Search Results (1,259)

Megalomyrmex ant species have a rich natural history that provides an interesting backdrop to understanding how venom has been shaped by evolution. However, like many other species in the tribe Solenopsidini, alkaloid investigations have dominated, limiting our understanding of the diversity of venom components. Here we use transcriptomics to qualify and quantify the proteins and peptides within Megalomyrmex milenae, a species of ant native to the Panamanian rainforest along the Panama Canal. RNA transcripts associated with and over-expressed in the venom gland allow the description of putative toxins and other significant protein components of the venom cocktail. Among other constituents, we find signatures for pore-forming toxins, neurotoxins, carbohydrate-digesting enzymes, proteins which potentially enhance trail pheromone efficacy, and peptides implicated in antimicrobial activity. This work greatly enhances our understanding of Megalomyrmex venoms, showing a multifaceted functional venom profile similar to other ant species. However, proteomic and functional assays are needed to clarify the venom functions hypothesized in this work. Full article

Ice accumulation on power transmission lines poses serious threats to operational safety and can lead to substantial social and economic impacts. While various anti-icing coatings have been investigated, their performance is often limited by the effectiveness and durability of anti-icing. Slippery lubricant-infused porous surfaces (SLIPSs) have shown remarkable anti-icing properties and durability, aided by their lubricant-infused and self-healing capability. In this study, SLIPSs were successfully fabricated on aluminum substrates using a two-step anodization process. The effects of the anodizing parameter of the current density on pore diameter and depth at each stage were systematically investigated. Compared to untreated aluminum and superhydrophobic coatings (SHCs), SLIPSs presented good anti-icing properties. First, at −6 °C, droplets slid off the surface completely within 4340.5 ms without pinning, indicating sustained droplet-shedding capability. It also significantly delayed ice formation, extending the freezing time to 80 min—eight times longer than that of the untreated surface. Moreover, the SLIPSs also exhibited ultra-low ice adhesion, with an initial strength of only 6.93 kPa. Meanwhile, after 100 frosting–defrosting cycles, SLIPSs could still maintain low ice adhesion strength (<20 kPa). The prepared SLIPS with a Y-shaped pore structure demonstrates good potential for anti-icing. Full article

Rainfall-induced failures in red clay slopes are common, yet the coupled influence of soil structure degradation and rainfall temporal patterns on slope hydromechanical behavior remains poorly understood. This study advances the understanding by investigating a cut slope failure in Yunnan through integrated field monitoring, laboratory testing, and numerical modeling. Key advancements include: (1) elucidating the coupled effect of structure degradation on both shear strength reduction and hydraulic conductivity alteration; (2) systematically quantifying the impact of rainfall temporal patterns beyond total rainfall; and (3) providing a mechanistic explanation for the critical role of early-peak rainfall. Mechanical and hydrological parameters were obtained from intact and remolded samples, with soil-water retention estimated via pedotransfer functions. A hydro-mechanical finite element model of the slope was constructed and calibrated using recorded rainfall, displacement data and failure surface. Six simulation scenarios were designed by combining three strength conditions (intact at natural water content, intact at saturation, remolded at natural water content) with two hydraulic conductivity values (intact vs. remolded). Additionally, four synthetic rainfall patterns, including uniform, peak-increasing, peak-decaying and bell-shaped rainfall, were simulated to evaluate their influence on pore water pressure development and slope stability. Results show remolding reduced hydraulic conductivity 4.7-fold, slowing wetting front advance and increasing shallow pore water pressure. Intact soil facilitated deeper drainage, elevating pressure near the soil-rock interface. Strength reduction induced by structure degradation (water saturating and remolding) enlarged the slope deformation zone by 1.5 times under same hydraulic conductivity. Simulations using saturated intact strength best matched field observations. The results from this specific slope indicate that strength parameters primarily control stability, while permeability affects deformation depth. Simulations considering different rainfall patterns indicate that slope stability depends more critically on the temporal distribution of rainfall intensity than on the total amount. Overall, peak-decaying rainfall led to the most rapid rise in pore water pressure, earliest instability and lowest failure rainfall threshold, whereas peak-increasing rainfall showed the opposite trends. Our findings outline a practical framework for assessing red clay slope stability during rainfall. This framework recommends using saturated intact strength parameters in stability analysis. It highlights the important influence of rainfall temporal patterns, especially those with an early peak, on failure timing and rainfall threshold. Full article

Understanding how primary structural features and secondary material properties adapt to functional loads is essential to determining their effect on changes in joint biomechanics over time. The objective of this study was to map and correlate spatiotemporal changes in primary structural features, secondary material properties, and dentoalveolar joint (DAJ) stiffness with age in rats subjected to prolonged chewing of soft foods versus hard foods. To probe how loading history shapes the balance between the primary and secondary features, four-week-old rats were fed either a hard-food (HF, N = 25) or soft-food (SF, N = 25) diet for 4, 12, 16, and 20 weeks, and functional imaging of intact mandibular DAJs was performed at 8, 12, 16, 20, and 24 weeks. Across this time course, the primary structural determinants of joint function (periodontal ligament (PDL) space, contact area, and alveolar bone socket morphology) and secondary material and microstructural determinants (tissue-level stiffness encoded by bone and cementum volume fractions, pore architecture, and bone microarchitecture) were quantified. As the joints matured, bone and cementum volume fractions increased in both the HF and SF groups but along significantly different trajectories, and these changes correlated with a pronounced decrease in PDL-space from 12 to 16 weeks in both diets. With further aging, older HF rats maintained significantly wider PDL-spaces than SF rats. These evolving physical features were accompanied by an age-dependent significant increase in the contact ratio in the SF group. The DAJ stiffness was significantly greater in SF than HF animals at younger ages, indicating that food hardness-dependent remodeling alters the relative contribution of structural versus material factors to joint function across the life course. At the tissue level, volumetric strains, representing overall volume changes, and von Mises bone strains, representing shape changes, increased with age in HF and SF joints, with volumetric strain rising rapidly from 16 to 20 weeks and von Mises strain increasing sharply from 12 to 16 weeks. Bone in SF animals exhibited higher and more variable strain values than age-matched HF bone, and changes in joint space, degrees of freedom, contact area, and bone strain correlated with joint biomechanics, demonstrating that multiscale functional biomechanics, including bone strain in intact DAJs, are colocalized with anatomy-specific physical effectors. Together, these spatiotemporal shifts in primary (structure/form), and secondary features (material properties and microarchitecture) define divergent mechanobiological pathways for the DAJ and suggest that altered loading histories can bias joints toward early maladaptation and potential degeneration. Full article

This work characterizes hybrid hydrogels prepared via the combination of natural and synthetic polymers. By incorporating a biocompatible compound, poly(ethylene glycol) diacrylate (PEGDA, M_n = 400), into alginate and carboxymethyl cellulose (CMC)-based hydrogels, the in situ UV crosslinking of these materials was assessed. A custom direct-write (DW) 3D bioprinter was utilized to prepare hybrid hydrogel constructs and scaffolds. A control sample, which consisted of 4% w/v alginate and 4% w/v CMC, was prepared and evaluated in addition to three PEGDA (4.5, 6.5, and 10% w/v)-containing hybrid hydrogels. Rotational rheology was utilized to evaluate the thixotropic behavior of these materials. Filament fusion tests were employed to generate bilayer constructs of various pore sizes, providing metrics for the printability and diffusion rate of hydrogels post-extrusion. Printability indicates the shape fidelity of pore geometry, whereas diffusion rate represents material spreading after deposition. Curing kinetics of PEGDA-containing hydrogels were evaluated using photo-Differential Scanning Calorimetry (DSC) and photorheology. The Kamal model was fitted to photo-DSC results, enabling an assessment and comparison of the curing kinetics for PEGDA-containing hydrogels. Photorheological results highlight the increase in hydrogel stiffness concomitant with PEGDA content. The range of obtained complex moduli (G*) provides utility for the development of brain, kidney, and heart tissue (620–4600 Pa). The in situ UV irradiation of PEGDA-containing hydrogels improved the shape fidelity of printed bilayers and decreased filament diffusion rates. In situ UV irradiation enabled 10-layer scaffolds with 1 × 1 mm pore sizes to be printed. Ultimately, this study highlights the utility of PEGDA-containing hybrid hydrogels for high-resolution DW 3D bioprinting and potential application toward customizable tissue analogs. Full article

Systemic anticancer therapy causes a number of side effects; therefore, local drug release devices may play an important role in this area. In this study, we developed polyurethane-dendrimer foams containing different amounts of third-generation poly (amidoamine) dendrimers (PAMAM G3) to evaluate their ability to encapsulate and release the model anticancer drug doxorubicin (DOX), as well as their biocompatibility and effectiveness against normal and cancer cells in vitro. PU–PAMAM foams containing 10–50 wt% PAMAM G3 were prepared using glycerin-based polyether polyol and castor oil as co-components. Structural and rheological analyses revealed that foams containing up to 20 wt% PAMAM G3 exhibited a well-developed porous structure, while higher dendrimer loadings (≥30 wt%) led to irregular cell shapes, pore coalescence, and thinning of cell walls, and indicated a gradual loss of structural integrity. Rheological creep–recovery measurements confirmed the structural findings: moderate PAMAM G3 incorporation (≤20 wt%) increased both the instantaneous and delayed elastic modulus (E₁ ≈ 130–140 kPa; E₂ ≈ 80 kPa) and enhanced elastic recovery, reflecting improved cross-link density and foam stability. Higher dendrimer contents (30–50 wt%) caused a decline in these parameters and higher viscoelastic compliance, indicating a softer, less stable structure. The DOX loading capacity and encapsulation efficiency increased with PAMAM G3 content, reaching maximum values of 35% and 51% for 30–40 wt% PAMAM G3, respectively. However, the most sustained DOX release profiles were observed for matrices containing 20 wt% PAMAM G3. Analysis of cumulative release and kinetic modeling revealed a transition from diffusion-controlled release at low PAMAM contents to burst-dominated release at higher dendrimer loadings. Importantly, matrices containing 10–20 wt% PAMAM G3 also indicated selective anticancer action against squamous cell carcinoma (SCC-15) compared to non-cancerous human keratinocytes (HaCaT). Moreover, the DOX they released effectively destroyed cancer cells. Overall, PU–PAMAM foams containing 10–20 wt% PAMAM G3 provide the most balanced combination of structural stability, controlled drug release, and cytocompatibility. These materials therefore represent a promising platform as passive carriers in drug delivery systems (DDSs), such as local implants, anticancer patches, or bioactive wound dressings. Full article

Zeolites and molecular sieves have demonstrated remarkable potential in adsorption, ion exchange, and separation processes since their industrial revolution in the 1950s. Zeolites and molecular sieves are materials of choice in separation applications because of their well-defined microporous architecture, remarkable shape-selectiveness, and tunable characteristics. The adsorption process can be evaluated using an isotherm to determine the feasibility of gas mixture separation for practical applications. We will also discuss the basic structure of zeolites and molecular sieves based on different metals, along with their distinctive properties in detail. The purpose of this review is to contextualize the importance of zeolites and molecular sieves in adsorption and separation applications. The review has been divided into groups based on how zeolites as well as molecular sieves are established in the adsorption and separation processes. The fundamental adsorption characteristics, structures, and various separation methods that make zeolites appealing for different uses are covered. By incorporating knowledge of adsorption mechanisms, isotherms, and material changes, this review discusses the most recent developments. To augment zeolite-based materials for certain pollutant removal applications, it offers a strategic framework for future study. In this review, we will comprehensively discuss a range of separation and adsorption applications, including wastewater purification, CO₂ capture from flue gases, and hydrogen storage. Furthermore, the review will explore emerging prospects of zeolites and molecular sieves in innovative fields such as energy storage, oil refining, and environmental remediation. Emphasis will be placed on understanding how their tunable pore structures, surface chemistry, and metal incorporation can enhance performance and broaden their applicability in sustainable and clean energy systems. Full article

The laser welding of 4 mm thick Ti80 alloy under different powers was analyzed, and the weld morphology, microstructure, and mechanical properties were studied. A simulation model was established based on ABAQUS, and laser welding simulations were conducted using 2520 W and 3000 W laser welding power sources to analyze the temperature field and stress field, which were verified by experiments. The increase in power changed the weld morphology from Y-shaped to X-shaped and affected the number of pores in incomplete and complete penetration. The microstructure in the weld zone presented fine acicular α′ phase. Subsequently, grain boundary distribution maps, Kernel Average Misorientation (KAM) maps, and geometrically necessary dislocation (GND) density maps were generated through electron backscatter diffraction (EBSD) analysis. These comprehensive data visualizations enabled multi-dimensional investigation, establishing and analyzing correlations between laser welding parameters, microstructural evolution, and mechanical properties in Ti80 titanium laser welding. The hardness of the base material was 320 HV to 360 HV, and it increased from 420 HV to 460 HV in the weld zone. At 3000 W, the tensile strength reached 903.12 MPa, and the elongation was 10.40%, indicating ductile fracture. The simulation results accurately predicted the maximum longitudinal residual stress in the weld zone, with an error of 1.65% to 1.81% of the measured value. Full article

In shale oil accumulation, the sealing capacity of roof strata is a key factor controlling hydrocarbon retention, primarily governed by pore–throat structures. This study examines the Chang 7₃ sub-member roof in the Ordos Basin using core and drilling samples, combined with SEM, mercury intrusion porosimetry, nitrogen adsorption, and breakthrough pressure tests. The roof rocks are dense and mainly composed of mudstone, silty mudstone, and argillaceous siltstone, which can be further classified into clay-rich and felsic-rich types. The pore system includes organic matter pores, dissolution pores, intergranular pores, clay interlayer pores, intercrystalline pores, and microfractures. Pores are dominated by mesopores (4–10 nm), with few macropores, and display slit-like, plate-, and wedge-shaped morphologies. Breakthrough pressure averages above 20 MPa, reflecting strong sealing capacity. Although dissolution of felsic minerals generates secondary porosity that may weaken sealing, the overall complex pore–throat system, reinforced by compaction and cementation of clay minerals, forms a dense fabric and favorable sealing conditions. These features restrict hydrocarbon migration and enhance the sealing performance of the Chang 7₃ shale oil roof. Full article

Microbial fermentation stands as the foundational technology in modern biorefineries, yet its industrial scalability is critically constrained by product inhibition, prohibitive downstream separation costs, and substrate inhibition. Metal–organic frameworks (MOFs) offer a tunable material platform to address these challenges through rational design of pore size, shape, and chemical functionality. This review systematically chronicles the evolution of MOF applications in biomass fermentation across four generations, demonstrating a synergistic mapping where the core fermentation challenges—product toxicity, substrate toxicity, and separation energy intensity—align with the inherent MOF advantages of high adsorption capacity, programmable selectivity, and tunable functionality. The applications progress from first-generation passive adsorbents for in situ product removal, to second-generation protective agents for mitigating inhibitors, and third-generation immobilization scaffolds enabling continuous processing. The fourth-generation systems transcend passive scaffolding to position MOFs as active metabolic partners in microbe-MOF hybrids, driving cofactor regeneration and tandem biocatalysis. By synthesizing diverse research streams, ranging from defect engineering to artificial symbiosis, including defect engineering strategies, this review establishes critical design principles for the rational integration of programmable materials in next-generation biorefineries. Full article

Intermetallic Fe₃Al-based alloys reinforced with Laves-phase precipitates are emerging as potential replacements for conventional high-alloy steels and possibly polycrystalline Ni-based superalloys in structural applications up to 700 °C. Their impressive mechanical properties, however, are offset by limited fabricability and poor machinability due to their severe brittleness. High tool wear during finish-machining, which is still required for components such as turbine blades, remains a key barrier to their broader adoption. In contrast to conventional manufacturing routes, additive manufacturing offers a viable solution by enabling near-net-shape manufacturing of difficult-to-machine iron aluminides. In the present study, laser powder bed fusion was used to produce an Fe-25Al-1.5Ta intermetallic containing strengthening Laves-phase precipitates, and the porosity, microstructure and phase composition were characterized as a function of the process parameters. The results showed that preheating the build plate to 650 °C effectively suppressed delamination and macrocrack formation, even though noticeable cracking still occurred at the high scan speed of 1000 mm/s. X-ray tomography revealed that samples fabricated with a lower scan speed (500 mm/s) and a higher layer thickness (0.1 mm) contained larger, irregularly shaped pores, whereas specimens printed at the same volumetric energy density (40 J/mm³) but with different parameter sets exhibited smaller fractions of predominantly spherical pores. All samples contained mostly elongated grains that were either oriented close to <001> relative to the build direction or largely texture-free. X-ray diffraction confirmed the presence of Fe₃Al and C14-type (Fe, Al)₂Ta Laves phase in all samples. Hardness values fell within a narrow range (378–398 HV10), with only a slight reduction in the specimen exhibiting higher porosity. Full article

A sustainable pathway for converting low-value solid waste (Coal gangue, CG) into high-performance thermal insulation materials through a green synthesis strategy has been demonstrated. The SiO₂ was successfully and efficiently extracted from CG in the form of sodium silicate. The subsequent sol–gel process of sodium silicate solution utilized an innovative CO₂ carbonation method, which replaced the conventional use of strong acids, thereby reducing the carbon footprint and enhancing process safety. Hydrophobic SiO₂ aerogel was subsequently prepared via ambient pressure drying, exhibiting a high specific surface area of 750.4 m²/g, a narrow pore size distribution ranging from 2 to 15 nm and a low thermal conductivity of 0.022 W·m⁻¹·K⁻¹. Furthermore, the powdered aerogel was shaped into a monolithic form using a simple molding technique, which conferred appreciable compressibility and resilience, maintaining the low thermal conductivity and hydrophobicity of the original aerogels, ensuring its functional integrity for practical applications. Practical thermal management tests including low and high temperature, conclusively demonstrated the superior performance of the prepared aerogel material. This work presents a viable and efficient waste-to-resource pathway for producing high-performance thermal insulation materials. Full article

Installation in sand is sensitive to its evolving pore structure, yet design models rarely update permeability for real-time fabric changes. This study tracks the stress-dependent pore size distribution of coarse sand under laterally constrained compression using high-resolution X-ray nano-CT. Scans taken at six axial stress levels show that the distribution shifts toward smaller radii while keeping its log-normal shape. A single shifting factor, defined as the current median radius normalized by the initial value, captures this translation. The factor decays with axial stress according to a power law, and the exponent as well as the reference pressure are calibrated from void ratio data. The resulting closed-form expression links mean effective stress to pore radius statistics without extra fitting once the compressibility constants are known. This quantitative relation between effective stress and pore size distribution has great potential to be embedded into coupled hydro-mechanical solvers, enabling engineers to refresh hydraulic permeability at every computation step, improving predictions of excess pore pressure and soil resistance during suction anchor penetration for floating wind foundations. Full article

Due to their unique functional properties, such as deformability, bendability, stretchability, and even biocompatibility, sensing, or actuation, flexible materials have become an indispensable and crucial component in electronic systems such as wearable electronic devices and soft robots. Facing the complex demands of various application scenarios, 3D printing technology can be utilized to customize the preparation of various flexible materials into desired shapes. However, compared to rigid materials, flexible materials still face printing issues such as pore defects and weak interlayer bonding during the 3D printing process. Therefore, this paper focuses on analyzing the key bottleneck issues and technical challenges currently existing in flexible material 3D printing technology, and provides an overview of the progress in preparing flexible materials using 3D printing technologies, such as Material Extrusion and Vat Polymerization. Finally, it looks forward to the technical challenges and future development of 3D printing with flexible materials. Full article