Search Results (255)

The increasing demand for lightweight aerospace structures has driven the continuous development of ultra-high-strength aluminum alloys (UHSAAs). Owing to their low density and high specific strength, UHSAAs remain the primary materials for next-generation aerospace structural components. Over the past decades, their tensile strength has increased from the 500 MPa level to beyond 700 MPa, accompanied by a shift in research focus from strength maximization to the synergistic optimization of strength, ductility, and damage tolerance. This work concentrates on 7xxx series and Al–Li alloys, systematically reviewing recent research advances and key challenges in alloy design and forming. Particular emphasis is placed on new strategies for strength–ductility synergy and the associated microstructural strengthening and toughening mechanisms. Finally, future development directions are discussed to provide guidance for the design and engineering application of high-performance aerospace aluminum alloys. Full article

To improve coating adhesion and tribological stability on aircraft-grade aluminum, this work utilizes periodic fiber-laser microtexts as a surface-engineering pre-treatment before applying an epoxy primer. AA2024-T3 panels were imprinted with rhombus, hexagon, and circular lattices (scale factors 100–250 µm; scan speeds 250–750 mm s⁻¹), then primed with an aerospace epoxy primer and evaluated within reciprocating sliding wear tests. Areal profilometry and sessile-drop goniometry measured topography and wettability, whereas friction–distance traces and scratch-track metrology resolved interfacial integrity. The textures expanded surface area and modified energy states in a geometry- and scale-dependent fashion, producing stable friction plateaus and smaller, less-lateral scratch scars compared to the untextured reference. Circular dimples reliably provided the best damage-tolerant behavior, a function of improved mechanical interlocking and debris/film management (reservoir and micro-trap effects), whereas polygonal lattices evidenced greater sensitivity to both scale and speed. Factorial analyses disclosed prevalent interaction effects amongst geometry, scale, and scan speed, reinforcing the notion that performance arises from co-optimized texture architecture rather than a single parameter. In systemic terms, laser-defined microtexts complemented with aerospace-standard primers represent a controllable pathway to vary friction, dampen wear, and improve coating–substrate adhesion. These results provide practical selection guides; and a broad selection prefers larger, well-spaced circular dimples for best-in-class performance and a transferable framework for designing texture-coating systems across aerospace and allied manufacturing contexts. Full article

Silicon is increasingly applied in agriculture to improve plant productivity under both abiotic and biotic stress constraints. Nevertheless, its mechanisms of action are often studied separately at the soil, plant, or microbiome levels, limiting a comprehensive understanding of its overall impact on agroecosystem functioning. This review proposes an integrated perspective of the soil–plant–microbiome continuum, linking silicon chemistry in soil solutions with the effects of silicon amendments on soil properties and the processes of uptake, transport, and deposition in the plants. We show that silicon bioavailability depends on maintaining a pool of dissolved silicon dominated by orthosilicic acid, regulated by mineral weathering, adsorption–desorption dynamics, polymerization, pH, iron and aluminum oxides, and organic matter. In soils, silicon inputs can improve structure, modulate acidity and cation exchange balances, influence nutrient availability, and reduce the mobility of certain metals. They may also affect enzymatic activities and microbial community composition. In plants, silicon uptake and transport, mediated by specific transporters, contribute to tissue silicification, the maintenance of leaf architecture, and the regulation of water, ionic, and redox homeostasis. These processes provide a basis for enhanced tolerance to drought, salinity, and metal toxicity, as well as biotic stress caused by pathogens and pests. Finally, we discuss key limitations to the agronomic application of silicon, including the diagnosis of the silicic status of soils, the choice of source and mode of application, and the genotypic variability of acquisition, as well as the need for multi-site tests and more robust mechanistic validations. This synthesis provides a coherent mechanistic framework to better define the conditions under which silicon can serve as a reliable tool for sustainable crop management under climate change. Full article

To address the challenge of controlling Fe impurity content during the recycling of aluminum alloys, this study utilized commercial 5083 aluminum alloy as a matrix to prepare alloy samples with four different Fe contents via smelting. The effects of Fe content on the microstructure, mechanical properties, and corrosion resistance of the as-cast 5083 aluminum alloy were systematically investigated. The results indicate that increasing the Fe content induces a significant morphological evolution of the Fe-rich phases, transitioning from compact Chinese-script α-Al(Fe,Mn)Si phases at low Fe levels to coarse needle-like β-AlFeSi phases. Concurrently, both the quantity and size of the second phases increase significantly. Mechanical testing reveals that the hardness of the alloy gradually rises from 67 HV to 72 HV due to second-phase strengthening. The tensile strength shows a trend of initially increasing and then decreasing, peaking at 0.45 wt.% Fe; however, excessive Fe leads to the formation of needle-like phases that cause stress concentration, resulting in a decline in tensile strength. The elongation decreases gradually with increasing Fe content, with a maximum reduction of 19.7%. Electrochemical tests show that higher Fe content increases the self-corrosion current density and decreases the capacitive loop radius, indicating a significant degradation in the alloy’s corrosion resistance. This work provides an experimental basis for the tolerance control of Fe impurities and the performance optimization of recycled 5083 aluminum alloys. Full article

Surface cracks in integral structures of aircraft pose a significant threat to structural integrity. This paper investigates the three-dimensional propagation behavior and crack-arrest characteristics of surface-initiated cracks in the web of an integral wing spar manufactured from 7050-T7451 aluminum alloy. A three-dimensional finite element model is developed in ANSYS 2024R2 to evaluate the stress intensity factors (SIFs) along the crack front under representative displacement-controlled loading conditions. This paper focuses on comparing the crack-arrest effectiveness of different tear strap configurations by varying their height-to-thickness (H/T) ratios while maintaining a constant mass. The results indicate that surface crack propagation in the spar web is dominated by Mode I (opening mode). Among the investigated designs (H/T = 0.5, 2.0, and 8.0), the configuration with the smallest ratio (H/T = 0.5) exhibits the most effective crack-arrest capability, yielding the lowest crack-driving force as the crack approaches the strap. Furthermore, fatigue life estimates based on Paris’ law illustrate the dependence of remaining service life on the evaluated stress intensity factor evolution. These findings provide a comparative basis for the damage-tolerant design of integral metallic aircraft structures, suggesting that selecting appropriate geometric proportions for crack-arrest features can enhance resistance to surface crack propagation. Full article

Background/Objectives: HEBERSaVax is a therapeutic cancer vaccine based on recombinant human VEGF antigen adjuvated with VSSP or Aluminum Phosphate (AP). Clinical trials demonstrated the vaccine’s safety and tolerability, with predominantly mild to moderate (grade 1–2) local adverse events. Initial dose optimization studies using the VSSP (Center of Molecular Immunology (CIM), Havana, Cuba) adjuvant showed that increasing the antigen dose to 800 μg significantly enhanced immunogenicity, as measured by improved seroconversion rates, stronger blockade of VEGF/VEGFR1-2 interactions, and reduced platelet-derived VEGF levels. Methods: The AP adjuvant was used to perform essential preclinical validation in non-human primates to support the transition of the 800 μg antigen dose to Phase II clinical trials (CENTAURO-4 and CENTAURO-6). Results: HEBERSaVax adjuvated with AP induced: (1) robust humoral responses with high-titer anti-VEGF antibodies (peak 1:15,000), (2) functional biological activity, specifically the suppression of VEGF-mediated signal transduction, in 90% (9/10 animals), and (3) measurable cellular immune responses. All immunogenic effects were achieved without evidence of systemic toxicity, confirming the safety profile of this preparation. Conclusions: These findings provide compelling preclinical evidence that the 800 μg HEBERSaVax/AP combination maintains the immunogenic potential previously observed with VSSP while demonstrating an equally favorable safety profile. The results strongly support continued clinical development of this VEGF-targeted immunotherapy for cancer treatment. Full article

Aluminum (Al) toxicity is a major constraint on crop growth and productivity in acidic soils, affecting root development, nutrient uptake, and photosynthetic performance. The use of Si is a promising strategy to overcome the adverse effects of Al toxicity on species of agronomic interest. Between 2020 and 2026, 15 studies across nine species consistently demonstrated that silicon mitigated aluminum toxicity, regardless of their classification as silicon accumulators. In plants, Si mitigates Al toxicity through a combination of physical, chemical, and biochemical mechanisms that operate simultaneously. In the rhizosphere, Si interacts directly with Al³⁺ ions, favoring the formation of hydroxyaluminosilicates (HASs), which reduces the bioavailable fraction of Al. Evidence indicates that solution pH is a critical factor governing HAS formation, with minimal attenuation of Al toxicity observed at pH values below 4.5. Within the plant, Si modulates the antioxidant defense system by enhancing the activity of enzymes such as catalase, peroxidase, and ascorbate peroxidase, thereby reducing oxidative stress typically triggered by Al toxicity. Moreover, Si influences the biosynthesis of lignin and phenolic compounds with Al-chelating capacity, contributing to detoxification at the cellular level. In soybean and rice, Si supply substantially reduced Al deposition in the root apical cell wall, with decreases of approximately 52% and 41.3%, respectively. This reduction was consistently associated with improved root elongation, maintenance of root structural integrity, mitigation of cellular deformation, and preservation of root thickness and vascular organization. Although these mechanisms have been described, a comprehensive synthesis of studies published from 2020 to 2026 has been lacking, particularly regarding the integration of in-plant processes and species-specific responses. This review fills this gap by critically examining recent findings, highlighting the multifaceted role of Si in alleviating Al stress, and discussing implications for agronomic applications in acidic soils. Collectively, the evidence underscores Si as an effective tool to enhance plant tolerance to Al; however, most available evidence is derived from early plant developmental stages and hydroponic or highly controlled systems, which limits the direct extrapolation of these findings to soil and field conditions. Future advances will require studies under soil environments, accounting for species-specific responses, soil properties, management systems, and plant developmental stages. Full article

Aluminum chloride (AlCl₃), a widely used inorganic polymeric coagulant in everyday products and industrial materials, has been associated with male reproductive toxicity, though its molecular mechanisms remain poorly understood. To investigate the complex molecular mechanisms underlying GC-1spg cells’ responses to AlCl₃ exposure, transcriptome and small RNA (sRNA) sequencing analyses were performed. Transcriptome sequencing identified 1168 differentially expressed genes (DEGs), while sRNA sequencing detected 65 differentially expressed microRNAs (DEMs). An mRNA–miRNA regulatory network was established, and functional enrichment analysis showed that its target genes were significantly associated with multiple signaling pathways, particularly the p53 pathway. Further validation via Western blot and Hoechst 33342 staining assays confirmed that GC-1spg cells underwent apoptosis upon AlCl₃ exposure via the p53 signaling pathway. Among the identified DEMs, mmu-miR-503-5p was found to enhance GC-1spg cells’ tolerance to AlCl₃-induced stress. Moreover, dual-luciferase reporter assays and RT-qPCR confirmed that mmu-miR-503-5p directly binds to the Islr gene, which plays a role in modulating GC-1spg cell tolerance to AlCl₃-induced stress. These findings provide critical insights into the molecular mechanisms governing GC-1spg cells’ responses to AlCl₃ exposure. Full article

The AP2/ERF superfamily is a key class of transcription factors involved in plant responses to various stresses. As an ancient species, the olive tree (Olea europaea L.) exhibits considerable stress tolerance and wide adaptability. In this study, we identified 348 AP2/ERF genes in the cultivated olive variety ‘Arbequina’ at the whole-genome level. According to protein sequence alignments and phylogenetic analyses via the Maximum Likelihood method, these genes were classified into four major families: AP2, ERF/DREB, RAV, and Soloist. The ERF/DREB family was further divided into DREB and ERF subfamilies, each encompassing six groups (A1–A6 and B1–B6), with the ERF subfamily being the largest. Members of each group exhibited relatively consistent gene structures and domain/motif compositions of their encoded proteins; however, the distribution of cis-elements and expression patterns varied. Each AP2/ERF gene contained 12 light-responsive, three MeJA-responsive, three ABA-responsive, two anaerobic induction, and one MYB binding site on average. With the threshold of p value < 0.5, control TPM > 0, and |log₂(fold change)| > 0, 50 candidate genes were simultaneously up-regulated (30) or down-regulated (20) under four stress treatments (acid–aluminum, cold, disease, and wound), among which nine showed potential protein–protein interactions. This study provides a comprehensive genomic characterization of the AP2/ERF family in olive and identifies key candidate stress-responsive genes, establishing a foundation for future functional studies on the molecular mechanisms of stress adaptation in the olive tree. Full article

Acid mine drainage (AMD) and acid-generating mine wastes exhibit low pH, high sulfate levels, and complex multi-metal loads that strain conventional treatment. Thermoacidophilic red algae of the order Cyanidiales, particularly Galdieria sulphuraria (G. sulphuraria), have attracted interest as a biological option because they tolerate extreme acidity and elevated temperatures, grow under low light in mixotrophic or heterotrophic modes, and display rapid metal binding at the cell surface. This review synthesizes about two decades of peer-reviewed work to clarify how G. sulphuraria can be deployed as a practical module within mine water treatment trains. We examine the mechanisms of biosorption and bioaccumulation and show how they map onto two distinct configurations. Processed freeze-dried biomass functions as a regenerable sorbent for rare earth elements (REEs) and selected transition metals in packed beds with acid elution for recovery. Living cultures serve as polishing units for divalent metals and, when present, nutrients or dissolved organics under low light. We define realistic operating windows centered on pH 2–5 and temperatures of approximately 25–45 °C, and we identify matrix effects that govern success, including competition from ferric iron and aluminum, turbidity and fouling risks, ionic strength from sulfate, and suppression of REE uptake by phosphate in living systems. Building on laboratory studies, industrial leachate tests, and ecosystem observations, we propose placing G. sulphuraria upstream of bulk neutralization and outline reporting practices that enable cross-site comparison. The goal is an actionable framework that reduces reagent use and sludge generation while enabling metal capture and potential recovery of valuable metals from mine-influenced waters. Full article

The multidrug and toxic compound extrusion (MATE) protein plays a crucial role in mediating plant responses to aluminum (Al) toxicity. The key candidate gene BnaMATE43b related to Al toxicity stress in rapeseed was identified using GWAS and transcriptome analysis. In this study, the BnaMATE43b gene was cloned and functionally characterized in rapeseed. Compared with wild-type rapeseed (WT), the BnaMATE43b overexpression lines (OE) demonstrated stronger aluminum tolerance, specifically manifested in higher relative elongation of taproots (RETs) and relative total root length (RTRL); under Al toxicity stress, the enzyme activities (SOD and POD) and root activity were significantly increased in the OE lines, whereas the MDA content and relative electrical conductivity were reduced in rapeseed root. Further transcriptome analysis of OE-3 showed that the differentially expressed genes (DEGs) were mainly enriched in zeatin biosynthesis (map00908), glucosinolate biosynthesis (map00966), phenylpropanoid biosynthesis (map00940), and ascorbate and aldarate metabolism (map00053). In addition, the yeast cDNA library of rapeseed was constructed, and twenty-two candidate upstream transcription factors (UTFs) of BnaMATE43b were screened; furthermore, four candidate UTFs were obtained through one-on-one interaction validation and luciferase assays, comprising three bHLH transcription factors (BnaA02g28220D, BnaA06g07840D, and BnaA08g24520D) and one ERF transcription factor (BnaA05g23130D). Collectively, these results suggest that BnaMATE43b could improve Al tolerance in rapeseed by mediating antioxidant enzyme activities and the related metabolic pathway, while the obtained UTFs lay the foundation for further analysis of the gene regulatory network under Al toxicity stress. Full article

Tea plants (Camellia sinensis) uniquely hyperaccumulate fluoride (F) and concurrently exhibit a preference for ammonium nitrogen (NH₄⁺-N) over nitrate nitrogen (NO₃⁻-N). However, the mechanistic basis for co-existence of NH₄⁺-N preference and F hyperaccumulation in C. sinensis remains unexplored. Here, we investigated F accumulation and translocation with varying N supplies (0 mM and 2.854 mM N with NH₄⁺-N:NO₃⁻-N ratios of 3:1, 4:0 and 0:4) and F concentrations (0, 8 and 16 mg·L⁻¹ NaF) to reveal the mechanism driving NH₄⁺-N preference and F hyperaccumulation in C. sinensis. Results show that NH₄⁺-N supply enhanced H⁺ efflux, mobilizing aluminum (Al) to form mobile Al-F complexes for translocation to shoots, thereby alleviating F toxicity in roots. This process was facilitated by transporters including CsCLCd, CsCLCe, CsCLCf2 and CsFEX. In contrast, NO₃⁻-N promoted root sequestration of F as immobile calcium (Ca)-F complexes, exacerbating damage. Under NO₃⁻-N supply, CsCLCb primarily mediated NO₃⁻ transport, while CsCLCc, CsCLCe, CsCLCf1, CsCLCf2 and CsFEX were involved in F transport. In leaves, CsCLCd, CsCLCe, CsCLCf1, CsCLCf2, CsCLCg and CsFEX mediated vacuolar sequestration under both N conditions. These findings elucidate that NH₄⁺-N preference is mechanistically linked to F hyperaccumulation through an Al-assisted translocation pathway, which confers tolerance by exporting F from roots. Full article

The inherent limitations of conventional polyolefin separators, particularly their poor thermal stability and insufficient mechanical strength, pose significant safety risks for lithium-ion batteries (LIBs) by increasing susceptibility to thermal runaway. In this study, we developed a novel multilayer separator through sequential coating of a commercial polyethylene (PE) substrate with aluminum oxide (Al₂O₃), para-aramid (PA), and polyethylene wax microspheres (PEWMs) using a scalable micro-gravure process, denoted as SAPEAS, signifying a PE-based asymmetric structure separator with enhanced thermal shutdown and dimensional stability. The SAPEAS separator exhibits an early thermal shutdown capability at 105 °C, maintains structural integrity with negligible shrinkage at 180 °C, and demonstrates comprehensive performance enhancements, including enhanced mechanical strength (tensile strength: 212.3 MPa; puncture strength: 0.64 kgf), excellent electrolyte wettability (contact angle: 12.8°), a high Li⁺ transference number (0.71), superior ionic conductivity (0.462 mS cm⁻¹), outperforming that of commercial PE separators. In practical LFP|Gr pouch cells with ampere-hour (Ah) level capacity, the SAPEAS separator enables exceptional cycling stability with 97.9% energy retention after 1000 cycles, while significantly improving overcharge tolerance compared to PE. This work provides an effective strategy for simultaneously improving the safety and electrochemical performance of LIBs. Full article

Eddy current testing is a widely used technique for electrical conductivity measurement due to its advantage of contactless measurement. However, the results are easily influenced by liftoff change. In this study, a new solution to compensate for the liftoff effect in eddy current measurements of conductivity is proposed. By measuring the inductance of coils with different frequencies, the liftoff–conductivity solution sets at each frequency are obtained from an analytical model. By finding a common solution for all frequencies, we can obtain the liftoff of the probe and the conductivity of the specimen simultaneously, thus improving the accuracy and reliability of conductivity measurements. For a liftoff variation of 1.14 mm, the introduced measurement error is up to 70.46% for aluminum alloys without liftoff compensation. By finding the common solution for multiple frequencies, the error is reduced to less than 5.57%. The selection of the frequency and tolerance limit is also discussed for the proposed method. Full article

Background: Plant citrate synthase (CSY) is involved in the iron deficiency (−Fe) response and aluminum (Al) detoxification. However, knowledge of CSY function in responding to excess iron (+Fe) or Al stress (+Al) is still limited. Methods: The CDS and promoter of GmCSY3 were isolated from soybean and bioinformatically analyzed. The GmCSY3 expression was detected by qRT-PCR and GUS assay. The growth of GmCSY3 recombinant yeast under +Fe or +Al was detected. The phenotype, CSY activity, citric acid concentration, chlorophyll content, MDA, H₂O₂, O₂⁻ contents, GST, CAT, SOD, and POD activities were examined in GmCSY3 overexpressed and RNAi-suppressed soybean chimeras under +Fe or +Al. Perls and Hematoxylin stained the roots, and the FCR activity was determined. Results: GmCSY3 was induced by +Fe or +Al, but not by −Fe. GmCSY3 enhanced yeast’s acid production and resistance to +Fe or +Al. GmCSY3 overexpression in soybean significantly enhanced CSY activity, promoted growth, alleviated oxidative damage caused by +Fe or +Al, with less free Fe³⁺ and Al³⁺, and reduced FCR activity, while GmCSY3 RNAi-suppressed showed the opposite effect. Conclusions: GmCSY3 promotes the process of citrate synthesis, chelates Fe³⁺ and Al³⁺, alleviates oxidative damage caused by +Fe or +Al, and modulates iron absorption in plants. Full article