Search Results (287)

Objective: To investigate the influence of chitosan-based nano-silver fluoride (CNSF) treatment of tooth tissues on shear bond strength (SBS) of resin composite (RC) and resin-modified glass ionomer (RMGI) restorations. Methods: 90 extracted human molars were collected. Specimens were randomly assigned to three groups (n = 30): non-pretreated (NPT) pretreated with either CNSF or silver diamine fluoride (SDF). Each group was subdivided into two restorative subgroups (n = 15): RC and RMGI. Specimens in CNSF and SDF groups were pretreated with CNSF or SDF per their manufacturer’s instructions. Then specimens in RC subgroups were etched, treated with chlorhexidine cleanser, followed by adhesive application. Specimens in RMGI subgroups were treated with cavity conditioner only. A cylindrical restoration (2.38 mm θ × 2 mm height) of RC or RMGI restoration was fabricated with a standardized mold and light-cured on all specimens. After 5000 times of thermocycling between 5 °C and 55 °C with dwell times of 30 s intervals, SBS was measured using the Ultradent UltraTester. Data was analyzed statistically (α = 0.05) using ANOVA/Tukey’s comparisons. Results: No statistically significant difference in SBS among RC restorations in the three treatment groups: NPT (17.48 ± 3.96), CNSF (18.38 ± 5.59), and SDF (14.03 ± 6.56). For RMGI restorations, SBS was significantly (p < 0.05) higher in NPT (15.99 ± 3.59) compared to CNSF-treated (11.45 ± 5.48), but there was no significant difference between NPT and SDF-treated (14.27 ± 2.17) or between SDF- and CNSF-treated groups. Conclusions: No difference in SBS of resin composite restorations when the dentin tissue is pretreated with either chitosan-based nano-silver fluoride or silver diamine fluoride. However, SBS of RMGI was lowered when the dentin tissue was pretreated with CNSF. Full article

Ferroelectric oxides, such as Pb(Zr,Ti)O₃ (PZT), have been shown to maintain stable ferroelectricity even in ultrathin film configurations. However, achieving controllable modulation of microstructure and physical responses in these ultrathin films remains challenging, limiting their potential applications in modern nanoelectronics and optoelectronics. Here, we propose a single-pulse femtosecond (fs) laser micromachining technique for high-precision engineering of microstructure and ferroelectric/piezoelectric responses in ultrathin PZT films. The results show that various microstructures can be selectively fabricated through precise control of fs laser fluence. Specifically, nano-concave arrays are formed via low-fluence laser irradiation, which is mainly attributed to the fs laser peening effect. In contrast, nano-volcano (nano-cave) structures are generated when the laser fluence is close to or reaches the ablation threshold. Additionally, applying an fs laser pulse with fluence exceeding a critical threshold enables the formation of nano-cave structures with controlled depth and width in PZT/Pt/SiO₂ multilayers. Piezoresponse force microscopy measurements demonstrate that the laser peening process significantly enhances the piezoelectric response while exerting minimal influence on the coercive field of PZT thin films. This improvement is attributed to the enhanced electromechanical energy transfer and concentrated compressive stresses distribution in PZT thin films resulting from the laser peening effect. Our study not only offers an effective strategy for microstructure and property engineering in ferroelectric materials at the nanoscale but also provides new insights into the underlying mechanism of ultrafast laser processing in ferroelectric thin films. Full article

This study conducts a comprehensive examination of a GaN channel-based nanobiosensor featuring a dielectrically modulated trigate FinFET structure, incorporating both uniform and Gaussian channel doping. The proposed device incorporates a nanocavity structure situated beneath the gate region, intended for the analysis of diverse biomolecules in biosensing applications. The proposed biosensor employs HfO₂ as the gate dielectric, characterized by a dielectric constant of 25, leading to an enhanced switching ratio for the device. This study examines the electrical properties relevant to biomolecule identification, including the switching ratio, DIBL, threshold swing, threshold voltage, and transconductance. The sensitivity of these properties concerning the drain current is subsequently assessed. Enhanced sensitivity increases the likelihood of detecting biomolecules. The electrical property of a biomolecule is examined in the absence of another biomolecule within the cavity. The apparatus is designed to detect neutral biomolecules. Simultaneously, further investigational research has been undertaken regarding the linearity behavior of GAA FET, nanobiosensors, and dielectrically modulated TGFinFET. This study’s results have been compared with those of GaN-based FinFET and GaN SOI FinFET technologies. The data indicates approximately ∼103% and ∼42% improvements in I_OFF and Switching ratio, respectively, when compared to IRDS 2025. The nanobiosensor (GAA FET) demonstrates enhanced linear performance concerning higher-order voltage and current intercept points, including VIP2, VIP3, IIP3, and P1dB. Full article

To increase wear resistance, (Zr,Nb)N, ZrN and (Zr,Hf)N coatings with columnar structures and (Zr,Ti)N and (Zr,Nb,Hf)N coatings with nanolayer structures were deposited on an AISI 321 stainless steel substrate. The samples with (Zr,Nb)N and ZrN coatings exhibited the best resistance to failure in the scratch test. The sample with the (Zr,Nb)N coating had the best wear resistance for the first 16,000 s. However, eventually the wear of this sample became notable, and after 20,000 s of testing, the lowest degree of wear was observed in the sample with the (Zr,Nb,Hf)N coating. The wear rate of the uncoated sample was 1.5 times greater than that of the sample with the (Zr,Nb,Hf)N coating. The (Zr,Nb,Hf)N coating also exhibited a low degree of indenter mass loss. The (Zr,Nb,Hf)N and ZrN coatings reduced the coefficient of friction (COF) most (COF of approximately 0.20–0.21, compared to COF = 0.28 for the uncoated sample). Defects (nanocavities) were detected in the interface area between the coatings and the substrate, which in some cases can have a negative effect on the wear resistance of the coating. The (Zr,Nb,Hf)N coating (72.07 at.% Zr, 24.87 at.% Nb and 3.05 at.% Hf) had the best wear resistance and a low friction coefficient. Full article

Nisin, a food preservative lantibiotic produced by Lactococcus lactis, exhibits potent antimicrobial activity against a wide range of Gram-positive pathogens, including antibiotic-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA). This study explores the development of a novel nano drug delivery platform comprising nisin-loaded niosomes, formulated via microfluidic mixing, and integrated into fast-dissolving oral films for targeted buccal administration. Microfluidic synthesis enabled the precise control of critical parameters including the flow rate ratio, surfactant composition, and lipid concentration, resulting in uniform niosomal vesicles with optimal size distribution (100–200 nm), low polydispersity index, and high encapsulation efficiency. Span 40 and Span 60 were employed as non-ionic surfactants, stabilized with cholesterol to improve bilayer rigidity and drug retention. The encapsulated nisin demonstrated improved physicochemical stability over time and protection against proteolytic degradation, thus preserving its antimicrobial potency. The niosomal suspensions were subsequently incorporated into polymer-based oral films as a final dosage form composed of polyvinyl alcohol (PVA) as the primary film-forming polymer, polyethylene glycol 400 (PEG400) as a plasticizer, and sucralose and mint as a sweetener and flavoring agent, respectively. A disintegrant was added to accelerate film dissolution in the oral cavity, facilitating the rapid release of niosomal nisin. The films were cast and evaluated for thickness uniformity, mechanical properties, disintegration time, surface morphology, and drug content uniformity. The dried films exhibited desirable flexibility, rapid disintegration (<30 s), and consistent distribution of nisin-loaded vesicles. In vitro antimicrobial assays confirmed that the bioactivity of nisin was retained post-formulation, showing effective inhibition zones (16 mm) against Bacillus subtilis. This delivery system offers a promising platform for localized antimicrobial therapy in the oral cavity, potentially aiding in the treatment of dental plaque, oral infections, and periodontal diseases. Overall, the integration of microfluidic-synthesized nisin niosomes into oral films presents a novel, non-invasive strategy for enhancing the stability and therapeutic efficacy of peptide-based drugs in mucosal environments. Physicochemical characterization of the niosomes and niosome films was performed using Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) to evaluate thermal stability and scanning electron microscopy (SEM) to assess surface morphology. In vitro peptide release studies demonstrated sustained release from both niosomal suspensions and film matrices, and the resulting data were further fitted to established kinetic models to elucidate the underlying drug release mechanisms. This delivery system offers a promising platform for localized antimicrobial therapy in the oral cavity, potentially aiding in the treatment of dental plaque, oral infections, and periodontal diseases. Overall, the integration of microfluidic-synthesized nisin niosomes into oral films presents a novel, non-invasive strategy for enhancing the stability and therapeutic efficacy of peptide-based drugs in mucosal environments. Full article

Background: Effusion-based lymphoma (EBL) is a rare and aggressive large B-cell lymphoma. It presents as a body cavity effusion without a solid mass, lacks HHV-8 association, and typically expresses CD20. Objectives: To better understand the biology of this entity, we performed transcriptomic profiling of eight EBL cases. Methods: We analyzed the cases with the NanoString PanCancer Immune Profiling Panel and compared the results with publicly available datasets representing follicular lymphoma (FL), mantle cell lymphoma (MCL), and large B-cell lymphoma (LBCL) subtypes. Results: Unsupervised clustering and differential expression analysis revealed that EBL cases cluster transcriptionally with the LBCL group. Lymphoma-specific signaling pathway enrichment (SignatureDB) predominantly identified non-germinal center (activated B-cell-type) pathways. In addition, KEGG pathway analyses revealed enrichment in specific inflammatory and immune response pathways that are associated with B-cell lymphoma development in the setting of chronic inflammation, including those linked to Toll-like receptor and NF-κB signaling. Conclusions: These findings support a post-germinal center origin for EBL, which arises in a background of chronic inflammation and persistent antigen stimulation. Full article

We theoretically studied the control of the extraction of anti-Stokes photoluminescence using photonic crystal (PhC) nanocavities. Our fabricated (erbium,oxygen)-codoped GaAs PhC nanocavity showed a positive feedback gain of heating through the excitation of the GaAs host, which suggests the possibility of higher laser-cooling efficiencies at lower temperatures in such systems. Based on this result, we constructed a theoretical framework of laser cooling in PhC nanocavities. The predicted laser cooling efficiency of a PhC nanocavity is six to eight times higher than that of the corresponding bulk system, and we predict that more than 24% can be achieved at 100 K using holmium-doped materials. Full article

Supported metal catalysts are extensively applied in the heterogeneous catalysis field. However, metal species are prone to migration and aggregation during catalytic reactions due to their high surface energy, which leads to deactivation. In recent years, the use of porous materials, particularly zeolites, to anchor metal species has gained significant attention. By confining metal single atoms, subnanometer metal clusters, and nanoparticles within the pores or nanocavities of these materials, the dispersion and stability of the metal species can be greatly enhanced, thereby improving the catalytic performance. This review systematically discussed the synthesis principles and diverse methodologies to fabricate zeolite-encapsulated metal catalysts. It further outlined their catalytic applications across various catalysis fields, emphasizing enhanced stability and selectivity enabled by confinement effects. Finally, the review provided critical perspectives on future developments, addressing challenges in precise structural control and scalability for industrial implementation. Full article

In the field of high-temperature in situ sensing, highly reflective Fabry–Perot (F-P) cavity mirrors with thermal stress matching are urgently needed. The quartz-based volume Bragg grating (VBG) can replace the dielectric high-reflection film to prepare a high-temperature and high-precision F-P cavity sensitive unit by virtue of the integrated structure of homogeneous materials. The reflectivity of the VBG is a key parameter determining the performance of the F-P cavity, and its accurate measurement is very important for the pre-evaluation of the device’s sensing ability. Based on the reflectivity measurement of quartz-based VBG with a large aspect ratio, a free-space optical path reflective measurement system is proposed. The ZEMAX simulation is used to optimize the optical transmission path and determine the position of each component when the optimal spot size is achieved. After completing the construction of the VBG reflectivity measurement system, the measurement error is calibrated by measuring the optical path loss, and the maximum error is only 1.2%. Finally, the reflectivity of the VBG measured by the calibrated system is 30.84%, which is basically consistent with the multi-physical field simulation results, showing a deviation as low as 0.85%. The experimental results fully verify the availability and high measurement accuracy of the reflectivity measurement system. This research work provides a new method for testing the characteristics of micron-scale grating size VBGs. Additionally, this work combines optical characterization methods to verify the good effect of VBG preparation technology, providing core technical support for the realization of subsequent homogeneous integrated Fabry–Perot cavity sensors. Furthermore, it holds important application value in the field of optical sensing and micro-nano integration. Full article

Hexagonal boron nitride (hBN) is a layered material with a wide variety of excellent properties for emergent applications in quantum photonics using atomically thin materials. For example, it hosts single-photon emitters that operate up to room-temperature, it can be exploited for atomically flat tunnel barriers, and it can be used to form high finesse photonic nanocavities. Moreover, it is an ideal encapsulating dielectric for two-dimensional (2D) materials and heterostructures, with highly beneficial effects on their electronic and optical properties. Depending on the use case, the thickness of hBN is a critical parameter and needs to be carefully controlled from the monolayer to hundreds of layers. This calls for quick and non-invasive methods to unambiguously identify the thickness of exfoliated flakes. Here, we show that the apparent color of hBN flakes on different SiO₂/Si substrates can be made to be highly indicative of the flake thickness, providing a simple method to infer the hBN thickness. Using experimental determination of the colour of hBN flakes and calculating the optical contrast, we derived the optimal substrates for the most reliable hBN thickness identification for flakes with thickness ranging from a few layers towards bulk-like hBN. Our results offer a practical guide for the determination of hBN flake thickness for widespread applications using 2D materials and heterostructures. Full article

In recent years, research on light-matter interactions in silicon-based micro/nano cavity optomechanical systems demonstrates high-resolution sensing capabilities (e.g., sub-fm-level displacement sensitivity). Conventional 2D photonic crystal (PhC) cavity optomechanical sensors face inherent limitations: thin silicon layers (200–300 nm) restrict both the mass block (critical for thermal noise suppression) and optical Q-factor. Enlarging the detection mass in such thin layers exacerbates in-plane height nonuniformity, severely limiting high-precision sensing. This study proposes a 500 nm thick silicon-based 2D slot-type PhC cavity design for advanced sensing applications, fabricated on a silicon-on-insulator (SOI) substrate with optimized air slot structures. Systematic parameter optimization via finite element simulations defines structural parameters for the 1550 nm band, followed by 6 × 6 × 6 combinatorial experiments on lattice constant, air hole radius, and line-defect waveguide width. Experimental results demonstrate a loaded Q-factor of 57,000 at 510 nm lattice constant, 175 nm air hole radius, and 883 nm line-defect waveguide width (measured sidewall angle: 88.4°). The thickened silicon layer delivers dual advantages: enhanced mass block for thermal noise reduction and high Q-factor for optomechanical coupling efficiency, alongside improved ridge waveguide compatibility. This work advances the practical development of CMOS-compatible micro-opto-electromechanical systems (MOEMS). Full article

Rare earth-doped upconversion nanoparticles (UCNPs) can convert low-energy photons (NIRs) into high-energy photons (visible light), offering advantages such as low background signal, good stability, and excellent biocompatibility. However, exploring a strategy to combine the advantages of high efficiency, low cost, and easy fabrication of a plasmonics–UCNPs system is still a challenge. Here, we reported a metal–dielectric–metal (MDM)-type plasmonic platform based on the aluminum metasurface, which can efficiently enhance the luminescence intensity of magnetic and non-magnetic rare earth-doped UCNPs. Attributed to the strong local field effect of the nanocavities formed by the aluminum anti-transmission layer at the bottom, the fluorescence of the two types of UCNPs in such a platform can be enhanced by over 1000 folds compared with that in the conventional substrate. It is found that the deposited UCNPs amount and the aluminum pillar size can both impact the enhancement. We confirmed that the constructed MDM nanocavities could enhance and regulate the local field strength, and the optimum enhancement can be achieved by choosing proper parameters. All these findings provide an efficient way of exploring the plasmon-enhanced UCNPs luminescence system with low cost, high efficiency, and easy fabrication and can be promising in the fields of biosensing and photovoltaic devices. Full article

Phase change materials (PCMs) are widely used in latent heat thermal energy storage systems (LHTESSs), but their low thermal conductivity limits performance. This study numerically investigates the enhancement of thermal efficiency in LHTESSs using nano-enhanced PCM (NePCM), composed of paraffin wax embedded with copper (Cu) nanoparticles. The NePCM is confined within a trapezoidal cavity, with the base serving as the heat source. Four different cavity heights were analyzed: cases 1, 2, 3, and 4 with the heights D of 24 mm, 18 mm, 15 mm, and 13.5 mm, respectively. The finite element method was employed to solve the governing equations. The influence of two hot base temperatures (333.15 K and 338.15 K) and Cu nanoparticle volume fractions ranging from 0% to 6% was examined. The results show that incorporating Cu nanoparticles at 6 vol% (volume fraction) enhanced thermal conductivity and reduced melting time by 10.71%. Increasing the base temperature to 338.15 K accelerated melting by 65.55%. Among all configurations, case 4 exhibited the best performance, reducing melting duration by 15.12% compared to case 1. Full article

Periodontitis is a prevalent oral condition worldwide. Azithromycin, a conventional lipophilic drug for periodontal treatment, often causes systemic side effects when administered orally. To address this, azithromycin-loaded nano-emulgels were developed using olive oil as a carrier within a xanthan gum aqueous gel phase. This oil-in-aqueous gel emulsion was actuated into a foam for localized drug delivery in gingival and periodontal disease. The solubility of azithromycin in various vehicles was tested, with olive oil showing the best solubility (0.347 mg/mL). Thermodynamic stability testing identified viable nano-formulations, with encapsulation efficiencies ranging from 98 to 100%. These formulations exhibited rapid drug release within 2–8 h. Muco-adhesion studies and ex vivo permeability tests on porcine buccal mucosa highlighted the beneficial properties of xanthan gum for local drug retention within the oral cavity. Antimicrobial efficiency was assessed using minimum inhibitory concentrations against various oral pathogens, where the formulation with equal surfactant and co-surfactant ratios showed the most potent antibacterial activity, ranging from 0.390 to 1.56 µg/mL. This was supported by the shear-thinning, muco-adhesive, and drug-retentive properties of the xanthan gel base. The study also examined the influence of the oil phase with xanthan gum gel on foam texture, rheology, and stability, demonstrating a promising prototype for periodontitis treatment. Full article

This study investigates the optical properties of ion-bombarded Au-SiO₂ nanocomposites, focusing on the enhanced Fano resonance observed in these samples. The formation of nanocrystals and nanocavities due to ion bombardment leads to significant interactions between plasmonic and vibrational modes, resulting in pronounced Fano resonance in the strong coupling regime. The study aims to explain the closer spacing of modes, the elevated baseline absorbance, and the asymmetric lineshape observed in the ion-bombarded samples. A detailed analysis is provided, comparing these findings with other sample preparations, such as Au-coated SiO₂ and 20 nm Au colloidal on SiO₂. The implications of these results for understanding plasmonic behavior and their potential applications in nanophotonics are discussed. Full article