Search Results (357)

Background/Objectives: This study aimed to investigate the associations of anthropometric characteristics with performance and potential biomarker changes resulting from a continuous 10 h ultra-marathon swimming effort in regional-level swimmers. Methods: Nine adult male swimmers (age: 43 ± 6 years) participated in a 10 h swim in a 50 m outdoor pool, self-managing their nutrition and hydration breaks. Pre- and post-swim measurements included body weight (BW), body fat percentage (BF%), limb lengths (LL), circumferences (C), lean mass (LM), body mass index (BMI), skinfold thicknesses, heart rate (HR) and blood pressure (BP). Results: A significant reduction was observed in bicep skinfold thickness (Fb) (p = 0.022), while both HR and systolic BP increased post-effort (p = 0.030 and p = 0.045, respectively). Also, most anthropometric parameters, such as BMI, LM, and some C, remained unchanged (p ≥ 0.05). A statistically significant negative correlation was found between post-swim hip circumference (Ph) and total swimming distance (r = –0.682, p = 0.043). Conclusions: While most anthropometric traits remained stable and unrelated to performance, isolated changes in specific biomarkers indicate a physiological response to prolonged exertion. Although pacing and nutritional strategies were not directly examined, observational data—such as consistent swimming rhythm, time allocation for active recovery (AR), and structured carbohydrate intake—suggest these factors may have contributed to performance maintenance and probably the lack of body composition differences after the ultra-marathon effort. These insights are interpretive and align with the existing literature, highlighting the need for future studies with targeted experimental designs. Full article

This study develops a one-pot anodic templating electrodeposition strategy using dual-cation-crosslinking and interpenetrating networks, coupled with pulsed electrical signals, to fabricate a vessel-mimetic multilayered tubular hydrogel. Typically, the anodic electrodeposition is performed in a mixture of sodium alginate (SA) and carboxymethyl chitosan (CMC), with the ethylenediaminetetraacetic acid calcium disodium salt hydrate (EDTA·Na₂Ca) incorporated to provide a secondary ionic crosslinker (i.e., Ca²⁺) and modulate the cascade reaction diffusion process. The copper wire electrodes serve as templates for electrochemical oxidation and enable a copper ion (i.e., Cu²⁺)-induced tubular hydrogel coating formation, while pulsed electric fields regulate layer-by-layer deposition. The dual-cation-crosslinked interpenetrating hydrogels (CMC/SA-Cu/Ca) exhibit rapid growth rates and tailored mechanical strength, along with excellent antibacterial performance. By integrating the unique pulsed electro-fabrication with biomimetic self-assembly, this study addresses challenges in vessel-mimicking structural complexity and mechanical compatibility. The approach enables scalable production of customizable multilayered hydrogels for artificial vessel grafts, smart wound dressings, and bioengineered organ interfaces, demonstrating broad biomedical potential. Full article

Infectious wounds pose formidable clinical challenges due to hypoxia, exacerbated inflammation, and persistent microbial colonization. To address this, we developed a bioinspired multifunctional hydrogel (PTDPs) through the in situ freeze-thaw co-assembly of polyvinyl alcohol (PVA), tea polyphenols (TP), polydopamine (PDA), and marine-derived self-assembling peptides (AAPs). The resultant PTDP hydrogel formed an intricate hydrogen-bonded network that enhanced mechanical robustness and substrate adhesion. TP and PDA synergistically confer potent antioxidant properties: TP scavenges radicals via phenolic hydroxyl groups while PDA enhances responsiveness to diverse radicals in hypoxic environments. Integrated with AAPs’ pro-regenerative functions and PDA’s broad-spectrum antimicrobial efficacy, this system generates therapeutic synergy. Characterization revealed outstanding physicochemical properties including tunable plasticity, high swelling ratios, and sustained hydration retention. In vitro studies demonstrated potent antioxidant activity, efficient inhibition of Staphylococcus aureus and Escherichia coli proliferation, and cytocompatibility facilitating endothelial cell migration/proliferation. In murine full-thickness infected wound models, the PTDP hydrogel significantly accelerated wound closure, enhanced neovascularization, and improved collagen deposition, underscoring its potential as an innovative therapeutic platform for infected and chronic wounds with strong translational prospects. Full article

Arginine plays a critical role in biomolecular interactions due to its guanidinium side chain, which enables multivalent electrostatic and hydrogen bonding contacts. In this study, atomistic molecular dynamics simulations were conducted across a broad concentration range (26–605 mM) to investigate the thermodynamic and structural features of arginine self-assembly in aqueous solution. Key observables—including hydrogen bond count, radius of gyration, contact number, and isobaric heat capacity—were analyzed to characterize emergent behavior. A three-regime aggregation pattern (dilute, cooperative, and saturated) was identified and quantitatively modeled using the Hill equation, revealing a non-linear transition in clustering behavior. Spatial analyses were supplemented with trajectory-based clustering and radial distribution functions. The heat capacity peak observed near 360 mM was interpreted as a thermodynamic signature of hydration rearrangement. Trajectory analyses utilized both GROMACS tools and the MDAnalysis library. While force field limitations and single-replica sampling are acknowledged, the results offer mechanistic insight into how arginine concentration modulates molecular organization—informing the understanding of biomolecular condensates, protein–nucleic acid complexes, and the design of functional supramolecular systems. The findings are in strong agreement with experimental observations from small-angle X-ray scattering and differential scanning calorimetry. Overall, this work establishes a cohesive framework for understanding amino acid condensation and reveals arginine’s concentration-dependent behavior as a model for weak, reversible molecular association. Full article

The rheological behavior of cementitious paste plays a pivotal role in determining the workability, pumpability, and uniformity of fresh concrete. Classical rheological models often struggle to capture the complex flocculation and hydration effects inherent in cement-based systems, and they typically depend on parameters that are difficult to measure directly, limiting their practical utility. This study presents a novel composition-based constitutive model that introduces a virtual maximum packing fraction (${\varphi }_{max}$) to account for interparticle flocculation and entrapped water effects. By establishing quantitative relationships between powder characteristics—such as particle size and specific surface area—and rheological parameters, the model enables physically interpretable and measurable predictions of yield stress and plastic viscosity. Our validation against 65 paste formulations with varying water-to-binder ratios, mineral admixture types and dosages, and superplasticizer contents demonstrates strong predictive accuracy (R² > 0.98 for plain pastes and >0.85 for blended systems). The influence of superplasticizers is effectively captured through modifications to ${\varphi }_{max}$, allowing the model to remain both robust and parameter efficient. This framework supports forward prediction of paste rheology from raw material properties, offering a valuable tool for intelligent mix design in high-performance concrete applications such as self-consolidating and 3D-printed concrete. Full article

This study investigates a prediction method for the compressive strength of concrete considering the pore relative humidity. Water within concrete not only facilitates the bonding of cementitious materials and aggregates but also influences the pore structure, thus affecting the compressive strength of concrete. While the relationship between the water–cement ratio and mechanical properties has been extensively explored, the quantitative effects of curing and moisture history on compressive strength remain insufficiently demonstrated. This research aims to fill this gap by proposing predictive models that consider the history of pore humidity. Experimental data from previous studies were utilized to develop and verify these models. Pore humidity was assessed through self-desiccation and diffusion processes. A self-desiccation model was formulated based on existing experimental results, and the finite element method was employed for diffusion analysis. The prediction model for compressive strength was derived from the rate constant model, incorporating apparent activation energy and adjusting for various curing conditions. The proposed models provide a robust framework for predicting the compressive strength of concrete under diverse curing scenarios. This research contributes to the development of practical tools for ensuring the safety and durability of concrete structures in the construction industry. Full article

Development of sensitive and convenient alkaline phosphatase (ALP) detection methods is of great significance for food analysis, biomedical applications, and clinical tests. In this work, a sensitive detection method for ALP was established based on nanochannel-modified electrodes, where the electrochemical luminescence (ECL) signal was quenched by the enzymatic reaction product. Vertically ordered mesoporous silica film (VMSF) was rapidly grown on low-cost ITO via the electrochemically assisted self-assembly (EASA) method. The resulting modified electrode (VMSF/ITO) exhibited a uniform and ordered nanochannel structure with nanochannel diameter of 2–3 nm and charge-selective permeability, enabling the enrichment of cationic ECL emitter tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)₃²⁺). Compared to the ITO electrode, VMSF/ITO increased the ECL signal by 60 times. In the presence of ALP, it catalyzes the hydrolysis of its substrate, disodium phenyl phosphate hydrate (DPP), generating phenol (Phe), which quenched the ECL signal of Ru(bpy)₃²⁺ and the co-reactant N,N-Dipropyl-1-propanamine (TPA). Based on this principle, ECL detection of ALP can be achieved. The linear detection range for ALP was 0.01 U/L to 30 U/L, with a limit of detection (LOD) of 0.008 U/L. The sensor exhibited high selectivity. Combined with the anti-contamination and anti-interference capabilities of VMSF, the constructed sensor enabled the detection of ALP levels in milk samples. Full article

Circulating fluidized bed combustion (CFBC) ash, a byproduct typically generated from coal-fired CFBC power plant boilers, contains high content of free lime and anhydrite. Due to its chemical composition, CFBC ash exhibits self-cementing properties; however, its performance is limited. One approach to enhancing the self-cementing properties of CFBC ash is through the incorporation of mineral admixtures such as gypsum. This study investigated the influence of desulfurization gypsum (DG) on the self-cementing behavior of CFBC ash. To this end, paste and mortar specimens were prepared and evaluated for their hydration and mechanical characteristics. The hydration behavior was analyzed using isothermal calorimetry, thermogravimetric analysis (TGA), setting time measurements, and X-ray diffraction (XRD) analysis. Mechanical properties were assessed by measuring the compressive strength at various curing ages. Additionally, changes in microstructure were examined by evaluating the pore size distribution through mercury intrusion porosimetry (MIP). The experimental results indicate that the appropriate incorporation of DG enhances the hydraulic reactivity of CFBC ash and significantly improves the compressive strength. Full article

The development of nanocarriers for drug delivery has drawn a lot of attention due to the possibility for tailored delivery to the ill region while preserving the neighboring healthy tissue. In medicine, delivering drugs safely and effectively has never been easy; therefore, the creation of surfactant-based vesicles (niosomes) to enhance medication delivery has gained attention in the past years. Niosomes (NIOs) are versatile drug delivery systems that facilitate applications varying from transdermal transport to targeted brain delivery. These self-assembling vesicular nano-carriers are formed by hydrating cholesterol, non-ionic surfactants, and other amphiphilic substances. The focus of the review is to report on the latest NIO-type formulations which also include biopolymers from the polysaccharide class, highlighting their role in the development of these drug delivery systems (DDSs). The NIO and polysaccharide types, together with the recent pharmaceutical applications such as ocular, oral, nose-to brain, pulmonary, cardiac, and transdermal drug delivery, are all thoroughly summarized in this review, which offers a comprehensive compendium of polysaccharide-based niosomal research to date. Lastly, this delivery system’s limits and prospects are also examined. Full article

Asphalt pavements face escalating challenges from traffic loading, climate change, and material degradation, necessitating innovative maintenance solutions. Thermally induced self-healing technologies, leveraging the viscoelastic properties of asphalt binders, can autonomously repair microcracks through targeted thermal activation. This review explored thermally induced self-healing in asphalt mixtures, with a focus on leveraging steel slag as a functional aggregate to enhance sustainability and durability. Two thermal-activation methods, electromagnetic induction and microwave heating, were critically analyzed, highlighting their distinct advantages in heating efficiency, depth, and uniformity. Steel slag offers dual benefits: improving mechanical interlock and skid resistance in mixtures while facilitating efficient heat generation via electromagnetic induction or microwave heating. However, challenges such as hydration-induced expansion, heterogeneous slag composition, and energy-intensive heating processes impede widespread adoption. Pretreatment methods, including natural aging, carbonation, and surface modifications, are essential to mitigate volumetric instability and optimize slag performance. Key factors influencing healing efficacy, including binder properties, operational parameters (e.g., microwave power, frequency), and environmental trade-offs, were systematically evaluated. Future research directions emphasized standardized pretreatment protocols, hybrid heating technologies for uniform temperature distribution, and smart-infrastructure integration for predictive maintenance. Full article

The long-term wear resistance of granite manufactured sand (HGY) concrete has not been sufficiently investigated. This deficiency makes it difficult to accurately predict and evaluate the service life and durability of such concrete pavements in practical engineering applications. Consequently, this study employed a self-developed indoor abrasion test device and combined it with scanning electron microscope (SEM) and X-ray diffraction (XRD) technologies. From the two dimensions of macroscopic performance and microscopic structure, the mechanisms’ influence of the effective sand ratio, stone powder content, and fine aggregate lithology on the wear resistance of HGY concrete were systematically investigated. The optimal content of the effective sand and stone powder content were determined, and the long-term evolution law of the wear resistance of HGY concrete was revealed. The results demonstrate that increasing the effective sand content will reduce the mass loss of concrete. When the stone powder content is 9%, the wear resistance of the concrete is optimal. The order of mass loss of different fine aggregate lithologies is river sand (HS) > limestone mechanism sand (SHY) > HGY, and the wear resistance of HGY is better than that of other fine aggregates. Increasing the effective sand content can enhance the bonding strength between the aggregate and the cement matrix and reduce the porosity, which is conducive to improving the wear resistance of the concrete. Under a relatively small stone powder content, as the amount of stone powder added increases, the pore structure becomes tighter, and the wear resistance of the concrete becomes better. Compared to HS, the manufactured sand (MS) containing stone powder can optimize the pore structure and hydration products of concrete, improve the pore structure of concrete, and improve the wear resistance. Full article

The preparation of low-cost and high-durability cement-based material systems using seawater mixing has become an urgent task in marine engineering construction. The requirements have addressed key challenges, including high transportation costs for fresh water and raw materials, poor structural durability, and difficulty in meeting actual construction schedules. Sulfatealuminate cement (CSA) has become an ideal material for marine engineering due to its high corrosion resistance, rapid early strength, which is 35–40 MPa of 3-day compressive strength and is 1.5–2 times compared ordinary Portland cement (OPC), and low-carbon characteristics, reduced production energy consumption by 35–50%, and CO₂ emissions of 0.35–0.45 tons/ton. The Cl⁻ and SO₄²⁻ in seawater can accelerate the hydration of CSA, promote the formation of ettringite (AFt), and generate Friedel’s salt fixed chloride ions, significantly enhancing its resistance to chloride corrosion. Its low alkalinity (pH ≈ 10.6) and dense structure further optimize its resistance to sulfate corrosion. In terms of environmental benefits, CSA-mixed seawater can save 15–20% fresh water. And the use of solid waste preparation can reduce environmental burden by 38.62%. In the future, it is necessary to combine multi-scale simulation to predict long-term performance, develop self-healing materials and intelligent control technologies, and promote their large-scale application in sustainable marine infrastructure. Full article

To validate the long-term performance of self-developed limestone calcined clay cement (LC3), this study evaluated the durability performance of LC3 produced using calcined excavated spoil. Results showed that LC3 exhibited a faster chloride adsorption rate than OPC, achieving peak binding capacity within 14 days, although its total chloride-binding capacity was slightly lower. The chloride diffusion coefficient of LC3 was approximately one order of magnitude lower than that of OPC, enhancing chloride resistance. However, LC3 demonstrated weaker carbonation resistance due to complete decomposition of portlandite (Ca(OH)₂) and ettringite (AFt), alongside partial degradation of calcium silicate hydrate (C-S-H) gels, resulting in pore structure coarsening. Compared to LC3 made with commercial metakaolin (K0), the self-developed LC3 using K1 and K2 clays from excavated spoil showed comparable chloride-binding capacity but slightly weaker chloride penetration resistance. Its carbonation resistance surpassed K0-based LC3. Overall, the self-developed LC3 matched commercial metakaolin-based LC3 in durability, validating the use of locally sourced clays. Producing LC3 from calcined excavated spoil addresses environmental challenges associated with spoil disposal while delivering satisfactory durability. Full article

Proper geologic reservoir characterization is crucial for energy generation and climate change mitigation efforts. While conventional techniques like core analysis and well logs provide limited spatial reservoir information, seismic data can offer valuable 3D insights into fluid and rock properties away from the well. This research focuses on identifying important structural and stratigraphic variations at the Mississippi Canyon Block 118 (MC-118) field, located on the northern slope of the Gulf of Mexico, which is significantly influenced by complex salt tectonics and slope failure. Due to a lack of direct subsurface data like well logs and cores, this area poses challenges in delineating potential reservoirs for carbon storage. The study leveraged seismic multi-attribute analysis and machine learning on 3-D seismic data and well logs to improve reservoir characterization, which could inform field development strategies for hydrogen or carbon storage. Different combinations of geometric, instantaneous, amplitude-based, spectral frequency, and textural attributes were tested using Self-Organizing Maps (SOM) to identify distinct seismic facies. SOM Models 1 and 2, which combined geometric, spectral, and amplitude-based attributes, were shown to delineate potential storage reservoirs, gas hydrates, salt structures, associated radial faults, and areas with poor data quality due to the presence of the salt structures more than SOM Models 3 and 4. The SOM results presented evidence of potential carbon storage reservoirs and were validated by matching reservoir sands in well log information with identified seismic facies using SOM. By automating data integration and property prediction, the proposed workflow leads to a cost-effective and faster understanding of the subsurface than traditional interpretation methods. Additionally, this approach may apply to other locations with sparse direct subsurface information to identify potential reservoirs of interest. Full article

The behavior of long-span concrete-filled steel tube (CFST) arch bridges during the pouring stage is complex. The coupling effect of the time-varying hydration heat and the evolution of the elastic modulus is crucial for the linear control of the structure. Most of the existing models focus on static self-weight analysis but generally ignore the above-mentioned dynamic heat–force interaction, resulting in significant prediction deviations. In response to this limitation, this paper proposes an analysis method for the injection stage considering the time-varying heat of hydration and elastic modulus of concrete inside the pipe. Firstly, based on the composite index model of the hydration heat and through the reduction of the participating materials, the heat source function of the hydration heat of the arch rib was obtained, and its accuracy was verified by using two test components. Secondly, the equivalent application method of the hydration heat temperature field of the bar system model was proposed. Combined with the modified time-varying model of the elastic modulus at the initial age, the analysis method for the pouring stage of concrete-filled steel tube arch bridges was established. Finally, the accuracy of the proposed method was verified by analysis and calculation combined with engineering examples and comparison with the measured results. The results show that the time-varying heat of hydration and the time-varying elastic modulus during the concrete pouring stage inside the pipe can lead to residual deflection after the arch rib is poured. The calculated value of the example reaches 154 mm, while the influence of the lateral displacement is relatively small and recoverable. The proposed method improves the calculation accuracy by 44.19% compared with the traditional method, which is of great significance for the actual engineering construction control. Full article