Search Results (936)

Silicon plays an important role in enhancing plant tolerance to abiotic stress. However, the differential regulatory effects of ionic silicon (Ion-Si) and silicon nanoparticles (SiNPs) on rice seedlings under low temperature (LT) stress have been less studied. This study aimed to investigate the effects of ionic silicon and silicon nanoparticles on rice growth, photosynthetic performance, carbon metabolism, antioxidant defense, and yield formation under low-temperature stress. The results indicated that low-temperature stress significantly inhibited the growth of rice seedlings. Exogenous application of Ion-Si and SiNPs effectively alleviated LT-induced growth inhibition and promoted the recovery of rice. SiNPs demonstrated a stronger effect than Ion-Si in maintaining seedling growth, particularly in enhancing plant height, root length, leaf area, dry weight, and root activity. Low-temperature stress significantly reduced chlorophyll content and photosynthetic capacity, including net photosynthetic rate, stomatal conductance, transpiration rate, intercellular CO₂ concentration, and Rubisco activity. However, under LT stress, both Ion-Si and SiNPs increased chlorophyll content, improved photosynthesis, and enhanced Rubisco activity, with SiNPs showing greater improvement in photosynthetic performance compared to Ion-Si. Additionally, silicon application regulated carbohydrate metabolism by increasing soluble sugar content and enhancing the activities of sucrose phosphate synthase and sucrose synthase, thereby promoting osmotic regulation and energy supply. SiNPs had a stronger effect on carbohydrate metabolism and photosynthate transport than Ion-Si. Furthermore, LT stress increased oxidative damage, manifested as elevated levels of H₂O₂ and malondialdehyde. Exogenous Ion-Si and SiNPs reduced ROS accumulation and lipid peroxidation by increasing the activities of antioxidant enzymes, including superoxide dismutase, peroxidase, and catalase. Compared with Ion-Si, SiNPs showed a stronger ability to enhance antioxidant defense and alleviate oxidative damage. Application of silicon mitigated yield loss under low temperature stress, and SiNPs was more effective than Ion-Si in maintaining rice yield, mainly by increasing the number of effective panicles, grains per panicle, and seed setting rate. This study revealed the distinct physiological roles of Ion-Si and SiNPs in rice cold tolerance and provided a theoretical foundation for the application of silicon-based fertilizers in rice production under low-temperature conditions. Full article

Background/Objectives: One of the ongoing clinical constraints is limiting microbial growth on prostheses, justifying the need for material surface enhancements to reduce microbial complications. This study aimed to investigate a potentially applicable and reproducible coating technique to overcome clinical microbial challenges. Methods: Silver (Ag) nanoparticles (NPs) were applied to three types of materials through spray, spin, and dip coating techniques. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy, energy-dispersive X-ray fluorescence (EDXRF), and inductively coupled plasma optical emission spectroscopy (ICP-OES) were performed. Subsequent optimization of spray numbers was determined. Antimicrobial performance of one- and three-layered coatings was evaluated through agar diffusion, direct contact, and adhesion (time-dependent) assays against Pseudomonas aeruginosa (P. aeruginosa). Results: Spray coating exhibited superior coating uniformity. In total, 15 sprays were determined as an effective number for a single-layer coating. EDS confirmed Ag NP presence; FTIR revealed no chemical alteration. Disk diffusion tests showed no inhibition zones. Adhesion and direct contact tests displayed antibacterial activity. The effect was superior in direct contact test. Short-term time-dependent adhesion test of one-layer coating of acrylic and silicone had a consistent decrease in bacterial amount, whilst zirconium had only a strong initial activity. In general, the three-layer coating did not reveal a higher antimicrobial activity, suggesting that the increase in layering can negatively impact surface effectiveness. Conclusions: Spray coating of Ag NPs represents a potentially feasible and relevant strategy for enhancing the antibacterial properties of dental and maxillofacial prosthetic materials without compromising their inherent physicochemical characteristics, pending further cytotoxicity and in vivo validation. Full article

Luminescent gadolinium oxide nanoparticles doped with europium were synthesized through a precipitation reaction using gadolinium and europium nitrates as precursors. The europium-doped gadolinium oxide nanoparticles were incorporated first into a gel matrix of silicon dioxide and second by mixing with polymethyl methacrylate. Both processes are synthesized by the simultaneous hydrolysis of tetraethyl orthosilicate and polymerization of 3-(Trimethoxysilyl) propyl methacrylate. The solid samples obtained are round in shape with a size of about 2.5 cm, which makes the material easy to handle to test different applications. The inclusion of Gd₂O₃:Eu³⁺ nanoparticles increases the level of absorbance in the ultraviolet region, which allows for the improved emission of the material at a wavelength of around 610 nm. Furthermore, it enables easy doping of the material and the fabrication of thin films and monoliths with potential optical applications. Full article

This work describes the preparation of PTFE (polytetrafluoroethylene)/SiO₂ (silicon dioxide)–ER (epoxy resin)/FR (fluorosilicone resin) superhydrophobic coatings using the spray method to improve the anti-icing and de-icing performance of transmission line insulators. The coatings exhibit a consistent fluorine distribution (32.86 wt%), which enhances their low surface energy, alongside SiO₂ nanoparticles that occupy the interstices between PTFE particles, resulting in a dense micro- and nanoscale hierarchical structure. Consequently, the coatings have good superhydrophobicity, featuring a contact angle of 173.9° and roll angle of 1.2°. Following 66 days of UV irradiation, the contact angle remains above 150°, and the roll angle is approximately 15°, accompanied by a slight increase in ice adhesion strength. Following 26 freeze–thaw cycles, the contact angle stabilizes at around 157°, showing good environmental durability. Natural icing studies validate the coatings’ good anti-icing and de-icing efficacy: in comparison to common insulators, the coated insulators demonstrate a 14.2% reduction in ice accretion weight and a 67.7% reduction in maximum ice ridge length. Full article

The emergence of three-dimensional heterogeneous integration (3D HI) has pushed forward the development of chip-to-wafer (C2W) hybrid bonding technology. To mitigate stress concentration during thermal annealing and wafer thinning processes of C2W bonding, a direct ink writing (DIW)-based 3D printing approach was proposed to fill the channel between two adjacent chips on the bonded wafer (i.e., wafer channels). A composite slurry consisting of polyimide (PI) as base material and aluminum nitride (AlN) nanoparticles as fillers was prepared. Through surface chemical modification and ultrasonic treatment, the slurry featured uniform filler dispersion (with particle size less than 1 μm) and adequate viscosity (3327 mPa·s), which fits the 3D printing process. The cured film demonstrated superior thermal stability and mechanical properties compared with pure PI, with a coefficient of thermal expansion (CTE) of 4.97 ppm/K, which matched that of silicon-based materials and exhibited excellent bonding. This approach provides a cost-effective and efficient alternative to chemical vapor deposition (CVD) techniques for filling wafer channels. Full article

Silicon-based anodes are considered promising alternatives to graphite anodes owing to their high theoretical lithium-storage capacity and abundant reserves. However, silicon nanoparticle anodes are severely limited by large volume expansion, unstable interfacial chemistry, and poor electrical connectivity during repeated lithiation/delithiation. Herein, we develop a yolk–shell N-doped carbon network (NCN) strategy to construct Si@void@NCN composites. The optimized Si@void@NCN-1 achieves a balanced architecture between void buffering and carbon network integrity, delivering a high initial discharge capacity of 1245.5 mAh g⁻¹ and an initial charge capacity of 735.8 mAh g⁻¹. It also demonstrates stable long-term cycling performance, retaining a reversible capacity of 402.5 mAh g⁻¹ after 500 cycles at 0.5 A g⁻¹ with a capacity retention of 68.66%, and shows improved rate reversibility and electrode structural stability, with an electrode thickness increase of only 80.4% after rate cycling, much lower than that of densely carbon-coated Si@C. Kinetic analysis, post-cycling structural characterization, and in situ EIS further reveal that the yolk–shell void-buffering structure and the N-doped three-dimensional conductive network act synergistically to mitigate Si volume expansion, enhance structural stability, and facilitate electron/ion transport. This study emphasizes the importance of integrating buffering structures with Si/C composites, providing guidance for the rational design of advanced silicon-based electrode materials. Full article

A method for synthesizing theranostic nanoparticles (NPs) based on a silica core, a mercapto spacer, a cardioprotector, and a fluorescent dye has been developed. The total amount of grafted mercapto groups was 0.079 mmol/g. The amount of accessible mercapto groups on the surface of the synthesized particles, calculated using the Kunkel, Buckley, and Gorin method, was 0.025 mmol/g. A total of 0.031 mmol/g of adenosine and 0.0087 mmol/g of indocyanine green are grafted onto the mercapto spacer. Both substances are presumably attached via hydrogen bonding to the modified silica nanoparticle in a ratio of 60/40% for adenosine and indocyanine green, respectively. The resulting nanoparticles exhibit no hemolytic activity. Intensive adenosine release occurs within 90 min and continues for up to 24 h. Based on biodistribution, significant accumulation of the nanoparticles occurs in the liver. Full article

Ascorbic acid plays an important role in the human body due to its antioxidant and anti-inflammatory properties, as well as its involvement in collagen synthesis, enzymatic regulation, and the biosynthesis of corticosteroids and selected neurotransmitters. Owing to these diverse functions, it is used both in the prevention and supportive treatment of several disorders and as a mild, non-toxic reducing agent in the synthesis of gold nanoparticles (AuNPs). In the present study, a method for synthesizing gold nanoparticles was developed using second-generation poly(amidoamine) dendrimers (PAMAM G2) with an ethylenediamine core as stabilizing agents and ascorbic acid as the reducing agent. The synthesis was performed using two techniques: sonication and microwave irradiation. A comparative analysis was conducted for colloidal systems obtained at various molar ratios of PAMAM G2 dendrimers to chloroauric acid (ranging from 1:1 to 1:5). The presence of gold nanoparticles was confirmed using ultraviolet–visible spectroscopy (UV–Vis). Nanoparticle diameters and zeta potentials were determined by dynamic light scattering (DLS). The sizes of the metallic cores were estimated using scanning transmission electron microscopy (STEM). Furthermore, the morphology and topography of entire complexes deposited on silicon substrates were visualized using atomic force microscopy (AFM). For cytotoxicity studies on human breast adenocarcinoma and human osteosarcoma cell lines, the most stable colloids—those obtained at a PAMAM G2:HAuCl₄ molar ratio of 1:3—were selected. Results indicate that the synthesized nanoparticles exhibit slightly higher cytotoxicity compared with AuNPs/PAMAM G2 complexes reduced with sodium citrate, as evidenced by lower EC₅₀ values (the concentration responsible for reducing cell viability to 50%). It should be emphasized, however, that AuNPs/PAMAM G2 reduced with ascorbic acid are significantly smaller, with diameters of approximately 10 nm, whereas citrate-reduced nanoparticles exhibit diameters of around 20 nm. These results indicate that nanoparticle size, rather than the chemical nature of the reducing agent, is a dominant factor governing the cytotoxic response of AuNPs/PAMAM G2 complexes. Full article

Graphene derivatives and nano-silicon dioxide (nano-SiO₂) have been widely studied as functional nanofillers for architectural coatings. They have the potential to improve mechanical performance, barrier properties, durability, and versatility. However, despite encouraging results in laboratory settings, their use in commercial coating formulations is still limited. This is mainly due to challenges with dispersing nanoparticles, ensuring compatibility with polymer binders, maintaining long-term durability, and achieving formulation stability. In this work, we conducted a thorough review and meta-analysis of 20 peer-reviewed studies to evaluate the performance and limitations of graphene-based materials and nano-SiO₂ in architectural and protective coatings. Our literature search followed PRISMA guidelines and included studies that provided quantitative data on dispersion methods, surface functionalization strategies, nanofiller loading levels, and coating performance metrics. This review highlights key relationships between structure, properties, and processing. It points out ongoing challenges that prevent practical use and suggests future research directions to enhance formulation design, improve dispersion stability, and extend the long-term performance of graphene- and nano-SiO₂-modified architectural and protective coatings. Full article

Gold and silver nanoparticles have attracted extensive attention in SERS detection due to their excellent plasmonic properties. In this study, a high-performance SERS substrate was successfully prepared by a liquid–liquid self-assembly strategy. Driven by the Marangoni effect, Au-Ag nanoparticles spontaneously form a uniform and dense monolayer structure on the silicon wafer, constructing an efficient plasmon “hotspot” region, which significantly improves the detection sensitivity of the substrate. The performance of the SERS substrate was systematically evaluated using CV and Me B as Raman probe molecules. The results show that the substrate exhibits an excellent enhancement effect and good SERS sensitivity for both probe molecules. The characteristic vibration peak can be clearly identified, and the detection limit (LOD) of crystal violet is 6.76 × 10⁻¹¹ M. The substrate was applied to detect thiram residues in lake water with a LOD of 1.084 × 10⁻⁷ M, achieving highly sensitive detection. This study shows that Au-Ag nanoparticles deposited on silicon wafers by liquid–liquid self-assembly strategy can be used as a high-performance SERS substrate. It can be used for rapid and sensitive detection of thiram pesticide residues in water, and provides an efficient and feasible analysis tool for water environment safety monitoring. Full article

Continuous intraocular pressure (IOP) monitoring is crucial for glaucoma management. Currently, traditional static IOP measurements often fail to detect circadian fluctuations, leading to a clinical dilemma where “normal IOP” is observed despite persistent visual field deterioration. This study presents a wireless, passive localized surface plasmon resonance (LSPR) sensing platform integrated into flexible silicone hydrogel contact lenses. Gold nanoparticles (AuNPs), synthesized via the sodium citrate reduction method, were incorporated into the lens periphery using a “swelling-induced nano-doping” technique to transduce IOP-induced corneal strain into detectable spectral shifts. Ex vivo porcine eye investigations established a physical mapping model, confirming significant LSPR peak wavelength response trends in correlation with IOP variations (10–50 mmHg) and corneal curvature changes. Subsequent 21-day in vivo rabbit studies demonstrated excellent ocular surface biocompatibility; quantitative histopathological analysis (HE, PAS, and Ki67 staining) revealed no significant adverse alterations in corneal endothelial cell density or conjunctival goblet cell function compared to control groups (p > 0.05). Furthermore, the platform maintained high structural integrity and anterior segment tolerance under transient high-IOP conditions. While currently a proof-of-concept, these results indicate that the LSPR-active hybrid system effectively captures dynamic IOP fluctuation patterns as an optical response to acute interventions, providing a foundational engineering path for next-generation, battery-free wearable diagnostics in personalized glaucoma care without the need for built-in electronics. Full article

Herein, we report the rational design of an A-SnO₂/Si@N-CNT nanocomposite, fabricated via facile ball milling followed by high-temperature annealing. In this design, surface-modified SnO₂ (A-SnO₂) serves as the primary active framework, silicon nanoparticles are introduced to enhance overall capacity, and nitrogen-doped carbon nanotubes (N-CNTs) provide a conductive and mechanically resilient network. The incorporation of silicon nanoparticles and N-CNTs into A-SnO₂ facilitated the formation of strong Si–C and Si–O–Sn bonds, thereby improving electrical conductivity and structural stability and reinforcing interfacial interactions between the active materials and the conductive CNT matrix, resulting in superior electrochemical performance. Morphological analysis confirmed that the composite maintained structural stability without severe cracking after 100 cycles at 100 mAh g⁻¹. The electrode delivered reversible capacities of 1002 and 622 mAh g⁻¹ at 0.1 and 0.5 A g⁻¹, with capacity retentions of 78.7% and 73.17%, respectively. Even at 1.0 A g⁻¹, a stable capacity of 441 mAh g⁻¹ with 80.96% retention was achieved. These findings demonstrate the effectiveness of coupling surface-modified SnO₂ with Si- and N-doped carbon frameworks for advanced lithium-ion battery anodes. Full article

In this study, carboxyl groups were introduced onto CNT surfaces via acid oxidation, and Ag nanoparticles were successfully deposited onto the CNTs through an in situ chemical reduction method. At an Ag-to-CNTs100 mass ratio of 3:1, the as-prepared composite achieved a thermal conductivity of 1.45 W/(m·K) in dimethyl silicone oil, representing enhancements of 187.5% and 76.9% relative to pure Ag nanoparticles and pristine CNTs100, respectively, at equivalent loadings. Concurrently, tribological tests revealed that the AgHTs-3 at a 3:1 mass ratio and 25 wt% loading exhibited a steady-state friction coefficient of 0.08–0.12, reflecting an approximately 72% reduction compared with pure dimethyl silicone oil. Electrical conductivity measurements demonstrated that CO-CNTs100 attained saturation at 30 wt% with a resistivity of 36.5 Ω·m, whereas the AgHTs-3 nanocomposite achieved a resistivity of 4.7 Ω·m at 35 wt%. The incorporation of Ag nanoparticles effectively enhanced the overall performance of the nanocomposites. Through the formation of a synergistic heterostructure with carboxyl-functionalized carbon nanotubes, the composite not only significantly improved the thermal conductivity of dimethyl silicone oil but also effectively optimized the interfacial lubricating film while substantially reducing the friction coefficient and wear volume. Moreover, the introduction of silver promoted the dispersion stability of the composites in dimethyl silicone oil, enabling higher filler loadings and thereby effectively boosting electrical conductivity. Full article

Drought frequently threatens the yield and quality of Carya cathayensis Sarg. cultivated in mountainous regions. To search for effective drought-resistant regulators is of great significance for alleviating short-term seasonal drought in C. cathayensis during dry seasons, thereby stabilizing its yield and quality. Silicon dioxide nanoparticles (SiO₂ NPs) mitigate abiotic stress in plants. To give insight into the regulatory role of SiO₂ NPs in mitigating drought stress, polyethylene glycol 6000 (PEG-6000) was used to simulate varying degrees of drought conditions, and the growth phenotype, photosynthetic physiological characteristics, antioxidant defense system, and cellular ultrastructure of C. cathayensis leaves were analyzed to evaluate the impacts of foliar-applied exogenous SiO₂ NPs. The results indicated that, compared with severe drought, 200 mg/L SiO₂ NP application to plants under severe drought treatment significantly increased superoxide dismutase and peroxidase activities and chlorophyll and nitrogen contents, while malondialdehyde levels decreased. Furthermore, SiO₂ NP application notably enhanced the net photosynthetic rate, stomatal conductance, and electron transport efficiency. This effectively alleviated both stomatal and non-stomatal limitations, thereby mitigating drought-induced photosynthetic inhibition. Additionally, Transmission electron microscopy revealed that SiO₂ NPs effectively preserved the structural integrity of chloroplasts, mitochondria, and nuclei, reducing drought-induced ultrastructural damage. In conclusion, exogenous SiO₂ NPs enhance drought tolerance in C. cathayensis by synergistically modulating photosynthesis, antioxidant defense, and cellular structural stability. Full article

Three-dimensional integrated circuits (3D ICs) have emerged as a key technology to sustain scaling trends in the microelectronics industry. This advancement calls for a fundamental shift in how electrical interconnects are implemented, with through-silicon vias (TSVs) playing a pivotal role in enabling vertical connectivity between stacked chips. However, the metallization of TSVs traditionally involves elaborate and demanding processes, which can limit the speed and flexibility of prototyping and design modifications. In this paper, we investigate the use of Ultra-Precise Dispensing (UPD) technology of novel silver nanoparticle-based pastes as a simple and adaptable alternative to the metallization of TSVs process. The TSV filling process is outlined, followed by a detailed analysis of their morphology, filling quality, and electrical performance. We successfully achieve filled vias through a 280 μm thick silicon substrate with diameters down to 20 μm, resulting in an aspect ratio of up to 14:1, exhibiting favorable electrical properties. This work contributes to the achievement of dense, high-aspect ratio TSV fabrication using additive manufacturing, demonstrating a path towards reduced complexity of standard technology processes cycle, lower cost potential, and increased design flexibility. Full article