Search Results (761)

The silkworm (Bombyx mori) is an economically important insect that plays a crucial role in agricultural development. Antimony tin oxide, a high-tech multifunctional nanomaterial, is extensively utilized in contemporary industries due to its properties of transparency, conductivity, and stability. Nevertheless, the toxicity and potential adverse effects of antimony tin oxide on living organisms remain poorly understood. In this study, we evaluated the effects of antimony tin oxide at varying concentrations (0–3.2 μg/μL) on the growth, oxidative stress response, gene expression, and midgut integrity of fifth-instar silkworm larvae. Exposure to high concentrations of antimony tin oxide resulted in a significant reduction in larval weight and severely disrupted the antioxidant defense system. RNA sequencing (RNA-Seq) analysis identified 239 differentially expressed genes (DEGs), which were confirmed by qPCR, revealing up-regulated lipid synthesis gene AGPAT5, down-regulated chitin degradation gene Chi, and suppressed glycerolipid hydrolysis gene H9J6N7_BOMMO. Histopathological and ultrastructural examinations revealed severe damage to the structure of midgut epithelial cells. Structural and functional analysis of conserved domains in key DEG-encoded proteins revealed that gene dysregulation disrupted energy metabolism and compromised the physical barrier, ultimately linking molecular abnormalities to observed tissue damage. These findings elucidate the mechanisms by which antimony tin oxide induces midgut toxicity through interference with critical metabolic pathways and functional perturbations at the molecular level. Full article

The demand for lead–zinc–antimony ore resources in China has increased steadily, while shallow deposits are approaching depletion, leading to intensified exploration for deep, concealed orebodies. Electro-geochemical surveys, as a penetrative geochemical exploration technique, are particularly effective in areas with thick overburden. In this study, the Bancai area in Hechi, Guangxi, was selected to evaluate the applicability of this method for concealed mineral exploration. Feasibility testing was conducted along the A4 profile over an engineering-controlled orebody. Distinct electro-geochemical anomalies were identified directly above the known orebody, showing strong spatial correspondence and favorable ore-indicating characteristics, confirming the effectiveness of the method in the study area. Based on the deposit’s geological characteristics, prospecting indicators were established by integrating geological features, electro-geochemical responses, and wall-rock alteration. A geological electro-geochemical prospecting model was constructed for the Bancai mining area and applied for deep exploration of the Bancai B block. By analyzing the spatial distribution of electro-geochemical anomalies and integrating geological conditions, mineralization potential, and related factors, three prospective target areas were delineated to provide guidance for subsequent explorations. Among these targets, Target Area III exhibits favorable structural conditions, well-developed calcite veins, and pronounced superposition of multi-element geochemical anomalies, indicating considerable potential for further mineral exploration. Full article

Polyethylene terephthalate (PET) plays a pivotal role in the chemical fiber industry, constituting over 50% of fiber consumption. However, the reduction of the recycled fiber-derived viscosity of the PET significantly impacts its spinning performance and restricts its closed-loop recycling to high-value regenerated fibers. To address these limitations, this study explored the viscosity improvement of black and white waste fiber-derived polyester particles through a two-step process involving micro-glycolysis and self-polycondensation. Initially, a continuous micro-glycolysis of fiber-derived PET was carried out in a twin-screw extruder with ethylene glycol (EG), which effectively cleaves the ester bonds in the PET chains, generating oligomers with reactive hydroxyl end groups. Subsequently, these oligomers were repolymerized without purification, and a higher molecular weight regenerated PET with enhanced intrinsic viscosity was obtained with antimony ethylene glycolate (Sb-EG) as a catalyst. The results revealed that the intrinsic viscosity decreased exponentially with increasing EG dosage during glycolysis, reaching approximately 50% of the initial value at 0.2–2 phr EG dosages. Optimal viscosity enhancement was achieved at a polycondensation time of 1–3 h, resulting in improved thermal stability and reduced crystallization temperatures. Importantly, regenerated PET samples with EG dosages of ≤2 phr demonstrated intrinsic viscosities of about 0.70 dL/g, meeting the standard for spin-grade polyester fiber, which is used to produce regenerated polyester fibers. This recycling process is low cost, environmentally friendly, and easy to scale-up, contributing significantly to the development of industrial recycling of waste polyester fabrics. Full article

In this work, a study of the chemical composition of the compound Sb₂(S_1−xSe_x)₃ used in thin-film solar cell fabrication, based on correlating data obtained from XRD and XPS analyses, is presented. This approach enables us to propose a mathematical expression for evaluating stoichiometric variations in the material, showing how the variable x evolves as a function of the diffraction angle 2θ. To establish this model, we analyzed the most intense diffraction peak, corresponding to the (221) plane. To validate the proposed method, a series of Sb₂(S_1−xSe_x)₃ thin films with different compositions were synthesized using RF-magnetron sputtering followed by conventional heat treatments in a controlled-atmosphere reaction furnace. The XRD results reveal a systematic 2θ shift in the crystalline diffraction peaks toward the positions of the binary precursor phases—from Sb₂Se₃ to Sb₂S₃—caused by the increased sulfur content during synthesis. XPS measurements confirm the presence of Sb, Se, and S, and high-resolution spectra indicate a decrease in selenium content as the sulfur fraction increases. These results allowed us to elucidate the stoichiometric behavior of antimony sulfoselenide Sb₂(S_1−xSe_x)₃ using trend curves fitted to the characterization data. Full article

Antimony oxide nanoparticles (Sb₂O₃ NPs) were synthesized via a chemical vapor deposition (CVD) method and systematically characterized to evaluate their multifunctional performance. Powder X-ray diffraction (PXRD) confirmed the formation of an orthorhombic Sb₂O₃ phase with an average crystallite size of 53.50 nm, while SEM analysis revealed elongated nanostructures with diameters in the range of 20–100 nm. The stoichiometric composition of Sb₂O₃ (Sb:O ≈ 2:3) was verified by EDAX, and optical studies indicated a direct band gap of 3.10 eV. The electrochemical sensing capability of Sb₂O₃ NPs was investigated using a modified nickel mesh electrode for the detection of Metronidazole (MTZ) in 0.1 N KOH. The presence of Sb₂O₃ NPs resulted in an additional irreversible reduction peak at −0.14 V, confirming enhanced electrocatalytic activity toward MTZ, along with excellent cycling stability (94.36% retention after 10 cycles). In addition, the photocatalytic performance of Sb₂O₃ NPs was evaluated through the degradation of Acid Orange (AO) dye under UV-Vis irradiation, achieving a degradation efficiency of 73.31%. These results demonstrate that Sb₂O₃ nanoparticles are promising multifunctional materials for environmental remediation and electrochemical sensing applications, highlighting their potential for industrial implementation. Full article

Antimony (Sb) is a key element used in flame retardants, lead–acid batteries, and polymer catalysis, and it is classified as a critical raw material. Its quantity for the worldwide economy is limited due to restricted natural resources and partial recycling of by-products. This is why recovering Sb from secondary sources is becoming increasingly important in terms of technological and economic aspects for ensuring its sustainable and safety supply. In this paper, we review the possibilities for extraction of antimony from various waste sources, such as ore processing and metal recovery residues, electronic and plastic waste, lead-antimony-containing waste, spent catalysts, fluorescent lamps, incinerated municipal waste, and the applied methods of waste processing (pyrometallurgy, hydrometallurgy, solvometallurgy) used to achieve recovery in high yield and purity. The methods for antimony quantification and speciation are also discussed and described in terms of principle of the technique, linear concentration range, limit of detection, and coupling with other techniques. As the concentration of Sb in environmental and biological samples is usually very low and requires good selectivity and sensitivity of the analytical method, suitable techniques for sample preparation and subsequent instrumental measurement are also included. Full article

Background: Both chronic kidney disease (CKD) and the haemodialysis procedure can contribute to disturbances in mineral homeostasis, which can potentially result in cellular pathologies. Our study aims to investigate trace element levels in haemodialysis patients and evaluate their potential impact on cellular adhesion molecules. This will clarify the clinical significance of trace element imbalances in this population. Methods: The study included 84 haemodialysis patients and 42 healthy controls. Trace element levels in blood (Zn, Cu, Mn, Mo, V, Sb and Cr) were measured using inductively coupled plasma mass spectrometry (ICP-MS), and cellular adhesion markers ICAM-1 and VCAM-1 were analysed by ELISA. Data analysis was conducted using SPSS 20.00, with significance set at p < 0.005. Results: Manganese (Mn) levels were significantly higher in haemodialysis patients (p = 0.019). Copper (Cu), Molybdenum (Mo), Vanadium (V), Antimony (Sb) and Chromium (Cr) levels were higher in the control group. Zinc (Zn) and Cr levels differed significantly between the control group (p = 0.018; p = 0.007). Cu levels were lower in hypertensive patients (p = 0.011), while Zn and Mn levels were higher in diabetic patients (p = 0.048 and p = 0.004, respectively). Dialysis duration, however, correlated with Sb (r = 0.295; p = 0.01), and Kt/V correlated with Mn, Sb and Cr (r = 0.256, r = 0.272 and r = 0.259, respectively; p = 0.05). Mo levels showed a positive correlation with both pre-dialysis (r = 0.230) and post-dialysis (r = 0.281) creatinine levels, and a negative correlation with post-dialysis GFR (r = −0.294). ICAM-1 and VCAM-1 levels were significantly elevated in dialysis patients (p = 0.001 for both); however, it was not found to be related to variables in the vascular access route. Conclusions: The levels of trace elements and adhesion molecules were examined in haemodialysis patients. High Mn levels indicate a risk of accumulation, while low Cu, Mo, V, Sb and Cr levels may require monitoring for deficiency. ICAM-1 and VCAM-1 levels in haemodialysis patients are associated with some trace elements (Mn and Zn); however, this relationship requires further evidence. In conclusion, the levels of trace elements and adhesion molecules in haemodialysis patients indicate the need for regular monitoring and show that the relationships between creatinine and GFR can be applied to larger patient groups. Full article

Soil heavy metal contamination in mining areas poses a serious environmental challenge, requiring monitoring approaches with both wide coverage and high accuracy. Hyperspectral remote sensing provides an effective solution, yet its performance in complex mining environments is often limited by mixed-pixel effects and nonlinear spectral responses. To address these issues, this study proposes a Physically-Constrained Collaborative Endmember Extraction (PCCEE) framework that integrates spectral unmixing with machine learning for multi-element inversion. Using Gaofen-5 hyperspectral imagery, a collaborative workflow combining Pixel Purity Index (PPI), Vertex Component Analysis (VCA), and prior-spectral-constrained Spectral Angle Mapper (SAM) was developed to improve endmember purity and physical interpretability. Among three unmixing models (LMM, NMF, and SVR), the Linear Mixing Model achieved the best balance between accuracy and efficiency. Random Forest regression using retrieved abundances enabled high-accuracy inversion of eight heavy metals (mean R² = 0.85). Spatial analysis revealed significant co-enrichment of Pb, Cd, and Zn related to sulfide weathering, while PCA distinguished compound and independent pollution sources. The proposed PCCEE framework effectively mitigates mixed-pixel interference and provides a transferable approach for heavy metal monitoring and risk assessment in complex mining environments. Full article

Antimony (Sb) contamination in water poses significant environmental and health risks due to its high toxicity, persistence and complex redox behavior. Magnetic spinel ferrites (MFe₂O₄) have shown promise for Sb removal; however, the intrinsic influence of divalent metal species (M²⁺) in regulating Sb(III)/Sb(V) adsorption performance and interfacial mechanisms remains poorly understood. In this study, MnFe₂O₄, ZnFe₂O₄ and NiFe₂O₄ nanoparticles were synthesized and systematically evaluated to elucidate how M²⁺ governs Sb immobilization behavior. Batch adsorption experiments revealed pronounced M–dependent selectivity. MnFe₂O₄ exhibited the highest Sb(III) adsorption capacity (229.89 mg·g⁻¹), whereas NiFe₂O₄ showed superior affinity toward Sb(V) (up to 257.07 mg·g⁻¹). Adsorption kinetics for both Sb species followed pseudo-second-order models, indicating chemically controlled processes. Isotherm analyses indicated predominantly monolayer complexation for Sb(III), while Sb(V) adsorption displayed mixed adsorption characteristics, reflecting surface heterogeneity. Mechanistic investigations based on FTIR and XPS analyses suggest that Sb(III) immobilization is dominated by inner-sphere complexation with surface Fe–O/Fe–OH groups, whereas Sb(V) adsorption involves synergistic coordination with both Fe–O and M–O (Mn–O/Ni–O) functional groups. XPS analysis of Sb-loaded ZnFe₂O₄ revealed the coexistence of Sb(III) and Sb(V) species after Sb(III) adsorption, indicating surface-confined partial oxidation; the extent of solution-phase conversion was not independently quantified. Therefore, the redox process is interpreted as an interfacial phenomenon rather than bulk oxidation in solution. These results clarify that M²⁺ species influence Sb removal behavior by modulating the reactivity of surface functional groups and interfacial redox characteristics, rather than merely altering adsorption capacity. This work provides spectroscopic insight into M-dependent structure–activity relationships in spinel ferrites and offers a theoretical basis for the rational design of magnetic adsorbents for selective and efficient Sb remediation. Full article

In this study, we investigate the reduction smelting of antimony concentrate, where sodium antimonate is the primary antimony-bearing component, in alkaline melts. This study aims to reduce the carbon footprint of metallic antimony production. It is shown that traditional carbon reduction is accompanied by significant formation of carbon-containing gases and sodium losses due to volatilization. Based on thermodynamic analysis and experimental investigations, carbon monoxide is established as the key active gaseous reducing agent for antimonate compounds, predominantly operating in the temperature range of approximately 320–900 °C, which corresponds to the stages of coke oxidation and sodium antimonate decomposition. The authors propose introducing sodium hydroxide into the charge to form an alkaline melt with a lowered melting point when mixed with the antimony concentrate, ensuring the sequestration of carbon dioxide through the formation of sodium carbonate. Experiments confirmed the possibility of chemically fixing up to 75.5% of CO₂ into the slag phase at the laboratory stage and up to 87% of CO₂ during pilot tests of reduction smelting under a flux layer. Crude metal with an antimony content of 94–96.2% Sb was obtained, while coke consumption was reduced by 16–20%. The proposed approach ensures a simultaneous increase in the degree of antimony recovery, the utilization of carbon-containing gases, and the formation of a stable eutectic slag melt. This allows the process to be considered an element of carbon-neutral pyrometallurgical technology for processing antimony concentrates. Full article

Cephalopods and crustaceans are known to bioaccumulate heavy metals, potentially posing both non-carcinogenic and carcinogenic health risks to consumers. This study was conducted to determine heavy metal concentrations and assess associated health risks in the edible tissues of 84 cephalopod and crustacean samples. Heavy metal concentrations and assess associated health risks in the edible tissues of 84 cephalopod and crustacean samples collected from selected wholesale markets and major fish landing ports throughout Peninsular Malaysia. The analysis focused on nine heavy metals: selenium (Se), cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn), antimony (Sb), tin (Sn), chromium (Cr), and manganese (Mn). The samples were digested using a microwave digestion system, and heavy metal concentrations were analysed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results showed that Mn was the most abundant metal, followed by Cr and Zn. Octopus (C. indicus) had the highest Mn concentration (5.01 mg/kg WW), while Rainbow shrimp (P. sculptilis) had the highest overall metal concentration (91.02 mg/kg WW). Significant differences were observed between cephalopods and crustaceans, with Cd and Sn concentrations being notably higher in cephalopods (p < 0.001). However, no significant associations were observed between heavy metal concentrations and sample weight or length, indicating a greater influence of environmental factors. Principal Component Analysis (PCA) explained 80.4% of the variance, with Cd, Sn, Pb, Cu, Zn, Cr, and Mn accounting for the majority of the variance. Estimated weekly intake (EWI) values ranged from 0.002 to 26.30 µg/kg bw/week for cephalopods and 8.02 × 10⁻⁶ to 243.175 µg/kg bw/week for crustaceans. All metal levels were below the permissible limits set by the Food and Agriculture Organisation of the United Nations/World Health Organisation (FAO/WHO). Hazard Index values were <1, indicating low non-carcinogenic risk, and Total Carcinogenic Risk values for Pb and Cr were below 1 × 10⁻⁴, suggesting negligible carcinogenic risk. Full article

Developing molecular electrocatalysts with controllable and predictable properties remains a central challenge in hydrogen evolution reaction (HER) catalysis. Herein, four Sb(III) corrole complexes (1–4) bearing zero to three p-cyano-substituted meso-phenyl groups (-CN Ph) were synthesized to investigate the effect of electron-withdrawing substituents on their catalytic HER performance, in which complexes 2–4 are newly reported. All prepared complexes were well characterized via UV–vis, NMR, HRMS, and XPS. SEM–EDS and UV–vis analyses indicated their uniform dispersion and excellent stability under organic and neutral aqueous solvent electrolysis conditions. When using TsOH as the proton source in DMF, complex 4 exhibited the highest activity with a TOF of 42.19 s⁻¹ at an overpotential of 895 mV. In mixed aqueous–organic media, the Faradaic efficiency of complex 4 reached 85.5%. The HER activity increases with the increasing number of cyano groups, and this observation has been rationalized via DFT calculations, which indicates a ligand-centered reduction and supports a possible ECEC pathway for the HER. These results highlight that cyano functionalization can modulate the electronic properties of Sb(III) corroles, thereby enhancing HER performance. This is helpful for designing efficient Sb(III) corrole-based HER catalysts. Full article

Artificial water bodies in post-mining landscapes often remain chemically altered and ecologically degraded, yet their ecological risk is frequently underestimated by conventional water quality assessments. Persistent toxicity in mining-impacted waters is a global challenge, as acidity alone often fails to explain the adverse biological effects observed. This study assessed the ecological condition of three artificial ponds in a former gold–antimony mining area (Midões, northern Portugal), using an integrated framework that combined physicochemical and biological (phytoplankton and macroinvertebrates) elements with ecotoxicological assays. Ecotoxicity was evaluated using Lemna minor (growth inhibition) and Daphnia magna (acute toxicity, survival, and feeding rate) under untreated water and pH-adjusted conditions to disentangle acidity-driven effects from other chemical stressors. According to Water Framework Directive metrics, all ponds were classified as having moderate ecological potential, driven by persistent acidic conditions and elevated heavy metal concentrations (e.g., zinc and cadmium). Biological communities showed marked temporal/spatial variability, reflecting physicochemical differences among ponds. Phytoplankton showed summer blooms of cyanobacteria, while macroinvertebrates were generally dominated by tolerant taxa (exhibiting low taxonomic richness/diversity). Ecotoxicological assays showed consistent toxicity across all sampling periods, with high mortality and reduced feeding rates in D. magna and growth inhibition in L. minor. Notably, toxicity often persisted even after pH adjustment, indicating that the observed biological effects were not driven by acidity but were largely attributable to residual metal contamination. These findings highlight the ecological vulnerability of mining-impacted water bodies and underscore the need for management and remediation strategies that address metal removal in addition to pH correction. Full article

Antimony (Sb) contamination in agricultural soils threatens the safety of rapeseed production, yet the mechanisms driving cultivar differences in seed Sb accumulation remain unclear. A pot experiment was conducted with two Sb-tolerant cultivars showing contrasting accumulation patterns, Nanyouza 1 (high-accumulating) and Fengyou 958 (low-accumulating), grown under increasing Sb levels. (1) Sb stress inhibited growth and reduced photosynthetic performance in both cultivars; antioxidant enzymes showed a “low stimulation–high inhibition” response and MDA increased under high Sb, indicating aggravated oxidative damage beyond the tolerance threshold. (2) Nanyouza 1 accumulated more Sb in vegetative tissues and exhibited stronger root-to-shoot translocation than Fengyou 958, whereas seed Sb remained relatively low in both cultivars and bioconcentration/translocation efficiencies declined with increasing Sb. (3) At maturity, rhizosphere bacterial communities shifted along the Sb gradient, and taxa associated with Sb differed, with Ramlibacter and Bacillus positively correlated. These findings provide mechanistic insights supporting the integration of cultivar selection and rhizosphere regulation to achieve both safe production and phytoremediation in Sb-contaminated farmland. Full article

Water pollution from industrial dyes is a critical challenge due to the resistance of these types of compounds to degradation and potentially harmful effects on living organisms and human health. In this study, the electrochemical degradation of methylene blue (MB) was investigated using ink-based copper foam electrodes with reduced graphene oxide (rGO), antimony trioxide (Sb₂O₃), and rGO/Sb₂O₃ composites. The materials used to synthesize the electrodes were characterized by X-ray diffraction (XRD), which showed the successful synthesis of GO, rGO, and the Sb₂O₃-rGO composite. Additionally, the synthesized electrodes were examined using SEM. The MB degradation was studied using kinetic behavior and removal efficiency at pH levels from 3 through 6, monitored using UV-Vis spectroscopy. The electrocatalytic degradation was studied using sodium sulfate as the electrolyte across a pH range of 3 to 8. All electrodes investigated were determined to follow first-order kinetics. The Sb₂O₃-rGO composite showed the highest rate constants of MB degradation at pH 7 and 8, with rate constants of 0.0160 and 0.0159 min⁻¹, respectively. At the same time, the rGO ink-based electrode worked fastest at pH 3 and pH 4 with rate constants of 0.0178 and 0.0158 min⁻¹, respectively. The Sb₂O₃ also works best at pH 3 and 4 with rate constants of 0.0151 and 0.0152 min⁻¹. SEM analysis shows the composite electrode was more resilient to degradation than other materials. Full article