Search Results (524)

The gut microbiome has emerged as a pivotal player in shaping host immune responses, with significant implications for vaccine efficacy and safety. Rather than detailing all influencing factors, this review focuses on the most critical and translational aspects of microbiome–vaccine interactions. Increasing evidence shows that the composition and functionality of the intestinal microbiota can influence both the magnitude and durability of vaccine-induced immunity. For instance, Bifidobacterium longum supplementation was shown to enhance influenza vaccine seroconversion rates by approximately 30% in clinical and preclinical models, underscoring the translational potential of microbiome modulation. Here, we provide a concise synthesis of mechanistic insights and key clinical findings that connect gut microbial composition and metabolism with vaccine outcomes. We further highlight microbiome-targeted interventions—such as probiotics, prebiotics, and postbiotics—that hold promise for optimizing vaccine responses in diverse populations. By emphasizing actionable evidence over descriptive variability, the review aims to clarify how microbiome modulation can be strategically harnessed to improve vaccine performance. Integrating microbiome modulation into vaccination strategies may enhance global immunization equity and effectiveness, offering a feasible pathway toward more durable and inclusive protection worldwide. Full article

Asphalt is a widely used polymeric material in pavement engineering. However, it is easily affected by heat and ultraviolet rays, which accelerate its molecular degradation and physicochemical aging, thereby limiting its service life. To improve the anti-aging properties of asphalt, three types of nano-zinc oxide (ZnO)-modified asphalt were prepared. The chemo-rheological behavior, structural evolution of polymeric components, molecular weight distribution, and nanoscale morphology of nano-ZnO-modified asphalt were studied via dynamic shear rheometry (DSR), Fourier transform infrared spectrometry (FTIR), gel permeation chromatography (GPC) and atomic force microscopy (AFM), and the aging resistance of nano-ZnO-modified asphalt was quantitatively analyzed using the rutting factor index, functional group index, molecular size ratio, and nanoscale parameters. The findings indicate that nano-ZnO enhances the high-temperature rheological properties of asphalt and delays the increase in the rutting factor of aged asphalt. Nano-ZnO is dispersed in the asphalt matrix in the form of a physical mixture without inducing new chemical bonds, and can reduce the nanoscale roughness of asphalt. After aging, the nanoscale roughness and the aspect ratio of the bee structure decreased, and the bee structure area increased. According to the changes in the functional group index and the proportions of molecular sizes in the asphalt, it was found that nano-ZnO can significantly improve asphalt’s aging resistance. The results of this study provide insights into the nanoscale modification and structure–property relationships of polymeric asphalt binders, providing a reference for the design and application of functional polymer nanocomposite systems with improved durability. Full article

Background/Objectives: Atrial fibrillation (AF) is the most common sustained arrhythmia, with catheter ablation outcomes differing significantly between paroxysmal and persistent forms. While pulmo-nary vein isolation (PVI) remains the cornerstone of ablation, persistent AF is often associ-ated with atrial remodeling and non-pulmonary vein triggers, reducing procedural success rates and necessitating repeat interventions. However, in selected patients with minimal atrial substrate, a single PVI may achieve durable rhythm control. This case report illus-trates such a scenario in a young patient with persistent AF and tachyarrhythmia-induced cardiomyopathy (TIC). Methods: A 42-year-old previously healthy male presented with newly diagnosed persistent AF complicated by TIC and heart fail-ure (left ventricular ejection fraction [LVEF] 25%). Despite rate control, anticoagulation, guideline-directed heart failure therapy, amiodarone pretreatment, and two failed electrical cardioversions, the patient remained symptomatic. Elec-troanatomic mapping was performed to assess atrial substrate prior to radiofrequency ablation. Results: Mapping revealed no extensive low-voltage zones, indicating absence of significant atrial fibrosis. During ablation, si-nus rhythm was restored spontaneously with a single application targeting the infero-posterior aspect of the right infe-rior pulmonary vein. No additional arrhythmogenic substrate was identified. The patient maintained sinus rhythm throughout 14 months of follow-up, with marked clinical improvement, normalization of LVEF (55%), regression of atrial and ventricular enlargement, and resolution of heart failure symptoms. Quality of life, assessed by the ASTA question-naire, improved from 24 to 0 points. Conclusions: This case highlights that even in therapy-resistant persistent AF with severe structural and functional cardiac impairment, arrhythmia may be driven by discrete pulmonary vein-dependent mechanisms. Careful patient selection, particu-larly in younger individuals without advanced atrial remodeling, can identify those in whom PVI alone achieves durable rhythm control and reverse cardiac remodeling. Full article

Pultrusion is a manufacturing process used to produce fiber-reinforced polymer composites with excellent mechanical, thermal, and chemical properties. The resulting materials are lightweight, durable, and corrosion-resistant, making them valuable in aerospace, automotive, construction, and energy sectors. However, conventional thermoset composites remain difficult to recycle due to their infusible and insoluble cross-linked structure. This review explores integrating vitrimer technology a novel class of recyclable thermosets with dynamic covalent adaptive networks into the pultrusion process. As only limited studies have directly reported vitrimer pultrusion to date, this review provides a forward-looking perspective, highlighting fundamental principles, challenges, and opportunities that can guide future development of recyclable high-performance composites. Vitrimers combine the mechanical strength (tensile strength and modulus) of thermosets with the reprocessability and reshaping of thermoplastics through dynamic bond exchange mechanisms. These polymers offer high-temperature reprocessability, self-healing, and closed-loop recyclability, where recycling efficiency can be evaluated by the recovery yield retention of mechanical properties and reuse cycles meeting the demand for sustainable manufacturing. Key aspects discussed include resin formulation, fiber impregnation, curing cycles, and die design for vitrimer systems. The temperature-dependent bond exchange reactions present challenges in achieving optimal curing and strong fiber–matrix adhesion. Recent studies indicate that vitrimer-based composites can maintain structural integrity while enabling recycling and repair, with mechanical performance such as flexural and tensile strength comparable to conventional composites. Incorporating vitrimer materials into pultrusion could enable high-performance, lightweight products for a circular economy. The remaining challenges include optimizing curing kinetics, improving interfacial adhesion, and scaling production for widespread industrial adoption. Full article

Polymer-based aerogels have recently received considerable research attention as a favorable option for oil–water separation due to their enhanced porous 3D structure with great specific surface area, low density and outstanding sorption behavior. Additionally, polymer-containing aerogels exhibit more favorable characteristic properties, such as being lipophilic–hydrophobic (superhydrophobic–superoleophilic), hydrophilic–lipophobic (superhydrophilic–underwater oleophobic), or other specific wetness forms, including anisotropic and dual-wettability. In this review, cellulose and cellulose-based materials used as an aerogel for oil–water separation are comprehensively reviewed. This review highlights the significance of cellulose and cellulose-based combinations through structure–property interactions, surface modifications (using different hydrophilic and hydrophobic agents), and aerogel formation, focusing on the light density and high surface area of aerogels for effective oil–water separation. This article provides an in-depth review of four primary classifications of cellulose-based aerogels, namely, cellulose aerogels (regenerated cellulose and bacterial cellulose), cellulose with biopolymer-based aerogels (chitosan, lignin, and alginate), cellulose with synthetic polymer aerogels (polyvinyl alcohol, polyetherimide, polydopamine and others), and cellulose with organic/inorganic (such as SiO₂, MTMS, and tannic acid) material-based aerogels. Furthermore, the aspects of performance, scalability, and durability have been explained, alongside potential prospect directions for the advancement of cellulose aerogels aimed at their widespread application. This review article stands apart from previously published review works and represents the comprehensive review on cellulose-based aerogels for oil–water separation, featuring wide-ranging classifications. Full article

The delamination of building facades creates a critical demand for inorganic adhesive mortars with high long-term adhesion. Geopolymer (GP) represents an eco-friendly alternative to Portland cement (PC). However, the effect of polymer additives, commonly used in cement-based adhesive mortars, on GP mortar remains insufficiently studied. This study examines the effects of hydroxypropyl methylcellulose (HPMC) and vinyl acetate-ethylene (VAE) polymer on the workability, mechanical properties, durability, and microstructure of GP mortar. Results show that an optimal HPMC content (0.4 wt%) improves the fluidity, compressive strength, and adhesive strength of GP mortar, approximately 6%, 16%, and 20%, respectively. These enhancements are attributed to the incorporation of uniformly distributed microbubbles in the mortar matrix. Beyond this optimal content, however, HPMC impairs flowability and adhesion due to its thickening effect. In contrast, VAE addition significantly enhanced adhesive strength by approximately 28%, albeit at the cost of a 17% reduction in compressive strength, resulting from the retardation of the alkali activation process. This gain in adhesion is associated with the formation of a continuous polymer film that establishes both physical interlocking and chemical bonding with the GP matrix. Furthermore, HPMC improved the durability of the GP mortar, while VAE did not contribute to this aspect. These insights offer valuable guidance for designing high-performance GP-based adhesive mortars suitable for building applications. Full article

Thermal cycling test is one of the reliability tests, which are important for metal-ceramic layered composites (metallized ceramic substrates), a part in power modules. Since thermal cycles are within a large range of temperature, the test has only been performed using a thermal chamber. It limited the understanding of degradation mechanism in metallized ceramics substrates. Among NDE techniques, Digital Image Correlation (DIC) is a simple and effective method, enhanced by modern digital imaging technologies, enabling precise measurements of displacement, strain, deformation, and defects with a simple setup. In this paper, we combined some of our previous work to make a review to present a full analysis of a silicon metallized substrate under thermal cycling test (from beginning to fail) using DIC method. The main content is the application of DIC in evaluating the reliability of metallized silicon nitride (AMB-SN) substrates under thermal cycling with temperatures from −40 °C to 250 °C. Three key aspects of the AMB-SN substrate are presented, including (i) thermal strain characteristics before and after delamination, (ii) warpage and dynamic bending behavior across damage states, and (iii) stress–strain behavior of constituent materials. The review provides insights into degradation progress of the substrate and the role of Cu in substrate failure, and highlights DIC’s potential in ceramic composites, offering a promising approach for improving reliability test simulations and advancing digital transformation in substrate evaluation, ultimately contributing to enhanced durability in high-power applications. Full article

Introduction: 3D-printing is an emerging technology in the field of prosthetics, offering advantages such as cost-effectiveness, ease of customization, and improved accessibility. While previous reviews have focused on limited aspects, the aim of this systematic review is to provide a comprehensive evaluation of the clinical outcomes of 3D-printed prostheses for both upper and lower limbs. Methods: A search was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines across six databases (PubMed, Web of Science, EBSCO, Scopus, Cochrane Library, and Sage). Studies on 3D-printed prostheses in human rehabilitation that focused on the clinical outcomes of the device were included, while studies lacking clinical data, 3D printing details, or focusing on traditional manufacturing methods were excluded. Finally, the risk of bias was assessed using the modified Downs & Black Checklist. Results: A total of 1420 studies were identified, with 11 meeting the inclusion criteria. The included studies assessed different 3D-printed prosthetic types and upper and lower limb prostheses. The main clinical outcomes analyzed were functional performance, design and material integrity, and overall effectiveness of 3D-printed prostheses. Studies on upper limb prostheses reported improved dexterity, range of motion (ROM), and user satisfaction, despite some durability limitations. Lower limb prostheses showed enhancements in comfort, gait parameters, and customization, particularly in amphibious and partial foot designs. Conclusions: 3D-printed prostheses show potential to improve functional performance, patient satisfaction, fit, and implementation feasibility compared to conventional methods. However, limitations such as small sample sizes, variability in assessment tools, and limited high-quality evidence highlight the need for further research to support broader clinical adoption. Full article

The rapid advancement of modern infrastructure and construction industries demands cementitious materials with superior mechanical performance, durability, and sustainability, surpassing the limitations of conventional concrete. To address these challenges, carbon-based nanomaterials—including carbon nanofibers (CNFs), carbon nanotubes (CNTs), and graphene—have gained significant attention as next-generation reinforcement agents due to their exceptional strength, high aspect ratio, and unique interfacial properties. This review presents a critical analysis of the latest technological developments in carbon-enhanced cement and concrete composites, focusing on their role in achieving high-performance construction materials, as there is a shortage of reviews of cement concretes based on carbon nanoadditives. We systematically explore the underlying mechanisms, processing techniques, and structure–property relationships governing carbon-modified cementitious systems. First, we discuss advanced synthesis methods and dispersion strategies for carbon nanomaterials to ensure uniform reinforcement within the cement matrix. Subsequently, we analyze the mechanical enhancement mechanisms, including crack bridging, nucleation seeding, and interfacial bonding, supported by experimental and computational studies. Despite notable progress, challenges such as long-term durability, cost-effectiveness, and large-scale processing remain key barriers to practical implementation. Finally, we outline emerging trends, including multifunctional smart composites and sustainable hybrid systems, to guide future research toward scalable and eco-friendly solutions. By integrating fundamental insights with technological advancements, this review not only advances the understanding of carbon-reinforced cement composites but also provides strategic recommendations for their optimization and industrial adoption in next-generation construction. Full article

The construction industry, as a major contributor to greenhouse gas emissions, urgently requires sustainable development solutions to achieve the Net Zero Emission Goal. Magnesium oxide (MgO)-based cementitious composites have emerged as promising alternatives due to their ability to reduce environmental impact and their potential to enhance structural integrity. Despite these advantages, limitations such as poor resistance to harsh environmental conditions and concerns over long-term durability continue to restrict their broader application. To better understand these strengths and limitations, this review investigates the influence of MgO; supplementary cementitious materials (SCMs) such as fly ash, silica fume, and rice husk ash. It also examines fibers, including polyethylene (PE), polypropylene (PP), polyvinyl alcohol (PVA), glass, sisal, and cellulose, and their effect on the mechanical and durability properties of MgO-based composites. Mechanical performance is assessed through compressive and tensile strength, while durability is evaluated in terms of porosity, permeability, water absorption, shrinkage (autogenous and drying), and carbonation resistance. Key challenges and future research directions to promote the use of MgO composites in sustainable construction are also identified. Full article

This article presents the results of a comprehensive investigation into geopolymer composites synthesized from fly ash, incorporating ground asphalt derived from reclaimed road pavement and quartz sand. The primary objective of this study was to elucidate the influence of mixture composition on the mechanical, physical, and microstructural characteristics of the developed materials. The innovative aspect of this research lies in the integration of two distinct filler types—mineral (quartz sand) and organic-mineral (milled asphalt)—within a single geopolymer matrix, while preserving key performance parameters required for engineering applications, including compressive and flexural strength, density, water absorption, and abrasion resistance. The experimental methodology encompassed the characterization of the raw materials by X-ray diffraction (XRD), chemical composition analysis via X-ray fluorescence (XRF), and assessment of particle size distribution. Additionally, the produced geopolymer materials underwent density determination, compressive and flexural strength measurements, abrasion testing, and mass water absorption evaluation. The chemical composition was further examined using XRF, and the surface morphology of the specimens was analyzed by scanning electron microscopy (SEM). The findings demonstrate that the incorporation of quartz sand enhances the density and mechanical strength of the composites, whereas the addition of recycled asphalt, despite causing a modest reduction in mechanical performance at elevated dosages, augments water resistance. Moreover, ternary composite material provide an optimal compromise between mechanical strength and durability under humid conditions. Overall, the results substantiate the feasibility of utilizing asphalt waste for the fabrication of functional and sustainable geopolymer materials suitable for construction applications. Full article

The presence of Giant Hogweed (Heracleum mantegazzianum) in agricultural landscapes raises concerns due to its impacts on agroecology. Physically removed biomass can serve as a feedstock for solid biofuel, representing a viable strategy reducing reliance on herbicides. Giant Hogweed’s bioenergy potential is currently underexplored, particularly regarding its seasonal variations in properties and the environmental impacts resulting from its use as a biofuel. This study assessed the processability of Giant Hogweed biomass into briquettes, to determine their mechanical durability and to evaluate their basic emission characteristics during combustion in a device commonly used at the household level. Biomass was sampled at two specific stages of plant development for a comparative study of briquette properties. For both summer- and autumn-harvested biomass, a high mechanical durability of the produced briquettes, approximately 97%, was achieved. Only carbon monoxide emissions from summer-harvested biomass exceeded the limits; nitrogen oxides concentrations were within the limits for both. Thermogravimetric analysis and differential scanning calorimetry revealed decomposition patterns. Autumn-harvested biomass showed better potential for briquetting, highlighting the advantages of later collection. The findings demonstrate the potential of plant and applied processing technology for valorisation as a solid biofuel, while certain aspects still need consideration. Full article

Turbine blades are the most critical parts of aircraft engines. They are exposed to complex forces at the highest temperature and an aggressive environment. For this reason, the highest demands are placed on their structural quality. In single-crystalline nickel-based superalloy blades, the quality of the dendritic structure, crystal orientation, and local lattice parameter homogeneity is important because such properties affect the strength properties of the casting. For this reason, the structural attributes mentioned above were studied for novel, model-cored blades made of Ni-based superalloy. The blades were studied using scanning electron microscopy, the dedicated original X-ray Ω-scan method, the Laue diffraction, and the X-ray diffraction topography. The differences in the dendrites’ morphology and their array, revealing changes in dendrites’ arm size and arrangement, and changes in dendrites’ symmetry, were observed. Misoriented areas were identified, forming subgrains separated by low-angle boundaries. The location of the subgrains concerning the blade geometry and reasons for their creation were analyzed. The relation between the observed local changes in the lattice parameter and the creation of structural defects was determined. Aspects influencing the formation of structural defects that may reduce the durability of castings in specific areas of the cored blade airfoils have been discussed. Full article

Heat-curing processes are often used to ensure the production rate of precast concrete elements, as this process increases the early strength of the material. However, the increase in curing temperature can negatively affect the final mechanical properties since cracking, and especially high porosity, may occur under these conditions. In order to compensate for the expected loss in mechanical and durability-related properties, the cement content is typically increased. This solution raises the cost of the final product and reduces its sustainability. Thus, in this study, the development of expansive self-compacting concretes (SCCs) is proposed to achieve higher final mechanical properties without increasing cement contents. The mechanical properties, expansive performance, and porous microstructure have been evaluated under different curing regimes. The obtained results show that it is possible to obtain similar or even better mechanical performance in expansive concretes cured at high temperatures than in those cured in standard conditions, particularly when using ettringite-based expansive agents (EAs). Moreover, the use of limestone filler (LF) proved to be more suitable than the use of fly ashes in the working conditions evaluated in the present study. In this sense, the compressive strength at 28 days of SCC with LF and ettringite-based EAs is 4.3% higher than the one obtained under standard curing; moreover, the total porosity is reduced (5%), and the drying shrinkage is also limited. These aspects have not been previously reported in non-expansive heat-cured concretes and represent a unique opportunity to reduce the cement content and, therefore, the carbon footprint of precast concretes without reducing their mechanical properties. When using CaO-based EAs, the results are also better than those of non-expansive SCC, although the improvement is less pronounced than in the previous case. Full article

The aim of this study is an interdisciplinary assessment of the potential of cement pastes to permanently bind carbon dioxide (CO₂) under anaerobic digestion conditions, considering technological, microstructural, environmental, and economic aspects. The research focused on three types of Portland cement: CEM I 52.5N, CEM I 42.5R-1, and CEM I 42.5R-2, differing in phase composition and reactivity, which were evaluated in terms of their carbonation potential and resistance to chemically aggressive environments. The cement pastes were prepared with a water-to-cement ratio of 0.5 and subjected to 90-day exposure in two environments: a reference environment (tap water) and a fermentation environment (aqueous suspension of poultry manure simulating biogas reactor conditions). XRD, TG/DTA, SEM/EDS, and mercury intrusion porosimetry were applied to analyze CO₂ mineralization, phase changes, and microstructural evolution. XRD results revealed a significant increase in calcite content (e.g., for CEM I 52.5N from 5.9% to 41.1%) and the presence of vaterite (19.3%), indicating intense carbonation under organic conditions. TG/DTA analysis confirmed a reduction in portlandite and C-S-H phases, suggesting their transformation into stable carbonate forms. SEM observations and EDS analysis revealed well-developed calcite crystals and the dominance of Ca, C, and O, confirming effective CO₂ binding. In control samples, hydration products predominated without signs of mineralization. The highest sequestration potential was observed for CEM I 52.5N, while cements with higher C₃A content (e.g., CEM I 42.5R-2) exhibited lower chemical resistance. The results confirm that carbonation under fermentation conditions may serve as an effective tool for CO₂ emission management, contributing to improved durability of construction materials and generating measurable economic benefits in the context of climate policy and the EU ETS. The article highlights the need to integrate CO₂ sequestration technologies with emission management systems and life cycle assessment (LCA) of biogas infrastructure, supporting the transition toward a low-carbon economy. Full article