dilution GC-ICP-MS using distillation and solvent extraction methods

Most often, only total mercury concentrations in soil samples are determined in environmental studies. However, the determination of extremely toxic methylmercury (MeHg) in addition to the total mercury is critical to understand the biogeochemistry of mercury in the environment. In this study, N2-assisted distillation and acidic KBr/CuSO4 solvent extraction methods were applied to isolate MeHg from wet peat soil samples collected from boreal forest catchments. Determination of MeHg was performed using a purge and trap GC-ICP-MS technique with a species-specific isotope dilution quantification. Distillation is known to be more prone to artificial MeHg formation compared to solvent extraction which may result in the erroneous MeHg results, especially with samples containing high amounts of inorganic mercury. However, methylation of inorganic mercury during the distillation step had no effect on the reliability of the final MeHg results when natural peat soil samples were distilled. MeHg concentrations determined in peat soil samples after distillation were compared to those determined after the solvent extraction method. MeHg concentrations in peat soil samples varied from 0.8 to 18 μg kg(-1) (dry weight) and the results obtained with the two different methods did not differ significantly (p=0.05). The distillation method with an isotope dilution GC-ICP-MS was shown to be a reliable method for the determination of low MeHg concentrations in unpolluted soil samples. Furthermore, the distillation method is solvent-free and less time-consuming and labor-intensive when compared to the solvent extraction method.

Antioxidant properties and inhibitory effects of Satureja khozestanica essential oil on LDL oxidation induced-CuSO(4) in vitro

OBJECTIVE

To assess various antioxidative activities of Satureja khozestanica essential oil (SKE) and its effect on oxidation of low density lipoprotein (LDL) induced by CuSO4 in vitro by monitoring the formation of conjugated dienes and malondialdehyde (MDA).

METHODS

The formation of conjugated dienes, lag time and MDA were measured. Inhibition of this Cu-induced oxidation was studied in the presence of several concentrations of SKE. Also total antioxidant activity and free radical scavenging of SKE were determinated.

RESULTS

It was demonstrated that SKE was able to inhibit LDL oxidation and decrease the resistance of LDL against oxidation. The inhibitory effects of SKE on LDL oxidation were dose-dependent at concentrations ranging from 50 to 200 µg/mL. Total antioxidant capacity of SKE was (3.20±0.40) nmol of ascorbic acid equivalents/g SKE. The SKE showed remarkable scavenging activity on 2, 2-diphenyl-picrylhydrazyl, IC50 (5.30±0.11) ng/mL.

CONCLUSIONS

This study shows that SKE is a source of potent antioxidants and prevents the oxidation of LDL in vitro and it may be suitable for use in food and pharmaceutical applications.

Nanoparticles of copper stimulate angiogenesis at systemic and molecular level

Copper is a key element affecting blood vessel growth and muscle development. However, the ions released from Cu salts are toxic. Given their specific physicochemical properties, nanoparticles of Cu (NanoCu) may have different bioactivity and affect the development of blood vessel and muscles in a different manner than Cu salts. The objective of the study was to evaluate the influence of NanoCu on embryo development and angiogenesis at the systemic and molecular level, in experiments using a chick embryo model. Fertilized chicken eggs were divided into a control group, and groups injected with a placebo, CuSO₄ or NanoCu. Embryo development at the whole body level and molecular indices using an embryo chorioallantoic membrane model were measured during embryogenesis. The present study indicated for the first time that NanoCu have pro-angiogenic properties at the systemic level, to a greater degree than CuSO₄ salt. The properties of NanoCu were confirmed at the molecular level, demonstrating significant effects on mRNA concentration and on mRNA gene expression of all pro-angiogenic and pro-proliferative genes measured herein.

Effect of continuously dosing Cu(II) on pollutant removal and soluble microbial products in a sequencing batch reactor

The effects of synthetic wastewater that contained 20 mg/L Cu(II) on the removal of organic pollutants in a sequencing batch reactor were investigated. Results of continuous 20 mg/L Cu(II) exposure for 120 days demonstrated that the chemical oxygen demand (COD) removal efficiency decreased to 42% initially, followed by a subsequent gradual recovery, which peaked at 78% by day 97. Effluent volatile fatty acid (VFA) concentration contributed 67 to 89% of the influent COD in the experimental reactor, which indicated that the degradation of the organic substances ceased at the VFA production step. Meanwhile, the varieties of soluble microbial products (SMP) content and main components (protein, polysaccharide, and DNA) were discussed to reveal the response of activated sludge to the toxicity of 20 mg/L Cu(II). The determination of Cu(II) concentrations in extracellular polymeric substances (EPS) and SMP throughout the experiment indicated an inverse relationship between extracellular Cu(II) concentration and COD removal efficiency.

Effect of different glycation agents on Cu(II) binding to human serum albumin, studied by liquid chromatography, nitrogen microwave-plasma atomic-emission spectrometry, inductively-coupled-plasma mass spectrometry, and high-resolution molecular-mass spectrometry

The ability of human serum albumin to capture unbound copper under different clinical conditions is an important variable potentially affecting homeostasis of this element. Here, we propose a simple procedure based on size-exclusion chromatography with on-line UV and nitrogen microwave-plasma atomic-emission spectrometry (MP-AES) for quantitative evaluation of Cu(II) binding to HSA upon its glycation in vitro. The Cu-to-protein molar ratio for non-glycated albumin was 0.98 ± 0.09; for HSA modified with glyoxal (GO), methylglyoxal (MGO), oxoacetic acid (GA), and glucose (Glc), the ratios were 1.30 ± 0.22, 0.72 ± 0.14, 0.50 ± 0.06, and 0.95 ± 0.12, respectively. The results were confirmed by using ICP-MS as an alternative detection system. A reduced ability of glycated protein to coordinate Cu(II) was associated with alteration of the N-terminal metal-binding site during incubation with MGO and GA. In contrast, glycation with GO seemed to generate new binding sites as a result of tertiary structural changes in HSA. Capillary reversed-phase liquid chromatography with electrospray-ionization quadrupole-time-of-flight tandem mass spectrometry enabled detection and identification of Cu(II) coordinated to the N-terminal metal-binding site (Cu(II)-DAHK) in all tryptic digests analyzed. This is the first report confirming Cu(II)-DAHK species in HSA by means of high-resolution tandem mass spectrometry, and the first report on the use of MP-AES in combination with chromatographic separation.

Synthesis, characterization, biological activity of binuclear Co(II), Cu(II) and mononuclear Ni(II) complexes of bulky multi-dentate thiosemicarbazide

The chelation behavior of 9,10-dihydro-9,10-ethanoanthracene-11,12-dicarbonyl) bis (N-ethylhydrazine-1-carbothioamide) (H6ETS)(1) towards Co(2+), Ni(2+)and Cu(2+) have been studied. The spectral data revealed that the ligand acts as a bi- and/or mono-negative multi-dentate. The isolated Ni(II) and Cu(II) complexes are square-planar while the Co(II) is tetrahedral. EPR spectrum of Cu(II) complex confirmed simulated an axial spin-Hamiltonian exhibiting a four-line pattern with nitrogen super-hyperfine couplings originating from imine hydrazinic nitrogen atoms and possess a significant amount of tetrahedral distortion leading to a pseudo-square-planar geometry with unpaired electron has d(x(2)-y(2)) ground state. Also, the thermal behavior and kinetic parameters were determined. Furthermore, the title compounds were investigated for their antibacterial activity using inhibition zone diameter and for DNA degradation, superoxide-scavenging activity as well as hydroxyl radicals that generated by the oxidation of cytochrome c in L-ascorbic acid/CuSO4-cytochrome c system.

Copper (Cu)-silica nanocomposite containing valence-engineered Cu: a new strategy for improving the antimicrobial efficacy of Cu biocides

Copper (Cu) compounds are widely used as antibacterial/antifungal agents for protecting food crops. Prolonged use of Cu biocides would lead to undesirable Cu levels in agricultural soil. In the absence of a suitable alternative, prudent use of Cu biocides is required. This paper reports for the first time a composite material of sol-gel silica host matrix loaded with mixed-valence Cu as an alternative to conventional biocides. In this composite material, Cu is present in different oxidation states. The hydrophilic silica matrix serves as a water-dispersible delivery vehicle for antimicrobial Cu. It is hypothesized that a mixed-valence Cu system, specifically enriched with Cu(0) and Cu(I), will exhibit enhanced antimicrobial efficacy over traditional Cu(II) compounds. Materials were characterized by high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy for the determination of particle size, morphology, crystallinity, and Cu oxidation states. Antimicrobial studies against Xanthomonas alfalfae and Escherichia coli (minimum inhibitory concentration) showed improved efficacy in MV-CuSiNG treatment compared to CuSiNG and other controls. Phytotoxicity studies performed (in Vinca sp. and Hamlin orange) under greenhouse conditions showed that the newly prepared nanocomposite is safe for plants, demonstrating potential usefulness of the material in agricultural biocides.

[Effects of antiseptic on the analysis of greenhouse gases concentrations in lake water]

To gain insight into antiseptic effects on the concentrations of CO2, CH4, and N2O in lake water, antisepetic (CuSO4 and HgCl2) were added into water sample, and concentrations of greenhouse gases were measured by the gas chromatography based on water equilibrium method. Experiments were conducted as following: the control group without antisepetic (CK), the treatment group with 1 mL CuSO4 solution (T1), the treatment group with 5 mL CuSO4 solution (T2), and the treatment group with 0.5 mL HgCl2 solution (T3). All groups were divided into two batches: immediately analysis (I), and after 2 days analysis (II). Results showed that CuSO4 and HgCl2 significantly increased CO2 concentration, the mean CO2 concentration (Mco2) of CK (I) and CK (II) were (11.5 +/- 1.47) micromol x L(-1) and (14.38 +/- 1.59) micromol x L(-1), respectively; the Mco2 of T1 (I) and T1 (II) were (376 +/- 70) micromol x L(-1) and (448 +/- 246.83) micromol x L(-1), respectively; the Mco2 of T2 (I) and T2 (II) were (885 +/- 51.53) micromol x L(-1) and (988.83 +/- 101.96) micromol x L(-1), respectively; the Mco2 of T3 (I) and T3 (II) were (287.19 +/- 30.01) micromol x L(-1) and (331.33 +/- 22.06) micromol x L(-1), respectively. The results also showed that there was no difference in CH4 and N2O concentrations among treatments. Water samples should be analyzed as soon as possible after pretreatment. Our findings suggest that adding antiseptic may lead an increase in CO2 concentration.

A kinetic study on the formation of poly(4 aminodiphenylamine)/copper nanocomposite using UV-visible spectroscopy

The course of the reaction between copper sulfate (CuSO4) and 4-aminodiphenylamine (4ADPA) was monitored by UV-visible spectroscopy in p-toluene sulfonic acid (p-TSA). Formation of poly(4-aminodiphenylamine)/copper nanoparticle composite (P4ADPA/CuNC) was witnessed through the steady increase in absorbance at 410, 580 and >700 nm. The absorbance at 410 nm as well as >700 nm are correlated to the amount of P4ADPA/CuNC formation and was subsequently used to determine the rate of formation of P4ADPA/CuNC (RP4ADPA/CuNC) at any time during the course of the reaction. RP4ADPA/CuNC shows a first-order dependence on [4ADPA] and a half-order dependence on [CuSO4]. A kinetic rate expression was established between RP4ADPA/CuNC and experimental parameters such as [4ADPA] and [CuSO4]. The rate constant for the formation of P4ADPA/CuNC was 8.98 × 10(-3) mol(-0.5) l(0.5) s(-1). Field emission scanning electron and transmission electron micrographs revealed that the morphology of the P4ADPA/CuNC was influenced by the reaction conditions.

Stabilization of the inverse Laplace transform of multiexponential decay through introduction of a second dimension

We propose a new approach to stabilizing the inverse Laplace transform of a multiexponential decay signal, a classically ill-posed problem, in the context of nuclear magnetic resonance relaxometry. The method is based on extension to a second, indirectly detected, dimension, that is, use of the established framework of two-dimensional relaxometry, followed by projection onto the desired axis. Numerical results for signals comprised of discrete T1 and T2 relaxation components and experiments performed on agarose gel phantoms are presented. We find markedly improved accuracy, and stability with respect to noise, as well as insensitivity to regularization in quantifying underlying relaxation components through use of the two-dimensional as compared to the one-dimensional inverse Laplace transform. This improvement is demonstrated separately for two different inversion algorithms, non-negative least squares and non-linear least squares, to indicate the generalizability of this approach. These results may have wide applicability in approaches to the Fredholm integral equation of the first kind.

Synthesis of cuprous chloride and simultaneous recovery of Ag and Pd from waste printed circuit boards

A benign and effective process for cuprous chloride synthesis and simultaneously recovery of Ag and Pd from waste printed circuit boards (PCBs) was developed in the present study. The main merit of the process is that neither corrosive acid nor strong oxidant was used. The PCBs were firstly pretreated by thermal shock process to obtain metallic particles (MPs), then cuprous chloride was synthesized by reacting MPs with cupric sulfate in the presence of sodium chloride. The optimum [Formula: see text] (mL/g) ratio, [Cu]/[Cu(2+)] mole ratio, treatment time and operation temperature were 6, 0.95, 30 min and 60°C, respectively. Approximately 98.5% of Cu could be recovered from the PCBs through two synthesis circles. During the synthesis process, Ag and Pd could be simultaneously recovered by forming a stable chloride complex since Cu(2+) played the role of oxidant in the system. The recovery percentages of Ag and Pd were 93.9% and 95.3%, respectively. Accordingly, it is believed that the process developed in the current study is benign and practical for copper and precious metal (Ag, Pd) recovery from waste PCBs.

Comparative analysis of click chemistry mediated activity-based protein profiling in cell lysates

Activity-based protein profiling uses chemical probes that covalently attach to active enzyme targets. Probes with conventional tags have disadvantages, such as limited cell permeability or steric hindrance around the reactive group. A tandem labeling strategy with click chemistry is now widely used to study enzyme targets in situ and in vivo. Herein, the probes are reacted in live cells, whereas the ensuing detection by click chemistry takes place in cell lysates. We here make a comparison of the efficiency of the activity-based tandem labeling strategy by using Cu(I)-catalyzed and strain-promoted click chemistry, different ligands and different lysis conditions.

Fate and toxicity of CuO nanospheres and nanorods used in Al/CuO nanothermites before and after combustion

Although nanotechnology advancements should be fostered, the environmental health and safety (EHS) of nanoparticles used in technologies must be quantified simultaneously. However, most EHS studies assess the potential implications of the free nanoparticles which may not be directly applicable to the EHS of particles incorporated into in-use technologies. This investigation assessed the aquatic toxicological implications of copper oxide (CuO) nanospheres relative to CuO nanorods used in nanoenergetic applications to improve combustion. Particles were tested in both the as-received form and following combustion of a CuO/aluminum nanothermite. Results indicated nanospheres were more stable in water and slowly released ions, while higher surface area nanorods initially released more ions and were more toxic but generally less stable. After combustion, particles sintered into larger, micrometer-scale aggregates, which may lower toxicity potential to pelagic organisms due to deposition from water to sediment and reduced bioavailability after complexation with sediment organic matter. Whereas the larger nanothermite residues settled rapidly, implying lower persistence in water, their potential to release dissolved Cu was higher which led to greater toxicity to Ceriodaphnia dubia relative to parent CuO material (nanosphere or rod). This study illustrates the importance of considering the fate and toxicology of nanoparticles in context with their relevant in-use applications.

CuS2-passivated Au-core, Au3Cu-shell nanoparticles analyzed by atomistic-resolution Cs-corrected STEM

Au-core, Au3Cu-alloyed shell nanoparticles passivated with CuS2 were fabricated by the polyol method, and characterized by Cs-corrected scanning transmission electron microscopy. The analysis of the high-resolution micrographs reveals that these nanoparticles have decahedral structure with shell periodicity, and that each of the particles is composed by Au core and Au3Cu alloyed shell surrounded by CuS2 surface layer. X-ray diffraction measurements and results from numerical simulations confirm these findings. From the atomic resolution micrographs, we identified edge dislocations at the twin boundaries of the particles, as well as evidence of the diffusion of Cu atoms into the Au region, and the reordering of the lattice on the surface, close to the vertices of the particle. These defects will impact the atomic and electronic structures, thereby changing the physical and chemical properties of the nanoparticles. On the other hand, we show for the first time the formation of an ordered superlattice of Au3Cu and a self-capping layer made using one of the alloy metals. This has significant consequences on the physical mechanism that form multicomponent nanoparticles.

The challenge of sample-stabilisation in the era of multi-residue analytical methods: a practical guideline for the stabilisation of 46 organic micropollutants in aqueous samples

Water sample storage and stabilisation may affect data quality, if samples are managed improperly. In this study three stabilising strategies are evaluated for 46 relevant organic micro-pollutants: addition of the biocides (i) copper sulphate and (ii) sodium azide to water samples directly after sampling with subsequent sample storage as liquid phase and (iii) direct solid phase extraction (SPE), stabilising the samples by reducing the activity of water. River water and treated effluent were chosen as commonly investigated matrices with a high potential of biotransformation activity. Analyses were carried out for sample storage temperatures of 4 and 28°C for water samples stored as liquid phase and for sample storage temperatures of 4, 20 and 40°C for SPE cartridges. Cooling of water samples alone was not sufficient for longer storage times (>24h). While copper sulphate caused detrimental interferences with nitrogen containing heterocyclic compounds, sodium azide proved to be a suitable stabilising agent. The best results could be obtained for SPE cartridges stored cool. Recommendations for samples preservation are provided.

Analytical determination of bioactive compounds as an indication of fruit quality

The aim of this investigation was to determine the bioactive compounds in kiwifruit as an indication of quality after extraction using methanol and ethyl acetate. Using FTIR and three-dimensional fluorescence spectroscopy and electrospray ionization/MS, the contents of polyphenols, flavonoids, flavanols, and tannins, and the level of the antioxidant activity by 2, 2-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt, 1, 1-diphenyl-2-picrylhydrazyl, ferric-reducing/ antioxidant power, and cupric reducing antioxidant capacity assays were determined and compared. It was found that the methanol extracts of kiwifruit showed significantly higher amounts of bioactive acetate extracts. The cultivar Bidan, in comparison compounds and antioxidant activities than the ethyl with the classic Hayward, showed significantly higher bioactivity. For the first time, Bidan organic kiwifruit was analyzed for its antioxidant activities and compared with the widely consumed Hayward organic based on its bioactive compounds and fluorescence properties. Relatively high content of bioactive compounds and positive antioxidant and antiproliferative properties of kiwifruit determined by the advanced analytical methods justify its use as a source of valuable antioxidants. The methods used are applicable for bioactivity determination, in general, for any food products.

Toxicity of pendimethalin containing formulation and copper sulphate to chicken embryos

The aim of this study was to determine the individual and combined toxic effects of STOMP 330 EC herbicide (33% pendimethalin) and copper sulphate on the development of chicken embryos. On the first day of incubation chicken eggs were dipped in the solution or emulsion of the test materials for 30 minutes. Applied concentration of copper sulphate was 0.01% and of herbicide STOMP 330 EC was 1.25%. The chicken embryos were examined for the followings: rate of embryo mortality, body weight, type of developmental anomalies, macroscopic examination. Our teratogenicity study revealed that, the individual toxic effect of copper sulphate and pendimethalin containing herbicide formulation (STOMP 330 EC) were embryotoxic but not teratogenic in chicken. The combined administration of STOMP 330 EC and copper sulphate did not increase the embryotoxic effect.

Effects of coenzyme Q(10) on LDL oxidation in vitro

Coenzyme Q(10), a lipid soluble benzoquinone, has excellent antioxidant and membrane stabilizing properties in the cardiac tissue. The present study quantitatively investigated the effects of coenzyme Q(10) on in vitro LDL oxidation. The formation of conjugated dienes, malondialdehyde (MDA) and electrophoretic mobility were monitored as markers of the oxidation of LDL, respectively. Coenzyme Q(10) showed a decrease the formation of conjugated dienes and MDA, respectively, against oxidation in vitro. Coenzyme Q(10) also reduced electrophoretic mobility of the oxidized human LDL. Thus, results showed that the coenzyme Q(10) exhibits strong antioxidant activity in CuSO(4)-mediated oxidation of LDL (P<0.05) in vitro. The inhibitory effects of the coenzyme Q(10) on LDL oxidation were dose-dependent at concentrations ranging from 20 nM to 300 nM. Moreover, the effects of coenzyme Q(10) on LDL oxidation were compared with vitamin E and vitamin C. This study showed that coenzyme Q(10) is a potent antioxidant to protect LDL against oxidation in vitro and may be a good alternative to reduce the risk of atherosclerosis and coronary heart disease and other free radical associated health problems.

Evaluation of joint toxicity of nitroaromatic compounds and copper to Photobacterium phosphoreum and QSAR analysis

The individual toxicities of Cu and 11 nitroaromatic compounds to Photobacterium phosphoreum were determined. The toxicity was expressed as the concentrations causing a 50% inhibition of bioluminescence after 15 min exposure (IC(50)). To evaluate the joint effect between the metal ion and the 11 nitroaromatic compounds, the joint toxicity of Cu and 11 nitroaromatic compounds were measured at different Cu concentrations (0.2IC(50), 0.5IC(50) and 0.8IC(50)), respectively. The result shows that the binary joint effect between Cu and nitroaromatic compounds is mainly simple addition at the low Cu concentration (0.2IC(50)). However, an antagonism effect, 55% and 64%, was observed between Cu and 11 nitroaromatic compounds for Cu at medium and high concentrations (0.5IC(50) and 0.8IC(50)). Quantitative structure-activity relationship (QSAR) analysis was performed to study the joint toxicity for the 11 nitroaromatic compounds. The result shows that the toxicity of nitroaromatic compounds is related to descriptors of Connolly solvent-excluded volume (CSEV) and dipolarity/polarizability (S) at low Cu concentration. On the other hand, the toxicity is related to Connolly accessible area (CAA) at medium and high Cu concentrations. The result indicates that different QSAR models on complex mixtures need to be developed to assess the ecological risk in real environments. Using single toxic data to evaluate the toxic effect of mixtures may result in wrong conclusions.

Physicochemical and thermal characteristics of the sludge produced after thermochemical treatment of petrochemical wastewater

The present work describes the physicochemical and thermal characteristics of the sludge generated after thermochemical treatment of wastewater from a petrochemical plant manufacturing purified terephthalic acid (PTA). Although FeCl3 was found to be more effective than CuSO4 in removing COD from wastewater, the settling and filtration characteristics of FeCl3 sludge were poorer. Addition of cationic polyacrylamide (CPAA; 0.050kg/m3) to the FeCl3 wastewater system greatly improved the values of the filter characteristics of specific cake resistance (1.2 x 10(8) m/kg) and resistance of filter medium (9.9 x 10(8) m(-1)) from the earlier values of 1.9 x 10(9) m/kg and 1.7 x 10(8) m(-1), respectively. SEM-EDAX and FTIR studies were undertaken, to understand the sludge structure and composition, respectively. The moisture distribution in the CuSO4 sludge, FeCl3 sludge and FeCl3 + CPAA sludge showed that the amount of bound water content in the CuSO4 and FeCl3 + CPAA sludges is less than that of the FeCl3 sludge and there was a significant reduction in the solid-water bond strength of FeCl3 + CPAA sludge, which was responsible for better settling and filtration characteristics. Due to the hazardous nature of the sludge, land application is not a possible route of disposal. The thermal degradation behaviour of the sludge was studied for its possible use as a co-fuel. The studies showed that degradation behaviour of the sludge was exothermic in nature. Because of the exothermic nature of the sludge, it can be used in making fuel briquettes or it can be disposed of via wet air oxidation.

Hybrid nanomaterials. Not just a pretty flower

Combining copper(II) phosphate and proteins leads to the formation of hybrid nanostructures that are shaped like flowers and have enhanced catalytic activity and stability.

Protein-inorganic hybrid nanoflowers

Flower-shaped inorganic nanocrystals have been used for applications in catalysis and analytical science, but so far there have been no reports of 'nanoflowers' made of organic components. Here, we report a method for creating hybrid organic-inorganic nanoflowers using copper (II) ions as the inorganic component and various proteins as the organic component. The protein molecules form complexes with the copper ions, and these complexes become nucleation sites for primary crystals of copper phosphate. Interaction between the protein and copper ions then leads to the growth of micrometre-sized particles that have nanoscale features and that are shaped like flower petals. When an enzyme is used as the protein component of the hybrid nanoflower, it exhibits enhanced enzymatic activity and stability compared with the free enzyme. This is attributed to the high surface area and confinement of the enzymes in the nanoflowers.

The influence of EDDS on the metabolic and transcriptional responses induced by copper in hydroponically grown Brassica carinata seedlings

To improve the knowledge about the use of plants for the removal of toxic metals from contaminated soils, metabolic and transcriptional responses of Brassica carinata to different forms of copper (Cu) were studied. Two-week-old hydroponically grown seedlings were exposed for 24 h to 30 μM CuSO₄ or CuEDDS. CuSO₄ appeared to be more toxic than CuEDDS as roots showed higher levels of thiobarbituric acid reactive substances (TBARS) and increased relative leakage ratios (RLR), although the superoxide dismutase (SOD, EC 1.15.1.1) activity increased following both exposures. In CuSO₄-exposed seedlings the higher toxicity was underlined by increased transcription of lipoxygenases (EC 1.13.11.12) and NADPH oxidases (EC 1.6.99.6) and by the higher Cu accumulation in both tissues compared to CuEDDS exposure. The presence of EDDS increased Cu translocation, which resulted 5-times higher than when exposed to CuSO₄. Decreases in catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) activities together with increases of reduced glutathione (GSH) and tocopherols and a reduction of lipoic acid (LA) were observed in roots of CuSO₄-exposed seedlings. On the contrary, CuEDDS exposure induced a general increase in enzyme activities and decreases in ascorbate (AsA) and tocopherol levels. In the primary leaves, in both exposures Cu differently affected the oxidative stress responses indicating that the cellular redox balance was anyway maintained. EDDS plays a crucial role in B. carinata tolerance to oxidative stress induced by Cu and might be proposed to improve the efficiency of Cu phytoextraction.