Search Results (806)

Nano-TiO₂ is widely used in many industrial fields due to its unique physical and chemical properties. In recent years, it has become a core material in the research of road engineering for degrading automobile exhaust. Under ultraviolet irradiation, it can excite electron-hole pairs and use its strong redox capacity to decompose automobile exhaust and improve air quality. From the perspectives of materials, performance and engineering application, this paper briefly describes the structure and physicochemical properties of nano-TiO₂, reviews the recent research progress of nano-TiO₂ in the photocatalytic degradation of automobile exhaust, systematically compares the effects of various strategies such as incorporation methods and modified materials on exhaust degradation efficiency, and conducts a quantitative analysis of performance differences. It is pointed out that insufficient road durability, poor compatibility with pavement materials and limited adaptability to unconventional environments are the main current problems and challenges in this research direction. The future development directions such as developing self-healing composite systems and constructing machine learning prediction models are also prospected. Full article

In recent years, bacteria-based self-healing has emerged as a promising bioengineering strategy to address the self-repair of cracks in cement-based materials, which represent one of the persistent durability challenges. This approach relies on microbiologically induced calcium carbonate (CaCO₃) precipitation (MICP), in which metabolically active bacteria promote CaCO₃ formation of crystals that can heal cracks and restore material integrity. This study compares the self-healing potential of a natural (N-) alkaline soil Bacillus licheniformis strain with a UV-strain (phenotypic mutant) generated through controlled UV exposure followed by adaptive evolution. Both strains were evaluated under conditions relevant to cementitious environments. The UV-strain exhibited enhanced ureolytic performance, reaching urease activity of 0.32 U/mg compared to 0.24 U/mg in the N-strain. This translated into improved biomineralization, with CaCO₃ precipitation reaching 2.37 mg versus 2.23 mg/100 mL in the N-strain. Additionally, the UV-strain showed increased cell hydrophobicity and aggregation, indicating improved nucleation potential and surface-mediated mineral deposition. Multivariate analysis confirmed strong correlations between ureolytic metabolism, alkalization, and mineral formation, while artificial neural network (ANN) modeling (MLP 6-10-14) successfully predicted biomineralization-related parameters with high accuracy (R² > 0.90 for urease activity, NH₄⁺, ΔpH, and CaCO₃). The results demonstrate that UV-induced phenotypic adaptation can enhance biomineralization efficiency with minor trade-offs in physiological robustness. For the first time, that controlled UV-induced phenotypic adaptation can be used as a targeted strategy to enhance biomineralization efficiency in B. licheniformis, while maintaining functional stability under cement-relevant conditions. These findings provide a novel framework for tailoring bacterial performance in self-healing systems for construction biotechnology. Full article

Background: In older people, syphilis diagnosis might be undervalued due to both clinical conditions and age-related changes that obscure symptom presentation and physician discomfort with sexual history-taking, creating a dual barrier to timely recognition. Methods: Case presentation with literature review. Results: An 80-year-old woman was referred to the Dermatology Department of Cagliari University by her oncologist, with a 2-month history of intermittent episodes of pruritus associated with papular–nodular skin lesion eruptions, accompanied with asthenia, night sweats, and unintentional weight loss, indicative of a paraneoplastic syndrome or an adverse drug reaction. Careful evaluation indicated the need to perform serological testing, which confirmed secondary syphilis (RPR 1:64 and TPHA 1:5120). Specific questioning regarding sexual behaviors pointed out oral and anal intercourse. The 83-year-old husband did not have active lesions at visit but reported a self-healing generalized skin rash, episodes of asthenia, arthralgia, and headache he had never suffered before. Blood tests showed positive RPR 1:64 and TPHA 1:5120. Targeted sexual history assessment disclosed patient’s engaging with commercial sex workers, clarifying the chain of transmission in this conjugal STI case. Treatment with Benzathine penicillin G 2.4 million units IM in a single dose resulted in complete recovery in both patients. Conclusions: The observation highlights the importance of maintaining a high index of suspicion for syphilis even at advanced age. Persistent stigma regarding elderly sexuality should be faced, and targeted interventions are necessary to improve the clinician’s ability to identify STIs in older adults, but also to reduce sexual stigma and taboo persistence in the general population. Full article

Road pavement rehabilitation increasingly incorporates innovative surface technologies aimed at improving pavement performance while reducing environmental impacts. In addition to conventional recycled asphalt pavement (RAP) maintenance strategies, advanced pavement surface systems such as reflective coatings, rejuvenator-based self-healing mixtures, and thin low-noise asphalt layers have been developed to enhance durability and functional performance. This study presents a comparative Life Cycle Assessment (LCA) of four pavement surface technologies using primary inventory data obtained from full-scale road sections. The systems evaluated include a conventional maintenance mixture and three alternative surface solutions: reflective pavement coatings, RAP mixtures incorporating rejuvenator-based self-healing systems, and thin low-noise asphalt layers. The assessment follows ISO 14040 and ISO 14044 standards and applies the ILCD 2011 midpoint+ (EF 2.0) method. To enable comparability between technologies with different durability, the functional unit was defined as 1 m² of rehabilitated pavement per year of service life. The results indicate that thin low-noise asphalt layers provide the highest environmental benefits across most impact categories due to significant material savings associated with reduced layer thickness. Reflective pavement coatings decrease several impacts, particularly fossil resource depletion and atmospheric emissions, although higher burdens are observed in some categories due to synthetic binder production. RAP mixtures incorporating rejuvenator-based self-healing systems improve resource efficiency and extend pavement durability but may increase impacts associated with binder manufacturing. Overall, the findings highlight relevant environmental trade-offs between different pavement surface technologies and demonstrate that parameters such as layer thickness, binder composition, recycled material content, and service life strongly influence environmental performance. The study illustrates how comparative Life Cycle Assessment supports the development and selection of more sustainable pavement surface systems. Full article

Bone tissue plays a vital role in the human body and possesses intrinsic self-repair mechanisms; however, large defects or pathological fractures may exceed its natural healing capacity. Bone tissue engineering provides promising strategies to restore bone integrity through the use of scaffolds, growth factors, and stem cells. While calcium phosphate (CaP)-based ceramics, such as hydroxyapatite (HAp) and tricalcium phosphate (TCP), represent the current benchmark, their limitations, including slow degradation (HAp) and limited osteoinductivity (TCP), have driven the development of alternative biomaterials. In this context, magnesium phosphate (MgP)-based materials have gained increasing attention due to their tunable resorption rate, improved biodegradability, and ability to stimulate osteogenesis and angiogenesis through the release of magnesium (Mg²⁺) ions. This study reports on composite scaffolds based on electrospun poly(ε-caprolactone) (PCL) fibres coated with MgP layers doped with lithium (Li) and zinc (Zn), designed to mimic the nanofibrous architecture of the extracellular matrix. Lithium and zinc were selected due to their known ability to modulate cellular response, with lithium promoting osteogenic activity and zinc contributing to improved cell proliferation and antibacterial potential. The phosphate phases obtained by coprecipitation were deposited onto the PCL fibres using Matrix-Assisted Pulsed Laser Evaporation (MAPLE), enabling controlled surface functionalization. Following thermal treatment, the formation of the crystalline magnesium pyrophosphate (Mg₂P₂O₇) phase was confirmed by chemical and structural characterization. The combination of a slowly degrading PCL matrix, providing sustained structural support, and a bioactive MgP coating, enabling rapid and controlled ion release, results in improved scaffold performance in terms of biocompatibility, biodegradability, and bioactivity. While the slow degradation rate of PCL ensures mechanical stability over an extended period, the surface-deposited MgP phase allows immediate interaction with the biological environment, facilitating faster ion release and enhancing cell–material interactions. These findings highlight the potential of the developed composites as promising candidates for trabecular bone regeneration and as viable alternatives to conventional CaP-based scaffolds in regenerative medicine. Full article

Stone heritage deteriorates through physical, chemical, and biological processes driven by water, climate, and microbial colonization. Multifunctional polymeric coatings combining hydrophobic and antimicrobial moieties have emerged as a promising conservation strategy, yet a substantial gap remains between laboratory innovation and real-world performance. This review critically examines advances from 2021 to 2026, covering wetting theory, antimicrobial mechanisms, and material architectures, including molecularly integrated systems, Sol–Gel hybrids, nanocomposites, and layered systems. Long-term studies on the Aurelian Walls in Rome and stone in Reims show that biocidal efficacy typically declines within one to two years despite the chemical persistence of the coatings. In parallel, hydrophobic performance often deteriorates over time due to UV exposure, particulate deposition, and surface chemical changes, leading to increased wettability and reduced protective efficiency. Substrate porosity governs durability and visual compatibility (ΔE* < 5 threshold), while treatments can reshape microbial communities, favoring stress-tolerant meristematic fungi. Regulatory pressure on fluorinated compounds drives the development of more sustainable alternatives. Emerging directions include stimuli-responsive systems, self-healing materials, slippery interfaces, and precision polymer architectures. However, future progress will depend on tailoring formulations to major lithotypes, improving compatibility with porous substrates, and validating performance through standardized accelerated aging and multi-year field trials. Bridging laboratory design with environmental exposure data and conservation practice will be essential for achieving durable and culturally acceptable protection strategies. Full article

Carbon dots (CDs) have demonstrated promising application prospects in the field of corrosion protection due to their small size, excellent dispersibility, abundant and tunable surface functional groups, low cost, environmental friendliness, and unique fluorescence properties. However, existing reviews have predominantly focused on the synthesis and photoluminescence properties of CDs, lacking systematic integration and in-depth mechanistic analysis of their diverse applications in corrosion protection. This review systematically summarizes the recent research progress and underlying mechanisms of CDs in five key areas: corrosion inhibitors, anticorrosive coatings, photogenerated cathodic protection, chloride binding, and corrosion monitoring. As corrosion inhibitors, CDs form compact protective films on metal surfaces through synergistic physical and chemical adsorption. In anticorrosive coatings, CDs not only enhance the physical barrier effect but also impart intelligent functionalities such as self-healing and corrosion monitoring. In the field of photogenerated cathodic protection, CDs broaden the light absorption range of semiconductors and facilitate the separation of photogenerated carriers. As chloride binding promoters, CDs promote the formation of cement hydration products, thereby improving the durability of reinforced concrete structures. As sensing platforms, CDs enable early visual detection of corrosion through their specific fluorescence response to ions such as Fe³⁺. Despite significant progress, challenges remain in scalable preparation, practical application performance in complex environments, and multifunctional integration. This review systematically outlines the research advancements of CDs in corrosion protection, providing a practical reference for subsequent studies and engineering applications. Future research should focus on scalable synthesis, machine learning-assisted design, and the development of integrated multifunctional protection systems to promote the practical application of CDs in the field of corrosion protection. Full article

Nano–bio hybrid catalysts have emerged as a promising platform for sustainable energy conversion by integrating the high selectivity of enzymes with the structural robustness and conductivity of nanomaterials. In recent years, the growing demand for clean energy technologies has driven the development of biohybrid systems capable of efficient electron transfer, enhanced catalytic activity, and improved operational stability. This review comprehensively discusses the design principles, mechanistic foundations, and performance metrics of enzyme–nanomaterial interfaces for energy-related applications. We first outline the fundamentals of enzymatic redox catalysis and the limitations of free enzymes in practical systems. Subsequently, we examine the functional roles of nanomaterials including carbon-based materials, metal and metal oxide nanoparticles, and two-dimensional platforms such as MXenes in facilitating enzyme immobilization and promoting direct or mediated electron transfer. Special emphasis is placed on engineering strategies at the bio–nano interface, including immobilization techniques, surface functionalization, and structural tuning to optimize catalytic efficiency. The review further highlights representative hybrid systems based on laccase, glucose oxidase, peroxidase, and hydrogenase enzymes, and evaluates their applications in biofuel cells, solar–bio hybrid systems, green oxidation reactions, and self-powered biosystems. Stability challenges, deactivation mechanisms, and enhancement strategies such as polymer coatings, cross-linking, and nanoconfinement are critically analyzed. Finally, emerging directions including artificial enzymes, AI-guided catalyst design, and self-healing bioelectrodes are discussed to provide a forward-looking perspective on next-generation sustainable bioelectrocatalytic systems. Full article

Chronic wounds resulting from bacterial infection remain one of the main challenges in clinical practice. There is a pressing need to develop an injectable hydrogel sealant with multifunctional properties, including remodeling capabilities, self-healing, painless removal, and antibacterial activity, to promote tissue remodeling. In this work, aldehyde carboxymethylated agarose (ACMA) is employed for the first time as a bio-template. Dopamine (DA) is introduced onto the ACMA template via a reversible Schiff-base reaction, endowing it with biomineralization properties to synthesize DA-modified ACMA-Ag nanoparticles (ACMA-DA-Ag). Further, the prepared ACMA-DA-Ag, which possesses both antibacterial activity and injectable behavior, is incorporated into a guar gum hydrogel through the formation of borate/diol bonds, thereby forming a multiple-dynamic-bond crosslinked network. This hydrogel demonstrates adequate mechanical strength, injectability, remodeling capabilities, and self-healing performance. It can reassemble into a new hydrogel within 4 ± 0.6 min upon simple physical contact, and supports tissue adhesion. Furthermore, the hydrogel effectively covers irregular-shaped wound and can be removed without causing secondary injury. More importantly, this multifunctional hydrogel is cost-effective, easy to synthesize, and simple to use, significantly accelerating skin regeneration and promoting the formation of skin appendages, such as hair follicles. The outcome of this research not only serves a tissue sealant for wound healing, but also presents a new strategy for creating novel polysaccharide-based biomaterials. Full article

Bamboo surfaces are susceptible to scratches and contamination during service, which limits their durability and aesthetic performance. To address this issue, this study aims to develop a natural self-healing coating based on tung oil microcapsules. Tung oil microcapsules encapsulated within chitosan and gum arabic (TO/CS–GA MCs) were prepared by spray drying at two feed rates (100 and 200 mL h⁻¹) and incorporated into tung oil coatings applied on bamboo substrates. The effects of microcapsule content (1.0–11.0 wt%) and feed rate on the optical performance, mechanical performance, and self-healing performance of the coatings were systematically investigated. The results showed that increasing the microcapsule content gradually increased the color difference (ΔE) and surface roughness of the coatings, while the gloss decreased. The hardness, impact resistance, adhesion grade, and self-healing efficiency of the coatings exhibited a similar trend, initially increasing and then decreasing with increasing microcapsule content. This behavior indicates that an appropriate amount of microcapsules can enhance the coating performance, whereas excessive addition leads to particle agglomeration and structural defects. Under the better condition of 5.0 wt% microcapsule content and a spray-drying feed rate of 100 mL h⁻¹, the coating exhibited the best overall performance, including higher gloss retention, a hardness of 2H, an impact resistance of 3 kg·cm, relatively low surface roughness, and a self-healing efficiency of 28.16 ± 0.63%. These results suggest that the spray-drying feed rate plays an important role in regulating the particle size distribution and encapsulation efficiency of the microcapsules, which in turn affects their dispersion and rupture–release behavior within the coating matrix. Therefore, controlling the spray-drying parameters is crucial for optimizing the performance of microcapsule-based self-healing coatings. Overall, this study provides a sustainable strategy for developing natural polymer-based self-healing coatings and offers useful insights into the design of functional microcapsules for bamboo surface protection. Full article

This study reported highly dispersible mesoporous silica (MSP) with a uniform particle size, which was used as host to load 1,10-Phenanthroline (Phen) to prepare Phen@MSP microcontainer. Improving the dispersion of microcontainers prevents performance degradation caused by their agglomeration. Phen can form a red-colored complex with Fe²⁺ ions generated during corrosion of steel substrate, enabling early corrosion warning while also acting as a corrosion inhibitor to suppress further corrosion of the substrate. Phen@MSP microcontainers were incorporated into a waterborne epoxy (EP) resin to construct a coating with dual functionality of corrosion self-diagnosing and self-healing. As a key component, the average diameter of Phen@MSP microcontainers is approximately 1 μm, with a Phen loading rate of 18.45 wt.% in the microcontainers. Surface observation shows that substrate corrosion can be detected within 10 min by the appearance of red color. After 30 d of immersion in 3.5 wt.% NaCl solution, the impedance modulus value (|Z|_0.01Hz) of the 5 wt.% Phen@MSP coating (2.27 × 10⁹ Ω·cm²) on Q235 carbon steel substrate is five orders of magnitude higher than that of the blank coating (8.79 × 10³ Ω·cm²). Salt spray tests demonstrate that the 5 wt.% Phen@MSP coating effectively suppressed corrosion propagation on the substrate. Full article

Timely fault detection, classification, and localization are fundamental to enabling fast service restoration in modern distribution networks, and are especially vital for maintaining the reliability and resilience of smart city electricity infrastructures. A new AI-based method for classifying and localizing fault types is presented in this paper, which enhances situational awareness in smart distribution grids that supply dense urban loads and critical smart city services. The proposed approach targets various fault conditions, which include three-phase-to-ground, three-phase, two-phase-to-ground, two-phase, and single-phase-to-ground faults. The proposed method utilizes a wavelet-based signal processing technique to analyze the feeder’s current data captured by waveform measurement units (WMUs) and extracts features for fault analysis. As a result of these features, a multi-stage machine learning architecture incorporating deep learning components is developed to accurately determine the occurrence, type, and location of faults. To evaluate the performance of the proposed approach, simulations were conducted on a 16-bus distribution network. Results show a high level of accuracy in fault detection, classification, and localization. This indicates that the method can be a valuable tool for enhancing the resilience and intelligence of future power grids, as well as supporting self-healing and fast service restoration in smart city services. Full article

In this work, we demonstrate that both carbon nanotubes (CNT) and graphene nanosheets (G) were successfully modified by π-stacking interactions with a pyrene derivative (PY), yielding the functionalized nanofillers CNT-PY and G-PY, which were subsequently dispersed within an aeronautical epoxy matrix. This functionalization is highly effective in preserving the remarkable electronic properties of carbon nanotubes and graphene nanosheets. At the same time, the non-covalent functionalization reduces the resin viscosity, enabling a more effective dispersion of the nanofillers. This results in improved rheological behavior and an overall enhancement of the structural performance of the nanocomposites compared to the resin containing unfunctionalized carbon nanofillers (CNT and G). Additional improvements are also observed in electrical properties, self-healing efficiency, and thermal stability. In particular, the samples containing functionalized carbon nanotubes (TBD + 1%CNT-PY) and functionalized graphene nanosheets (TBD + 1%G-PY) exhibit higher conductivities—0.391 S/m and 0.1 S/m, respectively—than the samples loaded with unfunctionalized carbon nanotubes (TBD + 1%CNT) and unfunctionalized graphene nanosheets (TBD + 1%G), which show conductivity values of 0.292 S/m and 4.82 × 10⁻³ S/m, respectively. The functionalized graphene nanosheets (G-PY) display significantly greater thermal stability, with degradation temperatures reaching 670 °C, compared to 310 °C for unfunctionalized ones (G). The functionalized carbon nanotubes (CNT-PY) show a 10% weight loss at 520 °C due to the degradation of the pyrene groups. Significant improvements in the final properties can be achieved when carbon-based nanofillers are homogeneously dispersed in the matrix and the external load is efficiently transferred through strong filler–polymer interfacial interactions, leading to composites with superior characteristics suitable for advanced applications. Tunneling Atomic Force Microscopy (TUNA) highlights the morphological features of the two types of carbon nanofillers, their dispersion within the polymer matrix and the effect of the functionalization on the electrical pathways and conductivity of the samples at both the micro- and nanometer-scale. The measured electrical conductivities are consistent with the electric currents detected at the micro/nanoscale. Full article

We introduce a class of specular and antispecular radially polarized partially coherent twisted beams by using a wavefront-folding interferometer and then investigate the propagation of such beams blocked by an opaque obstacle. One sees that these optical fields exhibit sharp internal spectral density with a central peak in the specular case and a central dip in the antispecular case. It is also seen that both the spectral density and the polarization feature present a good twist effect and a tendency to self-heal upon propagation. However, unlike the spectral density that can recover its profile perfectly, the self-healing ability of both the degree of polarization and the generalized Stokes parameters is only partial and not complete. While a smaller value of the twist factor enhances the self-healing performance of the beam field, it slows the beam’s rotation and degrades the degree of polarization. Moreover, the polarization distribution in the central area is mainly determined by the phase difference of the interferometer. The results of our work have important applications in the fields of free-space beam communication and particle trapping. Full article

Photovoltaic (PV) arrays frequently operate under non-uniform environmental conditions, including partial shading, dust accumulation, and temperature differences across the array. These factors introduce an electrical mismatch among PV modules, considerably reducing overall power output. This study proposes a self-healing reconfiguration strategy that mitigates mismatch losses by dynamically redistributing PV modules across array strings based on irradiance levels. The main goal is to balance the current generation among strings and demonstrate performance improvements within scenarios characterised by highly uneven irradiance patterns under non-uniform operating conditions. The effectiveness of the proposed method is evaluated through simulations conducted using MATLAB R2025b (MathWorks, Natick, MA, USA) under several environmental scenarios. Deterministic shading patterns—including row shading, column shading, diagonal shading, and irregular dust distributions—are first analysed to investigate the behaviour of the PV array under regulated conditions. In addition, a statistical analysis of 100 randomly generated irradiance scenarios is carried out to assess the method’s robustness. Finally, realistic desert-dust patterns representative of environmental conditions in Saudi Arabia are used to evaluate the practical usefulness of the proposed approach. Simulation findings show that the self-healing reconfiguration strategy reduces mismatch effects and improves current balance within the PV array, enabling operation closer to the optimal power point under non-uniform irradiance conditions. These results indicate that the proposed method boosts current balance among PV strings and increases power extraction under strongly non-uniform irradiance scenarios. Full article