Search Results (6,595)

SiC/Al matrix composites are prone to forming brittle Al₄C₃ phase via interfacial reactions during fabrication, which severely limits their mechanical properties and engineering applications. Microalloying is an effective method to inhibit this brittle phase, yet the interfacial mechanism of alloying elements at the atomic scale remains unclear. Centered on molecular dynamics simulation combined with experimental verification, this study systematically investigates the laws of Fe and Ni microalloying on the interface regulation and mechanical property optimization of SiC/Al composites. Simulation results show that Fe and Ni atoms tend to segregate at the SiC/Al interface, which can suppress interfacial reactions, promote dislocation nucleation and proliferation, induce new dislocation types, and achieve the synergistic improvement of strength and ductility—with Ni exhibiting a more prominent strengthening effect. Composites prepared by the pressure infiltration-hot extrusion process show no Al₄C₃ phase in phase detection. Mechanical property tests confirm that Fe and Ni microalloying can effectively enhance the comprehensive performance of the materials, among which Ni increases the strength–ductility product by 54%. This study clarifies the interfacial regulation mechanism of Fe and Ni microalloying at the atomic scale, providing theoretical guidance and experimental support for the microalloying design of SiC/Al composites. Full article

Hydrogen is frequently incorporated in alkaline-earth oxides during crystal growth or post-deposition annealing. For MgO, several studies in the past showed that interstitial monatomic hydrogen can also favourably bind with oxygen vacancies to form stable substitutional defect complexes (substitutional hydrogen or U-defect centers). The present study reports first-principles density-functional calculations of the formation energies of both interstitial and substitutional forms of the hydrogen impurity in MgO. Determination of the site-resolved densities of electronic states allowed for a detailed identification of the nature of the impurity-induced levels, both in the valence-energy region and inside the band gap of the host. The stability and diffusion mechanisms of both hydrogen defects was also studied with the aid of nudged elastic-band (NEB) calculations. Interstitial hydrogen was found to be an amphoteric defect with the lower formation energy for any realistic environment conditions (temperature and oxygen partial pressure). The NEB calculations showed that it is a fast-diffusing species when it is thermodynamically stable as a positively-charged state (bare proton). In contrast, the hydrogen-vacancy complex is a shallow donor, extremely stable against dissociation and virtually immobile as an isolated defect. Its formation is found to be favoured for a range of mid-gap Fermi-level positions where positively-charged interstitial hydrogen and neutral oxygen vacancies (F centers) are both thermodynamically stable low-energy defects. The present findings are consistent with the established consensus on the electrical activity of hydrogen in MgO as well as with experimental observations reporting the remarkable thermal stability of substitutional hydrogen defects and their ability to act as electron traps. Full article

Salinity has been recognized as one of the major environmental stresses that restrict the growth and quality of celery (Apium graveolens L.). Therefore, this study investigates the impact of different NaCl concentrations on celery growth and photosynthetic characteristics, as well as the potential regulatory role of exogenous trehalose application in mitigating the stress-induced effects. The results indicated that an increase in NaCl concentration from 50 to 200 mM markedly inhibited the growth of celery plants compared to that under control conditions. The application of different concentrations of trehalose mitigated the inhibitory effects of salt stress (100 mM NaCl) on celery growth and photosynthesis. Among the different trehalose treatments, T3 (10 mM trehalose) exhibited the most significant effects, increasing the aboveground biomass, belowground biomass, plant height, chlorophyll a, chlorophyll b, total chlorophyll, and net photosynthetic rate compared to that of salt stress alone, respectively. Furthermore, trehalose treatments enhanced the various fluorescence parameters, including the maximum efficiency of PSII photochemistry (Fv/Fm), coefficient of photochemical quenching (qP), fluorescence intensity, and photosynthetic performance index (PIabs) under salt stress. Meanwhile, trehalose reduced intercellular carbon dioxide concentration, excess excitation energy (1-qP)/NPQ, heat dissipation per unit area (DIo/CSm), and energy dissipated per reaction center (DIo/RC). Additionally, the results of principal component analysis (PCA) and membership function comprehensive evaluation indicate that an appropriate concentration of trehalose positively alleviates the salnitiy-induced effects in celery. Overall, the T3 demonstrated the most promising effects on mitigating the effects of salt stress by decreasing the excess excitation energy of PSII in celery leaves through the heat dissipation pathway. This reduction lowers the excitation pressure on the reaction centers, enhances the activity of PSII reaction centers per unit cross-section, and improves photosynthesis activity, thereby improving the growth of celery plants under salt stress. Full article

Red sea bream (Pagrus major) aquaculture represents one of the most economically important marine aquaculture industries in Japan and East Asia. However, viral diseases, particularly those caused by red sea bream iridovirus (RSIV), pose a serious threat to aquaculture production in this region. In this study, we applied high-hydrostatic-pressure (HHP) refolding technology to develop a recombinant vaccine targeting the RSIV major capsid protein (MCP). The recombinant MCP (RSIV-rMCP) expressed in Escherichia coli was insoluble; however, HHP treatment under alkaline (pH 10) conditions in the presence of arginine successfully solubilised the protein while preserving its structural integrity. The solubilised protein (HHP–RSIV-rMCP) induced strong RSIV-specific IgM responses and enhanced disease resistance in red sea bream. In contrast, sera from fish immunised with a commercial formalin-inactivated vaccine exhibited minimal reactivity to HHP–RSIV-rMCP but reacted significantly to formalin-treated HHP–RSIV-rMCP. These results indicate that the HHP–RSIV-rMCP vaccine induces conformation-specific IgM antibodies and that structural preservation is crucial for maintaining antigenicity. Collectively, our findings demonstrate that HHP refolding technology is an effective strategy for preparing structurally preserved antigens. Full article

Severe mitral regurgitation (MR) is one of the most common valvular heart diseases and is frequently associated with advanced left ventricular (LV) systolic dysfunction. Transcatheter edge-to-edge repair (TEER) offers effective symptom relief but may induce abrupt hemodynamic changes leading to afterload mismatch and acute LV failure. Levosimendan may help mitigate this complication by improving contractility, yet evidence supporting its use in this setting is scarce. Therefore, the aim of this study was to systematically evaluate the evidence on the effects of Levosimendan in patients with severe MR and LV dysfunction undergoing TEER. We performed a comprehensive search of PubMed, Embase, Scopus, and Google Scholar. Primary outcomes were postprocedural LV ejection fraction (LVEF) and systolic pulmonary artery pressure (sPAP). Secondary outcomes included procedural success, procedure duration, and in-hospital complications. Five studies comprising 315 patients (n = 141 Levosimendan, n = 174 controls) met the inclusion criteria. Pooled analysis showed no significant difference in postprocedural LVEF between Levosimendan-treated patients and controls (mean difference 0.45%, 95% CI [−1.46–2.35] p = 0.65) and no significant change from baseline. Similarly, postprocedural sPAP did not differ significantly. Procedural success was higher with Levosimendan, and procedure duration was shorter. These hypothesis-generating findings highlight the need for larger, prospective randomized trials to clarify the role of Levosimendan in this setting. Full article

The paper deals with the design of forward-inclined blades, where “forward inclination” is intended as the design-dependent amount of forward sweep to be incorporated in non-free-vortex blades to restore quasi-2D flow behaviour within the rotor passages. The aim of the work is to assess the effectiveness of this design modification in a 0.5 hub-to-tip ratio fan with radially stacked blades that induce a roughly constant swirl velocity at the rotor exit. To this end, the original blade has been modified by incorporation of a forward sweep amount that translates into a forward-inclined design, defined in accordance with a method suggested by the authors. Both the original and forward-inclined design were preliminary assessed by CFD and finally verified by experiments. The forward-inclined design demonstrated experimentally to improve the pressure rise and efficiency of the original fan in the whole operation range with ca. 10% gain at design operation. Full article

Bolted connections are critical in deep-sea engineering, yet classical theories (such as VDI 2230) implicitly assume atmospheric pressure conditions, neglecting the volume contraction of components due to hydrostatic pressure. This fundamental flaw hinders accurate prediction of preload retention—especially when bolts and clamped components exhibit differential compressibility (a common scenario in practical applications). To bridge this scientific gap, this paper establishes the first analytical model for bolt preload under pressure-induced volumetric contraction based on deformation coordination relations. The derived closed-form expressions explicitly quantify residual preload as a function of deep-sea ambient pressure, component bulk modulus, and geometric parameters. Model predictions closely match finite element calculations, showing that stainless steel bolts clamping aluminum alloys under 110 MPa pressure can experience up to a 40% preload reduction. This theoretical framework extends classical bolt connection mechanics to high-pressure environments, providing a scientific basis for optimizing deep-sea connection designs through material matching and dimensional control to effectively mitigate pressure-induced preload loss. Full article

To address the impact-induced damage to concrete pile foundations of transmission structures caused by nearby blasting vibrations, this study investigates the dynamic splitting tensile behavior of an environmentally friendly lightweight rubberized concrete—Rubber-Toughened Ceramsite Concrete (RTCC)—under impact loading. Quasi-static tests show that the static splitting tensile strength increases first and then decreases with increasing rubber content, reaching a maximum value of 2.01 MPa at a 20% replacement ratio. Drop-weight impact tests indicate that RTCC20 exhibits the highest peak impact force (42.48 kN) and maximum absorbed energy (43.23 J) within the medium strain-rate range. Split Hopkinson Pressure Bar (SHPB) tests further demonstrate that RTCC20 shows the highest strain-rate sensitivity. Overall, RTCC with 20% rubber content provides the best comprehensive performance, achieving a favorable balance between strength and toughness across the entire strain-rate range. These findings offer experimental support for applying RTCC to blast-vibration-resistant transmission structure foundations. Full article

Diabetes mellitus (DM) is a chronic disease characterised by chronic hyperglycaemia due to a defect in the production of or cell insensitivity to insulin. If left untreated, it might result in severe side effects such retinal, nephropathy, neuropathy, and cardiovascular disease. Extensive research has been made to develop more effective and less expensive alternatives to existing treatment regimes. This review aims to evaluate research done thus far to test the effect of Saccharomyces boulardii (S. boulardii or Sb) in treating DM and its complications. Searches were conducted using Scopus, Web of Science, PubMed and Google Scholar on 26 July 2025. Overall, 227 articles were identified, and 5 fulfilled the inclusion criteria. Results extracted were from two models of diabetes (type 1 and 2) and two strains of Sb. In type 1 diabetes models, a significant reduction in glycaemia was observed, while in type 2 diabetes models, a non-significant effect was noted, depending on the strain used. Furthermore, an improvement in cardiac function was observed through reduced heart rate variability, a decrease in blood pressure, an increase in C-peptide and hepatic glycogen stores, enhanced liver healing, a nephroprotective effect, as well as a reduction in oxidative stress, blood triglyceride levels, and the inflammatory response. Administration of Sb induced positive modulation of the intestinal microbiota, with a decrease in pathobionts in the stools. Overall, the few studies evaluated indicate that the use of Sb appears to be a promising approach to improve the management of diabetes and its associated metabolic and related complications. The protocol of this review is registered in PROSPERO under ID CRD420251012919. Full article

Eucommia ulmoides, a tree species native to China, holds considerable medicinal, ecological, and industrial importance. However, the absence of an efficient and stable genetic transformation system poses significant challenges to gene function studies and molecular breeding in E. ulmoides. Protoplasts, which lack cell walls, serve as effective receptors for transient transformation and are thus ideal for genetic engineering research. In this study, the optimal conditions for callus induction were identified, and formation of the embryogenic callus was confirmed by histological analysis. Furthermore, we developed an efficient protoplast isolation and PEG-mediated transient transformation system using suitable embryogenic callus as the starting material. Our findings revealed that the optimal medium for inducing embryogenic callus was B5 + 1.5 mg/L 6-BA + 0.5 mg/L NAA + 30 g/L sucrose + 7 g/L agar (pH = 5.8). In this medium, the induction rate of callus achieved 97.50%, and the rate of embryogenic callus formation was 86.30%. For protoplast isolation, the best conditions involved enzymatic digestion with 1.5% cellulase R-10 and 1.0% macerozyme R-10 at an osmotic pressure of 0.6 M for 4 h, resulting in 1.82 × 10⁶ protoplasts/g FW with 91.13% viability. The highest transfection efficiency (53.23%) was attained when protoplasts were cultured with 10 µg of plasmid and 40% PEG4000 for 20 min. This study successfully established a stable and efficient system for protoplast isolation and transient transformation in E. ulmoides, offering technical support for exploring somatic hybridisation and transient gene expression in this species. Full article

During deepwater drilling operations in the Baiyun block of the eastern South China Sea, high-temperature and high-pressure formation leakage was frequently encountered. Traditional plugging materials lacked adequate stability under these conditions and failed to establish reliable plugs. As the development of the Baiyun Block progressed, it was found that the formation temperature at the BY5 area well reached 182.2 °C at a depth of 4527 m. At a depth of 5206 m, the bottom-hole temperature of the well increased to 223.81 °C, and the pressure rose to 10 MPa. An urgent need has emerged to develop a plugging system capable of operating stably under high-temperature and high-pressure conditions to enhance the safety and success rate of deepwater drilling. In this study, a high-temperature-resistant polymer for controlling leakage rate, an inorganic pressure-bearing particulate material with supporting capability, and a gel that gradually solidifies under high-temperature conditions were developed. Through systematic optimization, a synergistic plugging system was established. Laboratory evaluations demonstrated that the system maintained favorable fluidity and structural integrity under high-temperature and high-pressure conditions, rapidly constructed stable plugging layers across fractures of varying widths, and withstood high differential pressures while resisting backflow-induced erosion. The results indicate that the system exhibits significant plugging performance and strong potential for engineering application, providing reliable technical support for deepwater oil and gas development. Full article

Regular exercise enhances heart function and metabolism. The N6-methyladenosine (m⁶A) RNA modification is related to myocardial homeostasis, with the demethylase fat mass and obesity-associated protein (FTO) crucial for myocardial remodeling. However, its role in exercise-induced heart protection is unclear. We analyzed m⁶A levels and methylation enzymes to evaluate FTO changes in transverse aortic constriction (TAC) mice hearts after six weeks of treadmill exercise. Further in vivo experiments explored the effect of FTO. High-throughput sequencing identified the target gene enoyl-CoA delta isomerase 1 (Eci1). Cardiac-specific Eci1 knockout mice were used to assess the role of Eci1. The influence of FTO on Eci1 expression was explored by eliminating demethylase activity. The results showed that exercise increased FTO expression in TAC mice hearts. Reducing FTO in the heart diminishes exercise benefits. The differential m⁶A-modified genes in TAC mice hearts were enriched in fatty acid metabolism, with increased methylation of Eci1 m⁶A and decreased protein levels, leading to abnormal lipid accumulation. Exercise could reverse these effects. Eci1 knockout partially weakened exercise benefits. FTO regulated Eci1 expression via m⁶A modification, and inhibiting FTO demethylase activity blunted its protective effects on hypertrophic cardiomyocytes. Thus, FTO modulates Eci1 expression through m⁶A-dependent mechanisms, facilitates fatty acid metabolism and mitigates pressure overload-induced heart failure during exercise. Full article

The rapid advancement of Artificial Intelligence (AI) has profoundly transformed organizational systems, reshaping how employees interact with technology and adapt to changing work environments. However, the systemic mechanisms through which AI-induced technostress influences employee career growth remain insufficiently understood. Grounded in a socio-technical systems perspective, this study conceptualizes organizations as adaptive systems where technological, organizational, and human subsystems dynamically interact. We propose a dual-path framework that distinguishes between challenge-related technostressors (a resource-gain process) and hindrance-related technostressors (a resource-loss process), elucidating how AI-related pressures can simultaneously foster and hinder career development. Furthermore, employee resilience and organizational AI support are incorporated as systemic moderators that modulate the intensity of these effects within the human–AI–organization system. Using two-stage survey data from 326 matched pairs of employees and supervisors, results largely support the proposed model, with some pathways showing marginal significance. The findings reveal that AI challenge-related technostressors stimulate proactive adaptation and skill development, whereas hindrance-related technostressors generate anxiety and insecurity, thereby impeding growth. This research extends systems theory by demonstrating how technostressors function as an emergent property of human–technology interactions and provides actionable insights for designing more adaptive and resilient socio-technical work systems. Full article

Calcium deposition within soft tissues is a significant pathological process, bearing significant implications for animal and human health. It is classified into four categories, including dystrophic, metastatic, idiopathic, and iatrogenic. It involves multiple molecular mechanisms. Vascular calcification includes medial artery mineralization, siderocalcinosis in equine cerebral arteries, and vitamin D-induced arterial mineralization in multiple species. Renal and urinary mineralization occurs with kidney disease, uremic gastropathy, and ethylene glycol toxicity. Calcinosis cutis is associated with renal insufficiency and systemic fungal infections and is commonly observed in dogs with hyperadrenocorticism, while calcinosis circumscripta occurs at pressure points secondarily to trauma. Multiple pathogens are responsible for soft tissue calcification; they can be zoonotic and include Mycobacterium spp., Brucella spp., Toxoplasma gondii, and Echinococcus granulosus, underscoring the translational role of veterinary medicine surveillance from a public health standpoint. In addition, the placental chorioallantois is frequently affected by idiopathic or infection-induced calcification, highlighting the convergence of metabolic dysregulation and infectious mechanisms. Tissue calcifications provide valuable insights into disease mechanisms and diagnostic challenges, with comparative pathology serving as a powerful tool to enhance our understanding of these processes from a One Health standpoint. Full article

This study employs computational fluid dynamics (CFD) to investigate the aerodynamic performance and static stability of hybrid wing aircraft, considering the interference of counter-rotating embedded propellers. Extensive numerical verification has been carried out, including comparisons with NASA’s high-lift propeller (HLP) data. Three configurations—no propeller, counter-rotating inboard-upwash (CNIU) and counter-rotating outboard-upwash (CNOU) are defined to analyze the aerodynamic force/moment characteristics and flow field structures over a range of angles of attack from −6° to 26°, in conjunction with crosswind velocities of 0, 5, 10, and 15 m/s. The propeller-induced slipstream alters the aircraft’s fundamental performance by modifying wing pressure distributions and vortex systems. Specifically, the CNIU configuration increases the low-pressure areas on both the fuselage and outer wing upper surfaces, enhancing the lift-to-drag ratio by 28.4% at low angles of attack. In contrast, the CNOU configuration improves longitudinal steady-static margin by 27.4% under typical conditions and demonstrates superior lateral static stability under 10 m/s leftward crosswind conditions. For engineering applications in the aerodynamic design of such aircraft, the CNIU configuration is recommended for high cruise efficiency, whereas the CNOU configuration is preferred for flight stability. Full article