Search Results (245,051)

Silicone rubber is extensively used in engineering applications due to its toughness and impact resistance; however, traditional characterisation methods fail to capture its nonlinear deformation characterisation and triaxial mechanical behaviour. To address this, we derived a constitutive model within the framework of continuum mechanics that assumes a condition of near incompressibility and conducted uniaxial, planar, and equibiaxial tension tests to fit the model parameters. Through systematic analysis of triaxial mechanical responses under these three loading modes, we determined the material’s nonlinear large-deformation behaviour and sensitivity to the biaxiality ratio. Comparative analyses with classical hyperelastic models show that the proposed model achieves a good balance between the number of parameters and fitting accuracy. After the parameter-fitting process, we performed finite element simulations of the three loading modes. The simulation results show good agreement with experimental data in terms of deformation patterns and stress–strain curves. This study provides a novel theoretical tool for evaluating the mechanical properties and structural designs of soft materials. Full article

The escalating threat of antimicrobial resistance (AMR) and the environmental impact of industrial pollutants, particularly synthetic dyes, emphasize the pressing requirement for novel solutions. This study investigates the green synthesis of ZnO/Fe₂O₃ nanocomposites using Urtica dioica extract with the aim of achieving dual functionality as both antimicrobial agents and photocatalysts for pollutant degradation. The nanocomposites were synthesized with varying loads of Fe₂O₃ (5–50%) and characterized using X-ray diffraction (XRD) and diffuse reflectance spectroscopy (DRS). XRD analysis confirmed the presence of both the hexagonal wurtzite ZnO phase and the α-Fe₂O₃ hematite phase in all the composites, while DRS analysis revealed that the bandgap energy decreased progressively (from 1.89 to 1.72 eV) as the Fe₂O₃ content increased. The photocatalytic efficiency of the composites was evaluated by degrading methylene blue (MB), Congo Red (CR) and safranin O (SO) dyes under visible light. This demonstrated that the degradation performance depends on the composition, with the best activity being observed at 5% Fe₂O₃. Antioxidant activity was assessed using a DPPH• free radical scavenging assay. This showed that Urtica dioica extract exhibits superior radical scavenging capacity (maximum inhibition of 38%) compared to ZnO/Fe₂O₃ nanoparticles (maximum inhibition of 18%). The antibacterial efficacy against Pseudomonas aeruginosa was evaluated using direct confrontation and disk diffusion methods. This revealed that the activity was dose- and light-dependent, with enhanced performance under light exposure (10 mm inhibition zone) compared to dark conditions (1 mm). This study demonstrates the successful green synthesis of biphasic ZnO/Fe₂O₃ nanocomposites with promising photocatalytic and antimicrobial properties. While the results suggest possible synergistic interactions between the oxides, the underlying mechanisms, including potential charge transfer effects, require further investigation using advanced characterization techniques. Using Urtica dioica extract as a biogenic source provides a promising eco-friendly approach to synthesizing nanomaterials, with potential applications in wastewater treatment and the biomedical field. Full article

Background: Population aging represents a major public health challenge, accompanied by an increasing prevalence of chronic diseases and age-related functional decline. Declines in lower-extremity physical function are particularly important, as they are strongly associated with mobility limitations, loss of independence, increased risk of falls, hospitalization, and mortality in older adults. Reliable and valid tools to assess physical performance are therefore essential in both clinical and research settings. The Short Physical Performance Battery (SPPB) is a widely used instrument for assessing lower-extremity physical performance in older adults and is recommended within the diagnostic algorithm of the European Working Group on Sarcopenia in Older People (EWGSOP2) for evaluating physical performance severity. However, the SPPB has not yet been psychometrically validated in the Croatian older population. This study aimed to evaluate the reliability and validity of the SPPB in Croatian older adults. Methods: This study examined the metric properties of the SPPB in a sample of 153 older adults recruited from nursing homes and community settings. Results: The SPPB demonstrated acceptable internal consistency (Cronbach’s alpha = 0.74) and good test–retest reliability (ICC = 0.893) for the total score. Convergent and construct validity were supported by significant associations with established measures of functional mobility and muscle strength. Conclusions: The Croatian version of the SPPB is a reliable and valid instrument for assessing lower-extremity physical performance in older adults. Its use is supported in clinical practice and research settings in Croatia. Further studies should examine responsiveness and predictive validity in nationally representative samples. Full article

In recent decades, the requirement for materials with excellent electromagnetic wave (EMW) absorption properties has been steadily expanding. Developing and designing multifunctional hybrid absorbers featuring diverse components and synergistic loss mechanisms have become a significant research field. MOF materials feature abundant heterogeneous interfaces and high porosity, and their derivatives exhibit superior magnetic effects. They can enhance EMW absorption through multiple scattering and reflection. These merits enable them to satisfy the demands of diverse EMW absorption applications. Therefore, this work summarizes the investigations and applications of MOF derivatives in EMW absorption. The EMW absorption mechanisms of MOF derivatives are thoroughly investigated from the aspects of precursor design, framework construction, and compounding with reinforcing phases. Meanwhile, the research progress of related materials is summarized, including multi-component MOF-derived EMW absorbers, MOF-derived biomass composite absorbing materials, and MOF-derived conductive polymer composite absorbers. In addition, the subsequent progress of EMW absorbers shows promising prospects. The various deficiencies of MOF-derived absorbers in current research are also analyzed. It is expected to provide more systematic and thorough guidance for the future investigations in related fields. Full article

Pomegranate marc is a major, underutilized juice industry by-product rich in lipophilic polyunsaturated fatty acids—notably conjugated α-linolenic acids (CLnAs)—and hydrophilic polyphenols with potent antioxidant and anti-inflammatory properties. Despite its potential for nutraceutical, cosmetic, and pharmaceutical applications, this matrix remains largely unexploited. This study presents a novel, sequential in-line extraction strategy combining supercritical CO₂ (ScCO₂) and subcritical water (scW) to recover complementary bioactive fractions. Both extraction steps were optimized via Response Surface Methodology (RSM). Box–Behnken optimization of ScCO₂ (43 MPa, 76 °C, 6.4 L min⁻¹, 124 min) yielded 30 g kg⁻¹ dry weight (dw) of oleoresin, achieving a 68% recovery of total oil. Subsequent scW extraction was optimized at 149 °C, with a 40 L kg⁻¹ water-to-solute ratio and 73 min extraction time, yielding 47 g kg⁻¹ dw of total phenolics (58% recovery). Strong agreement between experimental and predicted values confirmed the robustness of the models. Comprehensive profiling revealed a diverse phytocomplex including fatty acids, tocopherols, flavonoids, soluble sugars, and polysaccharides. Antioxidant assays confirmed that both γ-tocopherol and polyphenols significantly contribute to the extracts’ bioactivity. To improve physical handling, the aqueous fractions were converted into solid dispersions via spray drying with maltodextrin. Preliminary in vitro biological assessments on HEK-293 (human embryonic kidney) and MCF-7 (Michigan Cancer Foundation-7) cell lines suggested that the maltodextrin-based formulations may modulate the cytotoxic profile compared to the free extract, with exploratory results showing dosage-dependent variations in cell viability across the two lines. This work suggests a potentially scalable and sustainable biorefinery approach for the integral valorisation of pomegranate marc, offering a basis for a pathway to produce solvent-free bioactives. Full article

For the first time, hybrid nanocomposites based on poly(2,5-dichloro-3,6-bis(phenylamino)-p-benzoquinone) (PCPAB) and multi-walled carbon nanotubes (MWCNTs) were obtained and the influence of the preparation method on their structure and functional properties was demonstrated. The nanocomposites were obtained both by ultrasonic mixing of PCPAB and MWCNTs, and via in situ oxidative polymerization of CPAB in the presence of MWCNTs or MWCNTs with the addition of ZnO. The formation of hybrid nanocomposites occurs due to non-covalent interaction (π-stacking) between the graphene structures of the MWCNT surface and the phenyl rings of PCPAB. It was found that during the in situ oxidative polymerization of CPAB in the presence of MWCNTs, the growth of polymer chains occurred in close proximity to the filler surface, which led to the formation of a polymer coating. ZnO particles, localized on MWCNTs, on the one hand, prevent their aggregation, and on the other hand, create additional polymerization reaction centers due to the coordination of the Zn-O bond at the H and O atoms of the monomer. An increase in the concentration of reaction centers as a result led to a 2–2.5-fold reduction in the induction polymerization period. According to SEM data, in this case, a more ordered and denser polymer layer is formed due to intermolecular complexation between the main and side chains of the growing polymer with the participation of Zn²⁺ ions formed as a result of the transformation of ZnO to ZnCl₂ in the acidic reaction medium of polymerization. The results of the study of the frequency dependences of conductivity indicate a hopping mechanism of conductivity of nanocomposites. The electrical conductivity of nanocomposites depends on their production method and the MWCNT content and varies between 0.5 and 1.1 S∙cm⁻¹, which is 6–12 times higher than the conductivity of the original polymer. Thermogravimetric analysis revealed that the nanocomposites exhibit enhanced thermal stability compared to PCPAB. The best results were shown by nanocomposites with a higher content of MWCNTs, for which the residual mass at 450 °C was 51–53%. Full article

Micronutrient deficiencies, particularly of vitamins A, D₃, and folic acid, remain a significant global health challenge despite established dietary recommendations. This study proposes a novel fortification strategy using advanced emulsion technology to enrich extra-virgin olive oil (EVOO) with these essential micronutrients. Water-in-oil (W/O) and double oil-in-water-in-oil (O/W/O) emulsions were designed to enable the simultaneous encapsulation of lipophilic (A and D₃) and hydrophilic (folic acid) vitamins within a single functional food matrix. Vitamin concentrations were quantified using high-performance liquid chromatography (HPLC) coupled with a photodiode detector (PDA) to evaluate retention during processing. Bioaccessibility was assessed by subjecting vitamin-enriched emulsions to a standardized in vitro digestion model simulating gastrointestinal conditions. Results showed significantly higher incorporation efficiency in the O/W/O system compared to conventional W/O emulsions, regardless of the physicochemical properties of the vitamins. Both lipophilic (A and D₃) and hydrophilic (folic acid) compounds exhibited a satisfactory retention, highlighting the versatility of the double-emulsion approach. This study represents the first report of simple and multiple oil-continuous emulsions that simultaneously incorporate vitamins A, D₃, and folic acid, providing preliminary evidence of their stability and gastrointestinal release under simulated digestion conditions. Full article

Carbon-Fiber-Reinforced Polyetheretherketone (CFR-PEEK) instrumentation is increasingly preferred in spinal oncology for its physical properties, minimizing imaging artifacts and facilitating precise postoperative radiotherapy planning and tumor surveillance. However, a significant technical limitation exists: the current unavailability of dedicated CFR-PEEK pedicle screws for the cervical spine. The smallest available implants are designed for thoracic use (minimum diameter 4.5 mm, minimum length 25 mm), posing substantial risks of neurovascular injury when applied to smaller cervical pedicles. We present a technical note/feasibility report illustrated by a single case of robot-assisted placement of thoracic CFR-PEEK screws in the cervical spine for the treatment of a C7 Giant Cell Tumor. Following neoadjuvant therapy with Denosumab, a single-stage, two-step circumferential resection and reconstruction was performed. The anterior step was complicated by an iatrogenic injury to the highly adherent left vertebral artery (VA), which was successfully repaired. Consequently, the posterior step required maximal precision to preserve the sole remaining intact VA on the right side. Given the anatomical mismatch between the 4.5 mm thoracic screws and the narrow cervical pedicles (measuring as narrow as 3.2 mm on the critical right side), robotic navigation (ExcelsiusGPS^®) was utilized to plan and execute safe trajectories. Specifically, on the side of the intact VA, a small, controlled medial cortical violation was planned to avoid lateral vascular compromise. The procedure resulted in rigid, artifact-free stabilization with no immediate neurological sequelae. This single-case experience suggests that robotic guidance may facilitate adaptation of thoracic CFR-PEEK instrumentation to the cervical spine in selected oncologic scenarios; reproducibility, costs, and long-term outcomes remain uncertain. Full article

Lead-free double perovskites possess the capabilities of wide bandgap control, excellent photoelectric performance, and environmental friendliness. They are an ideal alternative system for addressing the heavy metal toxicity of lead-based perovskites and promoting their large-scale application. Precise control of their bandgap is key to the green transformation of optoelectronic devices. Bandgap, as a key parameter determining the photoelectric properties of materials, has limitations in traditional experimental determination and DFT calculation methods, such as being time consuming, labour intensive, costly, and difficult to achieve high-throughput screening. Deep learning provides an efficient solution to this problem, but current research has issues such as a single-model architecture and poor interpretability, which cannot effectively support bandgap regulation. This study utilised 2367 valid datasets of lead-free double perovskites sourced from the Materials Project database and relevant literature. Following preprocessing steps, including MinMaxScaler normalisation and Pearson correlation coefficient screening, the dataset was divided into a ratio of 7:1:2. The bandgap prediction capabilities of four models—MLP, deep ensemble learning, PINN, and Transformer—were systematically compared, with feature importance analysed using the SHAP method. The results show that the MLP model performs the best in medium-scale, structured feature prediction. The R² value of the test set is 0.9311, while the MAE, MSE, and RMSE are 0.1915 eV, 0.0975 eV², and 0.3122 eV, respectively. A total of 98% of the test samples have a prediction error of ≤0.4 eV, highlighting the stability of low bandgap systems. The Transformer is more suitable for large-scale, sequential feature prediction, while the MLP has limited generalisation ability for medium-to-high bandgap systems containing elements such as Si and Mg. The SHAP analysis revealed that the five electronic structure descriptors, such as B_HOMO+ and A_LUMO+, are the key influencing factors of the bandgap. The research results are helpful for the high-precision prediction and mechanism explanation of the bandgap of lead-free double perovskites, providing theoretical support for rational material design, performance optimisation, and bandgap-oriented regulation. They also point out the direction for subsequent model improvement. Full article

Nanoparticle-catalysed microwave-aided multicomponent reactions (MCRs) have been demonstrated to be competent and environmentally benign tools for the quick synthesis of a wide spectrum of fused heterocyclic systems. The distinctive physicochemical properties of nanoparticles, including a substantial surface area, readily modifiable surface functionality, and heightened catalytic activities, when coupled with microwave irradiation, have enabled a marked improvement in reaction rates, product yields, and selectivity compared to conventional heating methods. This review highlights recent advancements in microwave-assisted MCRs facilitated by diverse nanomaterials, such as magnetic nanocatalysts, metal and metal oxide nanoparticles, mesoporous silica systems, and nanohybrids. It emphasises catalyst design, catalytic efficacy, scope, recyclability, and alignment with green chemistry principles in both solvent-free and aqueous environments, as well as the utilisation of recyclable catalysts. In summary, microwave-assisted multi-component reactions catalysed by nanoparticles are ecofriendly and versatile methods for the sustainable synthesis of such fused heterocycles containing bioactive pyridine, pyrazole, phenazine, pyrimidine, pyran, imidazole, and relevant pyridine derivatives, possessing potential in medicinal and material chemistry. Full article

Blueberries (Vaccinium corymbosum L.) are widely appreciated for their flavor, bioactive compounds, and health promoting properties, yet cultivar-dependent differences in metabolic composition and postharvest stability remain incompletely understood. This study evaluated five commercial blueberry cultivars (‘Aurora’, ‘Chandler’, ‘Elliot’, ‘Legacy’, and ‘Liberty’) at harvest and after 15 days of cold storage (postharvest stage) (4 °C), assessing fruit color, size, firmness, primary metabolites, volatile organic compounds (VOCs), anthocyanins, phenolics, and antioxidant capacity. Cultivar-specific differences were observed in fruit morphology, sugar/acid balance, and biochemical composition: ‘Liberty’ and ‘Elliot’ accumulated higher monosaccharides and disaccharides, whereas ‘Aurora’ and ‘Chandler’ showed higher organic acids and amino acids. Volatile profiling at harvest revealed that ‘Liberty’ exhibited the richest aromatic profile, with elevated aldehydes, ketones, acids, phenols, alcohols, and esters. Postharvest storage caused minor changes in primary metabolites but altered anthocyanin content in a cultivar-dependent manner. Principal component analysis indicated that volatile compounds were the primary factors differentiating cultivars, while primary metabolites largely influenced sweetness–acidity balance. Overall, the results demonstrate that blueberry fruit quality is strongly cultivar-dependent, with cultivar-specific metabolic and volatile signatures shaping sensory and nutritional attributes, and provide valuable information for breeding, postharvest management, and cultivar selection to optimize flavor, bioactive content, and shelf-life. Full article

Karst rock desertification is an extreme form of land degradation that poses a serious threat to regional ecological security and sustainable development in Southwest China. Understanding the response patterns of plant communities and soil properties along desertification gradients is critical for developing effective ecological restoration strategies. This study focused on Qingzhen City, Guizhou Province, a representative karst desertification region. Using remote sensing to classify rock desertification intensity, together with systematic vegetation surveys and soil sampling, we investigated variation patterns in ecological parameters along the degradation gradient. The results revealed three key patterns. First, rock desertification was widespread across Qingzhen and exhibited pronounced spatial differentiation. Second, as desertification intensified, vegetation community structure became progressively simplified, transitioning from forests to shrublands. Biomass and vegetation cover declined from 77.25 kg/m² and 83% to 0.62 kg/m² and 15%, respectively. Notably, species diversity exhibited a bell-shaped relationship with desertification intensity, peaking at the potential desertification stage before declining under increasing environmental stress. Third, soil physicochemical properties showed complex nonlinear responses along the desertification gradient. Soil bulk density decreased, and pH increased with increasing desertification intensity, while volumetric water content fluctuated across stages. Soil total carbon and total nitrogen exhibited temporary enrichment during the light-to-moderate desertification stages, likely due to shifts in litter quality. Overall, these findings demonstrate that both plant communities and soil properties respond nonlinearly to rock desertification gradients. Together, the results enhance the understanding of the ecological processes underlying karst rock desertification and support the development of targeted regional restoration strategies. Full article

Vehicle-mounted sensing enables high-resolution urban monitoring but remains constrained by heterogeneous multimodal integration, intermittent connectivity, privacy-sensitive visual data, and the absence of enforceable multi-provider governance. This paper introduces a governance-aware private cloud architecture that treats provider isolation, role-based access control, and privacy-by-design as core architectural properties rather than application-layer add-ons. The layered, containerised microservice design supports asynchronous store-and-forward ingestion, modality-specific processing pipelines, and GPU-accelerated object detection for structured metadata extraction. A key innovation is ingestion-time visual abstraction, which structurally separates raw imagery from derived observations and enforces lifecycle-based retention policies, embedding data minimisation directly into the data flow. The fully open-source implementation is validated through a two-month multi-provider pilot with continuous multimodal collection. Results demonstrate stable ingestion without data loss, real-time visual inference (~200 ms per frame), strict provider-level isolation under concurrent access, and up to 95% storage reduction via metadata abstraction. The findings establish a replicable architectural paradigm for scalable, privacy-aware, multi-actor mobile sensing infrastructures suitable for metropolitan-scale smart city deployment. Full article

This study reports the synthesis of a high-entropy AlFeCuTiNi alloy via high-energy ball milling. The study investigates the effects of mechanical alloying time and sintering temperature on the microstructure, mechanical properties, wear, and corrosion behavior of the high-entropy AlFeCuTiNi alloy. XRD, SEM, and EDX analyses revealed that the mechanical alloying time and sintering temperature significantly affected the alloy’s homogeneity, phase structure, and oxide film stability. As the mechanical alloying time increases, the corrosion resistance of alloys sintered at 550 °C initially increases and then stabilizes. In samples sintered at 650 °C, corrosion resistance is generally higher. The highest corrosion resistance was achieved after 15 h of mechanical alloying and sintering at 650 °C. The study reveals that the best corrosion, wear, hardness, and wear density performance was observed in samples obtained at medium conditions, achieved after 20 h of mechanical alloying and sintering at 650 °C. These findings may contribute to optimizing production processes for sustainable material design. Moreover, this research highlights that high-entropy alloys and powder-metallurgy-based production methods enable industrial applications for energy-efficient, sustainable material design and contribute to sustainable production and circular-economy principles. Full article

Brown algae are a valuable source of bioactive secondary metabolites, particularly polyphenols and sulfated polysaccharides with photoprotective and antioxidant activities. Among them, fucoidan stands out for its biocompatibility, biodegradability, and demonstrated photoprotective effects, mainly through antioxidant and anti-photoaging properties, making it a promising natural component for UV-protective formulations. This study developed polyelectrolyte complex sub-micron particles based on fucoidan and chitosan (F/Cs) to encapsulate quercetin (Q) as a natural UV-active antioxidant. Fucoidan from Sargassum filipendula was extracted and fractionated by ultrafiltration. An RCBD was used to optimize pH and F/Cs mass ratio. The optimal blank formulation (F/Cs = 1:1, pH 5.0) yielded sub-micron colloidal carriers with a mean hydrodynamic diameter of 421 ± 23 nm (PDI 0.252 ± 0.059) with ζ = +43.5 ± 1.6 mV. Quercetin-loaded particles (F/Cs/Q = 1:1:0.5) presented 915 ± 87 nm (PDI 0.278 ± 0.093) and ζ = +54.6 ± 1.2 mV. UV–Vis spectra evidenced UVB and partial UVA absorption for fucoidan and broad UVA/UVB coverage for quercetin, preserved upon encapsulation. Antioxidant activity was retained post-encapsulation (EC50, DPPH: 0.094 mg/mL; ABTS: 0.0749 mg/mL). These results demonstrate the potential of fucoidan–chitosan colloidal systems as multifunctional, biodegradable carriers for natural photoprotective agents, supporting their application in next-generation dermatological and cosmeceutical formulations. Full article