Copper Content Research Articles

Mode of application of sulfonated graphene modulated bioavailable heavy metal contents and microbial community composition in long-term heavy metal contaminated soil

Nanomaterials are increasingly recognized for their potential in soil remediation. However, their impact on soil microbial communities in contaminated soil remains poorly understood. In this study, we investigated the dynamic effects of sulfonated graphene (SG) following one-time or repeated applications on heavy metal availability and soil microbial communities in long-term heavy metal-contaminated soil over 180 days. Our findings revealed that one-time SG application at 30 mg kg−1 significantly increased the bioavailable cadmium (Cd) and copper (Cu) contents by approximately 30 %–40 % after 2 and 180 days. Repeated SG applications, however, displayed no significant influence on heavy metal availability. One-time SG application, coupled with the increased available Cd, induced significant enrichment of some specific functional bacterial genera involved in glycan biosynthesis metabolism and biosynthesis of other secondary metabolites, thereby decreasing the available contents of heavy metals after 90 days. However, the shifts in bacterial community structure and function were subsequently partially recovered after 180 days. Conversely, repeated SG treatments led to minimal alterations after 90 days while leading to similar shifts in the bacterial community at 60 mg kg−1 after 180 days. The fungal community structure remained largely unaltered across all SG treatments. Intriguingly, SG treatments substantially stimulated fungal biomass, with the stimulation degree dependent on SG dosage. These results provide valuable insights for developing phytoremediation strategies, suggesting tailored SG applications during specific growth phases to optimize remediation efficiency.

Effects of copper doping on microstructural evolution and oxygen permeability of Ce0.8Sm0.2O2-δ-Sm0.6Sr0.4Fe1-xCuxO3-δ dual-phase oxygen permeable membranes

Ce0.8Sm0.2O2-δ(wt.70 %)-Sm0.6Sr0.4Fe1-xCuxO3-δ(wt.30 %) (SDC-SSFC) dual-phase oxygen permeable membranes were prepared by one-pot EDTA-citric acid combined complexing method. Effects of copper doping content on crystallographic phase, microstructure and oxygen permeability were deeply investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDXS). Systematic studies reveal that SDC as oxygen ion conductors and SSFC as electron conductor display an excellent synergistic effect only if a suitable doping content of copper was adopted. It can be found that Ce0.8Sm0.2O2-δ-Sm0.6Sr0.4Fe0.9Cu0.1O3-δ exhibits the highest oxygen permeation flux of up to about 0.61 ml cm−2 at 950 °C and lower oxygen permeation activation energy, which displays nearly a two-fold increase in oxygen permeability compared with the sample without any copper doping. If the copper doping content in B-site of SSFC perovskite exceeds about 30 %, a third phase, i.e., CuO, would appear in the bulk of SDC-SSFC dual-phase membrane and the grain size of CuO tend to gradually increase which would degrade the oxygen permeability of SDC-SSFC dual-phase membrane. Kinetical analysis showed that the critical membrane thickness (Lc) of Ce0.8Sm0.2O2-δ-Sm0.6Sr0.4Fe0.9Cu0.1O3-δ membrane is close to approximately 0.6 mm, i.e., if the membrane thickness is larger than 0.6 mm, its rate-determining step would transform into the bulk-diffusion exchange from surface exchange. Meanwhile, Ce0.8Sm0.2O2-δ-Sm0.6Sr0.4Fe0.9Cu0.1O3-δ membrane exhibits a stable oxygen permeation flux of up to 0.32 ml cm−2·min−1 in pure CO2 atmosphere for more than 120 h without any degradation.

Comparative Analysis of the Phytochemicals, Minerals, Antioxidant and Antimicrobial Activities of Aqueous and Ethanolic Extracts of Rauvolfia vomtoria Leafs

In this study, the phytochemicals, B vitamins, minerals, antioxidants and antimicrobial activities of aqueous and ethanolic extracts of Rauvolfia vomtoria leaves were determined and compared. Qualitative and quantitative phytochemical analysis, mineral and B vitamin composition, in vitro antioxidant capacity and antimicrobial properties of both extracts were determined using standard protocols. Precise analysis of R. vomtoria revealed that the moisture content of the leaves was 8.90%, ash content was 7.70% and crude fiber content was 20.00%. The carbohydrate content of the leaves was 41%, crude protein content was 17. 00% and total fat content was 5.28%. Cardiac glycosides, tannins, phenols, saponins, phytates, steroids, terpenoids and alkaloids were detected in both aqueous and ethanolic extracts. However, significantly higher concentrations of saponins, tannins, flavonoids, steroids, alkaloids, cardiac glycosides and phytates were detected in the ethanolic extract compared to the aqueous extract. There was no significant difference in the amount of phenols and terpenoids in the two extracts (p>0.05). The thiamine content in the aqueous extract was 0.20 whereas that in the ethanolic extract was 0.27. The riboflavin content was higher in the ethanolic extract (1.80) than in the aqueous extract (1.40). Similarly, the niacin content of the ethanolic extract was 0.81 whereas that of the aqueous extract was 0.81. There was no significant difference in the calcium, magnesium and phosphorus values recorded for the two extracts (p>0.05). In contrast, there was a significant difference in the sodium, potassium, zinc, iron and copper contents of the two extracts with the aqueous extract containing higher amounts of potassium and zinc. The aqueous and ethanolic extracts had zones of inhibition against Enterobacter faecalis, Klebsiella pneumoniae, Salmonella typhi, Cetrobacter freundii and Shigella flexlerii. However, the zone of inhibition of the ethanolic extract against the tested organisms was higher than that of the aqueous extract. At a concentration of 10%, the aqueous and ethanolic extracts showed 87.29% and 92.03% DPPH scavenging activity, respectively. The percentage of inhibitory activity of the extracts against DPPH radical increased in a dose-dependent manner, with the ethanolic extract showing the highest DPPH radical inhibitory activity at a concentration of 50%. The results confirm that ethanol is a suitable solvent for the extraction of biologically active molecules from R.vomtoria leaves.

Износостойкость и коррозионное поведение Cu-Ti-покрытий в растворе SBF

Introduction. Currently, titanium and its alloys have become the most popular metal implantable biomaterials. However, the main disadvantage of titanium alloys is low wear resistance due to high viscosity. It is known that copper-titanium coatings effectively improve the antibacterial properties of titanium alloy and at the same time increase its wear resistance. Purpose of the work is to study the effects of a solution simulating body fluid on corrosion properties, friction coefficient and the wear of copper-titanium coatings obtained by electrospark deposition method of the Ti-6Al-4V alloy. Method. A non-localized electrode consisting of copper and titanium granules in various ratios was used to form copper-titanium coatings on a titanium alloy by electrospark deposition. The structure of the coatings was examined using a DRON-7 X-ray diffractometer in Cu-Kα radiation and an X-max 80 energy dispersive spectrometer. The antibacterial activity of the deposited Cu-Ti coatings was studied on a non-pathogenic gram-negative culture of Escherichia coli. Polarization tests in SBF solution were carried out using a P-40X potentiostat with an impedance measurement module. The metal content in the SBF solution after immersion of the samples was measured using an ICP-MS 2000 mass spectrometer. The tribological characteristics of the coatings according to the ASTM G99-17 standard using the “ball-on-disk” scheme with sliding friction in the SBF solution at loads of 10 and 25 N were examined. Results and discussions. It is shown that the bactericidal activity of Cu-Ti coated samples to a non-pathogenic culture of Escherichia coli increased monotonously with an increase in copper content. With copper concentration increasing, the corrosion current density of the coatings increased from 3.455 to 17.570 μA/cm2. It is shown that the SBF solution accelerates the wear of a titanium alloy many times over due to its interaction with the electrolyte via the oxidative wear mechanism. The use of Cu-Ti coatings allows reducing the friction coefficient and greatly decreasing the wear of Ti-6Al-4V alloy in the presence of an electrolyte.

Application of soil amendments to reduce the transfer of trace metal elements from contaminated soils of Lubumbashi (Democratic Republic of the Congo) to vegetables

The extraction of copper and cobalt from mines has led to the contamination of agricultural soils by trace metal elements (TMEs) (e.g. Cu: 204 to 1355 mg/kg). The mining industry is one of the sources of metal discharges into the environment, contributing to water, soil, and air contamination and causing metabolic disorders in the inhabitants of the city of Lubumbashi (R.D. Congo). This study assessed the effectiveness of organocalcareous soil improvers applied to TME-contaminated soils to reduce their transfer to plants. Following a factorial design, increasing doses of organic soil improvers (chicken droppings and sawdust) and agricultural lime were applied to the soils of three market gardens (high, medium, and low Cu contamination). The experiment was monitored for 60 days. Soil physicochemical properties (pH, TOC, and total and available copper, cobalt, lead, cadmium, and zinc (mg/kg)) were determined for the three gardens and in the vegetable biomass. The daily consumption index of the vegetables was determined based on total TME content. The results show that organocalcareous soil improvers did not promote plant growth and survival on soils with high and medium levels of copper contamination. However, on soils with low copper content, organocalcareous soil improvers improved germination and plant survival and reduced the transfer of metals from the soil to the plants. The best germination and plant survival rates were obtained with the lightly contaminated market garden. In addition, the organo-limestone amendments applied to the soils slightly increased the soil pH from acidic to slightly acidic, with pH values ranging from (5.43 ± 0.07 to 7.26 ± 0.33). The daily vegetable consumption index obtained for cobalt in the low-contaminated garden ranged from (0.029 to 0.465 mg/60 kg/day), i.e. from 0.5 to 8.45 times higher than the FAO/WHO limit, unlike the other trace metals (Cd, Cu and Pb) for which the daily consumption index found was lower than the FAO/WHO limit. Organocalcareous soil improvers can only be applied to soils with low levels of TME contamination, but for soils with medium to high levels of metal contamination, new soilless production techniques such as hydroponics or bioponics are needed.

The orientation of intra-arc crustal fault systems influences the copper budget of magmatic-hydrothermal fluids

Some of the largest magmatic-hydrothermal copper ore deposits and deposit clusters are associated with arc-oblique fault systems. Whether this structural context impacts the geochemistry of hydrothermal fluids, including their copper contents, remains unknown. Here, we investigate the copper concentration and helium isotope signature of geothermal fluids as modern analogs of hydrothermal ore deposits in the Andes of central-southern Chile. We show that fault systems broadly parallel to the regional stress field facilitate the early release of fluids from deep primitive magmas. By contrast, fault systems oblique to the regional stress field prevent the early escape of fluids and promote magmatic enrichment in copper, volatiles, and ligands, enhancing the potential to form copper deposits. We conclude that the orientation of fault systems actively influences the copper budget of ascending hydrothermal fluids, explaining the contrasting distribution of metals along distinct structures often observed in porphyry-epithermal systems and other types of magmatic-hydrothermal deposits.

Performance and biotoxicity of electro-Fenton treatment of bisphenol A: Evaluation of copper recovered from microbial fuel cell cathodes for subsequent catalytic applications

A three-tank microbial fuel cell (MFC) is successfully constructed to achieve electromigration and is used in the electro-Fenton process to treat bisphenol A (BPA). The MFC system exhibits excellent mobility and efficiently aggregates Cu+ to the cathode. Under optimal operating conditions, the MFC achieves a maximum power density of 31.4 mW/m2, which is a 3.4-fold increase over that at 0.5 kΩ. Increasing the external resistance increased the MFC power output (ca 1.5 times) and copper ion migration (ca 4.6 times) while reducing the internal resistance of the system (ca 25.3 %). Surface analysis of the cathode carbon cloth shows a 5.5-fold increase in copper content at 1 kΩ over that at 0.5 kΩ. This also increases the oxygen reduction reaction rate, thereby increasing the H2O2 yield by 1.5 times. The recovered copper cathode at 1 kΩ exhibits the best catalytic degradation of BPA, removing 99.7 % of BPA in 180 min, increasing 1.4 and 1.8 times that obtained at 1.5 and 0.5 kΩ, respectively. The optimal operating conditions significantly increased the abundance of electrochemically active bacteria (Azospirillaceae) (3.2 %−41.7 %), indicating that the optimized MFC is favorable for the rapid acclimatization of electrochemically active bacteria.

Effect of Cu content on the microstructure and properties of sintered Fe-0.8C-xCu antifriction materials

Abstract Ferrous antifriction materials (FAMs) play a crucial role in powder metallurgy. Previous studies have primarily focused on exploring the antifriction properties of Fe-C-Cu materials with low copper content (0–5 wt%), while there have been fewer studies on high copper content FAMs. In this study, to investigate the effect of Cu content on the microstructure and properties of sintered FAMs, Fe-0.8C-xCu (x = 5–25 wt%) materials were prepared by powder metallurgy method. The density, microstructure, mechanical performance, friction and wear properties of the samples were analyzed. The results demonstrated a significant change in the relative density, hardness, friction and wear properties of sintered Fe-0.8C-xCu samples with increasing Cu content. Particularly, the Fe-0.8C-15Cu samples exhibited outstanding properties, with a relative density of 77.8%, a hardness of 43 HRB, crushing strength of 380 MPa, an average friction coefficient of 0.21, and a wear rate of 1.36 × 10−8 mm3 N·mm−1. The primary wear mechanisms of the Fe-0.8C-xCu specimens include abrasive wear, adhesion wear, chafing fatigue, pitting, and oxidation. This study aims to provide an experimental and theoretical basis for the development of ferrous antifriction materials suitable for heavy-load conditions.

Heavy Metal Contamination of Surface Sediments-Soil Adjoining the Largest Copper Mine Waste Dump in Central India Using Multivariate Pattern Recognition Techniques and Geo-Statistical Mapping

This detailed study assessed heavy metal contamination of sediments/soil near central India’s largest copper mining area using 38 sampling sites within 10 km of the mine using atomic absorption spectroscopy. This study utilized multivariate pattern recognition methods, namely hierarchical clustering analysis (HCA) and principal component analysis (PCA), for source identification. Twelve parameters, i.e., copper (Cu), manganese (Mn), cobalt (Co), zinc (Zn), nickel (Ni), lead (Pb), organic matter (OM), cation exchange capacity (CEC), soil pH, distance (D), and elevation (E) were analyzed. The hierarchical cluster analysis (HCA) was used to analyze the sample sites with similar metal contamination and principal component analysis (PCA) was used to analyze the relationship between the parameters as well as to identify sources of heavy metal pollution. Three major pollution hotspots were detected by AHC and were classified as unpolluted/low pollution sites (UPS: mean concentration factor of 1.35 for Cu), highly polluted sites (HPS: mean concentration factor of 22 for Cu), and extremely polluted sites (EPS: mean concentration factor of 74 for Cu). PCA revealed three hidden factors/components, namely PC1 (explaining 38% of the variability), PC2 (18% of the variability), and PC3 (14% of the variability). Metals showed strong positive loading in PC1, explaining the highest variability. The mean content of Cu in soil/sediment samples was 502.526 mg/kg. The mean copper content was 10 times higher than the natural crustal value of 45mg/kg, indicating severe pollution in several sites around the study area. Mapping of copper contamination was conducted to reveal the spatial distribution of copper contamination using QGIS. This study exposes the heavy metal contamination level in surface sediments/soil and the effectiveness of pattern recognition techniques for the assessment of multivariate datasets in discerning spatial disparities and identifying the contamination causes.

The influence of Cu on the microstructure and properties of TC4/Q345 high-entropy joints by laser welding

FeCoNiCrCu high-entropy alloy (HEA) and Cu foils were utilized as the intermediate layer to conduct laser welding of TC4 titanium alloy and Q345 steel. Welding is performed by adding single HEA and Cu/HEA double foils as interlayer respectively. We conducted in-depth studies on the microstructure and mechanical properties of the joint by stereomicroscopy, metallographic microscope, scanning electron microscope (SEM), micro-area X-ray diffraction (XRD), nanoindentation, electron backscatter diffraction (EBSD), and tensile testing. The results indicate that the position of the copper foil significantly affects the microstructure and performance of the joint. When the copper foil is on the TC4 side, its lower melting point causes a deeper keyhole, resulting in a narrower weld bead and then reduced content of Fe and Ti in the weld. Simultaneously, the increased proportion of Cu in the weld significantly enhances the content of Cu-rich phases. In the weld zone, we observed freely distributed Cu-rich phases and Ti-rich phases generated along the interface. Under tensile loads, cracks primarily initiate and propagate along the Cu-rich phases, leading to typical delamination on the fracture surface. With the copper foil on the TC4 side, due to the increased copper content in the microstructure, the hardness of the interface between the titanium alloy and the weld decreases, while the joint exhibits the highest tensile strength, reaching a maximum of 417 MPa.

Gandouling ameliorates liver injury in Wilson's disease through the inhibition of ferroptosis by regulating the HSF1/HSPB1 pathway.

Ferroptosis, an iron-dependent form of cell death, plays a crucial role in the progression of liver injury in Wilson's disease (WD). Gandouling (GDL) has emerged as a potential therapeutic agent for preventing and treating liver injury in WD. However, the precise mechanisms by which GDL mitigates ferroptosis in WD liver injury remain unclear. In this study, we discovered that treating Toxic Milk (TX) mice with GDL effectively decreased liver copper content, corrected iron homeostasis imbalances, and lowered lipid peroxidation levels, thereby preventing ferroptosis and improving liver injury. Bioinformatics analysis and machine learning algorithms identified Hspb1 as a pivotal regulator of ferroptosis. GDL treatment significantly upregulated the expression of HSPB1 and its upstream regulatory factor HSF1, thereby activating the HSF1/HSPB1 pathway. Importantly, inhibition of this pathway by NXP800 reversed the protective effects of GDL on ferroptosis in the liver of TX mice. In conclusion, GDL shows promise in alleviating liver injury in WD by inhibiting ferroptosis through modulation of the HSF1/HSPB1 pathway, suggesting its potential as a novel therapeutic agent for treating liver ferroptosis in WD.

Influence of substitution of Cr by Cu on phase equilibria and microstructures in the Fe–Ni–Co–Cr high-entropy alloys

The article describes how substitution of chromium by copper affects phase equilibria in Fe–Ni–Co–Cr high-entropy alloy. The alloys with copper content ranging from 0 to 20 % (at.) of Cu were prepared. The alloys were equilibrated at 900, 800, 700, and 650 °C. The samples were investigated by electron microscopy, EDX spectroscopy, and EBSD method. The face-centred cubic phases have only occurred in equilibrated alloys: austenite matrix, copper-rich FCC(Cu) phase, and regions containing these phases. The compositions of equilibrated samples at annealing temperatures are given. Fine microstructures including a semicoherent FCC phase rich in Cu and an FCC phase including the main magnetic elements (Fe, Co, Ni) were formed. The experimental results were compared with the calculated phase equilibria obtained by the CALPHAD method.

Electrochemical survey of electroactive microbial populations in deep-sea hydrothermal fields

Electric discharge in deep-sea hydrothermal fields leads us to expect the existence of electroactive microbial ecosystems in the environments. Electrochemical properties such as electric field distribution on the seafloor and electrical conductivity of the rock can be useful indicators of searching electroactive microbial community in natural environments. We performed electric field measurements in deep-sea hydrothermal fields and collected rock samples by a remotely operative vehicle (ROV) operation. Several spots on the seafloor with strong electric fields were detected, which included both active hydrothermal vent areas and inactive sulfide deposits far from the vents. The electrical conductivity of the rock samples was correlated with the copper and iron sulfide content. Microbial community compositions of the rock samples were characterized by small subunit (SSU) rRNA gene amplicon sequencing analysis. The abundance of several microbial components, which are highly related to electroactive microorganisms such as Geobacteraceae and Thiomicrorhabdus, was affected by the electrical properties of rock samples. The results suggested that electrochemical properties on the seafloor would be related to the abundance of possible electroactive microbial populations, and that the electrochemical survey may be a powerful tool for exploring electroactive ecosystems.

COPPER AND MICROPLASTIC EXPOSURE AFFECTS THE GILL GENE EXPRESSION OF COMMON CARP DURING SALTWATER CHALLENGE

The aim of the present study was to assess if pre-exposure to water copper and/or polyvinyl chloride microparticles affects the transcriptional responses of common carp, Cyprinus carpio, to saltwater exposure. Fish were exposed to 0.25 mg/L copper alone (Cu) or in the presence of 0.5 mg/L polyvinyl chloride microparticles (Cu-MPVC) for 14 days, followed by 72 hours of salt water exposure (0 to 13 ppt NaCl). The copper content in the gills and the expression of heat shock protein (hsp70) and cytochrome P450 family 1 (cyp1a) transcripts were examined. The results showed that gill copper levels increased significantly (P = 0.008) in the Cu and Cu-MPVC treatments after 14 days of exposure, compared to the control fish; the Cu and Cu-MPVC treatments had similar gill copper levels. After 14 days of exposure, branchial expression of the hsp70 and cyp1a genes was significantly up-regulated in the Cu and Cu-MPVC treatments. Exposure to salt water led to a significant down-regulation of the gene transcripts in all treatments after 24 h of exposure. At this point, the Cu and Cu-MPVC treatments showed transcripts similar to those of the control fish prior to saltwater exposure. The fish treated with Cu-MPVC showed significantly higher hsp70 expression 72 h after saltwater exposure than the other treatments. At this time point, the control and Cu fish had significantly lower cyp1a expression than before saltwater exposure. In conclusion, the present data suggest that copper exposure induces stress in the fish gills, and the presence of MPCV in the water hampers normal transcriptomic responses of the fish gills to saltwater exposure.

Impact of the copper load on the performance of Cu/UiO-67 in CO2 hydrogenation to ethanol at atmospheric pressure

CO2 hydrogenation to ethanol could be a potential approach to reduce dependence on fossil resources, but faces challenges related to product selectivity and catalyst stability. MOFs, particularly UiO-67, acting as a support for copper catalysts can contribute to overcoming these limitations by stabilizing intermediates, creating interfaces that protect active sites against deactivation and potentially generating synergistic effects that favor the formation of the C-C bond. In this scenario, the present work aims to synthesize Cu/UiO-67 for application in the CO2 hydrogenation to ethanol at atmospheric pressure. The impact of the copper loading (5–60 wt%) on the catalyst physical properties and ethanol productivity was evaluated. Using XRD, N2 physisorption, TEM-EDS, FTIR and H2-TPR, it was possible to confirm the maintenance of the UiO-67 structure, which begins to deform with increasing copper content. Catalytic results showed that ethanol, methanol, propanol, carbon monoxide, and acetaldehyde have been produced. The selectivity of alcohols is related to the amount of copper, decreasing at high contents, indicating the importance of active sites interaction with SBUs units in alcohols formations.

The potency of Thymus vulgaris seed extract in alleviating obesity complications and iron overload in obese rats

Natural products have long been recognized as valuable sources of bioactive compounds in therapeutic agents. Thymus vulgaris, commonly known as thyme and belonging to the Lamiaceae family, is widely distributed and extensively used in Egyptian folk medicine for its antibroncholitic, antispasmodic, carminative, and diuretic properties. However, there is a lack of research on the effects of T. vulgaris seed extract in mitigating obesity-induced iron overload in rats. Given its potent bioactive constituents, this study aimed to investigate the impact of T. vulgaris seed extract on iron overload associated with obesity by evaluating lipid profiles, iron status parameters—including plasma ferritin, total iron-binding capacity (TIBC), plasma transferrin, transferrin saturation percentage (TS%), and hepcidin gene expression in adipose tissue. About 30 flavonoids were identified in T. vulgaris seed extract using LC-MS. Among these, methoxyflavonoids were the most abundant metabolites. The administration of T. vulgaris seed extract to obese rats resulted in significant reductions in anthropometric features, hepcidin gene expression, cholesterol, triglycerides, low-density lipoprotein (LDL), TIBC, plasma ferritin, leptin, and iron and copper content in adipose tissue. Moreover, treatment with T. vulgaris extract led to a notable decrease in interleukin-6 (IL-6) levels (76.33 ± 4.31 ng/L and 40.83 ± 1.82 ng/L for low and high doses, respectively) compared to the obese control group (110.83 ± 5.82 ng/L). Conversely, plasma adiponectin levels were significantly increased with T. vulgaris supplementation (123.6 ± 7.9 µg/L and 217.4 ± 6.1 µg/L for low and high doses, respectively) compared to the obese group (54.6 ± 4.9 µg/L). Additionally, adipose tissue zinc levels were significantly elevated in response to T. vulgaris supplementation (2.54 ± 0.20 µg/g and 3.75 ± 0.14 µg/g for low and high doses, respectively) compared to the obese group (1.45 ± 0.23 µg/g). Our findings suggest that T. vulgaris could be a promising novel therapeutic agent for managing obesity-induced iron overload.

Investigating the interdependence of microstructure and properties in low-Cu content Al-Zn-Mg alloys via thermodynamic calculation

This paper redesigned the Al-Zn-Mg alloy composition by thermodynamic calculations and experiments, and also explained the precipitation strengthening of the 7xxx alloy. At a Zn/Mg ratio of 3.3–5.3, only the η phase is present. The η phase was experimentally verified as the main contributor to precipitation strengthening. The Al-7.6Zn-2.2Mg-0.2Cu-0.2Cr-0.4Mn-0.15Zr alloy exhibited excellent mechanical properties, with yield and tensile strengths of 510 MPa and 542 MPa under T6 treatment. The low copper content 7xxx alloy designed in this study achieves a yield strength exceeding 500 MPa solely through the compositional design of the Zn/Mg ratio.

Nutritional and phytochemical profile of a traditional beverage made from roasted roselle (Hibiscus sabdariffa) seeds

The consumption of locally available and affordable food with high nutritional properties is a recommended solution to prevalent undernutrition in low-income countries. The objective of this study was to investigate the nutritional and phytochemical profile of a traditional beverage made from roasted green or red roselle seeds. Proximate composition was determined using AOAC standard methods. Minerals and phytochemicals were quantified by atomic and molecular absorption spectrophotometry, respectively. The bioavailability of iron, zinc, and calcium was estimated using phytates/mineral molar ratios. A sensory analysis was conducted to evaluate the acceptability of the studied beverages, and their contribution to the Recommended Daily Intake of proteins, energy, iron, zinc, and calcium was also assessed. The beverage made from roasted green roselle seeds presented the highest content of proteins, fats, total fibres and energy, while the beverage made from roasted red roselle seeds was more concentrated in carbohydrates. Both beverages had similar contents of total phenols, oxalates, ascorbic acid but exhibited different phytates and carotenoids contents that were higher in the beverage made from roasted red roselle seeds. The mineral composition revealed higher contents of sodium, potassium, magnesium, phosphorus, zinc, and copper in the beverage made from roasted red roselle seeds, while iron and manganese were more concentrated in the beverage made from roasted green roselle seeds. A good bioavailability was observed for iron and zinc in the beverage made from roasted red roselle and green roselle seeds, respectively. An unfavourable calcium bioavailability was exhibited by both beverages. The consumption of 500 mL of the studied beverages, which were positively appreciated by the sensory test panel, could cover more than 100% of the Recommended Daily Intake of proteins, energy, zinc, and more than 50% of that of iron, for children up to 3 years old. The consumption of beverages made from roasted roselle seeds could be an efficient and affordable solution to undernutrition in low-income countries.

Soil Traits and Grapevine Rootstock Genotypes Modulate Arbuscular Mycorrhizal Rate and Species in a Mediterranean Environment

The soil microbiota is a key component of agroecosystems, and understanding its traits is crucial for effective agronomic management. Among beneficial microorganisms, arbuscular mycorrhizal fungi (AMFs) are mutually associated with grapevine (Vitis vinifera L.), enhancing the ability of this cropping system to adapt to soil conditions and bolstering its resistance and resilience against abiotic stresses, particularly drought, by promoting root growth and enhancing the roots’ absorption surface. The objective of this on-field study was to determine AMF species richness and diversity along with their relation to soil chemical, physical, and biological characteristics in two adjacent organic vineyards in Central Italy. The two tested vineyards of the autochthonous cv. Aleatico differed by the presence of grafted (Vitis berlandieri × V. riparia rootstock; AL-420) or own-rooted (ungrafted V. vinifera L.; AL-ORV) vines. To this aim, soil and root samples were collected and geo-referenced. Analysis of the AMF species colonizing roots of both AL-ORV and AL-420 revealed the presence of four species: Scutellospora alterata, Paraglomus laccatum, Acaulospora laevis, and A. baetica, with S. alterata being the most frequent. Mycorrhization parameters were higher in the roots of grafted plants compared to ungrafted ones. A high beta-glucosidase (BG):N-acetylglusosaminidase (NAG) ratio in two tested vineyards indicated that microbes utilized more cellulose than chitin and peptidoglycan as dominant C resources. A negative correlation between mycorrhization rate (MyCP) and BG was observed, likely because AMFs form mutualistic relationships with plants, depending on the host plant for carbon. Results revealed a positive correlation between the degree of mycorrhizal association and the species involved, with the presence of copper and nickel among metals. Negative correlations were found concerning soil clay content along with beta-glucosidase. In conclusion, the grapevine root system was characterized by a differential symbiotic relationship with AMF species, whose development is influenced by the root genotype, soil texture, and biochemistry. Specifically, the increased frequency of AMFs in relation to copper content strengthens the evidence of their role in maintaining a vine’s production capacity in the event of soil contamination by this element.

The effects of EDTA and Trichoderma species on growth and Cu uptake of maize (Zea mays) plants grown in a Cu-contaminated soil.

Metal contamination in soil poses a significant environmental concern worldwide, necessitating effective remediation strategies such as phytoremediation. The present study investigated the effects of EDTA dosage (1.5 and 3mmolkg-1) and two Trichoderma species (T. harzianum and T. aureoviride) on copper (Cu) content and growth of maize plants grown in a Cu-contaminated soil, as well as Cu fractionation in the soil. In the absence of EDTA, only inoculation with T. harzianum led to a significant increase in shoot biomass. Combining fungal inoculum with EDTA only yielded a significant increase in shoot biomass when using T. aureoviride at a low EDTA rate, highlighting the interplay between fungal species and EDTA rates on plant growth. Results also indicated that EDTA application increased Cu bioavailability, enhancing Cu dissolution and root (not shoot) Cu concentrations. Conversely, inoculation with both Trichoderma species reduced Cu mobility and bioavailability in soil, thereby decreasing the shoot Cu concentrations of plants. When combined with EDTA, only application of T. harzianum resulted in an enhanced shoot Cu concentration, whereas combined application of T. aureoviride and EDTA did not make a significant change compared to the corresponding control (no fungal inoculation, no EDTA), possibly due to a lower compatibility of the T. aureoviride isolate with EDTA. Our results demonstrated that EDTA application, in both non-inoculated and inoculated treatments, increased Cu availability by facilitating its redistribution and transformation from less plant-available fractions (residual, Fe/Mn oxide-bound, and carbonate-bound) to the more readily plant-available forms (water-soluble and exchangeable fractions). In conclusion, although individual Trichoderma application proved beneficial for phytostabilization by reducing Cu content and mitigating Cu toxicity in plants, the combined application of EDTA and a compatible Trichoderma isolate (here, the T. harzianum isolate) holds promise for enhancing the phytoextraction capacity of plants. Although using maize has the advantage of being a food crop, to optimize phytoextraction, plant species with superior metal tolerance and phytoextraction capabilities should be selected, exceeding those of maize.