Search Results (802)

Bi₂Sr₂CaCu₂O_8+x (Bi2212) high-temperature superconductor exhibits broad application prospects in strong magnetic fields, superconducting magnets, and power transmission due to its exceptional electrical properties. However, during practical applications, Bi2212 superconducting round wires are prone to mechanical loading effects, leading to crack propagation and degradation of superconducting performance, which severely compromises their reliability and service life. To elucidate the damage mechanisms under mechanical loading and their impact on critical current, this study establishes a two-dimensional model with existing cracks based on phase field fracture theory, simulating crack propagation behaviors under varying conditions. The results demonstrate that crack nucleation and propagation paths are predominantly governed by stress concentration zones. The transition zone width of cracks is controlled by the phase field length scale parameter. By incorporating electric fields into the phase field model, coupled mechanical-electrical simulations reveal that post-crack penetration causes significant current shunting, resulting in a marked decline in current density. The research quantitatively explains the mechanism of critical current degradation in Bi2212 round wires under tensile strain from a mechanical perspective. Full article

Background/Objectives: Streptococcus suis (SS), an important zoonotic pathogen, has caused significant economic losses to the global pig industry. Existing commercial vaccines for SS mainly provide effective protection against a single serotype. Due to the existence of many serotypes and their robust immune evasion capabilities, the development of multi-component subunit vaccines or multi-epitope vaccines that provide effective cross-protection against different strains of SS is a key focus of current research. Methods: We applied two-dimensional electrophoresis (2-DE) and immunoblotting to screen for candidate immunogens among the immunogenic cell wall proteins of SS. BALB/c mice were immunized intradermally with a multi-component, multi-epitope vaccine. The vaccine’s safety and immunogenicity were assessed via clinical monitoring, antibody titer detection, cytokine assays, and survival curve analyses. Results: In this study, eight immunogenic cell wall proteins (GH25, Pk, PdhA, Ldh, ExoA, Pgk, MalX, and Dnak) were successfully identified using MALDI-TOF-MS, all of which could induce high IgG antibody titers. Based on the conservation and immunoprotection demonstrated by these eight protective antigenic proteins, PdhA, Ldh, and MalX were screened to construct a multi-component subunit vaccine as a candidate vaccine for providing cross-protection against SS isolates of multiple serotypes. Challenge studies showed that mice immunized with the multi-component subunit vaccine (PdhA, Ldh, and MalX) were protected against challenges with the SS2 virulent strain ZY05719 (62.5% protection) and the SSChz virulent strain CZ130302 (75% protection). Subsequently, we utilized immunoinformatics techniques to design a novel multi-epitope vaccine (MVPLM) derived from the immunogenic proteins PdhA, Ldh, and MalX. However, challenge tests revealed that the MVPLM offered limited protection against SS. Conclusions: These data demonstrate that a multi-component subunit vaccine composed of PdhA, Ldh, and MalX proteins shows promise as a candidate universal vaccine against multiple SS serotypes. Full article

Abdominal fat is a key indicator of chicken meat quality. Excessive deposition not only reduces meat quality but also decreases feed conversion efficiency, making the breeding of low-abdominal-fat strains economically important. Genomic selection (GS) uses information from genome-wide association studies (GWASs) and high-throughput sequencing data. It estimates genomic breeding values (GEBVs) from genotypes, which enables early and precise selection. Given that abdominal fat is a polygenic trait controlled by numerous small-effect loci, this study combined population genetic analyses with machine learning (ML)-based feature selection. Relevant single-nucleotide polymorphisms (SNPs) were first identified using a combined GWAS and linkage disequilibrium (LD) approach, followed by a two-stage feature selection process—Lasso for dimensionality reduction and recursive feature elimination (RFE) for refinement—to generate the model input set. We evaluated multiple machine learning models for predicting genomic estimated breeding values (GEBVs). The results showed that linear models and certain nonlinear models achieved higher accuracy and were well suited as base learners for ensemble methods. Building on these findings, we developed a Dynamic Adaptive Weighted Stacking Ensemble Learning Framework (DAWSELF), which applies dynamic weighting and voting to heterogeneous base learners and integrates them layer by layer, with Ridge serving as the meta-learner. In three independent validation populations, DAWSELF consistently outperformed individual models and conventional stacking frameworks in prediction accuracy. This work establishes an efficient GEBV prediction framework for complex traits such as chicken abdominal fat and provides a reusable SNP feature selection strategy, offering practical value for enhancing the precision of poultry breeding and improving product quality. Full article

Developing classical three-dimensional consolidation theories considers the small-strain assumption. This small-strain assumption is inappropriate when studying the consolidation process of soft or very soft clay layers. Instead, this study derives a novel generalized mathematical model describing a three-dimensional finite-strain consolidation process and applies the deep Galerkin method to deduce its novel numerical solution. Developing this mathematical model uses the Reynolds transport theorem to describe mass and momentum balances for clay grain and pore water phases. The governing equation is the sum of the resulting mass and momentum balance equations. Next, the deep Galerkin method is applied to train a deep neural network to minimize the loss function defined by the governing equation and available initial and boundary conditions. The unknowns are the average velocity, effective stress, and pore water pressure. Predicting consolidation settlements is implemented by updating the problem domain using the resulting average velocity. Beneficial from the deep Galerkin method, two real-world examples demonstrate that the current mathematical model provides accurate predictions of consolidation settlements caused by the self-weight of two very soft clay layers. The deep Galerkin method helps resolve ill-posed problems by fitting a family of fields constrained by sampling/regularization rather than physics if the physics is under-determined. Full article

This paper provides an overview of various size-dependent theories based on modified/consistent couple stress and strain gradient theories (CSTs and SGTs), highlighting the development of two-dimensional (2D) refined and advanced shear deformation theories (SDTs) and three-dimensional (3D) pure analytical and semi-analytical numerical methods, including their applications, for analyzing the static and dynamic behaviors of microscale plates and shells made from advanced materials such as fiber-reinforced composites, functionally graded (FG) materials, and carbon nanotube/graphene platelet-reinforced composite materials. The strong and weak formulations of the 3D consistent CST, along with their corresponding boundary conditions for FG microplates, are derived and presented for illustration. A comparison study is provided to show the differences in the results of a simply supported FG microplate’s central deflection, stress, and lowest natural frequency obtained using various 2D size-dependent SDTs and 3D analytical and numerical methods based on the consistent CST. A parametric study is conducted to examine how primary factors, such as the effects of dilatational and deviatoric strain gradients and couple stress, impact the static bending and free vibration behaviors of a simply supported FG microplate using a size-dependent local Petrov–Galerkin meshless method based on the consistent SGT. Influences such as the inhomogeneity index and length-to-thickness ratio are considered. It is shown that the significance of the impact of various material length-scale parameters on the central deflection and its lowest natural frequency (in the flexural mode) of the FG microplate is ranked, from greatest to least, as follows: the couple stress effect, the deviatoric strain gradient effect, and finally the dilatational strain gradient effect. Additionally, when the microplate’s thickness is less than 10⁻⁷ m, the couple stress effect on its static and dynamic behaviors becomes saturated. Conversely, the impact of the dilatational and deviatoric strain gradients consistently influences the microplate’s static and dynamic behaviors. Full article

In this study, a new hybrid hydrogel based on PAM (polyacrylamide)-Ag-g/WS₂/Ti₃C₂T_x was synthesized by radical polymerization using a conductive heterostructural nanocomposite WS₂/Ti₃C₂T_x. The synergy between the polymer matrix and the interface between two-dimensional nanomaterials ensured the production of a hydrogel with high extensibility and conductivity, as well as sensory characteristics. The composite hydrogel exhibited excellent strain-sensing capabilities, with gauge factors of 1.4 at low strain and 2.8 at higher strain levels. In addition, the material showed a fast response time of 2.17 s and a short recovery time of 0.46 s under cyclic stretching, which confirms its high reliability and reproducibility. The integration of Ti₃C₂T_x and WS₂ promoted the formation of a conductive network in the hydrogel structure, which simultaneously increased its mechanical strength and signal stability under variable loads. Measurements confirm some potential of the PAM-Ag-g/WS₂/Ti₃C₂T_x composite hydrogel as a flexible wearable strain sensor. Based on measured numbers, we discussed the impact of the WS₂/Ti₃C₂T_x interface on the Gauge factor and conductivity of the composite. Theoretical modeling demonstrates significant changes in the electronic structure of the WS₂/Ti₃C₂T_x interface, and especially the WS₂ surface, induced by substrate strain. Possible applications of the peculiar properties of PAM-Ag-g/WS₂/Ti₃C₂T_x composite were proposed. Full article

In this work, the gas sensing properties and adsorption mechanisms of Ag- and Au-doped SnSe₂ monolayers toward NO, NO₂, SO₂, H₂S, and HCN were systematically investigated via first-principles calculations. The results demonstrate that NO₂ exhibits the strongest interaction and the highest charge transfer in both doped systems, indicating superior sensing selectivity. Biaxial strain (ranging from −8% to 6%) was further applied to modulate adsorption behavior. By evaluating changes in equilibrium height, adsorption energy, charge transfer, and recovery time across ten representative adsorption systems, it was found that both compressive and tensile strains enhance the interaction between gas molecules and doped SnSe₂ monolayers. Specifically, H₂S/Au–SnSe₂ and HCN/Au–SnSe₂ are highly sensitive to tensile strain, while NO/Au–SnSe₂, H₂S/Ag–SnSe₂, NO/Ag–SnSe₂, and NO₂/Ag–SnSe₂ respond more strongly to compressive strain. Systems such as NO₂/Au–SnSe₂, SO₂/Au–SnSe₂, and SO₂/Ag–SnSe₂ respond to both types of strain, whereas HCN/Ag–SnSe₂ shows relatively low sensitivity in charge transfer. Recovery time analysis indicates that NO₂ exhibits the slowest desorption kinetics and is most affected by strain modulation. Nevertheless, increasing the operating temperature or applying appropriate strain can significantly shorten recovery times. While other gas systems show smaller variations, strain engineering remains an effective strategy to tune desorption behavior and enhance overall sensor performance. These findings offer valuable insights into strain-tunable gas sensing behavior and provide theoretical guidance for the design of high-performance gas sensors based on two-dimensional SnSe₂ materials. Full article

Three previously undescribed clerodane diterpenoids, including two cis-clerodanes, solidagolactone IX (1) and solidagoic acid K (2), and one trans-clerodane, solidagodiol (3), along with two known cis-clerodane diterpenoids, (−)-(5R,8R,9R,10S)-15,16-epoxy-ent-neo-cleroda-3,13,14-trien-18-ol (4) and solidagoic acid J (5), were isolated and comprehensively characterized from the ethanolic and ethyl acetate root extract of Solidago gigantea Ait. (giant goldenrod). Compound 4 has previously been reported from the roots of this species, whereas compound 5 was identified from the leaves of S. gigantea but not from the roots. The bioassay-guided isolation involved thin-layer chromatography–direct bioautography (TLC–DB) with a Bacillus subtilis antibacterial assay, preparative flash column chromatography, and TLC–mass spectrometry (MS). The chemical structures of the isolated compounds (1–5) were elucidated through extensive in-depth spectroscopic and spectrometric analyses, including one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy, high-resolution tandem mass spectrometry (HRMS/MS), and attenuated total reflectance Fourier-transform infrared (ATR–FTIR) spectroscopy. Their antimicrobial activities were evaluated using in vitro microdilution assays against B. subtilis and different plant pathogens. Compound 3 was the most active against the tested Gram-positive strains, exerting particularly potent effects against Clavibacter michiganensis with a minimal inhibitory concentration (MIC) value of 5.1 µM as well as B. subtilis and Curtobacterium flaccumfaciens pv. flaccumfaciens (MIC 21 µM for both). Compound 4 also strongly inhibited the growth of C. michiganensis (MIC 6.3 µM). Compounds 2, 4, and 5 displayed moderate to weak activity against B. subtilis and C. flaccumfaciens pv. flaccumfaciens with MIC values ranging from 100 to 402 µM. Rhodococcus fascians bacteria were moderately inhibited by compounds 3 (MIC 41 µM) and 4 (MIC 201 µM). Bactericidal activity was observed for compound 3 against C. michiganensis with a minimal bactericidal concentration (MBC) value of 83 µM. Compounds 2 and 3 demonstrated weak antifungal activity against Fusarium graminearum. Our findings underscore the value of bioassay-guided approaches in discovering previously undescribed bioactive compounds. Full article

As the global shift toward renewable energy accelerates, large-scale energy storage is essential to balance intermittent supply and growing demand. While conventional Pumped Hydro Storage remains dominant, Underground Pumped Hydro Storage (UPHS) offers a promising alternative, particularly in flat regions with ample subsurface space. Southern Ontario, Canada, underlain by thick salt formations and a history of salt mining, presents favorable conditions for UPHS development, yet relative studies remain limited. This work presents the first UPHS-specific geomechanical feasibility assessment in the Canadian Salina Group, introducing a paired-cavern layout tied to Units B and A2 and explicitly capturing both elasto-plastic and creep behavior. Using COMSOL Multiphysics 6.3, a three-dimensional numerical model was developed featuring two vertically separated cylindrical caverns located in Unit B and the lower part of Unit A2. A 24 h operating cycle was simulated over a 10-year period, incorporating elasto-plastic deformation and salt creep. Minimum working pressures were varied to evaluate long-term cavern stability. The results show that a minimum pressure of 0.3 σ_v balances structural integrity and operational efficiency, with creep strain and volumetric convergence remaining within engineering limits. Beyond previous salt-cavern studies focused on hydrogen or CAES, this study provides the first coupled elasto-plastic and creep simulation tailored to UPHS operations in bedded salt, establishing a safe operating-pressure guideline and offering site-relevant design insights for modular underground energy storage systems in sedimentary basins. Full article

Verticillium wilt, caused by Verticillium dahliae, severely threatens various crops and trees worldwide. This study aimed to characterize the function of a CUE (coupling of ubiquitin conjugation to endoplasmic reticulum (ER) degradation)-domain-containing protein, VdCUE, in V. dahliae, which exhibits sequence divergence between the defoliating strain XJ592 and the non-defoliating strain XJ511. We generated ∆VdCUE-knockout mutants and evaluated their phenotypes in growth and virulence. Functional analyses included verifying the signal peptide activity of VdCUE, testing its ability to induce cell death or inhibit BAX-induced cell death in Nicotiana benthamiana leaves, and identifying host targets via yeast two-hybrid screening. The ∆VdCUE mutants showed reduced formation of melanized microsclerotia but no other obvious growth defects. Cotton plants infected with the ∆VdCUE mutants exhibited a significantly lower disease index and defoliation rate. VdCUE was confirmed to be secreted via a functional signal peptide, but it neither triggered cell death nor inhibited BAX-induced cell death. Three putative host targets were identified and supported by AI-based three-dimensional structural modeling, including tRNA-specific 2-thiouridylase, peptidyl-prolyl cis-trans isomerase, and 40S ribosomal protein, which may mediate VdCUE-dependent virulence regulation. These findings reveal VdCUE as a key virulence factor in V. dahliae, contributing to our understanding of its pathogenic mechanism. Full article

Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants composed of two or more fused benzene rings, posing serious threats to ecological environments and human health. Biodegradation is an efficient, economical, and sustainable approach for remediating PAHs pollution. In our previous work, we isolated and characterized a PAH-degrading bacterium, Burkholderia sp. FM-2. FM-2 demonstrated strong tolerance and efficient degradation capacity toward various PAHs, achieving 81.98% degradation of 2 mM phenanthrene within 3 days, and over 58% degradation of 2 mM fluorene, dibenzofuran, and dibenzothiophene under the same conditions. Through combined genomic and transcriptomic analyses, a putative PAH degradation gene cluster was identified in the FM-2 genome. Phylogenetic and domain architecture analyses were conducted on seven oxygenase genes within the cluster. Using AlphaFold 3, we predicted the three-dimensional structure of the downstream transport protein OmpW and proposed a potential transmembrane channel for PAHs uptake. To eliminate the phenanthrene degradation intermediate 1-hydroxy-2-naphthoic acid, a genetically engineered strain FM-2::nahG was constructed by heterologous expression of the salicylate hydroxylase gene (nahG). The modified strain completely abolished the accumulation of 1-hydroxy-2-naphthoic acid and achieved complete mineralization of phenanthrene. This study not only reveals the molecular basis of PAHs degradation in Burkholderia sp. FM-2 but also demonstrates the potential of metabolic engineering to enhance biodegradation ability, providing a promising microbial candidate for the bioremediation of PAH-polluted environments. Full article

The electronic and magnetic properties of lanthanide-doped GaN monolayers (Ln = La, Pr, Nd, Pm, Eu, and Gd) have been systematically investigated using density functional theory within the GGA-PBE approximation. Our results demonstrate that all Ln dopants except La introduce spin polarization and half-semiconductor behavior into the GaN monolayer. The observed magnetism primarily arises from unpaired 4f electrons, yielding magnetic moments of 2.0, 3.0, 4.0, 6.0, and 7.0 μ_B for Pr, Nd, Pm, Eu, and Gd, respectively. While La-, Pr-, and Gd-doped systems retain the indirect band gap characteristic of pristine GaN, an indirect-to-direct band gap transition occurs under biaxial tensile strains exceeding 2%. In contrast, Nd, Pm, and Eu doping directly induce a direct band gap without applied strain. Notably, under 6% tensile strain, the Pm- and Eu-GaN systems exhibit half-metallic and metallic properties, respectively. These tunable electronic and magnetic properties suggest that Ln doping offers a promising strategy for designing functional two-dimensional GaN-based electronic and spintronic devices. Full article

Background: Right ventricular (RV) strain using two-dimensional speckle tracking is a reliable and clinically significant tool for detecting RV systolic dysfunction, but it varies by age, vendor, and software. Objectives: To establish pediatric age-specific normal values and Z-score equations for biventricular strain using GE Healthcare equipment and software. Methods: Children 0–18 years with structurally and functionally normal hearts, who visited the Wilhelmina Children’s Hospital Utrecht between October 2020 and December 2023, were retrospectively included and divided into age groups: 0 years, 1–4 years, 5–9 years, 10–13 years, and 14–18 years. Left ventricular (LV) and RV global longitudinal strain (GLS) and RV free wall longitudinal strain (FWGLS) were analyzed. Results: We included 129 subjects (57% male) (0 years: n = 17; 1–4 years: n = 22; 5–9 years: n = 34; 10–13 years: n = 35; 14–18 years: n = 20). Low R² values were strain-adjusted for age, height, and body surface area (all < 0.3), and the sample size limited Z-score equation reliability. Therefore, data are presented as mean ± SD or median [IQR] stratified by age. LV GLS, RV GLS, and RV FWGLS showed a nonlinear relationship with age, peaking at the 1–4 years age group and decreasing with age. Conclusions: LV GLS, RV GLS, and RV FWGLS showed age-related differences in children using GE equipment and software, which highlights the importance of age-specific normal strain values, including Z-score equations as a function of age. Full article

The results of strain-induced crystallization (SIC) studies on natural rubber compounds containing different amounts of carbon black and silica are reported. Two-dimensional wide-angle X-ray diffraction (2D WAXD) experiments were performed to quantify the degree of SIC at ambient and enlarged temperatures. The influence of temperature and filler system on the degree of crystallinity of natural rubber was investigated, since the estimated temperatures in truck tire treads are in the range 60–80 °C. Interestingly, the degree of crystallinity for silica-filled natural rubber compounds was commonly at least similar or higher compared to carbon black-filled compounds with identical filler mass fraction. In addition, it was demonstrated that the temperature dependence of natural rubber compounds containing silica and carbon black is also similar. In both cases the SIC disappeared slightly above 100 °C. Hence, it was concluded that the SIC behavior is most likely not the decisive factor for the different abrasion resistance of silica- and carbon black-reinforced natural rubber compounds for truck tire treads. This is an important insight considering the rising demand for sustainable rubber compounds for truck tire treads with low CO₂ emissions as well as reduced abrasion. Full article

The thermal, thermomechanical, and viscoelastic properties of continuous unidirectional (UD) glass fiber/high-density polyethylene (GF/HDPE) and ultra-high-molecular-weight polyethylene/high-density polyethylene (UHMWPE/HDPE) tapes are characterized in this paper in order to support their use in extreme environments. Unlike prior studies that focus on short-fiber composites or limited thermal conditions, this work examines continuous fiber architectures under five operational environments derived from Army Regulation 70-38, reflecting realistic defense-relevant extremes. Differential scanning calorimetry (DSC) was used to identify melting transitions for GF/HDPE and UHMWPE/HDPE, which guided the selection of test conditions for thermomechanical analysis (TMA) and dynamic mechanical analysis (DMA). TMA revealed anisotropic thermal expansion consistent with fiber orientation, while DMA, via strain sweep, temperature ramp, frequency sweep, and stress relaxation, quantified their temperature- and time-dependent viscoelastic behavior. The frequency-dependent storage modulus highlighted multiple resonant modes, and stress relaxation data were fitted with high accuracy (R² > 0.99) to viscoelastic models, yielding model parameters that can be used for predictive simulations of time-dependent material behavior. A comparative analysis between the two material systems showed that UHMWPE/HDPE offers enhanced unidirectional stiffness and better low-temperature performance. At the same time, GF/HDPE exhibits lower thermal expansion, better transverse stiffness, and greater stability at elevated temperatures. These differences highlight the impact of fiber type on thermal and mechanical responses, informing material selection for applications that require directional load-bearing or dimensional control under thermal cycling. By integrating thermal and viscoelastic characterization across realistic operational profiles, this study provides a foundational dataset for the application of continuous fiber thermoplastic tapes in structural components exposed to harsh thermal and mechanical conditions. Full article