Search Results (1,598)

Cork oak is a strong emitter of volatiles, namely monoterpenes, which are important precursors of secondary air pollutants. Past studies have revealed distinct chemotypes in emitting as well as non-emitting individuals. Promoting non-emitters in afforestation and urban greening could improve air quality, but their rarity suggests that they are less resilient. To gain insight into this, we screened natural descendants from two non-emitting cork oaks for emissions and ecophysiological traits (CO₂/H₂O-gas exchange variables, budburst date, growth) and tested whether emitting and non-emitting descendants differ in their resistance to temperature and light fluctuations (sun-flecks). Both half-sib populations were composed of the same chemotypes in similar frequencies, comprising 32% of non-emitters and 50 and 18% of two emitting chemotypes with overall moderate emission rates. Based on this distribution, we identified an inheritance mode and compared it with the chemotype frequency of the mother population. In terms of ecophysiological traits, all chemotypes performed similarly, and non-emitters were as resistant to sun-flecks as emitters. We conclude that the chemotypes in emitters reflect a common polymorphism in monoterpene-emitting plants that is not related to adaptive selection. We also conclude that non-emission is heritable and that its phenotype should be evaluated in reforestation studies. Full article

This study explores the influence of precursor nature on the structural and mechanical characteristics of hydroxyapatite–yttria partially stabilized zirconia (HAp–YSZ) nanocomposites designed for biomedical applications. Precursor powders for obtaining these ceramic composites were synthesized via wet coprecipitation, using different calcium phosphate precursors: dibasic and monobasic ammonium phosphates for hydroxyapatite, and zirconyl chloride with yttrium acetate for YSZ. The dried precipitated powders were thermally treated at 600 °C and 800 °C and characterized by X-ray diffraction (XRD), thermal analysis (DTA–TG), transmission electron microscopy (TEM), and BET surface area measurements. The nanocomposites containing 70–90 wt.% HAp and 10–30 wt.% YSZ were sintered between 1000 °C and 1400 °C. Microstructural and physical properties were evaluated using scanning electron microscopy (SEM), open porosity, and compressive strength testing. Results revealed that precursor type and calcination temperature strongly affected crystallinity, particle size, and phase composition, influencing both porosity and mechanical strength of the final materials. An optimal sintering temperature of approximately 1200 °C was identified, balancing densification and phase stability. The findings demonstrate that controlling precursor chemistry and heat treatment enables fine-tuning of nanocomposite structure and performance, supporting their potential as bioactive, mechanically enhanced ceramics for orthopedic implant applications. Full article

This study examines how both the nature of the carbon support and the palladium precursor influence catalytic performance in acetylene hydrogenation. Six Pd-based catalysts were prepared on four carbon materials—high-heat-treated fibers (HHTs), carbon nanotubes, activated carbon and high surface area graphite—using either sulfate or chloride precursors. Catalytic tests performed in a continuous fixed-bed reactor reveal that HHT-supported catalysts achieve the highest ethylene selectivity and long-term stability, while in general catalysts derived from sulfate precursors exhibit enhanced selectivity compared to their chloride-derived counterparts. These improvements are consistent with the formation of sulfur, which may be incorporated as sub-stoichiometric sulfide species (S²⁻) interacting with metallic Pd, as revealed by the XPS results, rather than to palladium dispersion alone. The role of the carbon support in stabilizing these sites was further assessed by complementary characterization techniques, including transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. The combined results indicate that highly graphitic supports such as HHT fibers favor sulfur retention at the catalyst surface, thereby promoting the stability and catalytic performance of Pd–S active motifs during acetylene hydrogenation. Full article

Nitrite, as a widely present nitrogen oxide compound in nature, and is extensively distributed in production and daily life; precise and rapid detection of it is of great significance for ensuring human health. This study developed nitrogen-doped carbon dots (N-CDs) using malic acid and 3-diethylaminophenol as precursors by one-step hydrothermal treatment. The obtained N-CDs exhibited strong green fluorescence with a high quantum yield of 20.86%. More importantly, they served as a highly effective fluorescent probe for NO₂⁻ sensing, demonstrating a low detection limit of 28.33 μM and a wide linear response range of 400 to 1000 μM. The sensing mechanism was attributed to an electrostatic interaction-enhanced dynamic quenching process. Notably, the probe enabled dual-mode detection: a distinct color change from light pink to dark brown under daylight for visual semi-quantification, and quantitative fluorescence quenching. The N-CDs showed excellent selectivity over common interfering ions. Furthermore, their low cytotoxicity and good biocompatibility allowed for successful bioimaging of exogenous and endogenous NO₂⁻ fluctuations in live HeLa cells. This work presents a facile green strategy to synthesize multifunctional N-CDs that realized the sensitive, selective, and visual detection of NO₂⁻ in environmental and biological systems. Full article

Fungal secondary metabolites are valuable sources of natural antioxidants and antimicrobials. This study evaluated the submerged fermentation of Penicillium crustosum OR889307 supplemented with lemon peel as a co-substrate to enhance the production of bioactive compounds. Lemon peel was selected for its phenolic precursors and sustainable availability as an agro-industrial byproduct. Crude extracts, aqueous and organic fractions, and molecular-weight partitions were assessed for antioxidant activity using the DPPH assay and for antimicrobial activity against Escherichia coli, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa, and Candida albicans. Semi-purified extracts from co-substrate fermentations exhibited enhanced bioactivity, showing MIC values of 185 µg/mL against P. aeruginosa and 225 µg/mL against MRSA, along with strong ABTS radical-scavenging capacity (238.95 ± 2.17 µmol TE). RP-HPLC-ESI-MS profiling revealed phenolic acids, flavanones, flavonols, and lignans, including ferulic acid 4-O-glucoside, bisdemethoxycurcumin, secoisolariciresinol, and quercetin 3-O-xylosyl-glucuronide. These findings demonstrate that lemon peel supplementation promotes the biosynthesis of antimicrobial and antioxidant metabolites by P. crustosum. This approach supports sustainable agro-waste valorization and offers a promising strategy for obtaining natural bioactive compounds with potential applications in food preservation and health-related formulations. Full article

Alzheimer’s disease (AD) is a prevalent neurodegenerative condition that progressively impairs cognitive processes, particularly learning and memory. A key pathological feature of AD involves senile plaques mainly composed of β-amyloid (Aβ) peptides, generated via the amyloidogenic pathway from amyloid precursor protein (APP) through sequential β-secretase (BACE1) and γ-secretase cleavage, positioning BACE1 inhibition as a prime therapeutic target. In this study, we applied bioassay-guided fractionation of the butanol-soluble fraction from Dryopteris crassirhizoma rhizomes, previously reported to inhibit Aβ production, to isolate and characterize Aβ-lowering constituents. Through successive chromatographic steps, nine compounds were isolated and structurally classified into flavonoids, chromones, and phloroglucinols, including epicatechin (1), β-carboxymethyl-(-)-epicatechin (2), 7-methoxy-isobiflorin (3), biflorin (4), eriodictyol (5), noreugenin (6), phloroglucinols (butyrylphloroglucinol (7), 2-propionyl-4-methylphloroglucinol (8), and 2-butyryl-4-methylphloroglucinol (9) by comprehensive spectroscopic analysis (NMR, MS, UV, IR). These compounds were assessed for effects on sAPPβ and BACE1 (β-secretase) levels by Western blot, with Aβ production quantified via ELISA in a cellular AD model (APP-CHO cells). Compounds 5–9 significantly reduced sAPPβ and BACE1 expression while potently suppressing Aβ generation. These results demonstrate that diverse constituents from D. crassirhizoma rhizomes inhibited Aβ production through BACE1 suppression, highlighting their potential as natural lead compounds for AD prevention or therapy. Full article

The misuse of antibacterial agents has contributed to the growing prevalence of antibiotic resistance, highlighting an urgent need to explore alternative anti-infection therapeutic strategies. Antimicrobial peptides (AMPs) are naturally occurring molecules. They exhibit broad-spectrum antimicrobial activity and represent promising candidates for the development of novel therapeutics. A cysteine-rich antimicrobial peptide was identified and characterized from the genome of Tigriopus japonicus and designated “TjRcys1”. The precursor form of TjRcys1 comprises 96 amino acids. Structural analyses of TjRcys1 revealed random coils, two α-helices, and two β-strands. Recombinant TjRcys1 had inhibitory effects upon Staphylococcus aureus and Bacillus sp. T2, with a minimum inhibitory concentration of 64 μM for both. TjRcys1 did not show complete inhibition against Vibrio alginolyticus, Klebsiella pneumoniae, or Aeromonas hydrophila at 64 μM, but it did slow their growth rate. TjRcys1 could disrupt the permeability of the cell membrane of S. aureus. Transcriptomic analyses indicated that TjRcys1 could interfere with the ribosome biosynthesis and nucleotide metabolism of K. pneumoniae. Our results provide a valuable reference for the development of new AMPs and optimization of their design. Full article

With the rapid depletion of natural graphite, the synthesis of artificial graphite from high-carbon precursors has garnered growing interest. However, conventional artificial graphitization typically requires extremely high temperatures. This study demonstrates that natural halloysite mineral can serve as an effective catalyst to lower the graphitization temperature threshold of anthracite. The results show that halloysite exerts a pronounced catalytic effect within the temperature range of 1400–2300 °C. The enhancement in graphitization is primarily attributed to the formation and subsequent decomposition of intermediate phases between halloysite and the carbon matrix. From 1400 to 1700 °C, the interlayer spacing decreases significantly with halloysite as a catalyst due to the nucleation of highly ordered “multilayer graphene” structures surrounding intermediates. However, these graphene layers exhibit a confined and curved morphology that spatially restricts crystallite growth, resulting in relatively small in-plane (L_a) and stacking (L_c) crystallite dimensions. Moreover, multilayer graphene originating from intermediate crystal corners tends to generate numerous dislocation defects. From 1700 to 2300 °C, significant increases in both L_a and L_c are observed, accompanied by a marked improvement in structural order. This evolution is driven by the progressive inward decomposition of intermediate phases, which causes the “circular-shaped” graphene domains to collapse at the dislocation defects and subsequent straightening of the curved graphene layers. These findings provide new microstructural insights into mineral-catalyzed graphitization mechanisms in anthracite and present a promising pathway toward energy-efficient production of synthetic graphite. Full article

Allomelanin is a natural class of melanin found mainly in fungi and derived from nitrogen-free precursors such as 1,8-dihydroxynaphthalene (1,8-DHN). Despite its biological relevance, allomelanin remains significantly less explored than other synthetic melanin analogs, particularly compared to polydopamine, a synthetic analog of eumelanin. In this review, we provide a comprehensive overview of current knowledge on allomelanin, summarizing the main methods used to characterize its molecular structure, morphology, and chemical functionalities. We also present its emerging applications, ranging from human health to materials science, highlighting how its optical characteristics, ability to modulate redox processes, and antioxidant properties support its growing technological interest. Finally, we describe the natural presence and biological role of allomelanin, highlighting how knowledge of its biosynthetic processes and functions in nature can guide more effective strategies for the design and optimization of new allomelanin materials. Full article

The increasing energy crisis demands sustainable functional materials. Wood, with its natural three-dimensional porous structure, offers an ideal renewable template. This study demonstrates that microstructural engineering of wood is a decisive strategy for enhancing magnetothermal conversion. Using eucalyptus wood, we precisely tailored its pore architecture via delignification and synthesized Fe₃O₄ nanoparticles in situ through coprecipitation. We systematically investigated the effects of delignification and precursor immersion time (24, 48, 72 h) on the loading, distribution, and magnetothermal performance of the composites. Delignification drastically increased wood porosity, raising the Fe₃O₄ loading capacity from ~5–6% (in non-delignified wood) to over 14%. Immersion time critically influenced nanoparticle distribution: 48 h achieved optimal deep penetration and uniformity, whereas extended time (72 h) induced minor local agglomeration. The optimized composite (MDW-48) achieved an equilibrium temperature of 51.2 °C under a low alternating magnetic field (0.06 mT, 35 kHz), corresponding to a temperature rise (ΔT) > 24 °C and a Specific Loss Power (SLP) of 1.31W·g⁻¹. This performance surpasses that of the 24 h sample (47 °C, SLP = 1.16 W·g⁻¹) and rivals other bio-based magnetic systems. This work establishes a clear microstructure–property relationship: delignification enables high loading, while controlled impregnation tunes distribution uniformity, both directly governing magnetothermal efficiency. Our findings highlight delignified magnetic wood as a robust, sustainable platform for efficient low-field magnetothermal conversion, with promising potential in low-carbon thermal management. Full article

Flavor enrichment in commercial yogurts commonly relies on exogenous flavoring agents, failing to meet consumer demand for clean-label products with natural ingredients. This study developed a starter culture for malty-aroma yogurt by combining Lactococcus lactis BL-19 with a commercial yogurt starter culture. Evaluation by eleven trained sensory assessors indicated that malty-aroma yogurt exhibited a distinctive sensory profile compared with four commercially available plain yogurts. Time-series flavoromics identified 13 key aroma compounds and revealed the 3 h as the key time node of flavor evolution during fermentation. Furthermore, time-series metabolomics analysis revealed metabolic transitions from nutrient adaptation to active biosynthesis at 3 h, significantly increasing the odor-active values of the key aroma compounds. Moreover, correlation network analyses revealed potential metabolic precursors and metabolic bypass associated with the production of key aroma compounds and highlighted the valine, leucine and isoleucine biosynthesis pathway as central to malty-aroma formation. This study elucidates the evolution of flavor compounds and the underlying bioformation mechanisms of malty-aroma yogurts, offering insights for the precise flavor modulation of fermented dairy products. Full article

Alkali-activated materials (AAMs) or geopolymers have been considered for many years as a sustainable substitution for the traditional ordinary Portland cement (OPC) binder. However, their production needs energy consumption and creates carbon emissions. Since construction and demolition waste (CDW) can become precursors for manufacturing alkali-activated materials, their use as substitutes for traditional AAM (such as metakaolin, blast furnace slag, and fly ash) can solve both the problem of their disposal and the problem of sustainability. Furthermore, CDW can also be used as aggregate replacement, avoiding the exploitation of natural river sand and gravel. A new circular economy could be created based on CDW recycling, creating a new eco-friendly building practice. Unfortunately, this process is quite difficult owing to several variables that should be taken into consideration, such as the possibility of separating and sorting the CDW, the great variability of CDW composition, the cost of the mechanical and thermal treatment, the different parameters that compose an alkali-activated mix-design, and public opinion still being skeptical about the use of recycled materials in the construction sector. This review tries to describe all these aspects, summarizing the results of the most interesting studies performed on this subject. Today, thanks to a comprehensive protocol, the use of building information modeling (BIM) software and machine learning models, a large-scale reuse of CDW in the building industry appears more feasible. Full article

Marine invertebrates are a prime source of biologically active peptides due to their role in humoral immunity. These peptides typically exhibit broad-spectrum functions, including antibacterial, antifungal, anticancer, and immunomodulatory activities. In this report, we describe the identification and biological characterization of five novel bioactive peptides from the marine mollusk Pisania pusio. An extract of P. pusio was analyzed using nanoLC-ESI-MS-MS, and five peptides (PP1–5) were selected via bioinformatic screening as potential antimicrobial and anticancer peptides and subsequently validated experimentally. Among these, PP1, PP2, and PP4 were identified as cryptides derived from the proteolytic cleavage of actin, while PP3 and PP5 are novel peptides with no known protein precursors. All peptides exhibited moderate activity against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae with minimum inhibitory concentrations (MICs) predominantly at 100 µM. In contrast, only PP1 and PP5 were active against cancer cells, with PP1 being the most effective against A375 melanoma cells (IC₅₀ = 17.08 µM). This experimental validation confirmed the utility of the integrated in silico/peptidomic pipeline for lead identification. None of these peptides showed significant hemolytic activity or toxicity on fetal lung fibroblasts over 800 μM, demonstrating promising in vitro selectivity. These results highlight the multifunctional nature of P. pusio-derived peptides and their potential as lead compounds for further optimization and development into therapeutic agents against microbial infections and cancer, subject to more comprehensive safety evaluations in relevant models Full article

The ongoing emergence of antiviral drug resistance underscores the critical need for new broad-spectrum antiviral agents. Sulfonamides and their derivatives have emerged as promising candidates for the development of new antiviral therapeutics. In this study, a series of camphor-10-sulfonamide derivatives was synthesized through a feasible and sustainable synthetic approach starting from naturally available precursors and evaluated for antiviral properties. Their activity was examined against three structurally distinct viruses—herpes simplex virus type 1 (HSV-1), human coronavirus (HCoV-OC43), and feline calicivirus (FCV)—representing both DNA and RNA, enveloped and non-enveloped types. The compounds were examined for their effects on viral replication, the stage of viral adsorption to the cell, and extracellular virions. The weakest cytotoxicity and the most pronounced activity of all the tested substances was demonstrated by the tryptophan derivative 7a. A time-dependent inhibition of the stage of adsorption of HCoV-OC43 (Δlg = 2.0 at 120 min) and FCV (Δlg = 1.75 at 60 min) to susceptible cells was established, as well as virucidal activity on the three types of virions tested, with the most pronounced effect at 120 min—for HSV-1 (Δlg = 2.75) and Δlg = 2.0 for HCoV-OC43 and FCV. Molecular docking studies performed using Glide (Schrödinger) provided insights into the active conformations of the most effective ligands and predicted possible interactions with relevant viral targets, supporting their potential as lead structures for further therapeutic development. Full article

Agricultural biomass has potential as a renewable and versatile carbon feedstock for developing eco-friendly and biodegradable polymers capable of replacing conventional petrochemical plastics. To address the growing environmental concerns associated with plastic waste and carbon emissions, lignocellulosic residues, edible crop by-products, and algal biomass were utilized as sustainable raw materials. These biomasses provided carbohydrate-, lipid-, and lignin-rich fractions that were deconstructed through optimised physical, chemical, and enzymatic pretreatments to yield fermentable intermediates, such as reducing sugars, organic acids, and fatty acids. The intermediates were subsequently converted through tailored microbial fermentation processes into biopolymer precursors, primarily polyhydroxyalkanoates (PHAs) and lactate-based monomers. The resulting monomers underwent polymerization via polycondensation and ring-opening reactions to produce high-performance biodegradable plastics with tunable structural and mechanical properties. Additionally, the direct extraction and modification of naturally occurring polymers, such as starch, cellulose, and lignin, were explored to develop blended and functionalized bioplastic formulations. Comparative evaluation revealed that these biomass-derived polymers possess favourable physical strength, thermal stability, and biodegradability under composting conditions. Life-cycle evaluation further indicated a significant reduction in greenhouse gas emissions and improved carbon recycling compared to fossil-derived counterparts. The study demonstrates that integrating agricultural residues into bioplastic production not only enhances waste valorization and rural bioeconomy but also supports sustainable material innovation for packaging, farming, and consumer goods industries. These findings position agriculture-based biodegradable polymers as a critical component of circular bioeconomy strategies, contributing to reduced plastic pollution and improved environmental sustainability. Full article