Search Results (1,832)

The effect of water on the dynamics and ionic conductivity of the ionic liquids 1-ethyl-1-methylpyrrolidinium levulinate ([C₂C₁Pyr]Lev) and 1-butyl-1-methylpyrrolidinium levulinate ([C₄C₁Pyr]Lev) was investigated using differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS) over a wide temperature range. Although both ILs share the same levulinate anion, water induces markedly different dynamical responses depending on cation structure. In both systems, water acts as a plasticizer, lowering the glass transition temperature; however, the extent of plasticization and the resulting relaxation dynamics are cation-dependent. Stronger water–cation interactions are observed in [C₂C₁Pyr]Lev, whereas in [C₄C₁Pyr]Lev, water primarily disrupts alkyl-chain packing, enhancing ionic mobility. Increasing hydration shifts the main relaxation to higher frequencies and increases liquid fragility, while translational ionic motion remains decoupled from structural relaxation. These results demonstrate that water plays a cation-specific and mechanistically distinct role in levulinate-based ILs, providing new insights into hydration-controlled glassy dynamics and charge transport relevant to the design of IL-based electrolytes under non-anhydrous conditions. Full article

This paper presents the results of tests on concrete modified with waste powder from the production of epoxy powder coating, planned using design of experiment’s (DOE) experimental design methods. The scope of the investigation included detailed identification of the waste itself (TG/DTA, FTIR, SEM + EDS, laser diffraction), as well as evaluation of selected properties of concretes containing this waste, including compressive strength, density, and durability parameters such as frost resistance and chemical resistance. The scope of the experiment was defined by varying modifier content in the range of 4 to 11% of the cement mass and a water-cement ratio between 0.44 and 0.56. The concrete mixes obtained were characterized by good workability, fluidity, and consistency stability over time, despite the use of the modifier as an additional component in the concrete mix. No adverse effect of the waste used on the durability of the concrete was observed. Concretes modified with waste from the production of epoxy powder coating achieved a frost resistance class of F150 and showed good resistance to chemically aggressive environments (sulfates and chlorides). No products indicating adverse reactions between waste powder and reagents were found. The use of the DOE approach made it possible to determine, in the form of functional relationships, the influence of the modifier content depending on the water-cement ratio (w/c) of the concrete on its compressive strength and density. In general, a decrease in the compressive strength of concrete containing a waste powder modifier was observed, ranging from approximately 11% to 26% compared to unmodified concrete. However, the trend of decreasing compressive strength was reduced as the water-cement ratio of concrete decreased. At a water-cement ratio (w/c) of 0.443, no further decrease in compressive strength was observed. Concrete with 11% waste powder and a w/c ratio of 0.443 achieved 4.7% higher compressive strength than unmodified concrete with the same water-cement ratio. A beneficial interaction was found between a carboxylate-based plasticizer and the waste powder from the production of epoxy powder coatings. The proposed method of using waste as a concrete component is promising and may contribute to reducing the problem of waste management, as well as greenhouse gas emissions. Full article

Traditional analyses of transport phenomena rely on prescribed geometric boundaries, yet natural flow systems dynamically evolve their architecture to maximize access to currents. To address this disparity, we propose a field-theoretic framework for the constructal law that treats physical geometry as a dynamic state variable, represented by a time-dependent conductivity tensor. Using a variational approach grounded in non-equilibrium thermodynamics, we derive a general tensor evolution equation. Within this framework, macroscopic flow architecture emerges deterministically from the continuous competition between non-linear flux-induced accretion, linear entropic relaxation, and spatial smoothing. Scaling analysis reduces this dynamic to a tri-parameter dimensionless phase space: a morphogenic number driving structural growth, a structural diffusion number governing spatial coherence, and a stochastic intensity number providing the microscopic seeds for symmetry breaking. Our principal result is the analytical prediction of a critical bifurcation. When the local morphogenic number strictly exceeds unity, the system escapes its stable, isotropic configuration and branches into highly conductive, anisotropic architectures. We demonstrate the predictive validity and trans-scalar applicability of this continuum theory by mapping it to highly diverse phase transitions, successfully capturing phenomena ranging from microscopic aerosol agglomeration and microbial resistance, to macroscopic coral plasticity and crystal growth instabilities, and finally to the astrophysical launching of relativistic jets from black holes. Full article

Two-dimensional (2D) materials are promising candidates for nanoscale wear-protective coatings. The mechanisms governing their tribological behaviour (i.e., friction and wear) are material-dependent. In this work, we use atomistic molecular dynamics simulations to investigate nanoscale sliding, friction, and lithographic tracks in two 2D materials, graphene and MoS${}_2$, both placed on a SiO${}_2$ substrate. Our results reveal fundamentally different deformation mechanisms in the two materials, where deformation comes as a consequence of applied normal load. MoS${}_2$ deforms via the formation of a stable out-of-plane pucker beneath the contact, enabling efficient absorption and elastic redistribution of mechanical energy within the coating as well as simultaneous reduction of plastic deformation of the underlying material. Wear prevention in the substrate comes at the cost of localised damage to the MoS${}_2$ layer along the sliding path once it reaches the rupture point. On the contrary, graphene exhibits strongly localised deformation due to its high in-plane stiffness and atomic thickness, leading to plastic deformation of the underlying material and mitigating layer damage. These findings provide clear design guidelines for 2D coatings in nanotribological applications, and highlight layered materials, such as MoS${}_2$, as particularly effective for wear protection. Full article

Fibroin-based films represent a promising platform for sustainable and bio-derived materials. Existing literature has mainly focused on isolated molecules, plasticizers, or chemical cross-linkers, and the function of complex, multi-component natural extracts as structure-modulating agents in fibroin films remains poorly understood. In this study, edible films containing mulberry leaf extract (MLE; 2–8 wt%) and fibroin (8 wt%) were prepared by solution casting, and their structures were investigated using spectroscopic, morphological, thermal, mechanical, and barrier property analyses. The results reveal that MLE induces concentration-dependent changes in film performance through multicomponent, non-covalent interactions with the fibroin. An approximately 187% increase in tensile strength was achieved at high MLE concentration, confirming effective physical reinforcement. The water vapor transmission rate decreased markedly from 0.888 to 0.170 g·h⁻¹·m⁻², indicating an enhanced moisture barrier, whereas oxygen permeability increased at higher extract loadings, suggesting localized chain rearrangements. High optical transparency in the visible region was maintained (79.95–83.77%), while UV response was selectively altered with extract concentration. Overall, the 8MLE formulation exhibited the most balanced performance. This study demonstrates that plant-derived extracts can serve as effective natural modifiers for tailoring fibroin film properties without inducing crystallization, offering a sustainable strategy for designing bio-based and edible protein film systems. Full article

Microbial communities inhabiting natural and anthropogenically impacted environments are exposed to diverse abiotic stressors that can influence the distribution of functional traits. However, distinguishing the processes underlying phenotypic patterns remains challenging in microbial systems, where ecological and evolutionary dynamics often overlap. In this study, we experimentally assessed the distribution of biofilm formation and plastic degradation capacity in bacterial isolates across environments characterized by different stress regimes, to evaluate whether these traits are primarily associated with environmental context rather than phylogenetic relatedness, and may therefore reflect environment-dependent phenotypic modulation on a lineage-specific functional background. Taxonomic affiliation was assessed using 16S rRNA gene sequencing, while expressed biochemical profiles were characterized by Fourier-transform infrared (FTIR) spectroscopy. Multivariate ordination and Partial Least Squares analyses were used to explore relationships among taxonomy, biochemical profiles, functional phenotypes, and environment of isolation. Phylogenetic signal analysis confirmed that neither trait was strongly constrained by vertical inheritance, with Blomberg’s K ≈ 0 and Fritz & Purvis’ D = 0.51, consistent with environment-driven rather than phylogenetically conserved trait distributions. Both biofilm production and plastic degradation capacity showed significant environment-dependent differences in their relative frequencies (Fisher’s exact test, biofilm: p = 5.5 × 10⁻⁵; PCL degradation: p = 2.5 × 10⁻⁴) and were not directly associated with each other (Wilcoxon rank-sum test, p = 0.45; linear model, p = 0.68). Overall, these results indicate that microbial functional traits are unevenly distributed across environments and weakly constrained by taxonomy, consistent with the contribution of multiple, non-mutually exclusive processes that remain difficult to disentangle empirically. Full article

Over the past decades, global plastic demand has steadily increased due to the favorable physicochemical properties of these materials, including low weight, durability, versatility, and low production cost. Among synthetic polymers, polyvinyl chloride (PVC) is one of the most widely produced, accounting for approximately 10% of global polymer production. Suspension polymerization is commonly used for its manufacture because of its high productivity and suitable operational control; however, this process is associated with considerable energy consumption and emissions with potential environmental impacts. In this work, the Waste Reduction (WAR) Algorithm was applied to evaluate the environmental performance of a PVC production process with mass integration and direct water recycling. The Potential Environmental Impact (PEI) was quantified under four scenarios, considering both generation and output rates, as well as different fuel sources. The results showed that the environmental performance of the system strongly depends on the selected system boundaries and on the incorporation of energy-related effects. Under the gate-to-gate scope considered, some scenarios exhibited negative net PEI generation values, indicating that the PEI associated with the outlet streams was lower than that of the inlet streams within the modeled system. However, when energy consumption was included, it became the main contributor to total PEI, reaching 2560 and 3070 PEI/day in Cases 3 and 4, respectively. The toxicological assessment showed that ATP was the only category with positive PEI generation, while natural gas presented the lowest potential environmental impact among the energy sources evaluated. Overall, the process showed comparatively favorable environmental performance within the assumptions and methodological boundaries of the WAR analysis. Full article

Modern performance-based bridge design seeks to control damage in specific failure modes in order to balance safety and economy, particularly in high-seismic regions where inelastic and ductile deformation is expected to occur, both in the structure and soil, allowing potential reduction in seismic demand through fuse elements. In short-span bridges, abutments strongly influence longitudinal response, whereas transverse performance depends largely on seismic components such as shear keys and other energy-dissipation devices. Thus, performance assessment requires explicit representation of their hysteretic behavior. This study presents a numerical evaluation of the damping provided by common elements in typical bridge systems, using as reference damage observations from bridges affected by recent interface earthquakes in Mexico. Three-dimensional finite-difference models were developed, and nonlinear response-history analyses were performed to simulate ductile behavior and energy dissipation. The Sig3 hysteretic model available in FLAC^3D was used for abutments and foundation soils, while shear keys were represented as nonlinear springs. The results established a relationship between plastic deformation and energy dissipation, showing that incorporating the hysteretic behavior of both soil and sacrificial structural components enhanced the seismic bridge performance assessment, and led to more reliable and cost-efficient designs when inelastic deformation capacity was explicitly included in the numerical simulations. Full article

Plastic manufacturing depends heavily on petroleum-derived monomers like terephthalic acid, the main component of polyethylene terephthalate (PET). However, the depletion of fossil resources and increasing environmental concerns have heightened the need for sustainable alternatives. Lignocellulosic biomass has emerged as a promising resource due to its renewable, abundant, and eco-friendly nature. Understanding its chemical composition enables conversion of this biomass into platform chemicals, such as 2,5-furandicarboxylic acid (FDCA) and lactic acid, derived from cellulose and hemicellulose. These can be polymerized into bio-based plastics such as polyethylene furanoate (PEF), polylactic acid (PLA), and polyhydroxyalkanoates (PHAs), offering greener alternatives to fossil-based plastics. PEF features rigid furan rings that enhance thermal stability, mechanical strength, and barrier properties, and reduce gas permeability compared to PET. PLA is a renewable, biodegradable plastic widely used in packaging and medical applications. This review covers the chemical composition of lignocellulosic biomass cellulose, hemicellulose, and lignin, and various pretreatment strategies, chemical, physicochemical, and physical, to overcome biomass recalcitrance and improve conversion efficiency. It also highlights recent catalytic advances in transforming cellulosic carbohydrates into bio-based plastic precursors such as FDCA and lactic acid. Lastly, this review discusses polymerization pathways for producing PEF and PLA, emphasizing their role in reducing the environmental impact of polymer manufacturing and promoting green chemistry principles. Full article

In this study, an elastoplastic finite element (FE) contact model was developed to evaluate the plastic deformation of a surface induction-hardened tapered roller bearing used in wind turbines, incorporating depth-dependent material properties and heat treatment-induced residual stress distribution. The validity of this model was confirmed by comparing the calculated plastic deformation with measured profiles from static compression experiments. The results show that the residual stresses generated by induction hardening have a significant influence on the elastoplastic behavior of bearings. Based on this model, a parametric analysis was performed to investigate the effects of surface hardening depth (SHD), contact pressure, and residual stress on surface plastic deformation. Empirical formulas were developed to predict surface plastic deformation and evaluate material yielding for surface-hardened tapered roller bearings, thereby preventing excessive deformation during service. This allows for the rapid estimation of the maximum plastic deformation for different hardening depths and provides an efficient approach for assessing the yielding risk. Full article

Background: Cognitive and psychiatric disorders are caused by a complex interplay between genetic predisposition, environmental exposures, and dynamic molecular regulation in the brain. Animal models provide a controlled environment for examining these mechanisms, and advances in transcriptome and epigenomic technologies have greatly expanded our knowledge of disease-relevant pathways. Objective: This scoping review systematically maps and synthesizes the epigenetic and transcriptomic findings from the established animal models of four neuropsychiatric conditions—autism spectrum disorder (ASD), schizophrenia, depression, and Rett syndrome—drawing on a PRISMA-ScR-guided literature search. The review characterizes the breadth of evidence, identifies convergent and divergent molecular pathways, and highlights the translational gaps and therapeutic implications. Methods: Research employing chromatin accessibility testing, genome-wide DNA methylation mapping, single-cell and bulk RNA sequencing, histone modification profiling, and multi-omics integration in mouse and other validated animal models was thoroughly reviewed. A quality appraisal of the primary experimental studies (n = 63) was performed using a modified CAMARADES checklist. Results: Beyond generalized cellular stress responses, multi-omics analysis emphasizes the cell-type- and context-dependent nature of epigenetic changes in animal models, including isoform-specific histone modifications and model-dependent binding of HDAC/MeCP2 complexes to genes involved in synaptic plasticity. Single-cell RNA sequencing analyses have uniformly shown transcriptional changes in parvalbumin-positive (PV+) interneurons. Conclusions: The specific convergence of epigenetic disruptions in neural circuits involved in synaptic structure and inhibitory function could play a role in the generation of neuropsychiatric phenotypes in animal models, highlighting the importance of circuit- and cell-type-specific epigenetics while pointing to potential therapeutic avenues. Full article

Background: The wear resistance of modern commercial glass-ceramic materials used in dental prostheses was investigated under cyclic contact conditions that included a rotational component. This loading mode has been largely overlooked in conventional in vitro wear testing, yet may be clinically relevant in patients with parafunctional conditions such as bruxism. Methods: Rotational loading was applied using an all-electric testing machine equipped with a biaxial actuator. Loading cycles combined a normal load (50 N) and a rotation (30°), at a frequency of 1 Hz. Microstructure and damage were characterized using advanced microscopy. Results: Rotational loading induced substantial damage across this class of materials, including the formation of glassy tribolayers with limited protective capability under the low-humidity conditions examined. Significant microstructure-dependent variations in wear volume were observed, with specific wear rates indicating severe wear (SWR above 10⁻⁶ mm³/N·m threshold) in three of the five materials tested. Lithium disilicate glass-ceramics, characterized by a high fraction of elongated reinforcement crystals, exhibited the greatest resistance to damage, whereas leucite-based glass-ceramics showed the lowest. The dominant wear mechanisms were plastic-deformation-induced grooving and fracture-driven chipping. The findings are interpreted within established wear models for brittle materials (Archard and fracture-based) and supported by numerical simulations of stress fields across multiple length scales. Implications: The results provide mechanistic insight into rotational wear damage in glass-ceramic systems, a material class particularly susceptible to such loading, and inform strategies for material selection and microstructural design aimed at improving prosthetic durability. Full article

Background/Objectives: Essential oils (EOs) have multi-target antifungal activity, but their translation is limited by volatility and poor aqueous dispersibility. Randomly methylated β-cyclodextrin (RAMEB) inclusion may enhance effective exposure and thereby alter susceptibility, stress responses, and biofilm outcomes in a species-dependent manner. This study quantified species-specific planktonic and biofilm susceptibility to four EOs and their RAMEB complexes across clinically relevant Candida species. Methods: Lavender (L), lemon balm (B), peppermint (P), and thyme (T) oils and their RAMEB complexes (RL, RB, RP, and RT) were tested against C. albicans and non-albicans Candida. Susceptibility thresholds were used to derive phase plasticity metrics. Functional inhibition was assessed via planktonic metabolism/viability and established biofilm metabolism/viability/biomass. Mechanistic signatures were captured by ROS/RNS measurements and a qPCR analysis of antioxidant genes (CAT1, GPX1, and SOD1) was performed. Mixed-effects models and multivariate/unsupervised and interpretable classification approaches (k-means, PCA, and CRT) were used to integrate endpoints and stratify response phenotypes. Results: Susceptibility thresholds were strongly species-structured (lowest MIC₉₀/EC₁₀ for C. albicans; higher thresholds and broader sublethal windows in non-albicans species). RAMEB complexation produced formulation-dependent shifts in efficacy, with RT emerging as the most consistent broad-spectrum inhibitory condition across compartments. Biofilm biomass was comparatively insensitive even when viability was suppressed, indicating a decoupling of structural biomass from biocidal activity. Mechanistic signatures were broadly conserved across species and linked to antioxidant-program engagement, with CAT1-related rules contributing to responder/tolerant classification. Conclusions: Integrating MIC/EC plasticity with functional and mechanistic markers supports the rational selection of EO formulations; RAMEB complexation, particularly RT, prioritizes candidates for further pharmaceutical optimization while highlighting species-specific vulnerabilities. Full article

Background/Objectives: Malignant distal biliary obstruction (MDBO) is a frequent complication of pancreatic cancer and often leads to obstructive jaundice, impaired liver function, and delayed oncologic treatment. Endoscopic biliary drainage using endoscopic retrograde cholangiopancreatography (ERCP) with stent placement is the standard minimally invasive approach for restoring biliary flow. However, clinical outcomes and complication rates vary across studies depending on stent design, placement technique, and patient characteristics. The aim of this systematic review was to evaluate the clinical outcomes and complications associated with endoscopic biliary stenting in pancreatic cancer-related MDBO. Methods: A systematic literature search was performed in PubMed/MEDLINE, ScienceDirect, Web of Science, and the Cochrane Library for studies published between January 2016 and January 2026. Studies evaluating ERCP-guided biliary stenting in adult patients with pancreatic cancer-related malignant distal biliary obstruction were included. Study selection followed PRISMA 2020 guidelines, and methodological quality was assessed using the Newcastle–Ottawa Scale. Clinical outcomes including technical success, clinical success, stent patency, recurrent biliary obstruction, and procedure-related complications were analyzed. Results: Eighteen studies involving a total of 3291 patients were included in the qualitative synthesis. Technical success rates were consistently high, reaching up to 100% in several studies, while clinical success rates generally exceeded 90%. Median time to recurrent biliary obstruction ranged from approximately 102 to 541 days depending on stent type and placement technique. Recurrent biliary obstruction was the most frequently reported complication, occurring in 30.7% of patients. Stent migration occurred in 14.9% of cases, while post-ERCP pancreatitis was reported in approximately 4.2% of patients. Several studies demonstrated longer patency with self-expandable metal stents compared with plastic stents. Conclusions: Endoscopic biliary stenting performed during ERCP is an effective and safe strategy for the management of malignant distal biliary obstruction in pancreatic cancer. Self-expandable metal stents provide more durable biliary drainage and reduce the need for repeat interventions. Nevertheless, recurrent biliary obstruction remains a common limitation, highlighting the need for further improvements in stent technology and optimized placement strategies. Full article

The growing environmental impacts associated with conventional plastics and textiles have intensified interest in bio-based and circular material alternatives. This study presents a qualitative and structured literature review of the valorization of fruit and nut agricultural residues as sustainable feedstocks for biomaterials and biotextiles, with a strategic focus on Greece. Drawing on international literature, regional agricultural production data, and validated processing technologies, the review synthesizes existing evidence on residue availability, conversion routes, environmental performance, and market trends. The reviewed literature indicates that residues such as grape pomace, olive by-products, citrus peels, and nut shells have been widely reported as suitable sources of cellulose, lignin, and pectin for the development of fibers, films, and composite materials. Findings from published life cycle assessment (LCA) studies suggest potential reductions in water use, greenhouse gas emissions, and land-use intensity compared with conventional cotton and synthetic textiles, although results vary depending on system boundaries and processing conditions. The review further highlights enabling factors, technical limitations, and policy considerations relevant to the Greek context. This study provides a qualitative integrative perspective on the opportunities and constraints associated with agricultural residue valorization, identifying key research gaps and strategic directions for future development within Greece and similar Mediterranean regions. Full article