Search Results (834)

Background/Objectives: Combining chemotherapy with local magnetic hyperthermia (MHT) is promising because heating tumor tissue can increase cell damage, sensitize cells to cytostatic drugs, impair DNA repair, and change tumor microenvironment permeability. This creates conditions for enhancing the antitumor efficacy of chemotherapy while potentially reducing systemic toxicity. The aim of this study was to evaluate the efficacy of MHT with Zn_0.2Mn_0.8Fe₂O₄@OA nanoparticles alone and in combination with cisplatin in a Lewis lung carcinoma model. Methods: Four types of magnetic nanoparticles were synthesized and characterized: Fe₃O₄ and Zn_0.2Mn_0.8Fe₂O₄ coated with oleic acid (OA) or SiO₂-NH₂. Their physicochemical and magnetothermal properties, cytotoxicity, reactive oxygen species generation, and biodegradation in vivo were evaluated. Antitumor efficacy was studied in C57Bl/6 mice with LLC tumors after intratumoral administration of nanoparticles and two MHT sessions (100 kHz, 8 kA/m, 30 min). In combination therapy, ZnMn@OA and cisplatin at doses of 9 or 18 mg/kg were used. Results/Conclusions: Zn_0.2Mn_0.8Fe₂O₄@OA combined efficient heating, biodegradation, and the most pronounced effect among the MHT-alone groups, although MHT without chemotherapy did not provide sustained inhibition of tumor growth or a significant increase in survival. The combination of Zn_0.2Mn_0.8Fe₂O₄@OA-MHT with cisplatin 9 mg/kg produced the best therapeutic outcome: median survival increased significantly by two fold compared with the control group and by 1.8-fold compared with the chemotherapy-alone group at the comparable cisplatin dose. This regimen also stabilized body weight, reduced systemic toxicity, and restored RBC, HGB, and HCT parameters to the level of healthy animals by day 7 of the experiment. These data confirm the potential of MHT as a chemosensitizing approach that improves the efficacy and tolerability of cisplatin therapy. Full article

Understanding soil nutrients and stoichiometry across land-use types is essential for semiarid ecosystem management. We selected 130 sampling sites across four land-use types (dryland, paddy field, grassland, and forestland) in the Western Songnen Plain of China. We measured soil pH, nutrients (SOC, TN, TP, TK, and TS), trace elements (Mn, Zn, Cu, F, Se, and Cl), and oxides (MgO, CaO, Fe₂O₃, SiO₂, and TiO₂). One-way analysis of variance (ANOVA), Pearson correlation analysis, and redundancy analysis (RDA) were used to assess nutrient concentrations, stoichiometric ratios, and their environmental drivers. Our results showed that soils were generally alkaline, with the highest pH in grassland. Dryland had significantly higher SOC (12.47 g/kg), TN (1.05 g/kg), and TP (0.22 g/kg) than grassland (9.58, 0.79, and 0.19 g/kg, respectively). Forestland had the highest TK (23.18 g/kg). Most total nutrient concentrations were positively correlated with trace-element concentrations, except for TK. The C:N of paddy field (12.38) was significantly lower than those of grassland (14.24) and forestland (14.42), while both N:P (10.92) and N:K (0.13) were significantly higher than those in grassland (8.63, 0.11). The P:K of dryland (0.0137) was significantly higher than those in grassland (0.0108) and forestland soils (0.0106). RDA identified SOC and TP as common major factors associated with variation in nutrient stoichiometry, explaining 96.1%, 34.8%, 94.1%, and 93.2% of the variation in dryland, paddy field, grassland, and forestland, respectively. In addition, trace elements and oxides also explained the variation to varying degrees. This study provides a basis for sustainable land-use management in semiarid regions. Full article

Jarosite-type residues generated during zinc hydrometallurgical processing represent a significant environmental liability and a latent source of valuable metals (Zn, Pb, Ag). In this study, the thermal decomposition and mineralogical evolution of an industrial ammonium jarosite residue were investigated to 600–1400 °C. The behavior of the as-received residue was compared against a designed flux-assisted formulation comprising 45 wt% jarosite, 40 wt% Na₂CO₃, and 15 wt% SiC. The conventional roasting of pure jarosite forms refractory zinc ferrite (ZnFe₂O₄) and releases SO₂ above 800 °C, while the flux-assisted route stabilized the sulfur as Na₂SO₄ and CaSO₄, decreasing toxic gas emissions. Concurrently, the reducing effect of the SiC significantly inhibited bulk zinc ferrite formation up to 1200 °C and favored the partial reduction of iron to magnetite (Fe₃O₄). Thermodynamic assessment using FactSage reasonably matches experimental results by X-ray diffraction and SEM-EDS measurements. The thermodynamic evaluation predicts the formation of elemental silver available for subsequent pickup by a collector metal and a liquid slag phase at approximately 1000 °C for the flux-assisted jarosite samples. The ammonium jarosite flux-assisted roasting strategy enhances the potential for metal recovery while increasing environmental sulfur fixation in the slag, aligning with sustainable circular economy principles in non-ferrous metallurgy. Full article

A mass action concentration model of FeO-Fe₂O₃-SiO₂-CaO-MgO-Al₂O₃-ZnO multi-component slag was established to address the problems of high viscosity and high copper content in oxygen-enriched top-blown copper smelting slag. Theoretical calculations, combined with experimental investigations, were performed to evaluate the effects of ZnO additions (0–25 wt.%) on phase transformation, Fe₃O₄ reduction and copper content in the slag at temperatures ranging from 1200 to 1400 °C. The results indicate that ZnO addition decreases the mass concentrations of Fe₂O₃, Fe₃O₄, Fe₂SiO₄ and SiO₂, while increasing the proportions of zinc-bearing structural units and enhancing the reducing capability of the slag. In the copper slag system, Zn²⁺ substitutes for Fe in Fe₃O₄ and Fe₂SiO₄ through isomorphous substitution, forming Fe-Zn spinel and Fe-Zn olivine. As the addition of ZnO gradually increases to 25 wt.%, the liquid slag fraction increases and the slag viscosity decreases, resulting in a reduction in copper content from 5.64 wt.% to 2.04 wt.%. Furthermore, ZnO promotes the transformation of Fe₃O₄ into zinc–iron spinel, which is more readily reducible by carbothermic reaction than Fe₃O₄ itself, thereby facilitating the overall reduction of iron oxides in the copper slag. These findings provide a theoretical basis for slag-type regulation and the efficient separation of copper from slag via high-temperature gravity settling of matte. Full article

This study investigates the influence of Lewis acids on a novel stratified (Co²⁺,Pd²⁺)₂SiO₄-Pd⁰ olivine catalyst for the Heck–Mizoroki coupling of iodobenzene and methyl acrylate. Comprehensive characterization (ICP-OES, Raman, P-XRD, XPS) confirms the successful synthesis of a material with surface-incorporated Pd²⁺ and bulk Pd⁰ nanoparticles within a Co₂SiO₄ matrix. The promoter-free system with triethylamine base achieved the highest initial rate of 3.92 × 10⁻⁷ mol.s⁻¹ with an average rate of 1.18 × 10⁻⁷ mol.s⁻¹, despite a 30 min induction period. However, ZnCl₂, the weakest acid, showed the most substrate activation and lowered the induction period to 10 min, while AlCl₃ also reduced the induction period to 20 min. FeCl₃ showed the poorest performance, attributed to redox-mediated site poisoning rather than hydrolysis. Selectivity over the catalyst was maintained at >99 mol% towards methyl cinnamate irrespective of the Lewis acid or base used. However, recycling of the catalyst led to a gradual decrease in selectivity toward methyl cinnamate from >99 mol% to ~94.6 mol% over three cycles, while conversion remained consistently high at >99 mol% across all cycles, indicating that the catalyst’s primary activity was largely preserved despite surface evolution toward side-product formation. Lewis acids were found to function primarily as surface modifiers and/or productive substrate activators, with stronger Lewis acids also targeting the olivine framework, as seen from the preferential leaching of Co relative to Pd. Full article

This study investigates the acoustic response of ZnO-based SAW devices fabricated on ZnO/Si and ZnO/SiO₂/Si substrates through a combined finite element analysis and experimental approach. Two-dimensional FEA was used to analyze scattering parameters, three-dimensional FEA was used to determine eigenfrequencies and mode shapes, and ZnO thin films were deposited by RF magnetron sputtering with interdigital transducers defined by UV lithography. The ZnO/SiO₂/Si device exhibited Rayleigh and Sezawa-type mode resonances at 145 MHz (4350 m/s) and 234 MHz (7020 m/s), respectively, in close agreement with simulation, while the ZnO/Si device resonated at 166 MHz with a phase velocity of 4980 m/s. Incorporation of the Au sensing layer improved signal transmission by approximately 2 dB, consistent with modeling predictions. For biosensing evaluation, the device was functionalized with a thiolated ssDNA probe targeting the EGFR L858R point mutation, a clinically relevant lung cancer biomarker. Probe immobilization and target hybridization were confirmed by contact angle measurements and resonance frequency shifts, with the sensor demonstrating a linear detection range of 0.1 to 0.6 µM and LOD of 0.09 µM. These findings establish an integrated framework of acoustic modeling, microfabrication, and biofunctionalization for ZnO-based SAW biosensors toward label-free nucleic acid detection. Full article

Shanxi Province in China is one of the world’s major bauxite producers. The co-existence of coal and bauxite mining makes this province particularly prone to acid mine drainage (AMD) and, thus, a significant area for investigating heavy metal mobility in an aluminum-rich geological environment. In this study, heavy metal leaching from bauxite under simulated AMD conditions and the geochemical mechanisms controlling their mobility were examined in this study. XRF analysis demonstrated that the bauxite is predominantly composed of Al₂O₃, Fe₂O₃ and SiO₂, while XRD, FTIR, and SEM-EDS revealed that diaspore and kaolinite dominate bauxite, together with accessory Fe- and Ti-bearing phases, providing reactive surfaces for adsorption and precipitation. After batch leaching with synthetic acidic sulphate solutions (pH = 3), Ca(OH)₂ neutralization was regulated. The data reveal that pH is the key factor controlling heavy metal mobility. Acidic conditions enhanced metal release while alkaline conditions favored hydroxide precipitation, surface complexation and co-precipitation. The removal efficiency was 91%–99% for Cd and Zn, 100% for Cd and Zn, 69%–90% for Cr, 35%–100% for Cu, 92%–100% for Ni and up to 100% for Pb. The chemical and mineralogical composition played an indirect role by providing adsorption sites but did not prevent the release of metals under acidic conditions. These results reveal that pH adjustment is the major mechanism controlling heavy metal immobilization in AMD-impacted bauxite systems and contributes to the knowledge of geochemical processes controlling metal mobility in acidic mine drainage. Full article

In this work, the SiO₂-added MnZn power ferrites have been prepared by the conventional ceramic method, and the effect of stress on initial permeability and power loss has been investigated. With increasing SiO₂ content, initial permeability firstly increases and then decreases, whereas power loss firstly decreases and then increases. The sample with 50 ppm SiO₂ additive exhibits optimal magnetic performance, including the highest initial permeability and the lowest power loss. This optimal sample also exhibits the wide-temperature characteristics of power loss. Initial permeability decreases and power loss increases under the applied stress. The sample with 75 ppm SiO₂ additive exhibits the best stress insensitivity of initial permeability and power loss. Through the loss separation method, it is revealed that magnetic hysteresis loss is more sensitive whereas eddy current loss remains almost unchanged with stress. An appropriate addition of SiO₂ reduces the stress sensitivity of the initial permeability and power loss of MnZn ferrites. Full article

The selective separation of sphalerite from Fe-bearing sulphides remains a persistent challenge in the flotation of complex sulphide ores and can lead to Zn misreporting to Fe-bearing concentrates. This study aimed to identify the origins of Zn misreporting to a pyrite concentrate and to evaluate whether regrinding-assisted flotation could mitigate Zn misreporting. XRF, XRD, zinc phase analysis, flotation experiments, and process mineralogical characterisation were used to determine Zn deportment and evaluate the effect of regrinding on mitigating Zn misreporting to the pyrite concentrate. The results showed that the Zn was mainly associated with sphalerite rather than water-soluble Zn species. Reagent adjustment and additional cleaning stages reduced Zn misreporting moderately, but were insufficient to fully separate Zn-bearing phases from the pyrite concentrate. Process mineralogical characterisation further revealed that Zn was predominantly hosted in sphalerite, which commonly occurred as attached, locked, or disseminated particles associated with pyrite. Under the same Na₂SiO₃ dosage, regrinding-assisted flotation reduced the Zn grade in the final pyrite concentrate from 0.29% to 0.14%, indicating reduced Zn misreporting. These findings indicate that close sphalerite–pyrite association and incomplete sphalerite liberation were the principal mineralogical factors governing Zn misreporting, while regrinding-assisted flotation provides a practical approach for reducing Zn misreporting to pyrite concentrates. This study provides a process mineralogy-guided approach for diagnosing Zn misreporting and improving impurity control in pyrite-rich concentrate production. Full article

Significant amounts of smelting slag are generated during the production of steel, refined copper, and refined magnesium. These slags contain abundant valuable metallic elements, such as Fe, Cu, Zn, Co, and Mg, that have not been fully utilized in the past. This study proposes a method for modifying copper slag by mixing it with steel slag and magnesium slag, followed by roasting with additions of Fe₂O₃ and MgO. The samples were roasted at 1400 °C for 30 min, cooled to 1000 °C at 1.5 °C/min, and then water-quenched to room temperature. Phase transformations during modification were analyzed using FactSage 8.0, DSC–TG, and XRD. The effects of factors such as the content of Fe₂O₃ and MgO on the modification efficiency were investigated. The results indicate that, under the condition of maintaining a steel slag: copper slag: magnesium slag ratio of 37:37:26 and adjusting the basicity (CaO/SiO₂ ratio) with CaO to 2.0, the addition of Fe₂O₃ and MgO promotes the formation of spinel. However, excessively high contents of Fe₂O₃ and MgO lead to refinement of the spinel grains and reduce the iron grade of the concentrate. Within the investigated composition range, the samples with total Fe₂O₃ and MgO contents of 27.66 wt% and 7.56 wt%, respectively, showed the best magnetic separation performance among the tested compositions. Through magnetic separation, the concentrate has good economic and industrial application value in industries such as steelmaking and powder metallurgy, while the tailings can be utilized as raw materials for manufacturing ceramics, glass–ceramics, cement, and concrete. Full article

ZnS is one of the most promising wide-bandgap semiconductors for optoelectronic and sensing applications owing to its efficient ultraviolet–blue emission, high exciton binding energy, and chemical stability. However, the synthesis of ZnS nanocrystals in silicon-compatible porous matrices remains largely unexplored. In this work, ordered arrays of ZnS nanocrystals were synthesized for the first time in SiO₂/Si track templates fabricated by swift heavy ion irradiation followed by selective chemical etching. ZnS nanocrystals were deposited by electrochemical deposition from aqueous solutions containing ZnCl₂ and thiourea precursors. The structural, optical, and electrical properties of the resulting ZnS/SiO₂/Si nanocomposites were investigated using scanning electron microscopy, X-ray diffraction, Raman spectroscopy, photoluminescence spectroscopy, and electrical measurements. The fabricated templates contained vertically aligned pores with a density of approximately 10⁸ cm⁻² and an average diameter of about 500 nm. Electrochemical deposition resulted in a pore filling efficiency of approximately 88%. X-ray diffraction analysis confirmed the formation of crystalline ZnS with a cubic zinc blende structure. The nanocomposites exhibit intense ultraviolet–blue photoluminescence in the 335–477 nm range, with pronounced emission peaks at 372 and 400 nm characteristic of ZnS nanocrystals. Current–voltage measurements indicate predominantly electronic conductivity, with a conductivity of 1.54 × 10⁻⁶ Ohm⁻¹·cm⁻¹, comparable to values reported for polycrystalline ZnS films. To support the experimental observations, the electronic structure of ZnS was analyzed using density functional theory within the LCAO framework. The calculated bandgap of 3.4 eV is consistent with previously reported theoretical and experimental data. The obtained results demonstrate that SiO₂/Si track templates provide a promising platform for the fabrication of ordered ZnS nanoarrays with potential applications in silicon-compatible optoelectronic and sensing devices. Full article

This review summarizes recent studies on the use of nanoparticles (NPs) in plant in vitro clonal micropropagation and secondary metabolite production. The analyzed applications include culture initiation, shoot multiplication, rooting, acclimatization, callus culture, and hairy root culture. Because NPs’ effects are strongly endpoint-dependent, their effectiveness is evaluated separately for micropropagation endpoints, including contamination control, explant survival, multiplication rate, shoot and root development, and plantlet quality, and for metabolite-production endpoints, including biomass accumulation, target metabolite concentration, and total metabolite yield. Based on the quantitative analysis of published data, the most frequently beneficial NP size range was 20–60 nm, whereas effective concentrations, combining a positive effect on plant growth and the synthesis of secondary metabolites, were mainly within 1–120 mg L⁻¹. For the most extensively studied NPs, the corresponding indicative concentration ranges were 15–45 mg L⁻¹ for 25–40 nm Ag-NPs, 75–200 mg L⁻¹ for 15–45 nm ZnO-NPs, 120–150 mg L⁻¹ for 50–80 nm Se-NPs, and 90–145 mg L⁻¹ for 54–55 nm Si-based NPs. Ag- and carbon-based nanomaterials showed relatively strong overall responses in micropropagation datasets, whereas Ag- and Se-NPs were often associated with enhanced target metabolite accumulation. NP responses depend on particle composition, synthesis method, surface properties, dose, culture system, species, genotype, and may involve phytotoxic or residue-related risks. Full article

This study focuses on sustainable atmospheric water harvesting (AWH) using film-containing green nanomaterials. Particular emphasis is given to chitosan as a sustainable biopolymer matrix due to its intrinsic hydrophilicity, biodegradability, film-forming ability and abundance of amino and hydroxyl functional groups that favor water adsorption and nanoparticle interaction. ZnO, SiO₂ and Fe-Zn-SiO₂ nanoparticles with abundant hydroxyl groups were synthesized from plant-based materials such as biomass from peanut and banana wastes, as well as plant extracts. Nanocomposite membranes containing nanoparticles with a high specific surface area and moisture-sensitive behavior were successfully developed. Results showed that bilayer films outperformed monolayer systems in water harvesting performance. In particular, the bilayer film composed of Chitosan/G-ZnO (10 wt.%) on the top layer and Chitosan/G-SiO₂ (10 wt.%) in the bottom layer displayed outstanding hydrophilic properties with water contact angles reduced to 42–43°. The material demonstrated an equilibrium adsorption capacity for water at 0.90 g/g and a passive yield of 1.5–2.2 mL/g per day. The improved adsorption behavior was attributed to the synergistic effect between the hydroxyl-rich oxide nanoparticles, the intrinsic water affinity of chitosan, and the layered porous structure. Moreover, the samples showed good thermal and mechanical stability and retained their structure after several uses. These findings highlight the potential of chitosan-centered green nanocomposites as sustainable materials for passive AWH applications. Full article

This study presents both the analytical modeling and simulation of a cantilever pressure sensor with double-layer piezoelectric materials, specifically ZnO and PVDF, which have negative and positive voltage coefficients, in order to investigate the performance of the sensor and to validate the analytical model with simulation. A detailed three-dimensional sensor model was developed in FEM, comprising gold (Au) as electrodes, silicon dioxide (SiO₂) as an insulating layer, and silicon (Si) as a substrate. Simulations performed across a pressure range of 0–10 kPa revealed a linear output voltage response, and the average margin of error (MoE) between the calculated and simulated values is approximately 11.8%. The observed net potential difference exhibited a negative polarity, primarily due to the dominant effect of ZnO, which has negative piezoelectric voltage coefficients. Comparison of analytical and simulated results shows close agreement, with slope values of −1.16 mV/kPa and −1.03 mV/kPa, respectively, validating the FEM model’s accuracy. From the analytical model, it is observed that the sensitivity of the sensor varies with piezoelectric voltage coefficients, stress produced on the piezoelectric surface and the thickness of the piezoelectric material. Various simulation results show that the output voltage increases as the thickness of ZnO and PVDF decreases. Full article

The present work explores the modelling and design of Interface Acoustic Wave (IAW)-based delay lines in SiO₂/ZnO (4 µm)/SU-8/SiO₂ multilayer stacks and demonstrates that, by properly tailoring the acoustic wavelength and the SU-8 layer thickness, IAW delay lines can achieve performances comparable to, and in some cases superior to, those of conventional Surface Acoustic Wave (SAW) delay lines based on SiO₂/ZnO (4 µm) structures. In particular, the proposed devices exhibited untuned insertion losses down to 12 dB, propagation losses as low as 0.052 dB/λ, and electromechanical coupling coefficients K² approaching 4%, exceeding those calculated for the corresponding SAW devices. The obtained results support the feasibility of compact, high-performance, and potentially packageless acoustic-wave devices for future telecommunications and sensing applications, especially in harsh or contamination-prone environments. Full article