Search Results (2,575)

This study examines the influence of sintering temperature on the structural and transport properties of GdBa₂Cu₃O₇ (Gd123) superconductors prepared from nano-sized precursors via the co-precipitation method. The metal-oxalate precursor (average particle size < 50 nm) was calcined at 900 °C for 12 h, and then the prepared pellets were sintered under an oxygen atmosphere in the range of 920–950 °C for 15 h. All samples showed metallic properties and a sharp superconducting transition. Critical temperatures T_C(R=0) were 94–95 K, with higher sintering temperatures steadily boosting critical current density. X-ray diffraction confirmed orthorhombic Gd123 as the dominant phase, with its phase fraction increasing from 92% to 99.8% as the sintering temperature increased. SEM micrographs showed large, densely packed grains, with higher sintering temperatures promoting improved grain connectivity and reduced porosity. The sample sintered at 950 °C exhibited the most favorable transport performance, attributed to enhanced intergranular coupling and the presence of nanoscale secondary phases acting as effective flux-pinning centers. Overall, these results demonstrate that careful control of sintering temperature can significantly optimize the microstructure and superconducting properties of Gd123 materials, supporting their advancement for practical electrical and magnetic applications. Full article

Valsartan (Val)—a lipophilic non-peptide angiotensin II type 1 receptor antagonist—is highly effective against hypertension and displaying limited solubility in water (3.08 μg/mL), thereby resulting in low oral bioavailability (23%). The limited water solubility of antihypertensive drugs can pose a challenge, particularly for rapid and precise administration. Herein, we synthesize and characterize valsartan-containing silver nanoparticles (Val-AgNPs) using Mangifera indica leaf extracts. The physicochemical, structural, thermal, and pharmacological properties of these nano-conjugates were established through various analytical and structural tools. The spectral shifts in both UV-visible and FTIR analyses indicate a successful interaction between the valsartan molecule and the silver nanoparticles. The resulting nano-conjugates are spherical and within the size range of 30–60 nm as revealed in scanning electron-EDS and atomic force micrographs. The log-normal distribution of valsartan-loaded nanoparticles, with a size range of 30 to 60 nm and a mode of 54 nm, indicates a narrow, monodisperse, and highly uniform particle size distribution. This is a favorable characteristic for drug delivery systems, as it leads to enhanced bioavailability and a consistent performance. Dynamic Light Scattering (DLS) analysis of the Val-AgNPs indicates a polydisperse sample with a tendency toward aggregation, resulting in larger effective sizes in the suspension compared to individual nanoparticles. The accompanying decrease in zeta potential (to −19.5 mV) and conductivity further supports the idea that the surface chemistry and stability of the nanoparticles changed after conjugation. Differential scanning calorimetry (DSC) demonstrated the melting onset of the valsartan component at 113.99 °C. The size-dependent densification of the silver nanoparticles at 286.24 °C correspond to a size range of 40–60 nm, showing a significant melting point depression compared to bulk silver due to nanoscale effects. The shift in Rf for pure valsartan to Val-AgNPs suggests that the interaction with the AgNPs alters the compound’s overall polarity and/or its interaction with the stationary phase, complimented in HPTLC and HPLC analysis. The stability and offloading behavior of Val-AgNPs was observed at pH 6–10 and in 40% and 80% MeOH. In addition, Val-AgNPs did not reveal hemolysis or significant alterations in blood cell indices, confirming the safety of the nano-conjugates for biological application. In conclusion, these findings provide a comprehensive characterization of Val-AgNPs, highlighting their potential for improved drug delivery applications. Full article

This manuscript describes the development of a nano-sized synthetic smectic clay hydrogel (LAP) that enables controlled oxygen delivery, making it a promising candidate for treating skin wound infections and promoting healing. LAP is an ingredient in various dermatological products, including powders, creams and emulsions. We investigated the antibacterial effect of the LAP hydrogel by incorporating calcium peroxide (CPO), an oxygen-releasing agent, and measuring the size of the inhibitory halo. We found that CPO hydrogels in LAP showed a significant increase in oxygen release during the first five hours, especially at low CPO concentrations. For example, the hydrogel with 5% CPO showed a controlled release profile with a final percentage oxygen release of 2.47 ± 0.01% after 5 h. In contrast, the hydrogels with 10% and 20% CPO achieved lower final oxygen release values, 0.67 ± 0.01% and 0.75 ± 0.01%, respectively, suggesting that the encapsulation efficiency of LAP is higher at higher concentrations. LAP also proved to be an effective oxygen barrier and showed inherent antimicrobial activity. The research confirmed the antibacterial properties of the hydrogel, with inhibition sites observed against both E. coli and S. aureus. These results emphasize the potential of this hydrogel to serve as an effective tool for wound treatment by providing sustained oxygenation and fighting microbial infections. Full article

Spinel-based glass-ceramics face challenges such as a narrow crystallization window for the target phase and the difficulty in suppressing the competitive Li_xAl_xSi_1−xO₂ crystals. This study proposes a method to regulate the phase formation in ZnO-MgO-Al₂O₃-SiO₂ glass by precisely controlling the heat treatment temperature. The microstructural evolution was analyzed by DSC, XRD, Raman spectroscopy, SEM, TEM, and XPS. The results indicate that the heat treatment at a nucleation temperature of 780 °C for 2 h and a crystallization temperature of 880 °C for 2 h effectively inhibits the precipitation of the Li_xAl_xSi_1−xO₂ secondary phase, yielding a glass-ceramic with nano-sized MgAl₂O₄, ZnAl₂O₄ spinel as the primary crystalline phase. The obtained glass-ceramic exhibits excellent mechanical properties, including a Vickers hardness of 922.6 HV, a flexural strength of 384 MPa, and an elastic modulus of 113 GPa, while maintaining a high visible light transmittance of 84.3%. This work provides a clear processing window and theoretical basis for fabricating high-performance, highly transparent spinel-based glass-ceramics through tailored heat treatment. Full article

Background: Early childhood caries is defined as a carious disease affecting primary teeth in children under 6 years of age. It may lead to pain, infections, and difficulties with eating. Despite its burden, evidence on simple, non-invasive preventive approaches which can be implemented both in dental clinics and outreach services is fragmented. The aim of this review was to identify and map such methods for the secondary and tertiary prevention of ECC and to define priorities for future research. Material and Methods: The scoping review followed the PCC framework (Population–Concept–Context). Two databases were searched: PubMed and Scopus. A systematic search was conducted in PubMed and Scopus between 1 August and 30 September 2025. Eligible studies included children under 6 years of age with existing carious lesions, evaluated non-invasive methods for secondary and tertiary ECC prevention (such as sodium fluoride (NaF), silver diamine fluoride (SDF), nano-silver fluoride (NSF), and motivational techniques), requiring simple armamentarium, and reported data on the effectiveness in the context of ECC. Only publications from the past 5 years, available in English, and in open access, were considered. The results of the analysis were summarized narratively, outlining intervention types based on their characteristics, impact, and usage context. Results: Fifteen studies were included. Most were randomized controlled trials (eight studies), focusing primarily on silver diamine fluoride (SDF), often compared with other non-invasive methods, followed by systematic reviews (two studies), reviews (two studies), cross-sectional studies (two articles), and one qualitative study. Only one publication examined the use of motivational interviewing within the context of ECC. While the evidence on non-invasive approaches is growing, significant gaps remain. Small sample sizes, short follow-up periods, and heterogenous interventions and outcomes limit comparability. To strengthen the evidence base, future studies should recruit larger cohorts, adhere to standardized procedures, and use consistent reporting. Conclusions: The majority of studies focused on SDF, reflecting the increasing interest in its use. Research on motivational interviewing in ECC is particularly scarce. Further research under standardized conditions is needed to enable reliable comparisons across treatment protocols. Full article

The field of nanotechnology has witnessed a paradigm shift towards eco-friendly and sustainable synthesis methods for nanoparticles due to increasing concerns over environmental toxicity and resource sustainability. Among various metal oxide nanoparticles, zirconium dioxide (ZrO₂) nanoparticles have garnered significant attention owing to their exceptional thermal stability, biocompatibility, mechanical strength, and catalytic properties. Doping ZrO₂ with transition metals such as copper (Cu) further enhances its physicochemical attributes, including antibacterial activity, redox behaviour, and electronic properties, rendering it suitable for a diverse range of biomedical and industrial applications. In the present study, we report the green synthesis of copper-doped ZrO₂ nanoparticles (Cu-ZrO₂-CO NPs) using an aqueous extract of Calendula officinalis (marigold) flowers as a natural reducing and stabilizing agent. The complete characterization was performed using UV–vis spectrophotometry, dynamic light scattering (DLS), zeta potential, FTIR, SEM, EDAX, and XRD, revealing its size to be around 20–40 nm and zeta potential as −20 mV, indicating nano size and stability. The biocompatibility of the as-synthesized nanoparticle was analyzed in vitro using fibroblast cell viability and haemolysis assay, and in vivo using brine shrimp assay. The nanoparticles were safe up to a dose of 50 μg/mL, showing more than 95% cell viability and less than 2% haemolysis, which is within an acceptable range. Finally, the anticancer activity was explored for A549 cells by MTT assay and live-dead assay, with an IC50 value of 38.63 μg/mL. The chorioallantoic membrane (CAM) model was used to assess the anti-angiogenesis potential of the Cu-ZrO₂-CO NPs. The results showed that the nanoparticles could kill the cancer cells via apoptosis, and one of the reasons for the anticancer effect was angiogenesis inhibition. Further research is needed using other cancer cell lines and animal tumour models. Full article

Nanoplastics pose significant environmental and public health risks, prompting the need for sensitive, cost-effective, and rapid assays for ecotoxicity assessment. The present work proposes the use of a portable smartphone-based platform to enhance traditional Daphnia magna acute toxicity assays by integrating behavior analysis and heart rate measurements. The aim is to improve sensitivity in detecting toxic effects of nanoplastics. In particular, the study focused on nano-sized carboxylated polystyrene (PS) nanoparticles. Two variability factors that could influence biological effects of nanoplastics, the particle size and the age of the organisms, were considered. Results demonstrated that the application of the proposed integrated approach allowed the detection of early subtle effects such as a significant impact on the heart rate and behavior of Daphnia magna under short-term exposure to PS carboxylated nanoparticles. In particular, a stimulation of heart rate was observed for both neonates and adults either for 40 nm or 200 nm particles after 48 h exposure, presumably attributable to an interference of carboxylated PS NPs with adrenergic-type receptors. Behavioral alterations were detectable for 40 nm particles but not for 200 nm ones consisting of a decrease in velocity and alterations of trajectories. Obtained results demonstrated the suitability of the proposed smartphone platform for friendly and real-time integration of behavioral analysis with physiological outcome measurements during acute exposure of Daphnia magna to nano-sized carboxylated PS NPs, expanding the sensitivity of the traditional acute toxicity tests. It offers a novel, cost-effective, and field-applicable method for environmental monitoring of nanoparticle toxicity and impact. Full article

Background/Objectives: Wound healing is a complex biological process influenced by inflammation, oxidative stress, and cellular regeneration. Plant-derived bioactive compounds have shown potential to accelerate tissue repair through antioxidant and anti-inflammatory mechanisms. This study aimed to develop and evaluate a Platanus orientalis extract-loaded liposomal formulation for potential wound-healing applications. Methods: Four polar extracts (P1–P4) were prepared using different solvent systems and extraction techniques and were characterized by LC-HRMS to determine their phytochemical profiles. Among the identified constituents, quercetin was consistently detected across all extracts and selected as the reference compound due to its well-known wound-healing activity. Liposomes were prepared via thin-film hydration followed by probe sonication and characterized for particle size, polydispersity index (PDI), zeta potential, encapsulation efficiency, and total drug content. In vitro release, cytotoxicity, and wound-healing assays were subsequently conducted to assess performance. Results: The optimized liposome formulation had a mean particle size of 106.6 ± 5.4 nm, a PDI of 0.11 ± 0.04, and a zeta potential of −14.1 ± 0.5 mV. Environmental scanning electron microscopy (ESEM) confirmed the nanosized spherical morphology and homogeneous vesicle distribution, supporting the successful development of the liposomal delivery system. Encapsulation efficiency and total drug content were determined as 72.25 ± 1.05% and 96.15 ± 0.14%, respectively. In vitro release studies demonstrated a biphasic pattern with an initial burst followed by a sustained release, reaching approximately 75% cumulative quercetin release within 24 h. Physical stability testing confirmed that the optimized liposomal formulation remained physically stable at 5 ± 3 °C for at least 60 days. The optimized formulation showed no cytotoxic effects on CDD-1079Sk fibroblast cells and exhibited significantly enhanced wound closure in vitro. Conclusions: These findings indicate that the liposomal delivery of Platanus orientalis extract provides a biocompatible and sustained-release system that enhances wound-healing efficacy, supporting its potential use in advanced topical therapeutic applications. Full article

Background/Objectives: The growing threat posed by antimicrobial resistance to worldwide public health highlights the urgent need not only for new anti-infective candidates, but also for innovative formulation strategies capable of mediating effective delivery of anti-infective compounds. The current study, therefore, aimed to demonstrate the feasibility of formulating lipid-polymer hybrid nanoparticles (LPHNPs) with dual loading of both core and shell compartments for combination anti-infective delivery. Methods: LPHNPs containing the antibiotic cefotaxime within a chitosan polymer core and the novel antimicrobial peptide RN7IN6 within a bacteria-mimicking lipid shell were produced by microfluidic mixing, and optimized with respect to parameters including total flow rate, flow rate ratio, and lipid concentration. Minimum inhibitory concentrations of cefotaxime and RN7IN6 co-incorporated in LPHNPs were assessed as a preliminary indicator of antibacterial efficacy. Results: Uniformly nanosized LPHNPs were produced, with maximized loading of cefotaxime and RN7IN6 within particle cores and shells, respectively. Empty LPHNPs showed an appreciable antibacterial activity, particularly against the Gram-negative bacterium Escherichia coli, while RN7IN6 was indicated to enhance cefotaxime activity against E. coli when both actives were incorporated in LPHNPs. Conclusions: The current findings clearly demonstrate the feasibility of formulating LPHNPs for core-shell co-encapsulation and delivery of anti-infectives. The promising antibacterial efficacy of co-loaded LPHNPs warrants further in-depth investigation to determine the extent of co-loaded LPHNP applications as combination anti-infective delivery platforms. Full article

There is a growing demand for biocompatible, non-toxic nanomaterials with specific functional properties, including catalytic activity. In this study, magnetic iron oxide nanoparticles were synthesized via chemical co-precipitation in the presence of polyethylene glycol (PEG). PEG was used as a coating agent to reduce particle agglomeration. Comprehensive characterization of the synthesized nanocomposites was performed using scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX) and vibrating sample magnetometry (VSM). SEM studies confirmed the nanosized structure of the particles with an average diameter of 20–60 nm. The saturation magnetization values were 57.37 emu·g⁻¹ for nFe₃O₄-PEG6000, 11.95 emu·g⁻¹ for nFe₃O₄-PEG4000 and 3.97 emu·g⁻¹ for nCo_0.5Ni_0.5Fe₂O₄-PEG4000. In addition to their high magnetic properties, ferrofluids exhibited peroxidase-like activity, which makes them highly suitable for bioanalytical and biomedical use. The Michaelis–Menten constant (K_M) for hydrogen peroxide ranged from 1.15 to 4.98 mM. Transmission electron microscopy (TEM) proved the penetration of the nano-ferrofluids into the yeast cells of Ogataea polymorpha. The studied nano-ferrofluids were found to be non-toxic at concentrations up to 0.2 mg·mL⁻¹ for both prokaryotic and eukaryotic cells, showing no inhibitory effect on the growth of the bacterium Escherichia coli, the yeast Ogataea polymorpha, or animal and human cell lines. These results indicate that the advantages of synthetic nano-ferrofluids—including peroxidase-like activity, strong magnetic properties, cost-effective synthesis, stability, and low toxicity—make the synthesized nano-ferrofluids highly promising for future biomedical and bioanalytical applications. Full article

Alopecia areata (AA) is an autoimmune-mediated nonscarring alopecia with limited therapeutic options and frequent relapses. Exosomes, nanosized extracellular vesicles secreted by various cell types, have recently emerged as potential regenerative and immunomodulatory therapies. The aim of the study is to review the clinical and preclinical evidence regarding the efficacy and safety of EV-based therapies for alopecia areata. a systematic search of PubMed, Embase, Web of Science, and Cochrane Library was performed from 2020 to 2 October 2025. Inclusion criteria were original studies (clinical, preclinical, in vivo, in vitro) investigating exosome-derived interventions for AA. Outcomes of interest were hair regrowth, immune modulation, follicular regeneration, and safety. A total of 499 records were retrieved from electronic database searches. After deduplication and application of the inclusion/exclusion criteria, 40 studies met the eligibility criteria for the review. Of these, two were clinical studies (one retrospective cohort, one case report), while the remainder comprised five animal (in vivo) studies, six in vitro studies, and sixteen mixed translational studies (in vitro/in vivo ± clinical). Experimental studies reported hair coverage improvements of 50–99% and, in one instance, 30% regrowth in totalis and 16% in partialis, with nearly complete regrowth in incipient alopecia. Clinical reports noted density increases of 9–31 hairs per cm² (e.g., from 121.7 to 146.6 hairs/cm², p < 0.001) and improvements in hair count, length, and thickness. Several studies detailed activation of the Wnt/β-catenin pathway along with enhanced dermal papilla and hair follicle stem cell function, as well as anti-inflammatory effects. Reported safety profiles were favorable; when adverse events occurred, they were limited to mild, transient local reactions with no severe systemic issues. EV-based therapy is a novel and biologically plausible approach for AA, but robust randomized controlled trials (RCTs) are lacking. Standardization of small EV sources, doses, and delivery methods is essential before clinical translation. Full article

Phenolic aerogel holds great promise for applications in thermal protection against ablation, and constructing inorganic–organic hybrid networks is an effective strategy to enhance its oxidation and ablation resistance. This study introduces a stepwise hybridization strategy for the preparation of SiO₂–ZrO₂–phenolic resin aerogels (SZPA). First, nano-silica sol and nanometer-scale zirconia were physically blended to form a uniformly dispersed mixture. Subsequently, the modified silica was incorporated into a phenolic resin solution to construct a three-dimensional hybrid silica–phenolic network framework. Nano-sized zirconia was then uniformly dispersed within the matrix as a physical reinforcing phase through high-shear dispersion. Finally, the SZPA with a hierarchical nanoporous structure was obtained via ambient-pressure drying. Owing to its unique hybrid network structure, the aerogel exhibits markedly improved properties: the thermal conductivity is as low as 0.0419–0.0431 W/(m·K) (a reduction of approximately 24%), and the specific surface area is as high as 190–232 m²/g (an increase of approximately 83%). Meanwhile, the inorganic network considerably enhances the residual mass at elevated temperatures, as well as the oxidation resistance and thermal stability of the matrix. Among the tested materials, the SZPA-4 exhibited outstanding thermal insulation capability at high temperatures; its back surface temperature reached only 74.4 °C after 600 s of exposure to a 1200 °C butane flame. This study provides a feasible route for the preparation of high-performance phenolic-based composite aerogels for aerospace thermal protection systems, thereby expanding their potential applications in extreme thermal environments. Full article

To meet the requirements of high resolution, compact size, and ultra-lightweight for micro–nano satellite optoelectronic payloads while ensuring high structural stability during launch and in-orbit operation, mirrors were designed with high surface accuracy. The opto-thermo-mechanical system of the space camera was designed and analyzed accordingly. First, an optical system was designed to achieve high resolution and a compact form factor. A coaxial triple-reflector configuration with multiple refractive paths was adopted, which significantly shortened the optical path and laid the foundation for a lightweight, compact structure. This design also defined the accuracy and tolerance requirements for the primary and secondary mirrors. Subsequently, mathematical models for topology optimization and dimensional optimization were established to optimize the design of the main support structure, primary mirror, and secondary mirror. Two design schemes for the main support structure and primary mirror were compared. Steady-state thermal analysis and thermal control design were carried out for both mirrors. Simulations were then performed on the main system (including the primary/secondary mirror assemblies and the main support structure). Under the combined effects of gravity, a 4 °C temperature increase, and an assembly flatness deviation of 0.01 mm, the surface accuracy of both mirrors, the displacement of the secondary mirror relative to the primary mirror reference, and the tilt angle all met the overall specification requirements. The system’s first-order natural frequency was 156.731 Hz. After precision machining, fabrication, and assembly, wavefront aberration testing was conducted on the main system with the optical axis horizontal. Under gravity, the root mean square (RMS) wavefront error at the center of the field of view was 0.073λ, satisfying the specification of ≤1/14λ. The fundamental frequency measured during vibration testing was 153.09 Hz, which aligned closely with the simulated value and well exceeded the requirement of 100 Hz. Additionally, in-orbit imaging verification was conducted. All results satisfied the technical specifications of the satellite’s overall requirements. Full article

Installation in sand is sensitive to its evolving pore structure, yet design models rarely update permeability for real-time fabric changes. This study tracks the stress-dependent pore size distribution of coarse sand under laterally constrained compression using high-resolution X-ray nano-CT. Scans taken at six axial stress levels show that the distribution shifts toward smaller radii while keeping its log-normal shape. A single shifting factor, defined as the current median radius normalized by the initial value, captures this translation. The factor decays with axial stress according to a power law, and the exponent as well as the reference pressure are calibrated from void ratio data. The resulting closed-form expression links mean effective stress to pore radius statistics without extra fitting once the compressibility constants are known. This quantitative relation between effective stress and pore size distribution has great potential to be embedded into coupled hydro-mechanical solvers, enabling engineers to refresh hydraulic permeability at every computation step, improving predictions of excess pore pressure and soil resistance during suction anchor penetration for floating wind foundations. Full article

This study investigates the Serial Discontinuity Concept (SDC) by analyzing the size of phytoplankton structures across 13 cascade dams in the fragmented East River, China. The results showed that dam flow-regulation minimized seasonal differences in total chlorophyll-a (Chl-a). Spatially, midstream Chl-a was higher during the dry period, whereas increased wet periods were linked to reservoir effects and nutrient conditions. Nano-phytoplankton dominated during both periods, while micro-phytoplankton declined during wet periods due to higher pH and transparency. Micro-Chl-a increased downstream in dry periods as a result of dissolved oxygen levels and silicate. Self-organizing maps revealed greater size–class variability during dry periods, with pH and conductivity identified as key regulators. Aulacoseira granulata (micro-phytoplankton) and Anabaena oscillarioides (also micro-phytoplankton) were co-dominant. This pattern suggests that the flow regulation and water impoundment by cascade dams during the wet period created localized lentic conditions with enhanced water stability, which favored the proliferation of these species, despite the increased seasonal discharge at the basin scale. These findings support the SDC in that (1) longitudinal Chl-a variations empirically validated SDC, especially during dry periods, and (2) a spatially periodic Chl-a pattern was identified, termed the Cascade Cycle of SDC (CC-SDC). Full article