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The Tieshilong Pb-Zn polymetallic district is located along the northern margin of the Dongpo ore field in the middle section of the Nanling metallogenic belt, southern Hunan, China. It represents a typical granite-related, fault-controlled hydrothermal vein-type lead–zinc polymetallic deposit in southern Hunan. In recent years, large-scale tin mineralization has been newly discovered during exploration in the deeper and peripheral areas of the district. However, the timing and genetic nature of this tin mineralization remain undetermined, which limits understanding of the characteristics of the deposit’s metallogenic system and its deep exploration potential. In this study, we present in situ cassiterite U–Pb geochronology and trace element data from deep Pb-Zn-Sn orebodies in the Tieshilong mining district. LA-ICP-MS U-Pb analyses of cassiterite yield a Tera–Wasserburg lower-intercept age of 159.2 ± 6.2 Ma (MSWD = 1.4), indicating that Sn mineralization occurred during the Late Jurassic. This age overlaps, within uncertainty, with the main ca. 160~150 Ma W–Sn metallogenic event recognized throughout the Nanling belt. Trace element data reveal that Tieshilong cassiterite is enriched in Fe (1100–5800 ppm) and W (120–11,660 ppm), and depleted in Nb (0.1–87 ppm) and Ta (0–7.1 ppm). The Zr/Hf ratios range from 23 to 52, with a mean value of approximately ~36, which is close to the chondritic values. These geochemical signatures, together with the occurrence of cassiterite intergrown with hydrothermal quartz and its replacement by later sulfides, support precipitation from a granite-related magmatic–hydrothermal system. Based on the findings and the literature, the Tieshilong deposit is therefore interpreted as a Pb–Zn-dominant expression of a Late Jurassic granite-related polymetallic system, in which deeper Sn ± W mineralization was overprinted by later Pb–Zn–Cu sulfide mineralization along fault-controlled fluid pathways. The recognition of cassiterite-bearing, medium- to high-temperature assemblages at depth suggests that down-dip extensions, fault intersections, and strike-inflection zones of the ore-controlling structures represent priority targets for future exploration. Full article

The reliable joining of graphite and Cu holds significant promise for applications in electronic heat dissipation and sliding electrical contacts. However, the substantial differences in their physicochemical properties, poor wettability, and mismatch in coefficients of thermal expansion often result in low joint strength. In this study, a two-step joining strategy combines surface modification with low-temperature sintering, and this is proposed for fabrication of Cu/graphite joints. First, the graphite surface is modified using an AgCuTi active filler alloy under vacuum conditions. Ti preferentially segregates at and reacts with the graphite interface, leading to the formation of an Ag-Cu eutectic modified layer on the graphite surface. Subsequently, low-temperature joining of the modified graphite to a Cu substrate is achieved via a hot-pressing sintering process using a Ag paste. In the sintered joint, the Ag sintered layer forms sound metallurgical bonds with both the Cu substrate and the graphite-modified layer. When the sintering temperature is 250 °C, the joint exhibits a shear strength of 30 MPa, which is significantly higher than that of a directly brazed joint. This strategy effectively reduces thermal residual stress in the joint during cooling and shifts the failure location from the brittle graphite substrate to the ductile Ag sintered layer, thereby substantially enhancing the mechanical performance. Full article

This review analyzes electrochemically deposited polyaniline (PANI) nanocomposite thin films containing metallic, semiconducting, and dielectric fillers, including Ag/PANI, Mo/MoO_x/PANI, CeO₂/PANI, Fe₂O₃/PANI, Al₂O₃/PANI, CuO/PANI, Co₃O₄/PANI, and CoFe₂O₄/PANI. The work examines how filler chemistry and loading influence optical-gap evolution, Urbach disorder, dielectric dispersion, nonlinear optical response, structural coherence, and dc conductivity under comparable electrochemical growth conditions. The comparative analysis shows that optical-gap narrowing and conductivity enhancement are not necessarily coupled. Ag/PANI exhibits simultaneous optical softening and improved conductivity, consistent with metallic bridging, dielectric screening, and enhanced charge connectivity. In contrast, Mo/MoO_x/PANI shows strong optical-gap reduction but reduced conductivity, indicating that optically active interfacial states may remain localized or mobility-limiting. Oxide fillers produce additional regimes: CeO₂/PANI can suppress Urbach disorder and microstrain through order stabilization, whereas Al₂O₃/PANI may widen higher-energy transitions and reduce transport through wide-gap barrier effects. Based on these contrasts, a unified framework is proposed that separates the interfacial electronic function from the transport-connectivity function. This approach classifies PANI nanocomposites into transport-assisted metallic, mobility-limiting interfacial, order-stabilized oxide, and barrier-dominated dielectric regimes, providing practical criteria for selecting filler type and loading windows in optoelectronic, sensing, and photonic applications. Full article

In the current work, the microstructural characteristics and corrosion performance of an Al-3.6Cu-1.0Li-0.40Mg-0.32Mn-0.12Zr alloy are correlated across different artificial aging regimes (150 °C, 160 °C, and 170 °C). In the under-aging stage, the corrosion depth increases with rising aging temperature, from 342.86 μm at 150 °C to 495.13 μm at 170 °C, indicating deteriorated corrosion resistance at higher temperatures. This trend is closely related to the significant increase in the proportion of the T1 phase in the matrix’s primary precipitate. Upon artificial aging for 24 h, the hardness increases gradually as the aging temperature rises. At higher aging temperatures, short-term aging hardness is higher, likely due to the formation of the T1 phase, which can also provide a strengthening effect. In contrast, the corrosion resistance of the alloy is enhanced at higher aging temperatures after 24 h of aging. These corrosion phenomena are closely related to the dominance of the θ″ phase during low-temperature aging and the gradual increase in the S′ phase during high-temperature aging. Furthermore, a transition from intergranular corrosion to pitting corrosion is identified at the high aging temperature of 170 °C with extended aging time. This corrosion mode transformation behavior is speculated to result from intermittent formation of magnesium segregation near the grain boundary, which alters the electrochemical heterogeneity between grain boundaries and the alloy matrix. Full article

This work systematically investigates the effects of pre-deformation, post-aging temperature, and aging time on the mechanical properties, corrosion behavior, and microstructure of a 2A97 Al-Cu-Li alloy. Microstructural characterization indicates that the main precipitates are T₁ (Al₂CuLi), δ′ (Al₃Li), θ′ (Al₂Cu), and S′ (Al₂CuMg). At 160 °C with 0% pre-deformation strain, increasing aging time increases the size and number density of T₁, changing the size and number density of δ′ and θ′ accordingly, whereas raising the aging temperature to 180 °C mainly coarsens precipitates. Increasing pre-deformation from 0% to 12% increases T₁ number density and refines its size. Significantly, after aging at 180 °C, θ′ is absent in the 8% and 12% pre-deformed alloys, and T₁ re-dissolves in the over-aged 12% alloy. Grain-boundary (GB) phases evolve from fine/discontinuous (under-aged) to fine/continuous (peak-aged) to coarse/discontinuous (over-aged). At the same time, higher pre-strain reduces their size, and higher aging temperature promotes coarsening. Higher aging temperature and pre-deformation accelerate age hardening and shorten the peak-aging time. In the peak-aged state, strength increases but elongation decreases with increasing pre-deformation or aging temperature. Among all, the 4% pre-deformed alloy aged at 160 °C for 30 h shows optimal room-temperature properties, i.e., ultimate tensile strength ~613 MPa, yield strength ~564 MPa, and total elongation ~6.91%. Corrosion resistance was closely related to microstructural evolution during aging, and both prolonged aging and increased pre-deformation decreased the susceptibility to intergranular corrosion. The results provide a basis for optimizing the thermomechanical processing of 2A97 Al-Cu-Li alloys. Full article

The Huize Ge-rich Pb-Zn deposit is an important part of the Sichuan–Yunnan–Guizhou carbonate-hosted Pb-Zn metallogenic area and is one of the most representative super-large deposits in the northeastern Yunnan Pb-Zn ore concentration area. The orebodies mainly occur in NE-trending interlayer fault zones. The Pb-Zn mineralization process of this deposit can be divided into the dolomite stage (I), sphalerite-galena stage (II), galena-sphalerite stage (III), and pyrite-calcite stage (IV). Based on a study of the deposit geology, we utilized LA-ICP-MS for in situ microanalysis of trace element compositions and element mapping of sphalerite from different stages to reveal the characteristics of the sphalerite trace element composition and occurrence mechanisms, understand the mineralization process, and constrain the genetic type of the deposit. This research shows that sphalerite color variations result from the multi-factor coupling of multiple trace element contents, element associations, and isomorphic substitutions among elements. Trace elements such as Mn, Fe, Cu, Ga, Ge, Ag, Cd, In, Sn, Sb, and Hg occur in the sphalerite lattice in the form of isomorphic substitutions or nanoscale mineral inclusions, whereas Pb occurs mainly as microscopic mineral inclusions (galena) in sphalerite. From the early to late stages of mineralization (SpI → SpII → SpIII), the mineralization temperature (132–205 °C) and sulfur fugacity (log₁₀ fS₂ = −15.29 to −19.89) both show a gradual decrease. During sphalerite crystallization in different stages, multiple trace elements exhibit coupled multi-element substitutions at the microscale: SpI: Zn²⁺ ↔ (Fe²⁺, Mn²⁺, Cd²⁺), 2Zn²⁺ ↔ 2Ag⁺ + Ge²⁺; SpII: Zn²⁺ ↔ (Fe²⁺, Cd²⁺), 2Zn²⁺ ↔ 2Ag⁺ + Ge²⁺, 3Zn²⁺ ↔ 2Cu²⁺ + Ge²⁺, 3Zn²⁺ ↔ 2(Cu, Ag)²⁺ + Ge²⁺, 2Zn²⁺ ↔ Ga³⁺ + Cu⁺, 2Zn²⁺ ↔ Ga³⁺ + (Cu, Ag)⁺; and SpIII: Zn²⁺ ↔ (Fe²⁺, Mn²⁺), 3Zn²⁺ ↔ 2Cu²⁺ + Ge²⁺, 3Zn²⁺ ↔ 2(Cu, Ag)²⁺ + Ge²⁺). Mn, Fe, and Ge are mainly enriched in SpI; Ga and Ag are mainly enriched in SpII; and Cd is mainly enriched in both SpI and SpII. By comparing the sphalerite trace elements signature of the Huize Ge-rich deposit with those of global typical MVT, SEDEX, VMS, epithermal, and skarn-type Pb-Zn deposits, and considering the deposit’s geological and geochemical characteristics, we suggest that the Huize Pb-Zn deposit is best classified as a medium- to low-temperature, carbonate-hosted Pb-Zn deposit. Full article

Electrochemical nitrate reduction reaction (eNO₃RR) has emerged as a promising alternative to the energy-intensive and carbon-intensive Haber–Bosch process for green ammonia synthesis. However, the intrinsic complexity of the eight-electron transfer pathway and inevitable competing side reactions limit the activity and selectivity of eNO₃RR. Maximizing the utilization of active sites and ensuring structural stability in electrocatalysts are essential for promoting surface proton-coupled electron transfer and improving Faradaic efficiency. Herein, we present a copper metal–organic framework (Cu-MOF)-derived electrocatalyst synthesized via in situ electrosynthesis on copper foam, using cetyltrimethylammonium bromide (CTAB) as a structure-directing agent, followed by electroreduction to produce a self-supported, nano-dendritic structure. This three-dimensional architecture exposes abundant active sites and facilitates electron transport, enabling efficient nitrate-to-ammonia conversion. The optimized CTAB-assisted electrode achieves an ammonia yield of 14.33 ± 0.61 mg h⁻¹ cm⁻² with a Faradaic efficiency of 90.95 ± 2.28% at −1.7 V versus Ag/AgCl. This study introduces a versatile design strategy for copper-based electrocatalysts that integrates structural stability with high activity, offering a sustainable approach for both ammonia production and nitrate remediation. Full article

Freshwater ecosystems are increasingly exposed to metal contamination arising from natural and anthropogenic activities, potentially affecting fish physiology and ecosystem health. However, limited information is available regarding metal accumulation and associated biological responses in fish populations from Dukan Lake, northern Iraq. Therefore, this study investigated metal concentrations in water and tissues of common carp (Cyprinus carpio) and evaluated their relationships with selected fish health indicators. Water and fish samples were collected monthly from Dukan Lake, and a total of 60 fish were classified into three length groups (20–29 cm, 30–39 cm, and 40–49 cm). Metal concentrations in water, liver, and gonad tissues were analyzed using ICP-OES, while condition factor (CF), gonadosomatic index (GSI), and hepatosomatic index (HSI) were used to assess fish physiological condition. Sodium (Na), magnesium (Mg), potassium (K), iron (Fe), zinc (Zn), and barium (Ba) were detected in both water and fish tissues, with concentrations in water ranging from 50 to 7069 μg/L. In contrast, chromium (Cr), manganese (Mn), nickel (Ni), selenium (Se), silver (Ag), cadmium (Cd), antimony (Sb), lead (Pb), copper (Cu), and arsenic (As) were below detection limits. Biometric analysis revealed significant differences (p < 0.05) in the gonadosomatic index (GSI) among fish length groups, indicating size-dependent reproductive development. However, no significant relationship was observed between fish length and either the CF or HSI, suggesting relatively stable somatic condition or liver status across size classes. Correlation analysis showed no significant associations between water metal concentrations and CF or GSI. A significant positive correlation was identified between Zn concentration and HSI in the 30–39 cm length group, indicating a possible link between Zn exposure and hepatic physiological response. The findings indicate that essential elements dominate the metal profile in Dukan Lake, with limited evidence of toxic metal contamination. No major adverse effects on the general condition of the fish were observed. These results contribute to understanding metal bioaccumulation patterns and their implications for fish health in freshwater ecosystems. Full article

The Shiganghe tungsten–tin deposit and the Tiechang tin deposit are located in the northern part of the Baoshan Block, approximately 25 km apart. They were formed in the Late Cretaceous and Early Oligocene, respectively, and exhibit distinct deposit characteristics. This study presents a comparative analysis of in situ trace elements and S-Pb isotopes of pyrite from the two deposits to trace the sources of ore-forming fluids and materials and to further constrain the evolution of the metallogenic setting in the Baoshan Block. The trace element compositions of pyrite from the Shiganghe tungsten–tin deposit differ significantly from those of the Tiechang tin deposit. The former is relatively enriched in Se, Al, and W, while the latter contains relatively high concentrations of Cu, As, Sb, Pb, Bi, and Ag. The sulfur isotopic compositions of pyrite from the Shiganghe deposit are lower than those from the Tiechang deposit, with δ³⁴S_CDT values ranging from 2.11‰ to 6.86‰ and 6.74‰ to 8.72‰, respectively. The two deposits share consistent lead isotopic ratios, characterized by a mixture of upper crustal and orogenic belt sources. Therefore, the mineralization of the Shiganghe tungsten–tin deposit may be related to deep seated, concealed Late Cretaceous magmatism. Relatively oxidized and W-rich magmatic fluids contributed to tungsten–tin mineralization that characterized by a zoning pattern of “tungsten above and tin below”. In contrast, the Tiechang tin deposit is likely associated with coeval leucogranites present in the shear tectonic zone near Caojian. The ore-forming fluids underwent long distant migration with extensive crustal contamination, resulting in a relatively reduced hydrothermal system. Combined with the regional geological setting, the mineralization of the Shiganghe tungsten–tin deposit and the Tiechang tin deposit records the geological event from Neo-Tethys Ocean subduction to the collisional orogeny between the Indian and Eurasian blocks. The ore-forming materials originated from a mixture of upper crustal materials and orogenic belt materials. Full article

The Bastielieke W-polymetallic deposit, located in the Xinjiang Altay metallogenic belt, records a complex hydrothermal history critical to understanding multi-stage metallogenic processes in the southern Altay. This study integrates in situ U-Pb dating of hydrothermal titanite and zircon with textural and compositional analyses of titanite to reconstruct this history. Three types of hydrothermal titanite, identified from pyroxene skarn (TtnI), epidote skarn (TtnII), and quartz–sulfide ore (TtnIII), display dissolution–reprecipitation textures and systematic compositional variations, indicating distinct fluid compositions and origins. TtnI, TtnII, and TtnIII yield U-Pb ages of 244.7 ± 7.8 Ma, 252.4 ± 5.5 Ma, and 250.6 ± 3.0 Ma, respectively, and hydrothermal zircon from pyroxene skarn yields an age of 249.9 ± 2.1 Ma, constraining the hydrothermal event to the latest Permian to Early Triassic. These ages are interpreted to record the timing of U-Pb system resetting during regional shear–thrust movements. Compositional variations among the three titanite types reveal a two-stage hydrothermal history. The earlier stage involved W–Cu mineralization and protolith titanite precipitation related to magmatic–hydrothermal fluids exsolved from Permian granites. The later stage was driven by regional shear–thrust movements and metamorphic–hydrothermal processes, which reset the titanite U-Pb systems, partially altered TtnI and TtnII, precipitated TtnIII, and remobilized metals. This model links the Bastielieke deposit to multi-stage hydrothermal processes and provides insights into similar metallogenic events along the southern margin of Xinjiang Altay. Full article

Germanium (Ge) is a high-tech critical metal typically hosted at trace levels in sphalerite, making its detection and characterization challenging in both primary ores and mine residues. This study presents a multi-scale analytical workflow combining laser-induced breakdown spectroscopy (LIBS), electron probe micro-analysis (EPMA), and multivariate statistics to detect, map and quantify Ge distribution in a representative Pb-Zn sample from the Les Malines deposit (France). µ-LIBS mapping enables rapid centimeter-scale screening at 15 µm resolution and identifies Ge-bearing domains over large areas, which are subsequently investigated at micrometer scale using EPMA chemical mapping and quantitative analyses. Results reveal a strong µm-scale heterogeneity of Ge distribution within sphalerite, with Ge systematically concentrated in an Fe-rich intermediate zonation associated with prismatic growth textures, while Cu/Cd/Ag are enriched in distinct collomorph domains. Multivariate statistical analyses (correlation matrices and PCA) confirm a strong geochemical structuring opposing an Fe/Ge association against a Cu/Cd/Ag pole. These findings demonstrate that Ge incorporation is controlled by localized growth conditions rather than bulk composition. The proposed workflow provides an efficient and scalable framework for exploration, enabling rapid targeting of critical metal enrichments and supporting their extension to multiple mineralization stages, Pb-Zn deposits, and other high-tech critical metals (HTCMs) such as Ga and In. Full article

Chronic oxidative stress is a molecular hallmark of cardiovascular–kidney–metabolic (CKM) syndrome, yet its contribution to CKM-associated anemia beyond erythropoietin deficiency and iron restriction is poorly characterized. The serum copper-to-zinc (Cu/Zn) ratio reflects impaired Cu/Zn-SOD1 antioxidant capacity and inflammatory trace-element imbalance, but its relationships with circulating redox biomarkers and its hematological relevance in CKM syndrome has never been explored in a community-dwelling cohort of older adults. We analyzed 2,391 NHANES 2011–2016 participants ≥ 50 years of age with CKM stage I-IV. To explore whether the serum Cu/Zn ratio was associated with oxidative stress and immunomodulatory biomarkers as well as with the odds of anemia, we used survey-weighted Spearman correlations, linear regression (outcome: hemoglobin), and logistic regression (outcome: anemia); multivariate models were adjusted for a panel of antioxidant or immunomodulatory biomarkers (selenium, vitamin D), pro-oxidant biomarkers (lead, cadmium, cotinine, uric acid), red cell distribution width (RDW) as a composite biomarker of erythrocyte stress, neutrophil-to-lymphocyte ratio (NLR), CKM stage, and comorbidities. The molecular targets of the nine biomarkers were mapped onto a protein–protein interaction network using the STRING database v12.0 to contextualize regression findings within a systems biology framework. Anemia was present in 205 participants (8.6%). The Cu/Zn ratio was inversely correlated with the antioxidant marker selenium (r = −0.19; p < 0.001) and positively correlated with the pro-oxidant markers RDW (r = +0.21; p < 0.001) and cadmium (r = +0.10; p < 0.001), consistent with its role as a hub within the CKM redox network. In fully adjusted models, a higher Cu/Zn ratio was independently associated with prevalent anemia (OR = 2.94; 95% CI: 1.61–5.37) and lower hemoglobin (β = −0.55 g/dL); among included biomarkers, selenium and cadmium were independently protective (OR = 0.76 per 10 µg/L and 0.23 per µg/dL, respectively), and RDW and uric acid were independently harmful (OR = 2.20 per 1% and 1.33 per mg/dL, respectively). The Cu/Zn ratio correlated with both antioxidant depletion and pro-oxidant accumulation in CKM syndrome and was independently associated with anemia within this oxidative network. Together with selenium, cadmium, RDW, and uric acid, it defines an oxidative stress-driven hematological pathway that may contribute to the development and progression of anemia in patients with CKM syndrome. Full article

This study determined the etiological distribution of naturally occurring bovine dermatophytosis and evaluated associated serum macro- and trace-element and redox alterations. Seventy-five calves and young cattle aged 2–12 months, of both sexes and mixed local, Simmental, Brown Swiss/Montofon, and crossbred types, were included: 50 clinically and mycologically confirmed dermatophytosis cases and 25 clinically healthy controls. Skin scrapings and hair samples from affected cattle were examined by direct microscopy and culture. Single jugular blood samples were collected from all animals during the same seasonal period (February–May 2026), and serum mineral and redox markers were analyzed. Copper, zinc, cobalt, selenium, molybdenum, manganese, magnesium, calcium, sodium, iron, and chromium concentrations, catalase (CAT), reduced glutathione (GSH), and malondialdehyde (MDA) were measured. Data were analyzed using a general linear model including group and sex as fixed effects and age in months as a covariate. Model-adjusted results were expressed as least-squares means ± standard error (LSM ± SE). Trichophyton verrucosum and T. mentagrophytes were identified in 90% and 10% of affected cattle, respectively. Affected cattle had lower Cu, Zn, Se, Na, Fe (p < 0.01), Mg (p = 0.009), Ca (p < 0.001), CAT, and GSH (p < 0.001), but higher Co, Cr (p < 0.01) and MDA (p < 0.001). These findings suggest field associations between bovine dermatophytosis, mineral imbalance, and redox disturbance. Full article

Due to fractures in young and mature people, combined with aging and other factors increasing year by year, there is a demand for new materials to efficiently address fracture-healing-related issues. There are designs of new biodegradable Zn-based alloys whose chemical composition provides new opportunities to manufacture medical devices for supporting and assisting bones in their healing processes. To achieve this goal, it is well known that a strength–ductility balance and appropriate degradation are required. In this context, it is vital to know and understand how the addition of elements modifies the as-cast microstructure, which is the basis of further processing steps such as heat treatment and thermomechanical processing. In the present work, a broad characterization was performed of two as-cast hypoperitectic Zn-Ag-based alloys with Mg and Cu additions. First, cooling curves were presented, and a dissertation regarding the temperature appearance of their secondary phases was made. Also, XRD and SEM-EDS techniques were performed, and their mechanical and corrosion performance was analyzed to elucidate which third element is the best option for intended orthopedic applications. Full article

Background: Compomer materials combine the advantages of composite resins and glass ionomer cements, including fluoride release, durability, and aesthetics. This study evaluated the effects of silver nanoparticles (nAg⁰) and copper oxide (CuO) particles on fluoride ions release and the structural properties of a commercially available compomer. Methods: Compomer discs modified with 0.125 wt.%, 0.25 wt.%, and 0.5 wt.% nAg⁰ or CuO were prepared and analyzed in demineralized water and artificial saliva at various pH levels for 168 h. Fluoride release was measured using a fluoride-selective electrode, while structural and morphological properties were examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results: Under most of the tested conditions, the modified materials exhibited higher fluoride release than the unmodified compomer, with the greatest increase typically observed at higher additive concentrations. XRD analysis confirmed the presence of crystalline phases of Ag⁰ and CuO while maintaining the amorphous nature of the compomer matrix. SEM observations revealed better particle dispersion at lower additive concentrations and increased agglomeration at a 0.5% content. Conclusions: These results indicate that the incorporation of nAg⁰ and CuO particles may enhance the fluoride-releasing potential of compomer materials; however, further studies are necessary to evaluate their mechanical, antibacterial, cytotoxic, and aesthetic properties prior to clinical application. Full article