Search Results (2,651)

This paper focuses on optimisation of material parameters to describe the elastoplastic stress–strain relationship in finite element solvers. Two new methods are introduced to minimise the numerical error that occurs in the interspace between the experimental cyclic stress–strain curve and its representation using multilinear interpolation. Specifically, both methods are integrated into a Prandtl operator approach, which can be used to simulate the elastoplastic response of mechanical components subjected to variable thermomechanical loadings. The improvement as compared to standard interpolation is most substantial when the number of yield planes is limited, especially in the case of bilinear stress–strain curves. The innovation of this study is an algorithm that optimises positions of the stress–strain points across the temperature range of interest considering several input temperatures. It is shown that these methods are especially applicable for optimisation of material parameters when the stress–strain curves are available for a range of test temperatures that are needed for simulating thermomechanical fatigue. The improvement in the interpolation using these methods is exhibited for two materials with available experimental results: stainless steel EN 1.4512 and polyamide PA12. Full article

Auxetic metamaterials, characterized by negative Poisson’s ratio, have garnered significant interest due to their exceptional impact resistance. This study presents a type of auxetic metamaterial organized in re-entrant arrowhead lattices. The uniaxial impact behavior of a uniform auxetic lattice was first investigated through experiment and finite element simulation, which showed good agreement. Subsequently, two graded auxetic lattices with density-gradient profiles were proposed by varying the radius of the bars in the basic auxetic lattice. Numerical simulations demonstrate that, across various compression velocities, both graded architectures achieve higher plateau stresses and enhanced energy absorption compared to their uniform counterpart. Notably, the graded lattice with lower density at the impact end exhibited a reduced initial peak stress. An analytical framework was also established to characterize the compressive behavior of these auxetic lattices. Theoretical analyses elucidate the underlying mechanisms of impact energy dissipation and provide a solid basis for predicting dynamic compressive performance. Furthermore, a gradient-parametric study revealed that the stress–strain response is significantly influenced by both the density gradient and impact velocity, further demonstrating a high consistency between the theoretical predictions and the simulation results. This research is desirable to provide insights for designing graded auxetic metamaterials with tailored impact properties. Full article

Using molecular dynamics simulations of a planar graphene sheet, we investigate the temperature dependence of its mechanical behavior under uniaxial tensile stress applied either in the armchair or zigzag direction. Stress–strain curves are calculated for different temperatures, and the corresponding dependence of various elastic parameters is discussed. Fracture stress and strain, as well as the Young’s modulus, decrease almost linearly with temperature, in accordance with previous investigations. An almost linear variation in the third-order elastic modulus with temperature is demonstrated, revealing opposite trends for uniaxial loadings in the armchair or zigzag direction. The detailed dependence of the distributions of bond lengths and bond angles both on strain and temperature is presented for the first time, along with approximate analytical expressions. The latter accurately describe the numerically obtained distributions. Full article

Long non-coding RNAs (lncRNAs) are crucial regulators in eukaryotic organisms, yet their roles in filamentous fungi, particularly in environmental adaptation and metabolic changes, remain largely unexplored. Here, we investigated the roles of lncRNAs in salt stress response, morphological differentiation, and metabolic regulation in Eurotium cristatum. Using strand-specific RNA sequencing, we identified lncRNAs in sexual and asexual mycelia of E. cristatum and analyzed their expression profiles. We identified 203 lncRNAs, with 120 significantly differentially expressed (FDR < 0.01; |log₂ (fold change)| ≥ 1) under salt stress, including 57 upregulated and 63 downregulated in the asexual morph compared to the sexual morph. These lncRNAs correlated with physiological indicators like mycelial biomass, polysaccharide content, and melanin production. Target gene prediction and functional enrichment analysis revealed that these lncRNAs influenced morphogenesis and secondary metabolite synthesis in E. cristatum by regulating pathways including carbohydrate metabolism, peroxisome function, and protein ubiquitination. The lncRNA MSTRG.10627.3 showed the highest upregulation (log₂FC = 10.53, FDR < 1 × 10⁻¹⁰⁵), while MSTRG.3124.1 was significantly downregulated in the sexual morph (log₂FC = −4.94, FDR < 1 × 10⁻⁸⁸). A regulatory network of lncRNAs involved in salt stress responses was constructed, providing insights into fungal environmental adaptation mechanisms and potential targets for industrial strain improvement. Full article

Background/Objectives: Copper-based wood preservatives are widely used to protect timber from fungal decay; however, the emergence of copper-tolerant fungi reduces their long-term effectiveness. This study aimed to elucidate the molecular mechanisms underlying copper resistance in Saccharomyces cerevisiae through adaptive evolution and transcriptomic profiling. Methods: A copper-resistant mutant was developed via stepwise exposure to CuSO₄·5H₂O, and its gene expression profile was compared to the wild-type strain under copper stress and non-stress conditions using Affymetrix GeneChip Yeast Genome 2.0 arrays. Results: Differential expression analysis revealed upregulation of key genes involved in copper transport (ATX1 and CTR1), the oxidative stress response (RCK1 and SOD1), and metal ion detoxification (FRE3 and SLF1). Functional enrichment analysis highlighted the significant activation of pathways related to protein folding, mitochondrial function, and transcriptional regulation. Conclusions: These findings provide insights into the adaptive strategies employed by S. cerevisiae to tolerate copper stress and suggest potential gene targets for the development of more effective wood preservatives capable of mitigating fungal resistance. Full article

Amidst the green transition of the energy structure, as a sustainable innovation, photovoltaic pavement technology has garnered significant attention for its ability to utilize road surfaces for clean energy generation. However, roadway infrastructure must meet both load-bearing and safety requirements, making the structural performance analysis of photovoltaic pavements particularly crucial. This study focuses on load-bearing photovoltaic highways and employs finite element simulation to systematically analyze the effects of different surface transparent layer thicknesses and base sidewall thicknesses on the dynamic mechanical response of the photovoltaic pavement structure. The results indicate that increasing the surface transparent layer thicknesses significantly reduces structural deformation, stress, and strain, thereby enhancing overall stiffness and stability. Similarly, increasing the base sidewall thicknesses within a certain range also markedly improves structural performance, although the benefits tend to plateau beyond a specific thickness. Optimizing the structure can significantly enhance the load-bearing capacity and durability of photovoltaic pavements, thereby facilitating the achievement of green transportation and sustainable energy goals, and making a significant contribution to sustainable development. Full article

The growing demand for sustainable construction practices has driven research into self-sensing materials incorporating recycled waste for smart SHM (Structural Health Monitoring) systems. However, previous works did not investigate the influence of rheological behavior and piezoresistive properties of sustainable cementitious sensors containing red mud (RM) on the strain monitoring of concrete beams. To address this gap, this study presents an experimental analysis of the rheological, mechanical, and self-sensing performance of mortars incorporating carbon black nanoparticles (CBN) and varying levels of RM (25–100% sand replacement by volume), followed by their application in monitoring strain in a reinforced concrete beam under dynamic loading. The results showed that increasing RM content led to higher viscosity and yield stress, with a 60% reduction in consistency index. Compressive strength increased by up to 80%, while mortars with RM content higher than 50% showed high electrical conductivity and reversible resistivity changes under load cycles. Mortars containing 50–100% RM demonstrated improved piezoresistive response, with a 23% increase in gauge factor, and the best-performing sensor embedded in a concrete beam exhibited stable and reversible fractional changes in resistivity, closely matching strain gauge data during dynamic loading conditions. These findings highlight the potential of RM-based smart mortars to enhance sustainability and performance in SHM applications. Full article

Northern corn leaf blight (NCLB), caused by the fungal pathogen Setosphaeria turcica, is a devastating foliar disease that significantly threatens maize production in China. Previous studies have demonstrated that SET domain gene 102 (SDG 102), a gene encoding an H3K36 methyltransferase, plays a crucial role in regulating maize growth, development, and stress responses. This study used the wild-type (WT), SDG102 overexpression line (OE), and silencing line (SL) of the corn inbred line B73 as materials. After artificial inoculation with S. turcica, the phenotypic characteristics, disease index, yield, and other related traits of different strains were compared, and RNA-Seq was used to analyze the changes in the gene expression profile. The results showed that overexpression of SDG102 significantly inhibited pathogen spore germination and hyphal growth and enhanced the activity of antioxidant enzymes and the ability to scavenge reactive oxygen species in plants prior to S. turcica infection, the opposite trend was observed in SDG102 silencing lines. Compared with the wild-type, 1546 and 1837 differentially expressed genes (DEGs) responsive to S. turcica were identified in OE and SL, respectively. These differentially expressed genes primarily function in pathways such as plant–pathogen interactions, plant hormone signaling, and secondary metabolite biosynthesis. In the OE lines, genes related to plant–pathogen interactions, reactive oxygen species (ROS) production, and key phenylpropanoid biosynthesis genes exhibited higher expression levels. Furthermore, SDG102 regulates the synthesis of auxin (JA) and abscisic acid (SA) as well as the transcription of their signaling pathway genes, thereby influencing maize resistance to large leaf spot disease. Under corn leaf blight conditions, SDG102 overexpression increased yield by 9.29% compared to WT, while SL reduced yield by 10.10%. In conclusion, SDG102 enhances maize resistance to NCLB by positively regulating the expression of disease resistance genes, antioxidant enzyme activity, and hormone-mediated defense pathways. Full article

Activation of cGAS, a receptor recognizing cytosolic DNA, in macrophages might be associated with rabies (an RNA virus) through mitochondrial damage. A similar mortality rate was observed between cGAS-deficient (cGAS-/-) and wild-type (WT) mice post-CVS-11 strain injection. However, 2 out of 12 cGAS-/- mice (but not WT) survived for 15 days post-injection. At 7 days post-infection, less severe brain inflammation in cGAS-/- mice was demonstrated by the viral abundance in the hippocampus, the expression of proinflammatory genes (TNF-α and IL-1β), and the Evans blue dye assay (blood–brain barrier defect) with the presence of higher anti-inflammatory genes (TGF-β and arginase-1). Fecal Proteobacteria was more prominent in the infected WT mice, while serum cytokines (TNF-α and IL-1β) were similar in both mouse strains. There were less prominent responses against the rabies virus in cGAS-/- macrophages than in WT cells, as indicated by supernatant IL-6 and the gene expression of TLR-3, RIG-1, MDA-5, and iNOS. On the other hand, mitochondrial injury and cGAS activation were more prominent in WT macrophages over cGAS-/- cells, as indicated by cGAS expression, supernatant cGAMP (a secondary messenger of cGAS), and mitochondrial oxidative stress (MitoSox) together with a decrease in mitochondrial DNA and maximal respiration (extracellular flux analysis). In conclusion, (i) rabies-damaged mitochondria led to cGAS activation that was less severe in cGAS-/- than in WT, (ii) rabies-induced dysbiosis was demonstrated, and (iii) cGAS manipulation and gut–brain axis-associated inflammation warrants further investigation. Full article

The mechanical performance of cast iron is strongly governed by the morphology of its graphite phase, yet establishing a quantitative link between microstructure and macroscopic properties remains a challenge. In this study, a three-dimensional finite element method (FEM)-based micromechanical framework is proposed to analyze and predict the mechanical behavior of cast iron with representative graphite morphologies, spheroidal and flake graphite. Realistic representative volume elements (RVEs) are reconstructed based on experimental microstructural characterization and literature-based X-ray computed tomography data, ensuring geometric fidelity and statistical representativeness. Cohesive zone modeling (CZM) is implemented at the graphite/matrix interface and within the graphite phase to simulate interfacial debonding and brittle fracture, respectively. Full-field simulations of plastic strain and stress evolution under uniaxial tensile loading reveal that spheroidal graphite promotes uniform deformation, delayed damage initiation, and enhanced ductility through effective stress distribution and progressive plastic flow. In contrast, flake graphite induces severe stress concentration at sharp tips, leading to early microcrack nucleation and rapid crack propagation along the flake planes, resulting in brittle-like failure. The simulated stress–strain responses and failure modes are consistent with experimental observations, validating the predictive capability of the model. This work establishes a microstructure–property relationship in multiphase alloys through a physics-informed computational approach, demonstrating the potential of FEM-based modeling as a powerful tool for performance prediction and microstructure-guided design of cast iron and other heterogeneous materials. Full article

Background/Objectives: Bacteroides species are key members of the human gut microbiota but can act as opportunistic pathogens. This study investigated the genomic features of clinical Bacteroides isolates from southern Thailand. Methods: Sixteen isolates were collected from body fluids, tissues, and pus at Songklanagarind Hospital (2022–2024). Whole-genome sequencing was performed on the BGI platform, followed by genome assembly, annotation, average nucleotide identity (ANI), pairwise single-nucleotide polymorphism (SNP) analysis, antimicrobial resistance (AMR) gene profiling, plasmid prediction, virulence screening, and phylogenetic analysis. Results: ANI and SNP analysis revealed two clusters: one comprising B. ovatus, B. intestinigallinarum, and B. thetaiotaomicron, and another mainly B. fragilis with one B. hominis isolate. All isolates were resistant to ampicillin, cephalothin, and penicillin; six B. fragilis strains were resistant to all tested antibiotics. The β-lactamase gene cepA was detected in all B. fragilis isolates, and plasmids were predicted in two genomes. Three virulence types (capsule formation, lipopolysaccharide modification, and stress response) were identified. Phylogenomic analysis confirmed species-level assignments and revealed underrecognized lineages, emphasizing the value of genome-based approaches for accurate classification. Conclusions: Clinical Bacteroides isolates display diverse resistance and virulence profiles, highlighting the importance of strain-level genomic surveillance. Full article

The fatigue of wood is becoming increasingly important in modern engineering, as the safety of the structure must be guaranteed and the use of materials must be optimized at the same time. Predicting the fatigue behavior of wood remains a challenge for many researchers. Interest and the number of studies in this field have increased, highlighting the need for a comprehensive overview of the current state of knowledge on wood fatigue. In this paper, we focus on the study of the fatigue of wood-based materials to understand the similarities and peculiarities of fatigue behavior compared to other engineering materials and to identify opportunities for new research. We present the influence of physical and mechanical properties on fatigue life and identify similarities in the fatigue behavior of wood, polymeric materials and steel. The basic properties that differentiate the fatigue life of wood from that of other materials are heterogeneity, orthotropy, viscoelasticity, hygroscopicity, mechanosorptivity and the lack of a clear threshold value for fatigue strength. The differences in fatigue life between solid wood and laminated wood are not uniformly defined by researchers. We provide an overview of the measurement methods used to monitor the fatigue state, the models used to predict fatigue life and the simulations of the stress–strain response to cyclic loading. We identify areas where wood is subject to fatigue and determine which areas are most critical under cyclic loading. We make suggestions for further research that would contribute significantly to a better understanding and management of wood fatigue. Due to the wide variety of wood species used in the studies, it is impossible to compare the results. In order to obtain a comprehensive overview of the response of wood to fatigue under different test conditions, the test methods need to be standardized. Full article

To elucidate the influence of the extrusion-based 3D printing of concrete on the tensile performance of polyethylene fibre-based engineered cementitious composites (PE-ECC), quantitative analyses of reinforcing filament alignment and pore morphology were carried out using backscattered electron (BSE) imaging and X-ray computed tomography (X-CT). A micromechanics analytical model based on microstructural characteristics was further employed to predict the tensile response of additively manufactured PE-ECC. Due to the extrusion process, fibres in 3D-printed PE-ECC were predominantly oriented along the printing path, resulting in a smaller average inclination angle compared with the randomly distributed fibres in cast specimens. Internal pores exhibited elongated flattened ellipsoidal shapes, with more pronounced anisotropy in axial lengths across the three principal directions. Taking the major semi-axis of the equivalent ellipsoidal voids as a representative pore parameter, the analytical model accurately reproduced the cracking strength, stress-strain evolution, and crack pattern of the printed PE-ECC. This extrusion process enhanced multiple cracking capacity and strain-hardening performance by improving fibre orientation, strengthening interfacial bonding, and altering matrix fracture toughness. The integration of micromechanical modelling with experimentally measured microstructural parameters effectively revealed the intrinsic mechanisms underlying the enhanced tensile behaviour of 3D-printed PE-ECC and provides theoretical support for the optimized design of fibre-reinforced cementitious composites in 3D printing. Full article

This study examines the impact of jet misalignment on the mechanical performance of Pelton turbine runners. A comparative examination of the dynamic response characteristics of the runner under four operational conditions—Undeflected Jet (UJ), Radial offset+ (RO+), Radial offset− (RO−), and Axial offset (AO)—is undertaken based on fluid–structure interaction (FSI) numerical simulations. The findings demonstrate that functioning under misaligned conditions modifies the stress distribution on the runner surface, resulting in considerable stress concentration. The maximum Von-Mises stress attains 129.7 MPa, occurring at the bucket notch region under the RO+ condition. The strain distribution aligns with the stress distribution in the elastic regime, exhibiting a maximum Von-Mises strain of 0.000650 (0.650 × 10⁻³ mm/mm). The distortion of the runner varies from 0.181 mm to 0.190 mm, with the most significant deformation occurring near the trailing edge. The RO+ condition intensifies the risk of high-cycle fatigue in the runner structure, succeeded by RO− and AO situations. The results establish a theoretical foundation for the secure functioning and structural enhancement of Pelton turbines in misalignment scenarios. Full article

In order to surmount the characteristics of high steel consumption and cost in prefabricated buildings, as a novel structural component, reinforced concrete vierendeel sandwich plates (RC-VSP) could be effectively employed. However, RC-VSP is restricted by complex construction procedures and rigorous quality control demands. Reliable reinforcement connections are the keys to their prefabrication. This study employed the methods of 1:1 full-scale comparative tests and numerical analysis through finite- element modeling. It compared the mechanical behaviors of the continuous reinforcement control group and the upset sleeve assembly group under four-point cyclic bending conditions. It analyzed how sleeves’ distribution influences structural stress states and crack propagation processes. The results show a superior ductility and damage resistance, on the basis of the components’ attenuation amplitude of the secant stiffness remains around 50% after the loading test with a deflection of 1/100, and the equivalent damping ratio is greater than 13%. Furthermore, the high similarity of the strain responses demonstrated the connection achieves prefabricated structures’ “equivalent performance to cast-in-place ones”. Additionally, the sleeve joints have slightly better stiffness, minor stress concentration at sleeve ends. This study offers robust experimental and theoretical support for the integrated prefabricated application of RC-VSP and further facilitates the development of building structures toward higher efficiency and lower carbon emissions. Full article