Search Results (3,408)

Articular cartilage defects affect millions of patients annually and pose one of the most persistent challenges in orthopedic surgery, owing to the tissue’s inherent avascular and alymphatic nature. Current surgical approaches, microfracture, autologous chondrocyte implantation (ACI/MACI), and osteochondral grafting, share a common failure mode: inadequate adhesion between repair constructs and surrounding native cartilage, contributing to deterioration rates of 15–75% at five-year follow-up across all techniques. This review repositions adhesion not as a supplementary material property but as the central determinant of clinical success in cartilage repair. We systematically evaluate the biomechanical demands imposed by the joint environment and define clinically relevant adhesion thresholds. Adhesive hydrogel strategies are categorized by surgical context: microfracture augmentation, ACI/MACI enhancement, osteochondral graft integration, and standalone repair platforms. Material platforms are analyzed across catechol/dopamine systems, NHS ester chemistry, photocrosslinkable hydrogels, supramolecular approaches, and multi-mechanism hybrids. Injectable formulations for arthroscopic delivery are critically examined alongside key translational barriers, including fatigue durability, biocompatibility–adhesion trade-offs, sterilization compatibility, batch variability, and regulatory classification ambiguity. Future directions encompass 4D bioprinting, AI-guided formulation optimization, and stimuli-responsive reversible adhesion systems. Adhesive hydrogels represent the missing link that current cartilage repair paradigms require. Full article

The degradation of mulch materials in perennial cropping systems is governed by both polymer properties and environmental conditions. Their relative influence under field conditions remains unclear. To our knowledge, this study is one of the first to integrate mass loss measurements, polymer characterization, and soil microclimatic assessment under field conditions. A one-year field experiment was conducted under irrigated Mediterranean conditions to compare the degradation of Kraft^® paper and polybutylene adipate terephthalate (PBAT)-based (Kritifil^®) mulch with polypropylene (PP) geotextile fabric and polyethylene (PE) mulch in randomized blocks, with three replicates. Mass loss was quantified in situ using mesh bags, while soil moisture, temperature, and electrical conductivity (EC) were monitored monthly to characterize microclimatic and edaphic conditions underlying mulch treatments. Polymer changes were assessed by ATR-FTIR analysis of field-exposed mulch fragments. Kraft^® paper degraded rapidly (≈72% mass loss), consistent with moisture-driven biological processes and susceptibility to hydrolysis. In contrast, PBAT-based mulch showed limited degradation (≈3.5%) despite favourable conditions, suggesting constraints in enzymatic activity. No mass loss was observed for PE- and PP-based mulch. ATR-FTIR analysis indicated minimal structural changes in PBAT, PP, and PE, reflecting their high stability. Overall, polymer composition and inherent (bio)degradability, rather than soil thermal time, were the main drivers of mulch (bio)degradation under Mediterranean conditions. Full article

In this study, a fractional-order epidemic compartmental model is formulated using the Caputo derivative to account for the memory effects of the chikungunya virus. Based on Banach contractions, fixed-point theorems are used to prove existence and uniqueness, and fundamental properties such as positivity and boundedness are established. Normalized forward sensitivity indices are employed to evaluate the relative impact of model parameters on the transmission dynamics and control of the disease. To reduce the spreading of infection, an optimal control problem is formulated by introducing time-dependent control measures with four control strategies that include public health prevention, treatment enhancement, and vector-control measures. Necessary conditions for optimality are derived using Pontryagin’s Maximum Principle. The predictor–corrector Adams–Bashforth–Moulton scheme is applied across different fractional orders and effectively reduces infection levels. The influence of the fractional order $\xi$ on the epidemic dynamics is investigated, showing that lower values of $\xi$ slow disease progression through a memory effect inherent in the Caputo operator. Moreover, an artificial neural network (ANN) trained via the Levenberg–Marquardt algorithm independently validates the numerical solutions. Full article

A composite warm-mix additive (PNSK) was developed to improve asphalt workability by reducing viscosity while maintaining rheological performance at both high and low temperatures. The warm-mix asphalt binders (PWMA) were analyzed using an integrated approach combining conventional property tests with rheological analysis. Results showed that penetration, softening point, and ductility improved. The viscosity-reduction effect was enhanced with increasing PNSK dosage, yet the benefit plateaued beyond 11% content. Additionally, the adhesion strength between asphalt and aggregate began to decrease after 11% dosage, with 12% serving as the critical threshold for adhesion deterioration. Consequently, the optimal dosage was determined to be 11% based on comprehensive consideration of all factors. LAS results demonstrated that 11%PWMA exhibited lower strain sensitivity and superior fatigue resistance at low-to-intermediate temperatures, with fatigue life increasing by nearly an order of magnitude under low strain at 20 °C. MSCR results revealed that under low stress, 111%PWMAexhibited significantly lower non-recoverable creep compliance (J_nr) and higher percent recovery (R) than the 70^#, especially in the high-temperature range (54–66 °C), demonstrating superior resistance to permanent deformation. However, 1111%PWMAxhibited temperature-strain sensitivity characteristics under high-temperature, high-strain conditions, representing an inherent characteristic of WMA technology. Full article

Cycle-to-cycle variability of switching parameters inherent to memristive devices introduces significant problems in the design of neuromorphic systems and non-volatile memory. This study investigates the dynamics of a second-order memristive system incorporating capacitive effects that model parasitic charge within individual memristors, addressing both the technical need for accurate analysis of complex regimes and the demand for exploratory environments. Simulations were performed using CUDAynamics, an interactive software suite developed by the authors, which utilizes parallel computing, primarily via NVIDIA Compute Unified Device Architecture (CUDA). It integrates multiple analysis tools for dynamical systems, including bifurcation diagrams, the largest Lyapunov exponent and periodicity mapping, and interactive navigation in multidimensional parameter spaces. The memristive system was discretized applying multiple integration methods with a fixed time step and various waveforms of the input signal. Analysis tools revealed well-defined regions of chaotic dynamics in the memristor resistance parameter space as functions of input signal properties. Sinusoidal and triangular waveforms produced topologically similar distributions of dynamical regimes, whereas the square waveform, mimicking digital inputs, generated distinct dynamical patterns while still preserving chaotic trajectories under specific conditions. Interactive visualization capabilities of CUDAynamics effectively demonstrate attractor evolution and hysteresis deformation, providing immediate visual feedback that significantly enhances conceptual comprehension of nonlinear feedback mechanisms. Beyond its practical implications for the design of analog and digital memristive devices, CUDAynamics offers a scalable, open-source toolkit to aid researchers and engineers in exploring complex dynamical phenomena. Full article

In this study, the two-dimensional aligned steel fiber-reinforced micro-expansive concrete (2D) was prepared, aiming to address the inherent vulnerabilities of concrete, such as early-age shrinkage cracking and low tensile ductility. For this purpose, the steel fibers and expansive agent were utilized. Furthermore, the planar rotating magnetic field was used to randomly distribute the steel fibers in a two-dimensional plane. In order to verify its superior mechanical and shrinkage properties, the compressive, fracture and drying shrinkage tests were carried out. The results demonstrate that the 2D alignment method enhances the fiber utilization efficiency. Compared with fiber-free groups, the compressive strength and fracture parameters of specimens incorporating steel fibers were improved. Furthermore, compared with randomly distributed steel fiber-reinforced micro-expansive concrete (RD), the 2D alignment method made the cubic compressive strength and fracture energy improve 8–14.2% and 19.4–110%, respectively. Additionally, the advantage of the fiber 2D alignment method was also reflected in the inhibition of drying shrinkage. Compared with normal concrete, the 180-day shrinkage strain of the 2D1.2 group was reduced to 200 με (only 19.5% of that of normal concrete, or 30.6% of that of micro-expansive concrete). Mechanistically, these superior performances are fundamentally governed by a coupling effect: chemical shrinkage compensation and physical alignment constraint. Full article

Transparent object segmentation plays a critical role in indoor and outdoor scene understanding, particularly driven by the rapid advancements in autonomous driving and robotics. However, this task presents significant challenges due to the lack of distinct texture and chromatic features in transparent objects, causing their appearance to blend into the background. Existing methods face inherent architectural limitations: CNNs are restricted by limited receptive fields, while Transformer-based methods may inadvertently suppress the weak feature details of transparent surfaces due to the inherent low-pass filtering property of self-attention mechanisms, treating them as background noise. Consequently, these approaches struggle to consistently segment transparent objects across diverse scales, failing to preserve both fine details and large-scale structures. To address these limitations, we propose the Global Context-Aware Transformer (GCA-Trans). Specifically, we design a Multi-scale Context Mining (MCM) module that leverages parallel dilated convolutions with varying receptive fields to simultaneously extract features at multiple scales. This design allows the model to capture and fuse fine-grained local details (e.g., edges and textures) with coarse-grained global spatial context (e.g., overall object shapes), ensuring robust segmentation performance for transparent objects of varying scales. Extensive experiments on four benchmark datasets demonstrate that GCA-Trans sets a new state of the art, achieving significant improvements of 2.53% mIoU on Trans10K-v2, 2.1% IoU on RGB-D GSD, 2.2% IoU on GDD, and 1.9% IoU on GSD, validating the effectiveness and robustness of our approach. Full article

Background: Photothermal therapy (PTT), a highly efficient and controllable method with minimal drug resistance, transforms near-infrared (NIR) radiation into heat. This process exerts antibacterial effects, aids in tissue repair, and promotes healing. Methods: Our study presented a novel kind of composite wound dressing that incorporated adhesive conductive hydrogel combined with piezoelectric film for NIR-responsive applications. The inherent adhesiveness of the hydrogel ensured robust anchoring of the piezoelectric film to both hydrogel matrix and wound site. Its conductivity enabled synergistic endogenous electrical stimulation with the piezoelectric film, while also serving as therapeutic layer to augment hemostasis, analgesia, and antibacterial activity. Results: The hydrogel’s capacity for moisture retention and exudate absorption sustained optimal wound environment, thereby supporting debridement and recovery. Furthermore, the piezoelectric film possessed excellent photothermal properties and transferred heat to the hydrogel through heat conduction to enhance antibacterial activity and promote wound healing. The in vitro and in vivo experiments confirmed that the composite dressing exhibited strong promotion effect on wound healing under NIR irradiation. Conclusions: In summary, our research provided a new strategy for developing advanced piezoelectric biomaterials with great clinical potential for wound healing. Full article

Cellulose is a complex polysaccharide that serves as the primary structural component of plant cell walls. It is highly suitable for packaging films due to its inherent and tunable properties, which offer a sustainable alternative to conventional plastics. In this study, cellulose was extracted from vegetable waste (kale and cabbage) and processed into films using LiCl/N,N-dimethylacetamide (DMAc) as the solvent system. The regenerated cellulose films were characterized and compared with a film prepared from commercial microcrystalline cellulose (MCC) using the same procedure. The vegetable-waste films showed a lower degree of crystallinity than the MCC film. SEM micrographs revealed that the vegetable-waste films possessed smooth and uniform surfaces. Furthermore, they demonstrated good transparency, ductility, and thermal stability. Biodegradation tests indicated rapid decomposition of the vegetable-waste films, which fully degraded within 10 weeks, whereas the MCC film required 16 weeks. The cabbage-derived film exhibited a smoother surface and slightly better mechanical properties than the kale-derived film, suggesting that differences in the cellulose source can influence the regeneration process and, consequently, the properties of the resulting films. Overall, this work demonstrates that vegetable waste can be effectively upcycled into eco-friendly, low-cost cellulose films with strong potential for use in various sustainable material applications. Nevertheless, for edible applications, cytotoxicity testing is required to confirm the absence of residual health-risk reagents such as LiCl and DMAc in the resulting films. Full article

The modern world is confronting critical environmental and biomedical challenges, underscoring the urgent need for the development of multifunctional materials—an inherently interdisciplinary field, bridging materials science and engineering, environmental science and biomedicine. Titanium dioxide (TiO₂) is widely recognized for its photocatalytic and antiviral properties, enabling the degradation of pollutants and mitigation of viral contamination under solar irradiation. Nevertheless, it exhibits certain limitations, such as wide band gap and high recombination rate of photogenerated electron–hole pairs. To address these limitations, TiO₂ prepared by a co-precipitation method was modified with N-Doped Carbon Dots (N-CDs) via a hydrothermal treatment, which extend light absorption into the visible region and enhance charge separation. Further functionalization with silver nanoparticles (Ag NPs)—well known for their antimicrobial properties—via a simple thermal process under ambient conditions, introduced additional reactive oxygen species generation, creating a synergistic effect. The as-prepared TiO₂, TiO₂/N-CDs and TiO₂/N-CDs/Ag samples were characterized via several techniques, such as XRD, micro-Raman, FT-IR, TEM and UV-Vis. In addition, their photocatalytic and antiviral activity against methylene blue (MB) and nitrogen oxide (NO_x) pollutants, as well as SARS-CoV-2, was evaluated. Based on the results of liquid-phase photocatalysis, TiO₂, TiO₂/N-CDs and TiO₂/N-CDs/Ag presented a degradation efficiency of 78%, 85% and 95%, respectively, whereas different trends were observed under gaseous-phase conditions. The TiO₂/N-CDs/Ag hybrid material demonstrated superior antiviral activity against SARS-CoV-2 (IC₅₀: 1.24 ± 0.34 g/L), compared to both TiO₂ (IC₅₀: 1.78 ± 0.30 g/L) and TiO₂/N-CDs (IC₅₀: >2.5 g/L), highlighting its potential as an effective multifunctional material. Finally, TiO₂/N-CDs/Ag was incorporated onto a paper substrate, demonstrating antiviral activity, showing promising scalability for application across a wide range of future substrates. To the best of our knowledge, this is the first study presenting TiO₂/N-CDs/Ag with dual photocatalytic and antiviral activity. Full article

In oil and gas development, the oil displacement efficiency of single surfactants is inherently constrained. While synergistic interactions between salt ions and surfactants can enhance displacement performance by modulating interfacial properties and wettability, the underlying mechanisms remain insufficiently understood. This study systematically investigated the synergistic effects of two monovalent salts (NaCl, KCl) and four surfactants through macroscopic characterization of interfacial property and microfluidic displacement experiments using microfluidic device with dead-end structures. The results show that salt type and concentration significantly influence interfacial dynamics. The four selected surfactants exhibit gel-like behavior through molecular self-assembly in aqueous solutions, and their synergistic interaction with salt ions enhances oil displacement efficiency by modulating interfacial characteristics. High-salinity solutions reduce interfacial tension, with CTAB exhibiting a concentration-dependent decrease, while NP-10 behavior is governed by both surfactant and salt concentrations. The presence of Na⁺ generally resulted in lower IFT, improved interfacial viscoelasticity, and more favorable wettability alteration compared to K⁺. One-way analysis of variance confirmed that salt type is the main factor affecting recovery rate (p < 0.05). Notably, 0.2% CTAB+50,000 mg/L NaCl combination achieved the highest recovery rate owing to an optimal balance between interfacial adsorption, film viscoelasticity, and wettability alteration. This investigation elucidates the mechanisms driving surfactant–salt synergism and proposes an optimized surfactant and salt formulation to enhance oil recovery through tailored interfacial properties. Full article

Plastic pollution caused by poly(ethylene terephthalate) (PET) highlights the urgent need for efficient biodegradation strategies. However, PET hydrolases such as DuraPETase typically exhibit limited substrate affinity for PET and insufficient operational stability. Although conventional immobilization improves enzyme stability, it often compromises catalytic activity. Here, we design a PET-targeting, orientation-controlled immobilization strategy that overcomes this traditional trade-off and enables efficient PET biodegradation. Guided by rational structural analysis, three Cys variants (R53C, R59C, R224C) were engineered for site-specific covalent attachment to a PDA@SiO₂ support with inherent PET-binding capability. The resulting conjugates (Dura_R53C-PDA@SiO₂, Dura_R59C-PDA@SiO₂, and Dura_R224C-PDA@SiO₂) displayed distinct catalytic and stability profiles. Among them, Dura_R59C-PDA@SiO₂ achieved the optimal balance between activity and stability, retaining kinetic properties comparable to the free enzyme and maintaining 87.6% residual activity after 2 h at 80 °C. Water contact angle measurements confirmed its PET-targeting behavior, as evidenced by the reduction in the PET contact angle from 85° to 45°. In 10-day degradation assays at 50 °C, Dura_R59C-PDA@SiO₂ released a total of 4865.32 μM degradation products, representing a 2.37-fold increase relative to free DuraPETase. These findings demonstrate an effective strategy for industrial enzymatic PET degradation and recycling. Full article

Understanding the anisotropy in the physical and mechanical properties of layered rocks is essential for predicting and preventing instability in layered rock masses. However, in-situ sampling is often hindered by the difficulty of obtaining specimens with controlled bedding orientations. Cement-based 3D printing (3DP) offers an efficient approach for fabricating rock analogues, yet the inherent anisotropy induced by the layer-by-layer deposition process has not been well characterized, hindering its broader application. The objectives of this study are (i) to systematically evaluate the intrinsic anisotropy of cement-based 3DP rocks and (ii) to compare the mechanical anisotropy and failure modes of 3DP layered rocks with those of natural layered sandstone. The key findings are as follows: (1) The uniaxial compressive strength (UCS), P-wave velocity, and computed tomography (CT) number of the 3DP rock vary by less than 6% among the X-, Y-, and Z-directions, indicating lower intrinsic anisotropy compared to typical sandstones and several other natural rocks. (2) The UCS, elastic modulus, and secant modulus of the 3DP layered rocks all decrease initially and then increase with bedding dip angle, reaching a minimum at 60°. (3) The main fracture characteristics of the 3DP layered rocks are similar to those of layered sandstone; notably, the 3DP layered soft rock exhibits the most pronounced shear failure features. This study quantifies the low intrinsic anisotropy of cement-based 3DP rocks and validates their similarity to natural layered sandstone in both mechanical anisotropy and failure modes. It thereby provides a reliable, reproducible basis for physical modeling of layered rock masses using 3DP, offering a new approach for laboratory-scale investigations of layered rocks. Full article

Proton exchange membrane water electrolysis is a promising technology for large-scale green hydrogen production due to its high efficiency, compact design, and rapid dynamic response. However, its commercialization is strictly limited by high material costs, durability issues, and complex multiphysics coupling within the membrane electrode assembly. This work provides a comprehensive and critical review of key physicochemical processes and advanced predictive modeling approaches for PEMWEs. To capture recent paradigm shifts, we introduce an innovative multi-dimensional classification framework—incorporating spatial resolution, temporal dynamics, and methodological paradigms—to critically evaluate lumped-parameter, continuum, microscale, and multiscale models, explicitly defining their applicability bounds and inherent limitations. The fundamental mechanisms governing electrode kinetics, membrane water transport, and gas–liquid two-phase flow are analyzed, establishing state-of-the-art quantitative benchmarks for microstructural parameters and advanced 3D flow field topologies under high-current-density and high-pressure regimes. Furthermore, we systematically examine model validation rigor, typical prediction errors, and the critical failure of static models in capturing dynamic property shifts during extreme bubble breakthrough. Recent breakthroughs integrating in situ diagnostics, pore-scale simulations, density functional theory, and Physics-Informed Neural Networks are extensively discussed. Future efforts must prioritize mechanical–electrochemical–thermal coupling, transient degradation prognostics, and machine learning-driven predictive digital twin technologies to overcome current empirical limitations and accelerate the gigawatt-scale deployment of PEMWE systems. Full article

Ice accumulation on critical infrastructure surfaces threatens operational safety in aviation, power transmission, and transportation systems. Conventional anti-icing and deicing strategies, such as chemical deicers and energy-intensive active heating, have inherent drawbacks. These include environmental pollution, high energy consumption, and low efficiency. In recent years, photothermal-responsive extremely water-repellent surfaces have attracted widespread attention. They can harvest renewable solar energy and achieve efficient anti-icing and deicing through tailored interfacial wetting properties. This review summarizes photothermal extremely water-repellent surfaces based on the “water as a lubricating layer” strategy. This strategy reduces ice adhesion strength and enables low-energy deicing. It works by forming a continuous lubricating film via photothermally induced interfacial meltwater. We discuss photothermal conversion mechanisms and strategies to enhance performance for stable lubricating film formation. We also analyze the stagewise physics of anti-icing and deicing, focusing on the interfacial tribological behavior of the water film. Key engineering challenges are addressed, including mechanical durability and all-weather applicability. Finally, we clarify future research directions for industrial translation. This review aims to provide theoretical insights and technical pathways for developing next-generation anti-icing and deicing surfaces that are efficient, eco-friendly, and sustainable. Full article