Search Results (3,300)

The increasing generation of construction and demolition waste, along with the depletion of natural aggregates, has driven growing interest in recycled concrete aggregate (RCA) and reclaimed asphalt pavement (RAP) as sustainable alternatives in concrete production. However, a direct and systematic comparison between the two materials remains limited. This review addresses this gap by applying PRISMA guidelines to analyze 82 peer-reviewed studies published between 2010 and 2026. Both materials are evaluated across three key domains: physical properties, mechanical performance, and microstructural characteristics. The findings indicate that RCA can reduce compressive strength by up to 26%, mainly due to the presence of porous adhered mortar and a complex interfacial transition zone (ITZ). In contrast, RAP weakens bonding with cement paste because of its hydrophobic bituminous coating, leading to adhesive failure at the mortar asphalt interface. Despite these limitations, RCA and RAP exhibit distinct behaviors in terms of shear capacity, ductility, energy absorption, and durability. Enhancement techniques such as surface treatment, carbonation, supplementary cementitious materials, and fiber reinforcement show potential in improving performance. Additionally, life cycle and economic analyses reveal that RAP can reduce total costs and carbon emissions when efficiently processed. This study provides a unified comparative framework to support sustainable material selection and design optimization. Full article

Two 4-piperazine-1,8-naphthalimides were designed as fluorescent probes for exploring the local polarity and proton concentration at the interface of micelles. Designed with an anchor₁-fluorophore-spacer-receptor-anchor₂ layout, the hydrophobicity of the pH probes was tuned by substitution of the anchor modules with different alkyl chains (methyl, butyl and octyl) to facilitate the micellar penetration depth. Fluorescence switching ‘on’ in methanol/water media upon protonation of the piperazine receptor is driven by a competition between solvent polarity and photoinduced charge transfer. The solvatochromic properties were investigated to enhance visual naked-eye communication. The fluorescent probes were tasked with reporting on the local polarity and proton content within sodium dodecyl sulphate (SDS), cetyltrimethylammonium chloride (CTAC) and Triton X-100 micelles. The dimethyl-substituted probe reported on the environment about the micelle/bulk water interface. The more hydrophobic octyl-butyl-substituted probe explored deeper into the micelles. Insight was gained into the local polarity and proton gradients inside micelles, as corroborated by emission wavelength, fluorescence quantum yield and ΔpK_a values. The findings are discussed in the context of the benzofurazan polarity–ΔpK_a maps reported by Uchiyama and de Silva. Full article

Per- and polyfluoroalkyl substances (PFAS) are widely detected in aquatic environments, and their bioaccumulation, trophic magnification, and ecotoxicity have raised increasing concern. However, critical knowledge gaps remain regarding how differences in their molecular structures influence these processes and the mechanisms underlying such effects. This review synthesizes the current knowledge of the physicochemical properties, bioaccumulation, trophic magnification, and toxicity of PFAS in aquatic environments, with particular emphasis on the effects of the carbon-chain length, functional-group type, and acid or salt form. The current evidence generally indicates that long-chain PFAS exhibit higher bioaccumulation, trophic magnification, and toxicity than short-chain PFAS, largely because of their enhanced hydrophobicity, stronger protein-binding affinity, and slower elimination rates. As two major PFAS subclasses, perfluoroalkyl sulfonates (PFSAs) generally show higher bioaccumulation and toxicity than perfluoroalkyl carboxylates (PFCAs). For example, the bioaccumulation factor of perfluorooctane sulfonate (PFOS) is approximately two- to three fold higher than that of perfluorooctanoic acid (PFOA). Some ether-containing PFAS, developed as safer alternatives, also exhibit concerning ecological hazards, particularly a high potential for trophic magnification. In addition, acid form PFAS generally accumulate more readily and induce more severe toxic effects than their corresponding salt forms. These findings highlight the need to further improve structure-based frameworks for PFAS ecological risk assessment. Full article

Differences in the composition, microstructure, infrared spectral characteristics, and enzymatic hydrolysis properties of rice bran protein extracted by four methods were investigated, and the antioxidant and anti-photoaging activities of peptides derived from the resulting hydrolysates were further evaluated. Rice bran protein obtained via ultrasonic pretreatment combined with alkaline solublilization and acid precipitation (URP) exhibited relatively high purity (59.17%) and extraction yield (47.61%), together with increased surface porosity, enhanced hydration capacity, and improved enzymatic hydrolysis performance. The URP hydrolysate (URPP) showed a protein content of 81.00%, a degree of hydrolysis of 33.57%, and marked antioxidant activity (ABTS, 684.21; ORAC, 2016.15 μmol TE/g sample). The identified peptides were predominantly short and enriched in hydrophobic amino acids. Structural analysis suggested that the indole N-H group of tryptophan may play an important role in the antioxidant activity of these peptides. Moreover, these peptides alleviated UVB-induced photoaging in HaCaT cells by reducing oxidative stress and inflammatory responses and downregulating the mRNA expressions of AP-1, MMP-1 and MMP-3. Overall, these findings reveal an association between the extraction method, structural characteristics, and enzymatic hydrolysis properties of rice bran protein and the biological activities of its derived peptides, providing a basis for the high-value utilization of rice bran protein and the development of antioxidant and anti-photoaging functional ingredients. Full article

Protein solubility can limit enzyme performance in industrial applications. This is the case for some carbonic anhydrases (CAs), key enzymes for CO₂ capture and utilization. In this study, we investigated an α-class CA from the thermophilic bacterium Hydrogenimonas thermophila (HtCA), which was predominantly expressed as an insoluble protein in Escherichia coli. Surface analysis using Molecular Operating Environment (MOE) revealed extensive hydrophobic regions, suggesting a basis for its poor solubility. To improve solubility, three C-terminal fusion tags were evaluated (Gb1, ng3-NEXT, and T7B9). All tagged variants showed markedly increased soluble expression as determined by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) analysis. To reduce surface hydrophobicity, selected residues were substituted with charged amino acids. Most variants displayed improved solubility, and V136D showed enhanced thermostability, retaining 76% activity after exposure to 90 °C for an hour. However, the F177D variant completely lost all enzymatic activity, highlighting the importance of evaluating both solubility and catalytic function during protein engineering. Molecular dynamics simulations supported the experimental findings, revealing that thermostable variants exhibited reduced structural fluctuations and favorable free-energy landscapes, while the inactive F177D mutant sampled a broader conformational space and higher-energy conformations, consistent with decreased structural stability and loss of catalytic activity. Full article

Vascular stent implantation is a major treatment for vascular diseases, yet postoperative infection and persistent inflammation increase the risk of in-stent restenosis. Herein, core–shell structured PCL/PEO-PVP fiber membranes co-loaded with ciprofloxacin hydrochloride (CIP) and curcumin (CUR) were fabricated via coaxial electrospinning. Orthogonal experiments were conducted to optimize critical spinning parameters through multi-index comprehensive evaluation. Characterizations confirm intact core–shell architecture and stable polymeric backbone structure. In vitro release tests reveal sequential drug-delivery behavior: a rapid initial release of hydrophilic CIP and a delayed sustained release of hydrophobic CUR were observed, contributing to early-stage antibacterial and long-term anti-inflammatory effects, respectively. The “antibacterial zone” method verifies favorable antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). ELISA results demonstrate the enhanced anti-inflammatory capacity of the dual-drug-loaded coaxial fiber membrane. Cellular assays confirm satisfactory cytocompatibility, and endothelial cells achieve normal proliferation and exhibit typical polygonal morphology on the membrane surface. This dual-drug-loaded coaxial-fiber membrane realizes coordinated sequential antibacterial and anti-inflammatory properties, which provides a feasible strategy for developing functional coatings toward vascular stents. Full article

Gene delivery to target cells is required for bioengineering or medical/agricultural applications. However, the hydrophobicity of the cell membrane always makes it resistant to polar nucleic acids. This physicochemical barrier is usually overcome by a nano-formulation to hide the polarity. This study evaluated a specific formulation called star polycation (SPc) regarding its efficacy in DNA/RNA delivery to insect cells. The delivery efficiency of the SPc formulation was assessed by transient expression of green fluorescence protein (GFP) in Sf9 cells, in which SPc formulation significantly enhanced the gene expression compared with an unformulated vector. In vivo transient expression (IVTE) was performed by injection of the expression construct with the SPc formulation into larvae of S. exigua. Fluorescence was detected in all four tissues, namely, epidermis, midgut, hemocyte, and fat body, where the SPc formulation enhanced the expression in most tissues except epidermis. Under this IVTE condition, an additional injection of SPc-formulated dsRNA specific to GFP suppressed the gene expression significantly more than the unformulated vector. The enhanced RNA interference (RNAi) efficiency caused by the SPc formulation was confirmed against four endogenous genes of S. exigua, namely, Snf7, PSMB5, vATPase, and α-tubulin, by either injection or feeding of dsRNA. These RNAi treatments were lethal to S. exigua, in which dsRNA specific to vATPase formulated with SPc resulted in almost 80% mortality through oral delivery. A similar oral toxicity by SPc-formulated dsRNA was demonstrated in another lepidopteran Plutella xylostella. The oral delivery of dsRNA was applied to control sucking insects such as aphids and thrips by spraying SPc-formulated dsRNA onto plant surfaces. The sprayed dsRNA labeled with Cy3 fluorescence was detected in the internal tissues of plant leaves, in which the penetration of dsRNA into the plant tissues was further accelerated by SPc formulation. The SPc formulation of dsRNA specific to vATPase was effective at killing the sucking insects by spraying on plant surfaces. These results suggest the application of an SPc formulation to deliver DNA/RNA to insect cells. Full article

Prebiotics are predominantly indigestible carbohydrate-based substrates selectively-utilized by beneficial gut-microbes to support host-health. We previously developed protein-containing prebiotics that co-deliver carbohydrate and protein substrates to the colon, where gut-microbes compete for the limited nitrogen availability, thereby enhancing microbial growth, metabolic activity, and host health compared with conventional carbohydrate prebiotics. Resveratrol is a grape-derived polyphenol with antioxidant, anti-inflammatory, and emerging prebiotic activity. Here, we developed a multifunctional protein-containing prebiotic system based on Maillard conjugates of 2′-fucosyllactose–potato protein hydrolysate (2′-FL-PPH) micelles encapsulating resveratrol, followed by genipin crosslinking. This crosslinked 2′-FL-PPH-resveratrol system is designed to limit premature protein and resveratrol absorption, enhancing their colonic co-delivery. We characterized the encapsulation efficacy, physicochemical properties, digestibility and colonic delivery. The conjugates (10 mg/mL 2′-FL-PPH) effectively entrapped resveratrol (600 µM), exhibiting an average particle size of ~28 nm and an encapsulation efficiency of 79.5 ± 4.9%. Binding studies demonstrated predominantly hydrophobic interactions between resveratrol and 2′-FL-PPH. The conjugates prevented resveratrol crystallization in aqueous media, while genipin crosslinking enhanced resistance to simulated gastrointestinal digestion and inhibited premature resveratrol release, increasing the fraction expected to reach the colon. Collectively, this system enables colonic co-delivery of carbohydrate, peptides, and resveratrol, providing a novel strategy for promoting beneficial-microbiota and gut-health. Full article

Solid–liquid interfacial heat transfer plays a key role in microelectronic devices, energy systems, and liquid cooling technologies. However, the vibrational mismatch at solid–liquid interfaces produces an interfacial thermal resistance (ITR) that limits the heat-dissipation efficiency. Herein, molecular dynamics (MD) simulations were used to study the regulation of heat transfer at Ti–water interfaces by the Ti-O interaction strength. As the interaction strength increased, the Ti surface changed from strongly hydrophobic to complete wetting, with the contact angle spanning 153° to θ < 5° over the full droplet series. Over the range where the interfacial thermal conductance (ITC) was computed, the contact angle decreased from about 143° to 15°, and the ITC increased from 35.71 ± 4.26 to 231.97 ± 14.17 MW/m²·K. This increase originated from changes in the interfacial water structure, as the stronger interaction led to a denser and more ordered near-wall water structure that became more tightly bound to the surface, which enhanced the solid–liquid vibrational coupling. From the phonon perspective, the spectral overlap increased by only about 2%, from 0.01973 to 0.02008 THz⁻¹, while the ITC increased by a factor of 6.5, indicating that the spectral overlap is not the controlling factor. Instead, the phonon lifetime of the interfacial Ti shortened markedly while the phonon heat capacity remained stable, showing that the enhancement originates from the stronger interfacial coupling rather than from an increase in the spectral overlap. This work clarifies how wettability regulates the microscopic structure of interfacial water and interfacial vibrational coupling, and provides a basis for understanding heat transfer at metal–water interfaces. Full article

Ilmenite is the core carrier of titanium resources in China. Conventional flotation systems generally have the problems of insufficient collector adsorption efficiency and limited separation index. Microwave pretreatment can strengthen the flotation process by activating the surface of minerals, but its regulation mechanism on the interface properties of ilmenite and the adsorption behavior of collectors remains to be systematically elucidated. Based on the previous research on the flotation separation effect of the ‘OHA + HDPA composite collector + microwave pretreatment (power of 800 W and irradiation time of 180s)’ system, this paper uses the OHA + HDPA (mass ratio 3:1) composite system as the collector and uses surface tension, contact angle, Zeta potential, infrared spectroscopy and X-ray photoelectron spectroscopy, and other multi-scale complementary characterization methods to systematically study the effect of microwave activation on the wettability of ilmenite surface and the adsorption of collector interface. The results show that the wettability of ilmenite surface by microwaves presents a two-way regulation characteristic. In a pure water system, microwave activation increases the surface polar active sites, the water contact angle decreases from 48.44° to 46.65°, and the hydrophilicity is slightly enhanced. Under the action of the collector, microwaves promoted the directional adsorption and orderly arrangement of reagents, the contact angle of minerals increased to 85.24°, the adhesion work reached 0.560 J/m², and the surface hydrophobicity and solid–gas adhesion ability were significantly improved. Interfacial electrokinetic analysis showed that microwave activation enhanced the positive surface charge of ilmenite, and the isoelectric point shifted from pH 5.1 to alkaline to pH 6.3. In the range of pH 2–10, the Zeta potential of the sample after microwave treatment shifted more negatively, which was due to the synergistic enhancement of electrostatic attraction and chemical chelation sites. Microscopic characterization confirmed that the collector was attached to the surface of ilmenite in the form of chemical adsorption. Microwaves did not change the essential properties of adsorption but increased the adsorption capacity of the collector by 10.9%, and the adsorption layer was more compact and orderly. A mechanism analysis reveals that microwave irradiation induces the oxidation of surface Fe²⁺ to Fe³⁺, and its atomic proportion increases from 23.91% to 38.64%, which significantly enhances the chelation between the collector and the iron site and the stability of the chemical bond. At the same time, combined with the change of XPS coordination environment, it is speculated that microwaves can induce lattice distortion, change the coordination environment of titanium atoms, increase the proportion of Ti-O-Fe bridge oxygen structure, increase the unsaturated titanium active site, and strengthen the coordination between the collector and the titanium site. The synergistic activation of iron–titanium multi-sites together enhances the adsorption strength and adsorption capacity of the collector. This study can provide theoretical support at the interface chemical level for the development of high-efficiency ilmenite flotation process. Full article

The extensive use of common petroleum-based plastics in food packaging has raised serious environmental concerns, accelerating the search for biodegradable and functional alternatives. In this study, poly(butylene adipate-co-terephthalate)/curcumin (PBAT/Cur) bioactive composite films with colorimetric sensing properties were successfully prepared via solution casting. A systematic characterization was conducted on the structural, morphological, barrier, antioxidant, antibacterial, and colorimetric properties of the films. The optimal PBAT/Cur1% films exhibited potent antioxidant activity (DPPH scavenging up to 95.6%) and moderate antibacterial activity against E. coli and S. aureus. Additionally, curcumin incorporation not only increased the water contact angle of the PBAT/Cur1% films, indicating enhanced surface hydrophobicity, but also concurrently improved the barrier properties, as evidenced by a reduced water vapor permeability (WVP of 14.58 g·mm/m²·day·kPa) and a lower oxygen transmission rate (OTR of 7.533 × 10⁻³ cm³/m²·day·Pa) compared to the neat PBAT films. Notably, the films displayed a distinct and rapid color change from yellow to reddish-brown upon exposure to ammonia vapor, suggesting their promise for on-package visual freshness indication. These findings highlight PBAT/Cur composite films as a sustainable option for active and intelligent food packaging, with combined antioxidant, antibacterial, and colorimetric properties, making them promising for packaging protein-rich foods (e.g., meat and seafood). Full article

Reinforced concrete structures in marine environments are subjected to severe deterioration, particularly in tidal zones. The development of intrinsically hydrophobic concrete through internal modification provides a promising strategy to mitigate this challenge. This study employed sodium methyl silicate (SMS) as a hydrophobic agent to prepare recycled fine aggregate concrete (RFAC), which was subsequently subjected to accelerated indoor chloride dry–wet cycling. The deterioration behavior of RFAC and the degradation mechanism of the SMS-induced hydrophobic film during dry–wet cycling were investigated through evaluations of mechanical performance, hydrophobicity, chloride resistance, microstructure, phase composition, pore structure, chemical bonding, and functional groups. The results show that SMS improves the hydrophobicity of RFAC but inhibits its hydration process. The optimal SMS dosage for RFAC under dry–wet cycling is 9‰, which achieves a balance between hydrophobicity enhancement and pore structure optimization. Compared with ordinary RFAC, the specimen exhibits 12.9‰ and 17.6% increases in compressive strength and RDEM, respectively, after 30 cycles, accompanied by reductions of 25.8%, 52.7%, and 80.0% in peak free chloride content, chloride erosion depth, and convection zone depth, respectively. RFAC with 9‰ SMS exhibits a denser matrix with lower porosity and fewer corrosion products. SMS enhances chloride resistance mainly by reducing water transport and chloride ion ingress through hydrophobic modification. Dry–wet cycling gradually deteriorates the SMS-induced hydrophobic film through the weakening of Si-C-related structures, while the Si-O-Si framework remains relatively stable. A quantitative correlation between the contact angle and free chloride ion content is established, and the modified Lucas–Washburn equation provides a reasonable description of chloride ion penetration depth. Full article

To improve the antifouling and self-cleaning performance of 3003 aluminum alloy, a fluorine-free water-repellent surface was fabricated by combining nanosecond laser texturing with subsequent heat treatment. The effects of scanning speed, laser power, pulse frequency, and scanning interval on surface wettability were systematically investigated. Under the optimal conditions of 2700 mm/s, 6 W, 35 kHz, and 20 μm, the surface achieved a maximum static water contact angle of 154.3 ± 0.8°. Surface characterization showed that laser processing generated hierarchical micro-/nano-scale structures, while heat treatment promoted surface chemical evolution associated with enhanced hydrophobicity. The highly water-repellent behavior resulted from the synergistic effect of hierarchical roughness and heat-treatment-induced surface chemical changes. The fabricated surface exhibited effective self-cleaning performance, achieving a SiO₂ removal efficiency of 98.8% under the specified test conditions. In addition, relatively high water repellency was retained after repeated water-impact and tape-peeling tests. These results demonstrate that nanosecond laser texturing combined with heat treatment provides a simple and environmentally friendly strategy for fabricating water-repellent AA3003 surfaces for antifouling and surface-protection applications. Full article

Background/Objectives: Antimicrobial peptides (AMPs) have emerged as promising alternatives to conventional antibiotics in response to the escalating global threat of antimicrobial resistance (AMR), owing to their potent antimicrobial activity and low propensity for resistance development. However, their clinical application remains limited by poor selectivity and undesirable toxicity toward mammalian cells. Methods: In this study, the naturally occurring frog-derived AMP Dermaseptin-A4 (A4) was selected as a template for rational design. Guided by the principle that optimising the balance between peptide hydrophobicity and cationicity could improve bacterial membrane targeting while reducing interactions with mammalian membranes, three analogues were designed through the targeted modulation of these physicochemical properties. Results: Among the designed analogues, A4-3 exhibited the best overall biological profile. A4-3 maintained a stable α-helical conformation in membrane-mimicking environments and displayed potent antimicrobial activity against tested Gram-positive and Gram-negative bacteria while exhibiting lower haemolytic and cytotoxic effects than the parent peptide. As a result, A4-3 showed improved selectivity, achieving a selectivity index of up to 34.5. A4-3 rapidly eradicated bacterial cells through a membrane-targeting mechanism, leading to membrane disruption and the loss of cellular integrity, and exhibited a low propensity for resistance development following prolonged exposure. A4-3 also retained its antimicrobial activity under physiologically relevant conditions. Conclusions: Collectively, these findings demonstrate that achieving an optimal balance between peptide hydrophobicity and cationicity is an effective strategy for enhancing antimicrobial selectivity without compromising antibacterial activity, highlighting A4-3 as a promising lead candidate for the development of novel antimicrobial therapeutics against drug-resistant bacterial infections. Full article

Low-density lignocellulosic foams offer a sustainable alternative to conventional packaging materials; however, their low density increases shipping costs, and dust generation during handling can limit their practical use. In this study, we demonstrate that these foams can be compressed into thin sheets to reduce shipping volume and subsequently recover up to 65% of their original thickness when exposed to 85% relative humidity (RH). The recovered foams retained favorable thermal insulation properties suitable for packaging applications. We further show that surface coating with cellulose nanofibrils (CNFs) significantly reduces dust generation during handling while improving compressive strength compared to uncoated foams. Incorporation of alkyl ketene dimer (AKD) into the coating formulation further imparted hydrophobicity to the foam surface. Overall, the combination of compressibility, humidity-triggered shape recovery, improved mechanical performance, reduced dust generation, and enhanced surface hydrophobicity highlights the potential of CNF-coated low-density lignocellulosic foams as sustainable packaging materials with improved handling characteristics and transportation efficiency. Full article