In the last decade, several studies have reported enrichments of the heavy isotopes of moderately volatile elements in lunar mare basalts. However, the mechanisms controlling the isotope fractionation are still debated and may differ for elements with variable geochemical behaviour. Here, we present a new comprehensive dataset of mass-dependent copper isotope compositions (delta 65Cu) of 30 mare basalts sampled during the Apollo missions. The new delta 65Cu data range from +0.14 %o to +1.28 %o (with the exception of two samples at 0.01 %o and -1.42 %o), significantly heavier than chondrites and the bulk silicate Earth. A comparison with mass fractions of major and trace elements and thermodynamic constraints reveals that Cu isotopic variations within different mare basalt suites are mostly unrelated to fractional crystallisation of silicates or oxides and late-stage magmatic degassing. Instead, we propose that the delta 65Cu average of each suite is representative of the composition of its respective mantle source. The observed differences across geographically and temporally distinct mare basalt suites, suggest that this variation relates to large-scale processes that formed isotopically distinct mantle sources. Based on a Cu isotope fractionation model during metal melt saturation in crystal mush zones of the lunar magma ocean, we propose that distinct delta 65Cu compositions and Cu abundances of mare basalt mantle sources reflect local metal melt-silicate melt equilibration and trapping of metal in mantle cumulates during lunar magma ocean solidification. Differences in delta 65Cu and mass fractions and ratios of siderophile elements between low- and high-Ti mare basalt sources reflect the evolving compositions of both metal and silicate melt during the late cooling stages of the lunar magma ocean.
The pollution of metal ions triggers great risks of damaging biodiversity and biodiversity-driven ecosystem multifunctioning, whether microbial functional gene can mirror ecosystem multifunctionality in nonferrous metal mining areas remains largely unknown. Macrogenome sequencing and statistical tools are used to decipher linkage between functional genes and ecosystem multifunctioning. Soil samples were collected from subdams in a copper tailings area at various stages of restoration. The results indicated that the diversity and composition of soil bacterial communities were more sensitive than those of the fungal and archaeal communities during the restoration process. The mean method revealed that nutrient, heavy metal, and soil carbon, nitrogen, and phosphorus multifunctionality decreased with increasing bacterial community richness, whereas highly significant positive correlations were detected between the species richness of the bacterial, fungal, and archaeal communities and the multifunctionality of the carbon, nitrogen, and phosphorus functional genes and of functional genes for metal resistance in the microbial communities. SEM revealed that soil SWC and pH were ecological factors that directly influenced abiotic factor-related EMF; microbial diversity was a major biotic factor influencing the functional gene multifunctionality of the microbiota; and different abiotic and biotic factors associated with EMF had differential effects on whole ecosystem multifunctionality. These findings will
The socio-economic growth of a nation depends heavily on the availability of adequate infrastructure, which relies on essential materials like river sand (RS) and cement. However, the rising demand for RS, combined with its excessive extraction causing ecological damage, and its increasing cost, has raised significant concerns. At the same time, the production of cement contributes significantly to environmental damage, especially through CO2 emissions. In this scenario geopolymer technology has emerged as a sustainable alternative to cement, offering environmental benefits and reducing the carbon footprint of construction materials. This study investigates the impact of replacing RS with copper slag (CS) and laterite soil (LS) in geopolymer mortar (GM) on key properties such as setting time, flowability, compressive strength, and microstructure. The results showed that as LS content increased, setting time and flowability decreased considerably, while increasing CS content caused a reduction in these values. Unlike the other observed parameters, the compressive strength values showed no distinct upward or downward trend. Moreover, the microstructural analysis, including SEM, EDS, XRD, FTIR, TGA and BET, provided valuable insights to support the observed results across various mix designs. Overall, the findings highlight that optimised binary blends of CS, LS and RS not only improved the compressive strength but also enhanced the microstructural characteristics of geopolymer mortar, reinforcing their potential as sustainable and high-performance alternatives to conventional fine aggregates.
Environmental issues caused by plastic films promote the development of biodegradability packaging materials. Copper ion-modified nanocellulose films were prepared through a one-pot reaction and systematically investigated their structural characteristics, thermal stability, mechanical properties, antibacterial activity, and biodegradability. The results indicate that the film prepared by co-soaking CNCs and copper in NaOH solution for 12 h has favorable performance. Introduction of copper ions as crosslinkers increases tensile strength of film from 36.8 MPa to 56.4 MPa and water contact angle of film from 46 degrees to 92 degrees. Copper coordination also endows the film excellent antibacterial activity, inhibiting growth of Escherichia coli and Staphylococcus aureus. Moreover, biodegradability tests indicate that although the introduction of copper ions slightly reduce biodegradation rate of films, they could still be decomposed significantly within four weeks as burying in soil. This simple process for preparing cellulosic films with water resistance, thermal stable, antibacterial ability, and biodegradable shows potential application in flexible packaging film.
Copper (Cu) is a toxic metal that accumulates in soil due to agricultural and industrial activities, potentially impacting plant growth and productivity. Our study examined the phytotoxic effects of Cu on Vigna radiata L. by exposing plants to a series of Cu concentrations (1, 4 and 7 mM) under controlled conditions. Growth parameters, photosynthetic performance, biochemical traits, and oxidative stress indicators were analyzed in 21-day-old Cu-treated plants and compared with control plants. The results demonstrated a concentration-dependent decline in shoot and root biomass, relative water content (RWC), pigment content, photosynthetic efficiency, carbohydrates, and lipid content. Conversely, oxidative stress markers such as malondialdehyde (MDA), electrolyte leakage, superoxide dismutase (SOD) and ascorbate peroxidase (APX) activity and proline accumulation increased significantly with increasing Cu concentrations, indicating cellular damage. Notably, protein levels increased with increased Cu concentrations, which may contribute to their tolerance to metal stress, however, it was insufficient to mitigate stress. Further research is needed to validate these findings and explore the mechanisms underlying copper stress tolerance.
Resourceful utilisation of tailings waste remains a hotspot in global research. While silica-aluminate-rich copper tailings can serve as raw materials for geopolymer preparation, their high Si/Al ratio significantly limits the geopolymerization degree. This study investigates the feasibility of developing copper tailings-based geopolymers for road base applications, using copper tailings as the primary raw material supplemented with 30 % soft soil, 15 % fly ash, and 5 % cement. The effect of NaOH content on the strength characteristics of copper tailings-based geopolymers was explored by the unconfined compressive strength test and triaxial test. The mineral composition and microstructure of copper tailings-based geopolymers specimens were characterised based on the microscopic technique. The results show that: (1) With the increase of NaOH content, the unconfined compressive strength of the copper tailings base polymer increases and then decreases, and reach the maximum value when the NaOH content is 1 %. Compared with the sample without NaOH, the addition of 1 % NaOH increased the unconfined compressive strength by 47 % at the early stage and 69 % at 28d curing age. (2) An optimal NaOH content significantly improves the shear performance of the copper tailings-based polymer, primarily by enhancing its cohesion. Triaxial test results demonstrate that 1 % NaOH addition increases cohesion by 73 % at 28d curing age. (3) The NaOH promotes the formation of geopolymer gel, refines the pore structure, and increases sample density, thereby enhancing strength. Overall, the research results can provide a reference for the application of copper tailings solid waste in roadbed materials.
In recent years, copper pollution has gradually become one of the major problems of soil environmental pollution. Lignin plays an important role in plant resistance to biotic and abiotic stresses. CCoAOMT is a key enzyme in the lignin biosynthesis process. In this study, the CCoAOMT gene family members of Platycodon grandiflorus were identified by bioinformatics methods, and their basic characteristics and potential functions were analyzed. The results showed that five members of the PgCCoAOMT gene family were identified in P. grandiflorus, with protein lengths ranging from 246 to 635 amino acids, and were evenly distributed on four chromosomes. Phylogenetic analysis indicated that the PgCCoAOMT gene family was divided into two subclades, namely Clade1a, Clade1b, Clade1c, Clade1d, and Clade2. The cis-regulatory element analysis of the promoter revealed that the PgCCoAOMT members contained a large number of cis-regulatory elements responsive to stress, and conjecture PgCCoAOMT2, PgCCoAOMT4, and PgCCoAOMT5 were involved in the lignin synthesis. The qRT-PCR results showed that, within 5 days of copper stress treatment, except for the PgCCoAOMT4 gene, the other genes exhibited different expression levels. Furthermore, the expression levels of all five PgCCoAOMT genes increased significantly at 7 days of treatment. With the increase in the number of days of treatment, the content of lignin in the seedings of P. grandiflorus showed a trend of increasing first and then decreasing under copper stress. In general, in the copper stress treatment of 1-3 days, the transcriptional inhibition of PgCCoAOMT1 and PgCCoAOMT3 and the increase in lignin content contradicted each other, suggesting that there was post-translational activation or alternative metabolic pathways compensation. Meanwhile, in the 7-day treatment, the coordinated up-regulation of the genes was accompanied by the failure of lignin synthesis, which pointed to the core bottleneck of metabolic precursors depletion and enzyme activity inactivation caused by root damage. Research objective: This study reveals the expression level of the PgCCoAOMT gene in the seedings of P. grandiflorus under copper stress, providing a theoretical basis for elucidating the mechanism of P. grandiflorus response to copper stress and for subsequent improvement of root resistance in P. grandiflorus.
The abundances and isotopic signatures of volatile elements provide critical information for understanding the delivery of water and other essential life-giving compounds to planets. It has been demonstrated that the Moon is depleted in moderately volatile elements (MVE), such as Zn, Cl, S, K and Rb, relative to the Earth. The isotopic compositions of these MVE in lunar rocks suggest loss of volatile elements during the formation of the Moon, as well as their modification during later differentiation and impact processes. Due to its moderately volatile and strongly chalcophile behaviour, copper (Cu) provides a distinct record of planetary accretion and differentiation processes relative to Cl, Rb, Zn or K. Here we present Cu isotopic compositions of Apollo 11, 12, 14 and 15 mare basalts and lunar basaltic meteorites, which range from delta 65Cu of +0.55 +/- 0.01 %o to +3.94 +/- 0.04 %o (per mil deviation of the 65Cu/63Cu from the NIST SRM 976 standard), independent of mare basalt Ti content. The delta 65Cu values of the basalts are negatively correlated with their Cu contents, which is interpreted as evidence for volatile loss upon mare basalt emplacement, plausibly related to the presence Cl- and S-bearing ligands in the vapour phase. This relationship can be used to determine the Cu isotopic composition of the lunar mantle to a delta 65Cu of +0.57 +/- 0.15 %o. The bulk silicate Moon (BSM) is 0.5%o heavier than the bulk silicate Earth (+0.07 +/- 0.10 %o) or chondritic materials (from -1.45 +/- 0.08 %o to 0.07 +/- 0.06 %o). Owing to the ineffectiveness of sulfide segregation and lunar core formation in inducing Cu isotopic fractionation, the isotopic difference between the Moon and the Earth is attributed to volatile loss during the Moon-forming event, which must have occurred at- or nearequilibrium.
Copper (Cu) holds a significant importance in plant metabolism as it serves as an essential micronutrient but becomes toxic at higher concentrations. Nitric oxide (NO), a key signaling molecule, and nitrogen (N) play essential roles in combating toxicity of some metals. This study explores the potential of interactive effects of NO as 100 mu M SNP (sodium nitroprusside, NO source) and N (80 mg N kg-1 soil) in mitigating Cu (100 mg Cu kg-1 soil) stress in mustard (Brassica juncea L.) plants. The impaired physio-biochemical changes, photosynthetic efficiency, and the expression level of genes associated with photosynthesis, and N assimilation under Cu stress were ameliorated with the exogenous application of NO and N. The combined treatment of NO and N conspicuously lowered reactive oxygen species (ROS) and its related impacts. It also enhanced the activity and relative expression of antioxidant enzymes, including ascorbate peroxidase (APX), glutathione reductase (GR), and superoxide dismutase (SOD) as well as N assimilation enzymes, such as nitrate reductase (NR) and nitrite reductase (NiR). The supplementation of NO and N also triggered the expression of rbcL (large subunit of Rubisco), photosystem (photosystem II D1 protein; psbA and photosystem II protein B; psbB) and markedly improved photosynthetic capacity under Cu stress. The study highlights the significance of NO and N as a potential strategy to counteract Cu-induced stress in crops. It suggests a synergistic or interactive effect between the two substances as a phytoremediation strategy for enhancing crop growth and productivity in Cu-contaminated soils. Understanding the mechanisms behind NO and N mediated stress alleviation could facilitate the development of targeted approaches to enhance plant resilience against heavy metal stress.
Herein, CuO and ZnO nanoparticles (NPs) were biogenically synthesized using plant (Artemisia vulgaris) extracts. The biogenic NPs were subsequently evaluated in vitro for antifungal activity (200 mg/L) against Fusarium virguliforme (FV; the cause of soybean sudden death), and for crop protection (200-500 mg/L) in FV-infested soybean. ZnONPs exhibited 3.8-, 2.5-, and 4.9-fold greater in vitro antifungal activity, compared to Zn or Cu acetate salt, the Artemisia extract, and a commercial fungicide (Medalion Fludioxon), respectively. The corresponding CuONP values were 1.2-, 1.0-, and 2.2-fold, respectively. Scanning electron microscopy (SEM) revealed significant morpho-anatomical damage to fungal mycelia and conidia. NP-treated FV lost their hyphal turgidity and uniformity and appeared structurally compromised. ZnONP caused shriveled and broken mycelia lacking conidia, while CuONP caused collapsed mycelia with shriveled and disfigured conidia. In soybean, 200 mg/L of both NPs enhanced growth by 13%, compared to diseased controls, in both soil and foliar exposures. Leaf SEM showed fungal colonization of different infection sites, including the glandular trichome, palisade parenchyma, and vasculature. Foliar application of ZnONP resulted in the deposition of particulate ZnO on the leaf surface and stomatal interiors, likely leading to particle and ion entry via several pathways, including ion diffusion across the cuticle/stomata. SEM also suggested that ZnO/CuO NPs trigger structural reinforcement and anatomical defense responses in both leaves and roots against fungal infection. Collectively, these findings provide important insights into novel and effective mechanisms of crop protection against fungal pathogens by plant-engineered metal oxide nanoparticles, thereby contributing to the sustainability of nano-enabled agriculture.