Search Results (5,668)

Neural regeneration requires an optimal environment, including structural, chemical, mechanical, and electrical properties. Alginate (Alg) and graphene oxide (GO) are promising biomaterials for nerve tissue engineering, as Alg provides biocompatibility and hydrogel formation, while GO enhances mechanical strength and conductivity. For this study, GO was synthesized using the modified Hummer’s method, and Alg–GO scaffolds with varying GO concentrations were developed. FTIR spectroscopy confirmed the successful incorporation of GO into the Alg matrix, while UV–Vis and photoluminescence analyses demonstrated GO-induced modifications of the optical properties. Thermal analysis revealed improved stability with increasing GO content, whereas swelling tests showed enhanced water uptake and retention. Conductivity measurements indicated a clear improvement in electrical conductivity, particularly at moderate GO concentrations. SEM imaging confirmed a homogeneous distribution of GO within the Alg matrix, with structural uniformity across all samples. Cytocompatibility was assessed using SH–SY5Y neuroblastoma cells through MTT, LDH, and LIVE/DEAD assays. All composites supported cell attachment, viability, and proliferation, with GO concentrations up to 6% promoting optimal cell growth without inducing cytotoxicity. In contrast, excessive GO content (9%) resulted in reduced proliferation, although biocompatibility was maintained. These results highlight the potential of Alg–GO scaffolds as promising candidates for neural tissue engineering. The findings demonstrate the potential of Alg–GO scaffolds as advanced biomaterials for regenerative medicine. Future research should focus on in vivo evaluations to confirm their therapeutic applicability. Full article

This study evaluates the ecological impact of Robinia pseudoacacia L. (black locust) invasion on native chestnut (Castanea sativa Mill.) groves on Mount Amiata (Central Italy), focusing on both plant and macrofungal community dynamics. Surveys were conducted over a three-year period (2022–2024) across 16 plots to assess shifts in taxonomic alpha diversity, species richness, and trophic guild structure. Our results demonstrate that while R. pseudoacacia stands exhibit a higher Shannon–Wiener index for plants, native chestnut groves host significantly greater species richness and higher taxonomic distinctiveness across both biological groups. A major shift in fungal functional structure was observed with chestnut-dominated plots characterized by a predominance of ectomycorrhizal species (58.3%), whereas invaded stands were heavily dominated by saprotrophic fungi (73.4%). Non-metric Multidimensional Scaling (NMDS) further confirmed a clear separation in community composition between the two forest types, indicating that R. pseudoacacia invasion leads to a homogenization of the forest biota and a potential decline in ecosystem health, as evidenced by the sharp reduction in mycorrhizal diversity. These findings highlight the importance of monitoring macrofungal communities as sensitive bioindicators of the ecological degradation caused by invasive woody species. Full article

Bacterial nanocellulose (BNC) is gaining interest in multiple industrial applications. BNC dehydration would improve its industrialization while affecting its techno-functional properties (water binding or gelling capacity). This work analyses this aspect in a representative food system where these are fundamental properties: low-fat sausages with pre-emulsified sunflower oil. Native (n-BNC) and freeze-dried (d-BNC) bacterial nanocelluloses were studied at different concentrations. During thermal processing, all batters exhibited the typical viscoelastic transition associated with protein gelation. Formulations containing d-BNC developed a higher final elastic moduli and a broader concentration range of structural reinforcement compared to n-BNC systems. In the cooked sausages, BNC incorporation enhanced hardness, cohesiveness, and water-holding capacity, particularly at intermediate concentrations. Micrographs showed that d-BNC led to a finer and more homogeneous microarchitecture, while n-BNC aggregated in hollows of the meat protein network. Additionally, the Pickering effect of dried BNC produced meat emulsions with smaller oil droplets in agreement with the differences in lightness detected. Results suggest that freeze-dried BNC could be a convenient and effective option for the food industry due to its low weight, longer storage period, and easy handling compared to native BNC. Full article

This study explores a novel class of polynuclear superhalogen anions featuring heterovalent central atoms from groups 13 (B, Al) and 15 (P, As). The investigated species follow a modified general formula, (X_nY_n’F_{{(3n+5n’)+1}})⁻ where X = B and/or Al, Y = P and/or As, and n + n′ = 2–4. Low-energy isomers were identified using the Coalescence Kick method and subsequently optimized at the MP2/aug-cc-pVDZ level of theory. Electronic stability was assessed via the outer valence Green’s function (OVGF) approach with the same aug-cc-pVDZ basis set. All examined anions exhibit exceptional electronic stability, with vertical electron detachment energies (VDEs) ranging from 10.70 to 12.37 eV, significantly exceeding the superhalogen threshold of 3.65 eV. Thermodynamic analyses indicate that aluminum atoms play a crucial role in stabilizing larger clusters by acting as a structural “glue”, thereby suppressing fragmentation through the loss of neutral XF₃ or YF₅ units. In contrast, larger non-metallic analogs show an increased propensity toward dissociation. The potential of the heterovalent polynuclear superhalogen anions as weakly coordinating anions (WCAs) was further evaluated through molecular electrostatic potential (ESP) analysis. The results demonstrate that combining different central atoms within boron-based frameworks leads to a more homogeneous charge distribution, enhancing weakly coordinating behavior. Full article

Decoupling between CO₂ emissions and economic growth is critical to reversing climate change. The OECD plays a crucial role in this regard, given its considerable share of global CO₂ emissions and GDP. This study examines the decoupling performance and the roles of renewable energy transition, as well as specific eco-innovations on climate change mitigation and environmental technology development across the OECD economies. The preliminary tests on a large panel of OECD countries identify cross-sectional dependence, structural breaks and heterogeneity. For robustness, the study proposes Fourier-CS-ARDL, Fourier-AMG, and Fourier–Dumitrescu–Hurlin methods as generalizations of their linear counterparts. After identifying cointegration and its singularity with Fourier-bootstrapping bounds and Fourier–Johansen tests, the modeling stage suggested a positive, but significantly inelastic long- and short-run elasticity of emissions to economic growth. Most of these effects are reversed by renewable energy transition in the long run and partially reversed in the short run. These CO₂ mitigation effects are also evident across different eco-innovations with varying temporal impacts. Novel Fourier causality tests identify feedback loops between CO₂ and CO₂-mitigating factors, as well as unidirectional causality from growth to all mitigating factors, confirming the indirect effect of growth on CO₂ mitigation. Overall, these results clearly suggest “relative” decoupling in OECD accompanied by CO₂e mitigation effects from eco-innovations and energy transition, and highlight the potential for green growth following the successful adaptation of energy transition and eco-innovations. Policymakers in OECD are encouraged to leverage the identified feedback mechanisms and establish international technology transfer policies to homogenously curb CO₂ emissions. Full article

Background: Myricetin (MYR) is a natural flavonol with antioxidant, neuroprotective, anti-inflammatory, antidiabetic, and cardioprotective activities. Still, its pharmaceutical use is limited by very low aqueous solubility (~16.6 µg/mL) and poor oral bioavailability (<10%). This study aimed to enhance the solubility and potentially improve the bioavailability of MYR by developing an amorphous nanofibrous delivery system. Methods: Electrospinning was applied to fabricate MYR-loaded nanofibers using polyvinylpyrrolidone K30 (PVP30), and the influence of key processing parameters on MYR solubility was evaluated. Nanofibers produced under selected electrospinning conditions were characterized in terms of morphology, encapsulation efficiency, and physicochemical properties. Results: X-ray powder diffraction confirmed complete amorphization of MYR within the BB5 fiber structure (distance: 12 cm, voltage: 25 kV, flow rate: 1.5 mL/h). FTIR analysis indicated hydrogen-bonding interactions between MYR hydroxyl groups and PVP30 carbonyl groups, contributing to stabilization of the amorphous form. SEM images revealed homogeneous, defect-free fibers with diameters below 400 nm, although localized MYR agglomerates were observed. Solubility and release studies demonstrated a characteristic spring-and-parachute effect, enabling rapid MYR release and maintenance of a supersaturated state. Enhanced solubility resulted in significantly improved antioxidant activity in DPPH and CUPRAC assays compared with crystalline MYR. Conclusions: Electrospun PVP30 nanofibers represent a promising platform for improving the solubility, dissolution behavior, and functional activity of poorly soluble bioactive compounds such as myricetin, supporting their potential application in pharmaceutical formulations. Full article

Eleutherococcus senticosus, a medicinally important woody plant, is widely used in pharmaceuticals and functional foods due to its bioactive compounds. Its wild populations are facing severe threats due to over-harvesting. To inform scientific conservation and sustainable utilization strategies, this study aimed to comprehensively assess its genetic background. We developed 13 highly polymorphic expressed sequence tag-simple sequence repeat (EST-SSR) markers from full-length transcriptome data, with an average polymorphism information content (PIC) of 0.52. Using these markers, we systematically evaluated the genetic diversity of 405 individuals from 22 natural populations across Northeast China. The results indicate that E. senticosus maintains moderate genetic diversity at the species level (mean expected heterozygosity He = 0.43), but substantial variation exists among populations. The Linjiang population showed the highest diversity (He = 0.58), whereas peripheral populations such as Tonghua (He = 0.31) and Huinan (He = 0.32) exhibited lower diversity. Analysis of molecular variance (AMOVA) revealed that genetic variation primarily resided within populations (66.3%), but moderate differentiation among populations was also detected (Fst = 0.21). Both structure analysis and clustering consistently divided all populations into two major genetic lineages. Frequent gene flow (e.g., Nm > 10 between Raohe and Hulin) and high genetic homogeneity were observed among populations in the core distribution area (e.g., Raohe, Jixi, Hulin), whereas several peripheral populations displayed significant genetic distinctiveness and isolation. This study provides the first macro-scale insight into the population genetic structure of E. senticosus, offering crucial molecular tools and a scientific basis for in situ and ex situ conservation, core collection establishment, and future genetic improvement of this species. Full article

Fused deposition modeling/fused filament fabrication (FDM/FFF) enables architectural tailoring of mechanical response through layer configuration and multi-material manufacturing strategies. However, the combined effects of layer arrangement, infill ratio, and packing geometry in polymer–metal hybrid structures and interfacial load transfer mechanisms are still not sufficiently elucidated. In this study, the tensile behavior of single- and multi-material structures produced using PLA and 17-4 PH stainless steel filaments was systematically investigated. A total of 24 experimental parameter sets were created with four-layer configurations (PLA, 17-4 PH, PLA/17-4 PH/PLA, and 17-4 PH/PLA/17-4 PH), three infill ratios (20%, 60%, and 100%), and two packing patterns (linear and hexagonal); the samples were tested according to the ASTM D638 standard. Mechanical data were modeled using Response Surface Methodology (RSM) and ANOVA, and the developed regression models showed high accuracy (R² > 0.95). The findings showed that tensile and yield strength are primarily controlled by the layer arrangement, while infill ratio and infill pattern have a secondary effect. The highest strength was measured in 100% infill linear PLA samples (≈10.35 MPa), and the lowest value was measured in 17-4 PH “green part” samples without sintering (≈0.92 MPa). Hybrid structures exhibited intermediate performance in the range of 2.9–4.9 MPa. ANOVA results showed that the majority of the mechanical variance was explained by the layer arrangement (70–85% contribution), while infill ratio and infill pattern had a secondary effect. Fracture surface analyses showed that high performance was associated with homogeneous filament fusion and low porosity; Studies have confirmed that poor performance is associated with delamination and interfacial separation. Full article

A hybrid material based on the copolymerization of EDOT (3,4-ethylenedioxythiophene) and Py (pyrrole), 1:1 monomer ratio, onto multi-walled carbon nanotubes (MWCNTs) was synthesized through a multistep functionalization approach. The resulting P(EDOT-co-Py)@MWCNT hybrid, poly(3,4-ethylenedioxythiophene-co-pyrrol)@MWCNT hybrid, was characterized by Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). These characterizations confirmed the successive functionalization steps, the effective anchoring of the monomers, and the subsequent formation of the copolymer. Transmission electron microscopy (TEM) images revealed a homogeneous polymer coating along the nanotube surface while preserving the structural integrity of the MWCNTs throughout the functionalization and polymerization processes. The P(EDOT-co-Py)@MWCNT hybrid was evaluated as an active electrode material for aluminum-ion storage in an aqueous aluminum sulfate electrolyte. The system exhibited two distinct charge-storage mechanisms: at high current densities, proton surface adsorption dominated, whereas at lower rates, a faradaic contribution associated with polymer chain redox activity and the reversible extraction/insertion of Al³⁺ became prevalent. The hybrid electrode delivered high specific capacities, reaching 200.6, 106.3, and 44.3 mAh g⁻¹ at 0.10, 0.25, and 0.50 A g⁻¹, respectively. These values are comparable to—or even exceed—those reported for similar cathodic materials designed for Al³⁺ storage, highlighting P(EDOT-co-Py)@MWCNT hybrid as a highly promising cathode candidate for aqueous aluminum-ion energy-storage systems. Full article

This study explored the enhancement of exopolysaccharide (EPS) production by Ganoderma lucidum through bidirectional liquid fermentation, employing Clinacanthus nutans (Burm. f.) Lindau leaves as a medicinal substrate. The optimal concentration of C. nutans leaf powder was determined to be 6 g/L, resulting in a significant increase in both mycelial biomass (61.78%) and EPS yield (116.6%). Structural analyses indicated that the EPS supplemented with C. nutans underwent notable modifications. Fourier-transform infrared spectroscopy suggested the introduction of potential carbonyl groups and a shift in glycosidic linkage configuration. Monosaccharide composition analysis revealed a significant transition from a glucose-dominated profile in the control to a galactose-rich, more diverse profile, including uronic acids and amino sugars, in the experimental group. High-performance gel permeation chromatography demonstrated a transformation from a low, homogeneous molecular weight (4.7 kDa) to a heterogeneous, bimodal distribution featuring a prominent high-molecular-weight fraction (38.5 kDa). Consequently, the modified EPS exhibited significantly enhanced antioxidant activities, with scavenging rates for DPPH, hydroxyl, and ABTS radicals increasing to 55.5%, 35.1%, and 88.0%, respectively, at a concentration of 2 mg/mL. These findings demonstrate that C. nutans is an effective supplement for modulating the fermentation process of G. lucidum, not only boosting EPS production but also tailoring its structural characteristics to obtain polysaccharides with superior bioactivities, highlighting its potential in functional food and nutraceutical applications. Full article

The paper investigates the structural properties of self-gravitating fluid spheres composed of a dilute, homogeneous, and ultracold Bose gas, assuming repulsive, short-range interactions. For the first time, the Lee–Huang–Yang (LHY) correction is incorporated to the standard polytropic equation-of-state with index $n=1$, which extends beyond the Hartree mean-field approximation by accounting for quantum fluctuations. The findings indicate that this correction significantly affects the mass–radius relationships and other properties of condensate dark stars, such as the compactness factor and tidal Love numbers. Notably, the impact of the LHY correction is more pronounced for equations of state that support higher maximum stellar masses. Full article

This work investigates the fabrication and performance of axially compressed isotropic epoxy-bonded NdFeB-type magnets produced from melt-spun powders with partial substitution of (Nd,Pr) by (La,Ce). Four alloy compositions were synthesized and processed into bonded magnets using two powder-to-binder weight ratios (95:5 and 96.5:3.5). Structural analysis confirms that all substituted alloys retain the tetragonal Nd₂Fe₁₄B phase (up to ~95 wt%) even at high substitution levels, while the lattice parameters decrease slightly with increasing (La,Ce) content. Microscopy analysis confirms a homogeneous distribution of the binder phase around the powder particles, demonstrating uniform binder–powder integration. Thermal analysis reveals composition-dependent Curie temperatures and enhanced crystallization onset in highly substituted powders. Magnetic measurements on both powders and bonded magnets show that increasing substitution leads to a gradual reduction in remanence, coercivity, and energy product, though all samples maintain strong hard-magnetic behavior. Increasing the powder fraction to 96.5 wt.% significantly improves all magnetic parameters due to higher magnetic-phase density and enhanced interparticle coupling, yielding bonded magnets with densities up to ~80% of the theoretical value. The resulting magnets achieve competitive performance, uniform field distribution and isotropic magnetization with (BH)max values about 65 kJ/m³, a coercivity around 660 kA/m, and superior thermal stability compared with commercial bonded NdFeB magnets. Overall, partial substitution with light rare-earth elements (La,Ce) provides a cost-effective route to high-density bonded NdFeB magnets that combine strong magnetic performance, enhanced thermal stability, and suitability for lightweight, complex-shaped industrial applications. Surprisingly, the coefficients of the temperature variation of coercivity and (BH)_max are much better compared to the commercial NdFeB bonded magnets. Full article

This paper analyzes factors affecting school absenteeism due to an injury or illness among the US school student population between 6 and 15 years of age. The number of missed school days displays overdispersion and is modeled using the Finite Mixture Roy (FMR) model for count variables. The married/single parent family status (treatment) is potentially endogenous to the dependent variable (missed days). The Roy structure controls observed heterogeneity due to the mother’s marital status. Finite mixtures are intended to control unobserved heterogeneity due to healthy and unhealthy children in the sample. This approach facilitates identification of latent subpopulations in which treatment and marginal effects are relatively homogeneous. The model also incorporates two application-driven extensions. First, probabilities of the latent components are modeled as functions of regressors. Secondly, the mother’s income affects treatment nonparametrically. The FMR model is estimated with two latent components in each state, corresponding to healthy and unhealthy students. The results indicate that maternal marital status decreases annual missed school days by approximately 13 percent for a randomly drawn child; however, this increases absenteeism by about 14 percent among families that self-select into two-parent households, which is evidence of adverse selection. Full article

Fungal communities exhibit strong spatial and environmental structuring across forest ecosystems, yet the drivers shaping their diversity patterns remain incompletely understood. In this study, we combined multivariate ordination, clustering analyses, and Zeta diversity (ζ-diversity) metrics to characterize fungal assemblages across environmental gradients. Canonical Correspondence Analysis (CCA) revealed that fungal community composition was significantly associated with climatic variables, particularly seasonal precipitation, thermal variation, and elevation. Hierarchical and K-means clustering identified coherent community clusters that differed in species richness and alpha diversity. Bray–Curtis distances and a Ward-based dendrogram further supported this separation, revealing a clear hierarchical structure in community similarity. Zeta diversity analysis indicated a slower species turnover, suggesting niche assimilation and habitat homogenization. Furthermore, the grouping of fungal assemblages followed a power-law model, emphasizing the role of deterministic environmental filtering. Critically, our findings reveal that only 1208 (33.5%) of the 3606 recorded species are present within existing Protected Natural Areas (PNAs), indicating a significant conservation gap. Together, these results provide an integrated ecological understanding of fungal diversity patterns, highlighting how climate–topography interactions structure communities and emphasizing the urgent need to align conservation strategies with these environmental drivers. Full article

This study examines the perceptions, learning sources, ethical–social associations, and academic influences that shape Ecuadorian undergraduate students’ relationship with science, incorporating a gender perspective. A cross-sectional quantitative design was employed using a survey administered to undergraduate students from four urban universities in Quito, Ecuador. Participants were recruited through institutional mailing lists and academic coordination channels, resulting in a non-probabilistic, institutionally distributed sample of 212 complete responses. Data were analyzed using descriptive statistics and Structural Equation Modeling (SEM) to test the hypothesized relationships among latent constructs. The findings indicate an absence of statistically significant differences between genders, thereby suggesting a homogeneous perception of science. The results demonstrated that a robust correlation exists between conceptual understanding and ethical–social awareness. Furthermore, they indicated a significant relationship between the academic impact of science and personal and social appropriation. The originality of the study lies in its critical, intersectional and situated approach to conceptualizing science, with a focus on factors such as gender and educational context. The findings provide valuable insights for the design of educational policies that promote the social appropriation of science in Ecuador and Latin America. Full article