Search Results (3,575)

Metal nitride coatings have been considered as a promising approach to improve the performance of metal bipolar plates for proton exchange membrane fuel cells (PEMFCs). In this study, NbN_x coatings with three different ratios of N₂/Ar (1:2, 1:1 and 3:1) were prepared on TC4 alloy substrates using the double glow plasma alloying technology. The NbN_x coatings are homogeneous and dense, and the phase of the coating transforms from hexagonal β-Nb₂N to δ′-NbN phase as the nitrogen content increases. All coatings demonstrate high protective efficiency, with the coating (N₂/Ar ratio of 3:1) displaying the lowest current density of 8.92×10⁻⁶ A/cm² at a working voltage of 0.6 V. The EIS results also show that this coating has the best corrosion resistance. Notably, it also presents the lowest interfacial contact resistance of 7.29 mΩ·cm² at 1.5 MPa and good hydrophobicity. More importantly, this study provides a new idea and method for corrosion-resistant coatings of metal bipolar plates for PEMFC applications. Full article

We have developed a generalisable machine learning framework for reservoir quality prediction in deeply buried clastic systems. Applied to the Lower Jurassic deltaic sandstones of the Tilje Formation (Halten Terrace, North Sea), the approach integrates sedimentological facies modelling with mineralogical and petrophysical prediction in a single workflow. Using supervised Extreme Gradient Boosting (XGBoost) models, we classify reservoir facies, predict permeability directly from standard wireline log parameters and estimate the abundance of porosity-preserving grain coating chlorite (gamma ray, neutron porosity, caliper, photoelectric effect, bulk density, compressional and shear sonic, and deep resistivity). Model development and evaluation employed stratified K-fold cross-validation to preserve facies proportions and mineralogical variability across folds, supporting robust performance assessment and testing generalisability across a geologically heterogeneous dataset. Core description, point count petrography, and core plug analyses were used for ground truthing. The models distinguish chlorite-associated facies with up to 80% accuracy and estimate permeability with a mean absolute error of 0.782 log(mD), improving substantially on conventional regression-based approaches. The models also enable prediction, for the first time using wireline logs, grain-coating chlorite abundance with a mean absolute error of 1.79% (range 0–16%). The framework takes advantage of diagnostic petrophysical responses associated with chlorite and high porosity, yielding geologically consistent and interpretable results. It addresses persistent challenges in characterising thinly bedded, heterogeneous intervals beyond the resolution of traditional methods and is transferable to other clastic reservoirs, including those considered for carbon storage and geothermal applications. The workflow supports cost-effective, high-confidence subsurface characterisation and contributes a flexible methodology for future work at the interface of geoscience and machine learning. Full article

Boron (B) is widely used as a neutron-absorbing nuclide and has significant applications in the nuclear industry. B₄C/Al composites combine the high hardness of B₄C with the ductility of Al, making them commonly used neutron-absorbing materials. Under current preparation methods, the poor wettability and low reactivity of B₄C with molten Al limit its effective incorporation into the matrix, and the addition of B₄C in B₄C/Al composites has reached its threshold limit, making it difficult to achieve breakthrough improvements in neutron absorption performance. However, incorporating additional B elements into the B₄C/Al composite can break this limit, effectively enhancing the material’s neutron absorption performance. Nevertheless, research on the impact of this addition on the mechanical properties of the composite remains unclear. The requirements for B₄C/Al composites as spent fuel storage and transportation devices include high mechanical strength and certain machinability. This study fabricated B₄C/Al composites with varying B contents (5 wt.%, 10 wt.%, and 15 wt.%), and the influence of B addition on the microstructure and mechanical properties of B₄C/Al composites was investigated. The results demonstrate that the composites exhibit a density of approximately 99% with well-established interfacial bonds. Increasing B content leads to a higher quantity of interfacial reaction products Al₃BC and AlB₂, enhancing the Vickers hardness to 370.93 HV. The bending strength and fracture toughness of composites with 5 wt.% and 15 wt.% B addition decreased, whereas those with 10 wt.% B exhibited excellent resistance to crack growth and high-temperature plastic deformation due to a high content of ductile phase. Full article

Intracranial aneurysms are a serious cerebrovascular condition with a risk of subarachnoid hemorrhage due to rupture, leading to high mortality and morbidity. Flow Diverter Stents (FDSs) have become an important endovascular treatment option for unruptured large or wide-neck aneurysms. Hemodynamic factors significantly influence treatment outcomes in aneurysms treated with FDSs, and Computational Fluid Dynamics (CFD) has been widely used to evaluate post-deployment flow characteristics. However, conventional wire-resolved CFD methods require extremely fine meshes to reconstruct individual FDS wires, resulting in prohibitively high computational costs. This severely limits their feasibility for use in clinical treatment planning, where fast and robust simulations are essential. To address this limitation, we developed a computationally efficient CFD method that incorporates a porous media model accounting for local variations in wire density after FDS deployment. Based on Virtual Stent Simulation, the FDS region was defined as a hollow cylindrical domain with spatially varying resistance derived from cell-specific wire density. We validated the proposed method using 15 clinical cases, demonstrating close agreement with conventional wire-resolved CFD results. Relative errors in key hemodynamic parameters, including velocity, shear rate, inflow rate, and turnover time, were within 5%, with correlation coefficients exceeding 0.98. The number of grid elements, the data size, and total analysis time were reduced by over 90%. The method also allowed comparison between Total-Filling (OKM Grade A) and Occlusion (Grade D) cases, and evaluation of different FDS sizing, positioning, and coil-assisted strategies. The proposed method enables practical and efficient CFD analysis following FDS treatment and supports hemodynamics-based treatment planning of aneurysms. Full article

γ-TiAl alloy is a lightweight high-temperature structural material, featuring low density, excellent high-temperature strength, creep resistance, etc. It is a key material in the aerospace field. However, the essential defects of γ-TiAl alloys, such as poor room-temperature plasticity and low fracture toughness, have become the biggest obstacles to their practical application. Therefore, in this paper, the physical mechanism of modification of the mechanical properties and electronic structure of γ-TiAl alloys by doping with Sc, V, and Si was investigated by using the first-principles pseudopotential plane wave method. This paper specifically calculates the geometric structure, phonon spectrum, mechanical properties, electron density of states, Mulliken population analysis, and differential charge density of γ-TiAl alloys before and after doping. The results show that after doping, the structural parameters of γ-TiAl have changed significantly, and the doping models all have thermodynamic stability. The B, G, and E values of the doped system are, respectively, within the range of 94–112, 57–69, and 143–170 GPa, indicating that the material’s ability to resist compressive deformation is weakened. Moreover, the B/G values change from 1.5287 to 1.6350, 1.7279, and 1.6327, respectively, and a transformation from brittleness to plasticity occurs. However, it is still lower than the critical value of 1.75, indicating that the doped γ-TiAl alloy material retains its high-strength characteristics while also exhibiting a certain degree of toughness. The total elastic anisotropy index of the doped system increases, and the degree of anisotropy of mechanical behavior significantly increases. The total electron density of states diagram indicates that γ-TiAl alloys possess conductive properties. The covalent interactions between doped atoms and adjacent atoms have been weakened to varying degrees, which is manifested as a significant change in the charge distribution around each atom. The above results indicate that the doping of Sc, V, and Si can effectively tune the mechanical properties and electronic structure of γ-TiAl alloys. Full article

High-density tactile sensor arrays that replicate human touch could restore texture perception in paralyzed individuals. However, conventional tactile sensor arrays face inherent trade-offs between spatial resolution, sensitivity, and crosstalk suppression due to microstructure size limitations and signal interference. To address this, we developed a tactile sensor featuring 10 μm-scale pyramid tips that achieve ultra-high sensitivity (8.082 kPa⁻¹ in 0.2–0.5 kPa range). By integrating a flexible resistive sensing layer with a 256 × 256 active-matrix thin-film transistor (TFT) readout system, our design achieves 500 μm spatial resolution—surpassing human fingertip discrimination thresholds. The sensor demonstrates rapid response (125 ms), exceptional stability (>1000 cycles), and successful reconstruction of 500 μm textures and Braille patterns. This work establishes a scalable platform for high-fidelity tactile perception in static fine texture recognition. Full article

Electrochemical water splitting for hydrogen production is considered a key pathway for achieving sustainable energy conversion. However, the sluggish reaction kinetics of the oxygen evolution reaction (OER) and high overpotentials severely hinder the large-scale application of water electrolysis technology. Nickel–iron layered double hydroxide (NiFe-LDH) has gained attention as a promising non-precious metal OER catalyst due to its abundant active sites and good intrinsic activity. However, its relatively low conductivity and charge transfer efficiency limit the improvement of catalytic performance. Therefore, this study used a simple hydrothermal method to generate a NiFe-LDH/Cs_0.32WO₃ heterojunction composite catalyst, relying on the excellent electronic conductivity of Cs_0.32WO₃ to improve overall charge transfer efficiency. According to electrochemical testing results, the modified NiFe-LDH/Cs_0.32WO₃-20 mg achieved a low overpotential of 349 mV at a current density of 10 mA cm⁻², a Tafel slope of 67.0 mV dec⁻¹, and a charge transfer resistance of 65.1 Ω, which represent decreases of 39 mV, 23.1%, and 40%, respectively, compared to pure NiFe-LDH. The key to performance improvement lies in the tightly bonded heterojunction interface between Cs_0.32WO₃ and NiFe-LDH. X-ray photoelectron spectroscopy (XPS) shows a distinct interfacial charge transfer phenomenon, with a notable negative shift of the W4f peak (0.85 eV), indicating the directional transfer of electrons from Cs_0.32WO₃ to NiFe-LDH. Under the influence of the built-in electric field within the heterojunction, this interfacial charge redistribution improved the electronic structure of NiFe-LDH, increased the proportion of high-valent metal ions, and significantly enhanced the OER reaction kinetics. This study provides new insights for the preparation of efficient heterojunction electrocatalysts. Full article

Adenosine deaminase (ADA) is one of the most important enzymes in nucleoside metabolism, regulating the levels of adenosine and deoxyadenosine triphosphate (ADT/dATP) on either side of the cell membrane. This small protein (weighing approximately 40 kDa) exhibits deamination properties towards other pharmaceuticals built on adenine as the leading structure, which requires co-administration of ADA inhibitors. 3′-deoxyadenosine (Cordycepin, Cord) is an active compound isolated from the fungus Cordyceps, which has been used in traditional Chinese medicine for over 2000 years. Its anticancer activity is likely related to the inhibition of primer elongation of lagging strands during genetic information replication. Unfortunately, Cord is rapidly deaminated by ADA into inactive 3′-deoxyinosine, necessitating its co-administration with ADA inhibitors. Here, for the first time, the synthesis and discussion of the oxidised form of Cord are presented. The 7,8-dihydro-8-oxo-3′-deoxyadenosine (Cord^OXO) exhibits high resistance to ADA because of its syn conformation, as shown experimentally by UV spectroscopy and RP-HPLC monitoring. Theoretical Density Functional based Tight Binding (DFTB) studies of the Michaelis complex ADA-Cord^OXO have revealed significant distance increases between the “active” H₂O molecule and C6 of the 8-oxo-adenine moiety of Cord^OXO, i.e., 4 Å as opposed to 2.7 Å in the cases of ADA-dAdo and Cord. In conclusion, it can be postulated that the conversion of Cord to Cord^OXO enhances its therapeutic potential; however, this needs to be verified in vitro and in vivo. It should be emphasised that the therapeutic effect, if any, can be achieved theoretically without ADA inhibitors, e.g., pentostatin, thus reducing adverse effects. These promising preliminary results, presented here, warrant further investigations. Full article

The Qinghai–Tibet Plateau presents a unique challenge for infrastructure development due to its extreme geological and climatic conditions—high elevation, large diurnal temperature fluctuations, frequent freeze–thaw cycles, intense ultraviolet radiation, and seasonal precipitation. These factors greatly accelerate the weathering of rock materials, leading to aggregates with increased porosity, microcracking, and weakened mechanical properties. While the engineering implications of such degradation are evident, the underlying material science of weathered aggregates—particularly their microstructure–property relationships—remains insufficiently explored, necessitating further investigation to inform material selection and design. In this study, three representative types of weathered aggregates (silica-rich, carbonaceous, and alumina-rich), alongside unweathered natural aggregates, were examined through both macro-scale (density, water absorption, crushing value, abrasion resistance) and micro-scale (scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS)) analyses. To capture the material evolution, we introduced a simplified classification framework based on the Si/Al ratio and porosity and applied a gray entropy correlation model to quantify the coupling between microstructure and mechanical performance. Results show that weathering reduces the Si/Al ratio from 2.45 to 1.82, increases porosity from 4.2% to 12.7%, enlarges the average pore size to 0.85 μm, raises microcrack density to 1.40 μm/μm², and increases the proportion of connected pores to 68.2%. These microstructural degradations correlate with decreased aggregate density, increased water absorption (up to 8.0%), higher crushing value (27.4%), and abrasion resistance loss (26.0%). Based on these findings, a weathered aggregate classification and pretreatment strategy is proposed, offering a practical reference for engineers to improve material performance in high-altitude road construction. Full article

Perovskite solar cells (PSCs) have emerged as a promising contender in photovoltaics, owing to their rapidly advancing power conversion efficiencies (PCEs) and compatibility with low-temperature solution processing techniques. Single-junction architectures reveal inherent limitations imposed by the Shockley–Queisser (SQ) limit, motivating adoption of a dual-absorber structure comprising Cs₄CuSb₂Cl₁₂ (CCSC) and Cs₂TiI₆ (CTI)—lead-free perovskite derivatives valued for environmental benignity and intrinsic stability. Comprehensive theoretical screening of 26 electron/hole transport layer (ETL/HTL) candidates identified SrTiO₃ (STO) and CuSCN as optimal charge transport materials, producing an initial simulated PCE of 16.27%. Subsequent theoretical optimization of key parameters—including bulk and interface defect densities, band gap, layer thickness, and electrode materials—culminated in a simulated PCE of 30.86%. Incorporating quantifiable practical constraints, including radiative recombination, resistance, and FTO reflection, revised simulated efficiency to 26.60%, while qualitative analysis of additional factors follows later. Furthermore, comparing multiple algorithms within this theoretical framework demonstrated eXtreme Gradient Boosting (XGBoost) possesses superior predictive capability, identifying CTI defect density as the dominant impact on PCE—thereby underscoring its critical role in analogous architectures and offering optimization guidance for experimental studies. Collectively, this theoretical research delineates a viable pathway toward developing stable, environmentally sustainable PSCs with high properties. Full article

Titanium and its alloys are widely used in orthopedics because of their excellent mechanical properties and biocompatibility; however, their bioinert surface results in sluggish osseointegration and renders implants susceptible to bacterial infection. This study innovatively constructed a “CHP-Ti-MAO” composite coating, which aims to simultaneously improve early osseointegration and antibacterial performance. CHP micron coatings coated with hydroxyapatite (HA) and curcumin (Cur) at different PLGA concentrations (50%, 100%, and 150%) were deposited on the basis of calcium–phosphorus ceramic coatings prepared by micro-arc oxidation (MAO) following the emulsification-solvent volatilization method. It was found that increasing the concentration of PLGA can increase the particle size of the coating, enhance the hydrophilicity, and significantly improve the sustained release performance of the drug. Among them, the 100% PLGA concentration group performed the best: the drug-release half-life reached 75 h, and the corrosion current density was the lowest (9.5 × 10⁻⁹ A/cm²), showing the best corrosion resistance. This group of coatings has a strong and long-term antibacterial effect on Escherichia coli, with an antibacterial rate of more than 95% at 24 h and more than 99% by day 17. The hemolysis rate of all coatings was lower than 5%, indicating good biocompatibility. This study confirmed that 100% CHP-Ti-MAO composite coating successfully solved the limitations of excessive pore size and insufficient antibacterial persistence of an MAO layer and also had excellent slow-release, corrosion resistance, and high-efficiency antibacterial capabilities, which provided an important basis for the development of a new generation of multifunctional titanium-based implants. Full article

Objective: This study systematically examined the effects of recreational football on body composition and cardiometabolic health in overweight or obese individuals via subgroup analyses of potential moderators. Methods: A systematic search was conducted across six databases (PubMed, Web of Science, the Cochrane Library, CNKI, VIP, and Wanfang Data) in May and July 2025 to identify controlled trials evaluating recreational football among overweight or obese individuals. A meta-analysis was performed to pool the effect estimates, reported as standardized mean differences (SMDs), with heterogeneity explored through subgroup analyses. Results: Recreational football interventions across 32 studies (1126 participants, aged 11–68) led to significant improvements in body composition and cardiometabolic health. The training programs ranged from 4 to 48 weeks, with sessions lasting 4 to 30 min. Key body composition outcomes included reductions in body weight (SMD = −0.51), body mass index (SMD = −0.41), body fat percentage (SMD = −0.53), fat mass (SMD = −0.40), and waist circumference (SMD = −1.43), along with increases in lean body mass (SMD = 0.18). The effects were more pronounced in females and younger participants (≤18 years). Cardiometabolic benefits included reductions in systolic blood pressure (SMD = −0.59), diastolic blood pressure (SMD = −0.75), and mean arterial pressure (SMD = −0.91), as well as resting heart rates (SMD = −0.85), especially among females, obese males, and those subject to shorter rest intervals. Participants’ peak oxygen uptake also improved (SMD = 0.81). Concerning lipid metabolism, participants’ total cholesterol, low-density lipoprotein cholesterol, and triglycerides decreased significantly, particularly in females, younger and obese individuals, and those who trained more than twice per week. High-density lipoprotein cholesterol increased significantly only in females and those involved in frequent training. In regard to glucose metabolism, participants’ fasting insulin declined (SMD = −0.47), especially in regard to programs exceeding 12 weeks, whereas no significant changes were observed in fasting blood glucose, glycated hemoglobin, or the homeostatic model assessment of insulin resistance. According to the GRADE assessments, the certainty of the evidence ranged from very low to moderate across these outcomes. Conclusions: Recreational football improves the body composition and cardiometabolic health in overweight or obese individuals, resulting in reductions in adiposity, blood pressure, lipids, and insulin, with greater benefits observed in females, younger individuals, and those engaging in more frequent training. These findings support its potential as a practical intervention for weight and cardiometabolic risk management, in both clinical and community settings. Full article

To reveal the effects of genotype–herbivore interactions on leaf quality, foliar variations in phytochemicals, morphoanatomy, and herbivory damage ratio were investigated in a Cyclocarya paliurus (Batalin) Iljinsk. (Juglandaceae) germplasm resources bank. Results showed less herbivory damage in genotypes with a higher leaf thickness, but more herbivory damage in genotypes with a higher leaf stomatal density. Herbivory damage ratios were significantly correlated with the contents of leaf secondary metabolites, whereas the response of secondary metabolites to insect attack was type-specific and varied between intact leaves and damaged leaves. Based on key indicators of leaf quality (contents of triterpenoids, flavonoids, polyphenols, pterocaryoside A, pterocaryoside B, and cyclocaric acid B), the investigated genotypes were divided into three distinct groups by integrating TOPSIS and cluster analysis, while four genotypes with slight insect damage demonstrated the prioritization for future applications. Our findings lay a foundation for further selection of its superior varieties with both insect resistance and high leaf quality. Full article

Sarcopenia, the progressive loss of skeletal muscle mass and function with age, significantly contributes to frailty and mortality in older adults. Notably, muscles do not age uniformly—some retain structure and strength well into old age. This review explores the mechanisms underlying differential resistance to muscle aging, with a focus on sarcopenia-resistant muscles. We analyzed current literature across molecular biology, genetics, and physiology to identify key regulators of muscle preservation during aging. Special attention was given to muscle fiber types, mitochondrial function, neuromuscular junctions, and satellite cell activity. Muscles dominated by slow-twitch (type I) fibers—such as the soleus, diaphragm, and extraocular muscles—demonstrate enhanced resistance to sarcopenia. This resilience is linked to sustained oxidative metabolism, high mitochondrial density, robust antioxidant defenses, and preserved regenerative capacity. Key molecular pathways include mTOR, PGC-1α, and SIRT1/6, while genetic variants in ACTN3, MSTN, and FOXO3 contribute to interindividual differences. In contrast, fast-twitch muscles are more vulnerable due to lower oxidative capacity and satellite cell depletion. Unique innervation patterns and neurotrophic support further protect muscles like extraocular muscles from age-related atrophy. Resistance to sarcopenia is driven by a complex interplay of intrinsic and extrinsic factors. Understanding why specific muscles age more slowly provides insights into muscle resilience and suggests novel strategies for targeted prevention and therapy. Expanding research beyond traditionally studied muscles is essential to develop comprehensive interventions to preserve mobility and independence in aging populations. Full article

ZrB₂-HfB₂ composites allow us to obtain materials characterized by the high chemical resistance characteristic of HfB₂ while reducing density and improving sinterability due to the presence of ZrB₂. Since boride composites are difficult-to-sinter materials. One way to achieve high density during sintering is to add phases that activate mass transport processes and, after sintering, remain as composite components that do not degrade and even improve some properties of the borides. The following paper is a comprehensive review of the effects of various and the most commonly used sintering aids, i.e., SiC, B₄C, WC, MoSi₂, and CrSi₂, on the thermo-chemical properties of the ZrB₂-HfB₂ composites. High-density composites with a complex phase composition dominated by (Zr,Hf)B₂ solid solutions were obtained using a hot pressing method. The tests showed differences in the properties of the composites due to the type of sintering additives used. From the point of view of the thermo-chemical properties, the best additive was silicon carbide. The composites containing SiC, when compared to the initial, pure borides, were characterized by high thermal conductivity λ (80–150 W/m·K at 20–1000 °C), a significantly reduced thermal expansion coefficient (CTE ~6.20 × 10⁻⁶ 1/K at 20–1000 °C), and considerably improved oxidation resistance (up to 1400 °C). Full article