Search Results (730)

Salt stress is a major form of abiotic stress that disrupts soybean germination and early seedling establishment. In this study, physiological, biochemical, and transcriptomic analyses—including germination index, antioxidant enzyme activity, and RNA-seq profiling—were conducted during soybean germination to elucidate early responses to salt stress and biostimulant treatment. A preliminary screening of six biostimulants (nanoparticle zinc oxide (NP-ZnO), nanoparticle silicon dioxide (NP-SiO₂), silicon dioxide (SiO₂), glucose, humic acid, and fulvic acid) revealed NP-SiO₂ as the most effective in promoting germination under salt stress. Under 150 mM NaCl, NP-SiO₂ increased the germination rate and length of the radicle compared with the control, also enhancing peroxidase and ascorbate peroxidase activities while reducing malondialdehyde accumulation, suggesting alleviation of oxidative stress. RNA sequencing revealed extensive transcriptional reprogramming under salt stress, identifying 4579 differentially expressed genes (DEGs) compared with non-stress conditions, while NP-SiO₂ treatment reduced this number to 2734, indicating that NP-SiO₂ mitigated the transcriptional disturbance caused by salt stress and stabilized gene expression networks. Cluster analysis showed that growth- and hormone-related genes suppressed by salt stress were restored under NP-SiO₂ treatment, whereas stress-responsive genes that were induced by salt were attenuated. Hormone-related DEG analysis revealed that NP-SiO₂ down-regulated the overactivation in the abscisic acid, jasmonic acid, and salicylic acid pathways while partially restoring gibberellin, auxin, cytokinin, and brassinosteroid signaling. Overall, NP-SiO₂ at 100 mg/L mitigated salt-induced oxidative stress and promoted early soybean growth by fine-tuning physiological and transcriptional responses, representing a promising nano-based biostimulant for enhancing salt tolerance in plants. Full article

Silicon dioxide nanoparticles (SiO₂NPs) are widely used in various industries, raising concerns about their potential toxicity in aquatic organisms. Although several studies have investigated the general toxic effects of SiO₂NPs, little is known about their impact on the nervous system and behavior of aquatic vertebrates. Furthermore, the combined assessment of behavioral, histological, and biochemical responses remains scarce. The study aimed to evaluate the effects of SiO₂NPs on behavioral, histological, and biochemical parameters in adult zebrafish (Danio rerio). Fish were exposed to sublethal concentrations of SiO₂NPs and their behavior was assessed using the social interaction test and the color preference test. Significant alterations in social behavior, such as reduced group cohesion and increased isolation tendencies, were observed. Additionally, exposed zebrafish exhibited a marked shift in color preference, indicating potential disruptions in sensory or cognitive function. Histological analyses revealed dose dependent tissue changes in brain structures, while biochemical assays indicated reduced activity of antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), suggesting elevated oxidative stress (OS). To the best of our knowledge, this is one of the first studies to integrate behavioral, histological, and biochemical endpoints in zebrafish to assess the neurotoxic potential of SiO₂NPs. These findings suggest that SiO₂NPs can induce histological alterations in brain structures, neurobehavioral changes, and OS in zebrafish, underscoring the novelty and relevance of this interdisciplinary approach, and the importance of further studies on SiO₂NPs environmental and health impacts. Full article

In micro gas turbines, electrical power from the high-speed generator is delivered to the grid through a converter that influences overall efficiency and energy quality. This subsystem is often overlooked in efforts to improve turbine performance, which have traditionally focused on combustors and turbomachinery. This study investigates how replacing conventional silicon switching devices in the converter with silicon carbide technology can directly reduce greenhouse gas emissions from micro gas turbines. Although silicon carbide is widely used in electric vehicles and distributed energy systems, its emission reduction impact has not been assessed in micro gas turbines. A MATLAB-based model of a 100 kW Ansaldo Energia micro gas turbine was used to compare the performance of silicon and silicon carbide converters across the 20–100 kW operating range. Silicon carbide reduced total converter losses from 4.316 kW to 3.426 kW at full load, a decrease of 0.889 kW. This improvement lowered carbon dioxide emissions by 5.7 g/kWh and increased net electrical efficiency from 30.03% to 30.29%. Each turbine can therefore avoid about 1.53 tonnes of carbon dioxide annually, or 11.61 tonnes over a 50,000 h service life, without altering turbine design, combustor geometry, or fuel composition. This work establishes the first quantitative link between wide-bandgap semiconductor performance and direct greenhouse gas mitigation in micro gas turbines, demonstrating that upgrading converter technology from silicon to silicon carbide offers a deployable pathway to reduce emissions from micro gas turbines and, by extension, lower the carbon intensity of distributed generation systems. Full article

Seaweed fiber is a new type of functional fiber made from natural seaweed as raw material. Seaweed fiber has excellent moisture absorption, bio compatibilization, controlled degradation profile, and flame retardancy, and can be used to develop high-performance and high value-added textiles. However, seaweed fibers are prone to swelling in salt ion solutions, making dyeing with traditional chemical dyes very difficult. In recent years, the research and application of controllable structural colors have been an important direction and hot spot in the textile field. SiO₂ nanospheres of different sizes were synthesized and combined with polydopamine as an additive to produce structural colors with high visibility. The resulting photonic crystals exhibited vibrant rainbow hues and were successfully applied to stain seaweed fibers. The color of polydopamine-coated silica photonic crystals (PDA/SiO₂) depended on the diameter of the SiO₂ microspheres, while their spectral purity could be tuned by adjusting the ratio of SiO₂ microspheres to dopamine hydrochloride. Full article

The uptake and accumulation of nanoplastics by plants have emerged as a major research focus. Exogenous selenium nanoparticles (SeNPs) are widely used to mitigate the toxicity of abiotic stresses, such as nanoplastics (NPs) and polyethylene (PE—NPs) nanoplastics, and represent a feasible strategy to enhance plant performance. However, the molecular mechanisms by which SeNPs alleviate the phytotoxicity of microplastics and nanoplastics remain poorly defined. To address this gap, we used Pistia stratiotes L. (P. stratiotes) as a model and silicon dioxide nanoparticles (SiO₂NPs) as a comparator, integrating physiological assays, ultrastructural observations, and proteomic analyses. We found that NP stress caused ultrastructural damage in root tips, exacerbated oxidative stress, and intensified membrane lipid peroxidation. SeNPs treatment significantly mitigated NP-induced oxidative injury and metabolic suppression. Compared to the NPs group, SeNPs increased T-AOC by 38.2% while reducing MDA and ·OH by 33.3% and 89.6%, respectively. Antioxidant enzymes were also elevated, with CAT and POD rising by 47.1% and 39.2%. SeNPs further enhanced the photosynthetic capacity and osmotic adjustment, reflected by increases in chlorophyll a, chlorophyll b, and soluble sugar by 49.7%, 43.8%, and 27.0%, respectively. In contrast, proline decreased by 17.4%, indicating stress alleviation rather than an osmotic compensation response. Overall, SeNPs outperformed SiO₂NPs. These results indicate that SeNPs broadly strengthen anti-oxidative defenses and metabolic regulation in P. stratiotes, effectively alleviating NP-induced oxidative damage. Proteomics further showed that SeNPs specifically activated the MAPK signaling cascade, phenylpropanoid biosynthesis, and energy metabolic pathways, enhancing cell-wall lignification to improve the mechanical barrier and limiting NPs translocation via a phytochelatin-mediated vacuolar sequestration mechanism. SiO₂NPs produced similar but weaker alleviative effects. Collectively, these findings elucidate the molecular basis by which SeNPs mitigate NPs’ phytotoxicity and provide a theoretical foundation and practical outlook for using nanomaterials to enhance phytoremediation in aquatic systems. Full article

This study designs stable fast-disintegrating oral granules (FDGs) of volatile liquid essential oils (cinnamon, lemon, rose, and peppermint oils) for olfactory rehabilitation. By adsorbing liquid-type essential oils onto colloidal silicon dioxide (1:1 w/w) and incorporating olive oil (1:1:0.25 w/w) as a volatile restrainer, the retention of major odorants—cinnamaldehyde, citral, phenethyl alcohol, and menthol—in cinnamon, lemon, rose, and peppermint oils, respectively, was markedly improved after 12 h of exposure at 40 °C. Then, free-flowing FDG system was formulated with sugar alcohols (mannitol, xylitol, and sorbitol), low substituted hydroxypropyl cellulose, and magnesium stearate, exhibiting rapid spreading and disintegration (<31.2 s) upon contact with aqueous media. The package of FDGs into four-layer laminated pouch afforded markedly prevent volatility of olfactory components, preserving >82% of cinnamaldehyde, citral, phenethyl alcohol, and menthol for 8 weeks under 25 °C/65% relative humidity (RH) conditions. In an in vitro volatilization test, major odorants were effectively volatilized from artificial saliva-wetted FDGs within 90 min depending on the volatility of each constituent. Therefore, this novel oral FDG system is expected to be a promising alternative for olfactory training for neurogenic smell dysfunction, providing enhanced storage stability, precise dosing, and patient compliance. Full article

Zirconia, also known as zirconium dioxide ZrO₂, is well known for its good mechanical properties, like its inertness, good wear resistance, high temperature resistance and good strength. To enhance the mechanical properties of many materials, a technique known as transformation toughening is widely used today. This research focuses on achieving an optimized composition of zirconia and alumina Al₂O₃ to achieve zirconia-toughened alumina ZTA with a maximum density and other mechanical properties using a cost-effective and time-efficient approach. Doing so will make it possible to make more and more use of this valuable ceramic. The curing of zirconia and alumina samples with 3d—printing resins in silicone dies was performed so that we could obtain the optimum ratio of the resin and ZTA powder that would produce the most desirable results and properties. For 3d printing, ZTA samples with 19% zirconia ZrO₂ were used with alumina at two different temperatures (i.e., Sample 1, consisting of three pellets weighing 5–6 g, was sintered at 1500 °C, and Sample 2, also containing three pellets weighing 5 g (approx.), was sintered at 1600 °C). The green-state preparation of these samples (Sample 1 and Sample 2) was performed using milling media of WC balls/ethanol and a milling ratio of 1:3, and a milling time of 4 h 100 rpm was used while drying at 80 °C for 5.5 h. The relative density (70%) and Vickers hardness (14–17 GPa) were obtained for Al₂O₃/ZrO₂/MgO samples. Mechanical properties like hardness and strength strongly depend on the holding time, the rate of the temperature increase while sintering and the sintering temperature itself. Full article

This study proposes a high-contrast photoacoustic (PA) imaging methodology based on a dual-wavelength confocal metalens, designed to monitor the dissemination of cancer cells and to inform subsequent cancer treatment strategies. The metalens is composed of two metasurfaces that perform filtering and focusing functions, effectively reducing the cross-talk between the two wavelengths of light in space and achieving a confocal effect. Furthermore, to minimize process complexity, a uniform material system of silicon dioxide (SiO₂) and titanium dioxide (TiO₂) is employed across the different metasurfaces of the metalens. The designed metalens has a radius of 25 µm and an operational focal length of 98.5 µm. The results confirm that this dual-metasurface design achieves high focusing efficiency alongside precise focusing capability, with the deviations of the actual focal lengths for both beams from the design values being within 1.5 µm. Additionally, this study developed a skin tissue model and simulated multi-wavelength photoacoustic imaging of cancer cells within the human body by integrating theories of radiative transfer, photothermal conversion, and the wave equation. The results demonstrate that the enhancement trend of the reconstructed signal closely matches the original signal, confirming the model’s excellent fitting performance. The sound pressure values generated by cancer cells are significantly higher than those of normal cells, proving that this method can effectively distinguish cancerous tissue from healthy tissue. This research provides new theoretical support and methodological foundations for the clinical application of multi-wavelength photoacoustic imaging technology. Full article

Understanding the impact of hydric stress on medicinal plants in the context of climate change is becoming increasingly important. This study aimed to assess the quality of a seed lot of Agastache mexicana subsp. mexicana (Amm) through a novel calculation of the Vigour Index on time basis (${VI}_T$). The evaluation was based on relationships among plant height, leaf number, survival time, and plant density across six irrigation regimes, referred to as stages, which differed in the timing and quantity of water, designed to impose water stress from seedling emergence until plant death. To maximise growth and survival time, we utilised two input factors: Artificial Shade Levels (ASLs) of 38%, 87%, and 94%, as well as Silicon Dioxide Levels (SDLs) of 0.0%, 0.2%, 0.4%, and 0.8%. The effects of these treatments were measured using the Survival Index (SI) and the ${VI}_T$. The plants achieved their highest SI and ${VI}_T$ values influenced by minimum mortality and maximum height and leaf number in stage three. This behaviour aligned with the field capacity of the substrate, supporting the evaluation of stages one and two as waterlogging stress, while the remaining stages were classified as drought stress. The ${VI}_T$ results showed statistically significant effects from ASL, particularly at 94%. However, the ${VI}_T$ in relation to SDL was not statistically significant. The ${VI}_T$ measurements were visualised using spline interpolation, a method that provides an effective approach to quantify adverse conditions affecting Amm’s development and that it can support to identify the hydric stresses type. Full article

This study synthesizes three new composites: chitin-cross-linked poly(ortho-phenylenediamine)-grafted silicon dioxide (CT-PoPD-grafted SiO₂), chitosan-cross-linked PoPD-grafted SiO₂ (CS-PoP-grafted SiO₂), and guar-gum-cross-linked PoPD-grafted SiO₂ (GG-PoPD-grafted SiO₂). These biopolymer-based materials were developed as cost-effective, biocompatible adsorbents with increased surface area for removing Acid Red 1 AR1) and Crystal Violet (CV) dyes. Structural and morphological analyses through Fourier-transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy (XPS) confirmed their successful synthesis. Adsorption studies were conducted under various conditions, including adsorbent dosage, pH, temperature, and contact time. Among the composites, GG-PoPD-grafted SiO₂ demonstrated superior performance, achieving 99.1% and 95.6% removal of AR1 and CV, respectively. Kinetic analysis revealed a pseudo-second-order model, while thermodynamic results indicated a spontaneous and endothermic adsorption process. In conclusion, the GG-PoPD-grafted SiO₂ composite exhibits significant potential as an effective and sustainable material for wastewater treatment. Full article

The work is focused on the study of the influence of different types of inorganic fillers, in combination with modifiers, on the rheological, thermal, and mechanical properties of a biodegradable mixture based on PLA/PHB. Ten types of inorganic fillers based on talc, magnesium hydroxide, aluminum hydroxide, calcium carbonate, and silicon dioxide were used in the study, along with three types of modifiers. It was concluded that fillers containing reactive OH groups on their surface act as strong pro-degradants in PLA/PHB blends, and their degrading effect can be suppressed by the addition of reactive modifiers. Each modifier acts specifically with different types of fillers. Therefore, it is necessary to select a suitable filler/modifier combination not only for fillers with different chemical compositions but also for fillers with different morphologies within the same chemical type. Moreover, the preparation of PLA/PHB/magnesium hydroxide blends with suitable processing and application properties opens the possibility of developing environmentally friendly polymeric materials with a reduced flammability. The addition of talc, which has a platelet structure, can increase the barrier properties of the mixture. Full article

In the presented work, a natural mineral—rock crystal—was used as a filler to obtain new silicone adhesive tapes. It was expected that, properly crushed, this hard mineral, consisting almost entirely of silica (silicon dioxide), should enhance the thermal resistance and cohesion of the self-adhesive composition with no/or low reduction in the rest of performance properties of the products. For this purpose, tests were conducted on the functional properties of new self-adhesive tapes, such as adhesion, cohesion, and tack. The obtained results confirmed the scientific assumptions and the thermal resistance of adhesive layers reached over 225 °C. The material itself turned out to not agglomerate in the adhesive composition and to be compatible with it. The new self-adhesive materials have application potential and can be used as materials for special applications in the field of heating, e.g., in connecting pipes, where thermal resistance and thermal expansion are of immense importance. Full article

Objective: Maxillofacial silicone elastomers represent a standard material in maxillofacial prosthetic applications due to their excellent biocompatibility and aesthetic properties. However, their long-term performance is limited by color degradation and susceptibility to fungal colonization. Incorporating nanoparticles into silicone matrices has emerged as a potential solution to enhance durability and hygiene. This study aimed to evaluate the effect of zinc oxide (ZnO) and titanium dioxide (TiO₂) nanoparticles used individually and in combination to evaluate the color stability and antifungal activity of pigmented maxillofacial silicone elastomers. Material and Methods: Fifty specimens were fabricated for each test and divided into five groups: Group (A) control (pigmented silicone only, no nanoparticles), Group (B) ZnO (1.5 wt%), Group (C) TiO₂ (2.5 wt%), and two combinations: Group(D1) (0.75 wt% ZnO + 1.25 wt% TiO₂) and Group (D2)(0.5 wt% ZnO + 0.83 wt% TiO₂) ratios. Color stability was assessed before and after 500 h of artificial aging using CIELAB-ΔE values and visual scoring. Antifungal activity was evaluated against Candida albicans using the disk diffusion method. Attenuated Total Reflectance with Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning electron microscopy (SEM) along side with Energy-dispersive X-ray spectroscopy (EDS) were applied for Specimen characterization. Data were analyzed with one-way ANOVA and Tukey’s post hoc test (α = 0.05). Results: The dual-nanoparticle group with 0.75% ZnO and 1.25% TiO₂ demonstrated the best color stability (ΔE = 0.86 ± 0.50) and strongest antifungal activity (inhibition zone: 7.8 ± 3.8 mm) compared to the control (ΔE = 2.31 ± 0.62; no inhibition). Single-nanoparticle groups showed moderate improvements. A significant Association (r = 0.89, p < 0.01) was found between nanoparticle dispersion and material performance. Conclusions: Incorporating ZnO and TiO₂ nanoparticles into maxillofacial silicone elastomers significantly enhances color stability and antifungal efficacy. The combined formulation showed a synergistic effect, offering promising potential for improving the longevity and hygiene of maxillofacial prostheses. Full article

SiCp/Al composites (Silicon Carbide Particle-Reinforced Aluminum Matrix Composites), due to their light weight, high strength, and superior wear resistance, are extensively utilized in aerospace and other sectors; nonetheless, they are susceptible to tool wear and surface imperfections during machining, which negatively impact overall machining performance. Supercritical carbon dioxide minimal quantity lubrication (SCCO₂-MQL) is an environmentally friendly and efficient lubrication method that significantly improves interfacial lubricity and thermal stability. Nonetheless, current lubrication models are predominantly constrained to gas–liquid two-phase scenarios, hindering the characterization of the three-phase lubrication mechanism influenced by the combined impacts of SCCO₂ phase transition and ultrasonic vibration. This study formulates a lubricant film thickness model that incorporates droplet atomization, capillary permeation, shear spreading, and three-phase modulation while introducing a pseudophase enhancement factor β_ps(p,T) to characterize the phase fluctuation effect of CO₂ in the critical region. Simulation analysis indicates that, with an ultrasonic vibration factor Af = 1200 μm·kHz, a lubricant flow rate Q_f = 16 mL/h, and a pressure gradient Δp_tot = 6.0 × 10⁵ Pa/m, the lubricant film thickness attains its optimal value, with Δp_tot having the most pronounced effect on the film thickness (normalized sensitivity S = 0.488). The model results align with the experimental trends, validating its accuracy and further elucidating the nonlinear regulation of the film-forming process by various parameters within the three-phase synergistic lubrication mechanism. This research offers theoretical backing for the enhancement of performance and the expansion of modeling in SCCO₂-MQL lubrication systems. Full article

This study evaluated the effect of polyethylene glycol (PEG 1500 and 4000) addition on the enzymatic hydrolysis (EH) of ground rice husk (≤250 μm). To reduce the amount of enzyme adsorbed on silicon dioxide and lignin and to evaluate the enzymatic hydrolysis, PEG 1500 and 4000 g/mol were added at three concentrations (0.3, 0.4 and 0.5 g PEG/g SiO₂). When PEG 1500 was added at 0.5 g/g SiO₂, the conversion of cellulose to cellobiose was not significantly increased (p ≥ 0.05); the conversion to glucose was 41.76%, and the conversion of hemicellulose to xylose was 93.45%, all with respect to the control assay. Addition of PEG 4000 at 0.5 g/g SiO₂ showed an increase of 14.78% in the hydrolysis of cellulose to cellobiose, 56.59% in that of cellulose to glucose, and 93.24% in that of hemicellulose to xylose. The addition of PEG shows that at a higher molecular weight and higher concentration, there are significant differences in the percentage of conversion of cellulose and hemicellulose into fermentable sugars, achieving efficiencies of ≈75%. Full article