Search Results (426)

Nanopriming with metal nanoparticles (NPs) is a promising strategy for improving seedling quality in horticultural crops. This study evaluated the effects of hydropriming, ZnO, SiO₂, ZnO + SiO₂, a ZnMo nanofertilizer, and two commercial biostimulants (Osmoplant and Codasil) on the early development of Capsicum annuum L. seedlings. Morphological, physiological, and biochemical traits, including biomass, stem architecture, number of leaves, chlorophylls, carotenoids, SPAD index, and nitrate reductase (NR) activity, were measured under controlled conditions. The ZnO and ZnO + SiO₂ treatments promoted stronger root growth, higher pigment content, and higher NR activity. SiO₂ alone and ZnMo showed intermediate improvements, while Osmoplant and Codasil had more limited effects. Multivariate analyses provided complementary information: heat maps revealed correlations between traits, PCA differentiated treatment responses, and radar charts integrated performance profiles. Overall, the results provide promising evidence that seed nanopriming, particularly with ZnO and ZnO + SiO₂, improves seedling vigor and transplant potential in jalapeño peppers. Full article

Silicon (Si) has emerged as a promising tool for mitigating the negative effects of biotic and abiotic stresses, such as caused by heavy metals, on plants. The aim of the study was to summarize knowledge about the mechanisms underlying the interaction between silicon and cadmium. This review first discusses silicon compounds in plant physiology, then examines mechanisms of silicon–cadmium interaction, including antioxidant defense, metal chelation, nutrient transport, molecular responses, subcellular changes, and future directions. Recent studies show that various forms of Si, such as conventional Si and Si-nanoparticles (Si NPs), can have various effects on the ability of a plant to absorb and utilize Si for protection. Silicon, taken up mainly as soluble orthosilicic acid (H₄SiO₄) and Si NPs, can be absorbed by plants and subsequently deposited predominantly in cell walls. It has been found that Si and Si NPs increase the activity of antioxidant enzymes, including CAT, SOD, and POD, in plants under cadmium (Cd) stress. Furthermore, Si reduces the expression of Cd transport-related genes, including OsNRAMP5 and OsHMA2 in rice. It has also been shown that supplementation with Si and Si NPs in plants under Cd stress reduces the Cd content in their tissues and changes the uptake of elements necessary for the proper functioning of the plant organism. Furthermore, Si supplementation increases the content of pectins, which are involved in the binding and neutralization of Cd. The following overview highlights the importance of both Si and SiNPs in neutralizing the harmful effects of Cd on the environment and agriculture. Full article

In this work, different passive solid composites of 1,2-naphthoquinone-4-sulfonic acid sodium salt (NQS) embedded in polydimethylsiloxane (PDMS) and tetraorthoethylsilicate (TEOS) doped with silica nanoparticles (SiO₂NPs) were obtained. New composites including deep eutectic solvent (DES) and choline chloride (ChCl) were synthetized and compared here vs. ionic liquid (IL) which was previously proposed, from their passive response with time. Monitoring and controlling of ammonia levels inside poultry and rabbit farming facilities are essential for animal welfare, workers’ exposure assessment, and measurement of environmental emissions. Real poultry and rabbit farm atmosphere samples were analyzed at different sensor exposition times, obtaining results between two and eight ppmv of NH₃ in all cases. The results were compared by air sampling with Tedlar bags and analysis by UHPLC-QTOF from a miniaturized SPE supported derivatization that was developed. As primary amine group NH₃ was the major component in the farm atmosphere, the presence of methylamine was negligible. PDMS-based sensors with DES or ChCl add new potential for previously developed composites, improving the versatility for controlling ammonia by using new sustainable composites with different time responses. Full article

This study investigates the novel application of silicon nanoparticles (SiO₂ NPs) to enhance drought tolerance and medicinal quality in the threatened medicinal plant Sophora tonkinensis, providing technical support for its conservation and cultivation. Six treatments were applied: control (CK), CK + 100 mg/L SiO₂ NPs, CK + 200 mg/L SiO₂ NPs, drought stress (SD), SD + 100 mg/L SiO₂ NPs, SD + 200 mg/L SiO₂ NPs. After 21 days of foliar application, we assessed biomass, physio–biochemical parameters (including soluble protein, soluble sugar, superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), malondialdehyde (MDA), superoxide anion (O₂⁻), and hydrogen peroxide (H₂O₂)), as well as concentrations of matrine, oxymatrine, genistin, genistein, total alkaloids, and total flavonoids. Under drought stress, the application of 100 mg/L SiO₂ NPs was the most effective treatment for enhancing biomass accumulation and eliciting a coordinated physio–biochemical response. This was demonstrated by a significant increase in leaf soluble protein content and root SOD activity, along with a decrease in oxidative stress markers (H₂O₂ and O₂⁻). Furthermore, SiO₂ NPs application under both normal and drought conditions selectively enhanced the accumulation of bioactive compounds in the roots, with the optimal concentration being compound-specific. Notably, under drought conditions, the application of 200 mg/L SiO₂ NPs proved optimal for enhancing the biosynthesis of several key medicinal compounds in the roots. Specifically, this treatment significantly maximized the content of matrine (214.15 μg/g), genistin (4.06 μg/g), genistein (48.56 μg/g), total alkaloids (9.96 mg/g), and total flavonoids (11.44 mg/g) compared to the drought-stressed control (SD). These results demonstrate that SiO₂ NPs significantly improve yield and key medicinal components of S. tonkinensis under drought stress, with a differential efficiency depending on the concentration, plant organ, and target compound. Full article

Lilium species produce some of the most commercially valuable ornamental flowers in the world, characterized by their attractiveness and high demand in cut flower markets. However, it is necessary to strengthen the competitiveness of this sector in the global market. Due to strong competition from international producers and an increasingly demanding market regarding quality, shelf life, and sustainability, alternatives are being sought to counteract the use of conventional agrochemicals. The use of nanoparticles has emerged as a promising strategy in ornamental horticulture due to their ability to enhance plant growth, improve stress tolerance, and stimulate physiological processes, ultimately contributing to higher quality and productivity. The hypothesis of this research is that the foliar application of selenium and titanium dioxide nanoparticles during the vegetative growth and flowering stages significantly enhances the growth, development, and flowering of Lilium plants when compared with untreated plants. Therefore, the physiological effects of SeNPs and TiO₂NPs applied via foliar application in two concentrations (SeNPsD1, SeNPsD2, TiNPsD1, and TiNPsD2) were evaluated against absolute control. The treatments were applied in two phenological stages (vegetative and reproductive development), and their effects on vegetative and reproductive variables in Lilium plants were evaluated from 120 to 270 days after sowing. The surface of seeds obtained from SeNPsD1-treated plants was further analyzed via scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS). The results demonstrate that the application of SeNPs generated variable effects depending on the phenological stage. In the vegetative stage (46 DAS), SeNPsD2 increased the number of leaves by 118%, while SeNPsD1 increased the fresh weight of leaves by 110%. Regarding ovaries, the application of SeNPsD2 resulted in a 276% increase in fresh weight and a 230% increase in dry weight, while SeNPsD1 achieved an increase of 164% in fresh weight. Furthermore, at this stage, SeNPsD2 promoted a 223% increase in the number of bulbils, a 240% increase in fresh weight, and a 199% increase in dry weight. In the reproductive stage (69 DAS), SeNPsD1 increased the leaf fresh weight by 1% and yielded a 107% increase in the number of ovaries, in addition to 307% and 328% increases in their fresh and dry weights, respectively. In the same stage, SeNPsD2 increased the fresh ovary weight by 153%, compared with the control. Finally, capsule formation was observed only under the SeNPsD1 treatment. Meanwhile, TiO₂NPs had an effect on the number of buds and the number of open buds: the number of buds increased by 115% with TiNPsD1 (69 DAS) and the number of open buds increased by 104% (46 DAS) with TiNPsD1; in the reproductive stage, the number increased by 115% with TiNPsD1 compared with the control. In the seed capsules of plants treated with selenium nanoparticles (SeNPsD1), although no surface selenium was detected via EDS, elements that had possibly been physiologically redistributed were identified, including iron (Fe), silicon (Si), and aluminum (Al). These findings confirm the hypothesis of this research, demonstrating that the foliar application of SeNPs and TiO₂NPs to Lilium plants during the vegetative and reproductive stages significantly improves their vegetative growth, reproductive development, and floral quality under controlled conditions. This work presents the first comparative evidence regarding the effects of SeNPs and TiO₂NPs on the vegetative and reproductive characteristics of Lilium Sunny Oriental, providing unprecedented information for the use of nanotechnology in ornamental horticulture. The findings confirm the potential use of nanoparticles as agents to optimize the productivity and commercial quality of ornamental flowers in highly competitive markets. Full article

Coastal ecosystems have faced escalating environmental degradation in recent years, with eutrophication and nutrient imbalances emerging as critical concerns, particularly in estuarine regions. Understanding the spatiotemporal dynamics of key nutrients, including dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and silicate (SiO₃-Si), is essential for effective coastal management. This study examines the spatial and seasonal variations in these nutrients across 36 sampling sites in the Yellow River estuary from 2016 to 2018. Results indicate that DIN was the primary contributor to water quality degradation, with more than 27% of sampling sites exceeding the Class II seawater quality standard in 2018. Nutrient concentrations were notably elevated near the estuary. The eutrophication index (EI) revealed predominantly mild-to-moderate eutrophication levels throughout the study area. The study area exhibited a widespread phosphorus (P) limitation, with 44.4–94.4% of coastal waters experiencing P-restricted eutrophication. The N/P ratio significantly exceeded the Redfield ratio (16), indicating a pronounced nutrient imbalance. Furthermore, SiO₃-Si concentrations displayed a declining trend, highlighting the need for balanced nutrient management alongside eutrophication mitigation. Full article

The utility of nanostructured TiO₂ in the degradation of organic compounds and the disinfection of pathogenic microorganisms represents an important endeavor in photocatalysis. However, the low photocatalytic efficiency of TiO₂ remains challenging. Herein, we report a robust photocatalytic route to benzene removal rendered by enhancing its adsorption capacity via rationally designed mesoporous SiO₂-coated TiO₂ colloids. Specifically, amorphous, mesoporous SiO₂-coated TiO₂ nanoparticles (denoted T@S NPs) are produced via a precipitation-gel-hydrothermal approach, possessing an increased specific surface area over pristine TiO₂ NPs for improved adsorption of benzene. Notably, under UV irradiation, the degradation rate of benzene by T@S NPs reaches 89% within 30 min, representing a 3.1-fold increase over that achieved by pristine TiO₂. Moreover, a 99.5% degradation rate within 60 min is achieved and maintains a stable photocatalytic activity over five cycles. Surface coating of TiO₂ with amorphous SiO₂ imparts the T@S composite NPs nearly neutral characteristic due to the formation of Ti-O-Si bonds, while manifesting enhanced light harvesting, excellent stability, adhesion, and photocatalytic bacteriostatic effects. Our study underscores the potential of T@S composites for practical applications in photocatalysis over pristine counterparts. Full article

Nb₂O₅ (niobia) coatings were prepared by spin coating of niobium sol, synthesized using niobium chloride as the precursor and ethanol and water as solvents, followed by high-temperature annealing. Doping of the films was achieved by incorporating commercially available SiO₂ (Ludox) and noble metal nanoparticles (NPs) into the sol prior to its deposition. Various sizes of Pt (5 and 30 nm), Ag (10, 20, and 40 nm), and Au (5, 10, and 20 nm) NPs were used to enhance sensing behavior of coatings. After annealing, films were subjected to chemical etching to remove the silica phase. This process generated porosity within the films, which in turn enabled the tailoring of both their optical and sensing properties. It was demonstrated that both the type and size of the incorporated nanoparticles significantly influenced the sensing behavior. The most effective enhancement was observed with the addition of 10 nm AuNPs. Optical characterization indicated that 10 nm AuNPs had a minimal effect on the optical properties. In contrast, doping with 20 nm AuNPs led to a reduction in the refractive index and an increase in Urbach energy. No significant alteration in the optical band gap due to doping was observed. Full article

Chronic wounds pose a great challenge due to their slow healing and susceptibility to infections, hence the need for innovative alternatives to conventional antibiotics, as increasing bacterial resistance limits the efficacy of current treatments. This paper addresses the development of novel electrospun membranes based on polyvinyl alcohol (PVA) and sodium alginate, incorporating therapeutic ZnO and bioglass (54SiO₂:40CaO:6P₂O₅) nanoparticles. While nanocomposites presented smaller fiber diameters than pure polymers, ternary nanocomposites displayed higher values, e.g., in porous areas, values were in the ca. 80–240 nm range and 0.06–0.60 μm², respectively. The Young’s modulus of the PVA/SA membrane, initially 15.9 ± 2.0 MPa, decreased by 65% with 10 wt.% ZnO NPs, whereas 10 wt.% BG NPs increased it by 100%. The membranes demonstrated efficacy against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) isolated from a human wound secretion, as well as two ATCC strains: Staphylococcus aureus and Staphylococcus epidermidis. A cell viability assay conducted with HaCaT cells demonstrated nearly complete survival following 72 h of membrane exposure. Their combined Gram-positive antibacterial activity and cytocompatibility support their potential application as biofunctional dressings for the management of chronic and hospital-acquired topical infections, while also contributing to the global effort to combat antibiotic resistance. Full article

Among the new strategies for managing diseases in agricultural crops is the application of metallic nanoparticles due to their ability to inhibit the development of phytopathogenic microorganisms and to induce plant defense responses. Therefore, this research evaluated the effects of silver (AgNPs), zinc oxide (ZnONPs), and silicon dioxide (SiO₂NPs) nanoparticles on symptom progression and physiological parameters in two pathosystems: Pseudomonas syringae pv. tomato (Psto) in tomato (pathosystem one, culturable pathogen) and Candidatus Liberibacter solanacearum (CaLso) in pepper plants (pathosystem two, non-culturable pathogen). For in vitro pathosystem one assays, SiO₂NPs did not inhibit Psto growth. The minimum inhibitory concentration (MIC) was 31.67 ppm for AgNPs and 194.3 ppm for ZnONPs. Furthermore, the minimum lethal concentration (MLC) for AgNPs was 100 ppm, while for ZnONPs, it was 1000 ppm. For in planta assays, ZnONPs, AgNPs, and SiO₂NPs reduced the number of lesions per leaf, but only ZnONPs significantly decreased the severity. Regarding pathosystem two, AgNPs, ZnONPs, and SiO₂NPs application delayed symptom progression. However, only AgNPs significantly reduced severity percentage. Moreover, treatments with AgNPs and SiO₂NPs increased the plant height and dry weight compared to the results for the control. Full article

In this study, we report the development of a novel magnetized coal fly ash-supported nano-silver composite (AgNPs/MCFA) for dual-functional applications in wastewater treatment: the efficient degradation of methyl orange (MO) dye and broad-spectrum antibacterial activity. The composite was synthesized via a facile impregnation–reduction–sintering route, utilizing sodium citrate as both a reducing and stabilizing agent. The AgNPs/MCFA composite was systematically characterized through multiple analytical techniques, including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM). The results confirmed the uniform dispersion of AgNPs (average size: 13.97 nm) on the MCFA matrix, where the formation of chemical bonds (Ag-O-Si) contributed to the enhanced stability of the material. Under optimized conditions (0.5 g·L⁻¹ AgNO₃, 250 °C sintering temperature, and 2 h sintering time), AgNPs/MCFA exhibited an exceptional catalytic performance, achieving 99.89% MO degradation within 15 min (pseudo-first-order rate constant k_a = 0.3133 min⁻¹) in the presence of NaBH₄. The composite also demonstrated potent antibacterial efficacy against Escherichia coli (MIC = 0.5 mg·mL⁻¹) and Staphylococcus aureus (MIC = 2 mg·mL⁻¹), attributed to membrane disruption, intracellular content leakage, and reactive oxygen species generation. Remarkably, AgNPs/MCFA retained >90% catalytic and antibacterial efficiency after five reuse cycles, enabled by its magnetic recoverability. By repurposing industrial waste (coal fly ash) as a low-cost carrier, this work provides a sustainable strategy to mitigate nanoparticle aggregation and environmental risks while enhancing multifunctional performance in water remediation. Full article

Epoxy-based nanocomposites have drawn much interest in high-voltage insulation applications due to their improved dielectric properties. The determination of the optimal nanoparticle (NP) concentration required to achieve a significant enhancement in nanocomposite dielectric properties remains a subject of ongoing research. Previous work has employed iterative experimental methodologies, often characterized by the hit-and-trial method, in attempts to find the optimal nanoparticle concentration. However, these efforts have yielded suboptimal or inconsistent results. Moreover, experimental procedures for optimizing the nanoparticle concentration require significant time and cost. This research study proposed the predictive capabilities of machine learning (ML) for the selection of the nanoparticle concentration in epoxy-based nanocomposite insulators. The authors employed a novel systematic approach in this research work, comprising dataset preparation, ML model implementation, and experimental validation. A real-time dataset with varying concentrations of NPs (TiO₂, SiO₂, Al₂O₃) was developed in the High Voltage Lab, KFUEIT, Pakistan. Several advanced machine learning models are trained on this dataset. Support Vector Regression (SVR) exhibits the highest prediction accuracy, with an R² score of 0.97. SVR predicted a breakdown voltage (BDV) of 46.26 kV, with a (w/w %) concentration of 5% TiO₂, 1.17631% SiO₂, and 3.95755% Al₂O₃. To validate the SVR prediction, a hardware prototype with predicted NP concentration is developed and tested. The experimentally measured BDV of the predicted nanocomposite sample, registering 44.72 kV, authenticates the predictive accuracy of machine learning. This work demonstrates the efficacy of machine learning as a viable and efficient alternative to traditional experimental methods for optimizing nanoparticle concentrations using a predictive approach in epoxy-based nanocomposites for high-voltage insulation applications. Full article

Background/Objectives: Silicon dioxide nanoparticles (SiO₂NPs) do not exist in isolation in the environment but can interact with other substances, thus influencing their toxic effects on aquatic organisms. We assessed the combined impact of SiO₂NPs and N-acetylcysteine (NAC), an antioxidant with the potential to counteract nanoparticle-induced oxidative stress (OS). Methods: Behavioral assessments, including the social interaction test and color preference test, were performed to evaluate neurobehavioral changes. OS biomarkers, including malondialdehyde (MDA) levels for lipid peroxidation and the activity of key antioxidant enzymes such as glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD), were assessed to evaluate the extent of cellular damage. Results: The results indicate that prolonged exposure to SiO₂NPs induces significant behavioral disruptions, including reduced exploratory behavior and increased anxiety-like responses. Furthermore, biochemical analysis revealed increased OS, suggesting nanoparticle-induced cellular toxicity. NAC co-treatment partially reversed these effects, particularly improving locomotor outcomes and antioxidant response, but was less effective on social behavior. Conclusions: These findings highlight the ecological and health risks posed by SiO₂NPs and point toward the need for further toxicological studies on their long-term biological effects. Full article

With the gradual depletion of high-quality iron ore resources, global steel enterprises have shifted their focus to low-grade, high-impurity iron ores. Using low-grade iron ore to produce pellets for blast furnaces is crucial for companies to control production costs and diversify raw material sources. However, producing qualified pellets from limonite and other low-grade iron ores remains highly challenging. This study investigates the mechanism by which basicity affects the consolidation and reduction behavior of high-Al₂O₃ limonite pellets from a thermodynamic perspective. As the binary basicity of the pellets increased from 0.01 under natural conditions to 1.2, the compressive strength of the roasted pellets increased from 1100 N/P to 5200 N/P. The enhancement in basicity led to an increase in the amount of low-melting-point calcium ferrite in the binding phase, which increased the liquid phase in the pellets, thereby strengthening the consolidation. CaO infiltrated into large-sized iron particles and reacted with Al and Si elements, segregating the contiguous large-sized iron particles and encapsulating them with liquid-phase calcium ferrite. Calcium oxide reacts with the Al and Si elements in large hematite particles, segmenting them and forming liquid calcium ferrite that encapsulates the particles. Additionally, this study used thermodynamic analysis to characterize the influence of CaO on aluminum elements in high-aluminum iron ore pellets. Adding CaO boosted the liquid phase’s ability to incorporate aluminum, lessening the inhibition by high-melting-point aluminum elements of hematite recrystallization. During the reduction process, pellets with high basicity exhibited superior reduction performance. Full article

The pressing need for sustainable construction materials has identified alkali-activated materials (AAMs) as eco-friendly alternatives to conventional Portland cement. This study explores the synergistic performance of alkaline-activated natural pozzolan and limestone powder (AANL) blends against sulfate attack, evaluating mortar specimens immersed in sodium sulfate, magnesium sulfate, and a combined sulfate solution over 12 months. The samples were synthesized using natural pozzolan (NP) and limestone powder (LSP) in three distinct binder combinations to evaluate the influence of varying precursor ratios on the material’s performance, as follows: NP: LSP = 40:60 (AN₄₀L₆₀), 50:50 (AN₅₀L₅₀), and 60:40 (AN₆₀L₄₀). At the same time, the alkaline activators of 10 M NaOH_(aq) and Na₂SiO_3(aq) were combined in a ratio of 1:1 and cured at 75 °C. The research examines the weight variations of the samples, their residual compressive strength, and microstructural characteristics under exposure to magnesium sulfate, sodium sulfate, and a combined sulfate solution. In terms of weight change, samples exposed to Na₂SO₄ gained weight slightly, with AN₄₀L₆₀ recording the highest gain (3.2%) due to the ingress of sulfate ions and pore filling. Under MgSO₄, AN₆₀L₄₀ had the lowest weight gain (29%), while AN₄₀L₆₀ reached 54%. In mixed sulfate, AN₆₀L₄₀ showed negligible weight gain (0.11%); whereas, AN₅₀L₅₀ and AN₄₀L₆₀ gained 2.43% and 1.81%, respectively. Compressive strength retention after one year indicated that mixes with higher NP content fared better. AN₆₀L₄₀ exhibited the highest residual strength across all solutions—16.12 MPa in Na₂SO₄, 12.5 MPa in MgSO₄, and 19.45 MPa in the mixed solution. Conversely, AN₄₀L₆₀ showed the highest strength degradation, losing 47.22%, 58.11%, and 55.89%, respectively. SEM-EDS and FTIR analyses confirm that LSP’s vulnerability to sulfate attack diminishes with increased NP incorporation, highlighting a synergistic interaction that mitigates degradation and retains structural integrity. The combination of 60% NP and 40% LSP demonstrated superior resistance to all sulfate environments, as evidenced by visual durability, minimized weight gain, and retained compressive strength. This study highlights the potential of tailored NP-LSP combinations in developing durable and sustainable AAMs, paving the way for innovative solutions in sulfate-prone environments, while reducing environmental impact and promoting economic efficiency. Full article