Search Results (100,694)

The properties of a Ca₉La(VO₄)₇ single crystal were studied using dielectric spectroscopy and second-harmonic generation. The crystal structure of Ca₉La(VO₄)₇ grown using the Czochralski technique was refined using single-crystal data. The distribution of Ca²⁺ and La³⁺ cations over structural positions was determined. The crystal structure refinement results were compared with those obtained previously from powder X-ray diffraction data. It was shown that the refinement carried out using two different data sets leads to approximately the same results for the distances in the polyhedra, but their distortion is significantly less in the case of using single-crystal data for calculation. Dielectric properties and conductivity measurements were performed on polished single-crystal wafers cut parallel and perpendicular to the c axis. Second-harmonic generation and dielectric temperature measurements revealed the presence of a reversible ferroelectric first-order phase transition at about 1224 K from the ferroelectric β-phase (space group R3c) to the paraelectric β′-phase. The ferroelectric–paraelectric phase transition is accompanied by a complex structural rearrangement, including a 60° rotation of the V1O₄ tetrahedron, as well as slight displacements of the Ca²⁺ and La³⁺ cations. It has been shown that the conductivity differs only slightly along the polar axis and perpendicular to it. Above the phase transition temperature, the activation energy of the conductivity is the same for all directions, E_a~1.2 eV. The influence of composition on the phase transition temperature and the formation of ferroelectric and nonlinear optical properties is discussed. Full article

This work aims to develop a controlled ball milling strategy for preparing FeCoCrNiCu high-entropy alloy (HEA) powders with improved compositional homogeneity while maintaining limited oxygen uptake. Specifically, a novel two-step combined ball milling strategy integrating gradient ball-size configurations with a sequential milling procedure is proposed and systematically evaluated. Compared with conventional single-step milling, the mixed-ball and two-step configurations enhance mechanical alloying (MA) efficiency and promote the formation of more stable FCC and BCC dual-phase structures, as confirmed by X-ray diffraction (XRD) analysis. Compositional standard deviation derived from energy-dispersive X-ray spectroscopy (EDS) measurements indicates improved macroscopic uniformity, while oxygen/nitrogen/hydrogen (ONH) analysis verifies that oxygen incorporation remains limited within the tested processing window. Systematic comparison of jar filling degrees and sampling interruptions further reveals the coupled influence of collision energy distribution and exposure frequency on oxidation behavior. The results demonstrate that controlled energy distribution and minimized atmospheric disturbance are critical for balancing alloying efficiency and oxygen control in FeCoCrNiCu powders. Full article

Yeasts such as Cutaneotrichosporon oleaginosum can convert low-value side streams into single-cell oils with fatty acid profiles comparable to vegetable oils. Crude glycerol (CG), a byproduct of biodiesel production, offers a cost-effective substrate, but its variable impurity load often causes strong growth inhibition. In this study, two untreated industrial CG batches were characterized and evaluated in 2.5 L and 19 L stirred-tank fermentations. Direct batch cultivation on CG resulted in no measurable growth, whereas an adapted stepwise feeding strategy effectively mitigated early inhibition and restored biomass formation, metabolic activity, and lipid accumulation. In 2.5 L cultivations, apparent growth rates up to 0.51 h⁻¹ and volumetric productivities up to 0.22 g L⁻¹ h⁻¹ were achieved, with lipid contents of ~30% and oleate-dominated fatty acid profiles. Fatty acid profiles remained oleate-dominated (~53–55% C18:1). Transition-scale (19 L) repeated-batch fermentations confirmed process robustness across > 640 h of operation, during which lipid content (~30–36%) and fatty acid composition (oleate ~51–53%) remained stable despite pronounced substrate-batch variability and increasing nitrogen limitation. These results demonstrate that untreated CG can be reliably valorized for lipid production using scalable feeding strategies without prior detoxification. This closes a gap between laboratory-scale feasibility studies and process-oriented, multi-cycle operation on industrial-grade feedstocks, confirming that feeding-driven inhibition control can ensure robust performance without substrate purification. Full article

Deep coalbed methane resource evaluation is limited by weak coupling among key controlling factors and by the lack of unified methods for Computational Unit delineation. This study focuses on the No. 8 coal seam of the Benxi Formation in the Ordos Basin. A geological–engineering integrated framework for delineation and evaluation of deep coalbed methane units was established based on the concept of “one body and four levels.” Results indicate that a depth of 1500 m represents a critical boundary for changes in coalbed methane occurrence. Gas in deep coal seams occurs mainly as a combination of adsorbed gas saturation and free gas enrichment. Vitrinite reflectance was used to evaluate gas source conditions, and a threshold of Ro = 1.2% was identified. Cap rock sealing performance was evaluated using lithological assemblages, with mudstone–limestone combinations showing the most favorable preservation conditions. A brittle–ductile index based on rock mechanical parameters was applied to assess reservoir fracability. Gas source effectiveness, preservation conditions, and reservoir transformability were quantified using thermal simulation experiments, formation pressure and temperature analysis, sealing tests, and coal–rock mechanical experiments. GIS-based spatial overlay analysis was used to divide the No. 8 coal seam into 16 computational units. The total deep coalbed methane resources were estimated at approximately 16.49 × 10¹² m³. Accordingly, the research findings provide a crucial scientific basis for the rational delineation of computational units in deep coalbed methane systems. They also offer significant theoretical support for subsequent applications of machine learning and coupled geomechanics–flow modeling methods, enabling accurate dynamic prediction and optimal zone selection within the study area. Full article

Laser powder bed fusion (LPBF) of AA7075 is severely constrained by a narrow process window and susceptibility to defect formation (hot cracking and porosity), which often dominates performance. In this study, 5 wt.% AlCoCrFeNi_2.1 high-entropy alloy (HEA) particles, volumetric energy density (VED = 74–222 J·mm⁻³), and subsequent T6 heat treatment were systematically investigated to reveal their combined effects on defect structure, crystallographic texture/substructure, and tensile behaviour. Quantitative EBSD shows a measurable grain refinement in the as-built state (average grain size 13.44 → 11.80 µm, ~12%) accompanied by a pronounced weakening of the <001> fibre texture (maximum MRD 4.94 → 2.38), indicating disrupted epitaxial growth and a more dispersed orientation distribution. After T6, the reinforced alloy retains a higher low-angle boundary fraction (31.62% vs. 24.17% in unreinforced AA7075) and a higher kernel average misorientation (0.80° vs. 0.60°), consistent with particle-stabilised substructure retention and retarded recovery. Across all VEDs, AA7075-HEA exhibits higher microhardness (compared with AA7075, the addition of HEA increases the hardness by roughly 20–50 HV) and tensile strength, with the intermediate VED (140.74 J·mm⁻³, T6 states) yielding the best performance. While macroscopic cracking is not fully eliminated, the results clarify that HEA-enabled texture/substructure modifications can contribute to enhanced defect tolerance and are more effectively translated into tensile performance when the as-built defect severity is controlled. These findings provide quantitative insights into defect–microstructure–property coupling in LPBF AA7075-HEA composites from as-built to T6 states. Full article

Thermal energy storage (TES) systems are widely employed in concentrated solar power (CSP) applications as a means of storing and dispatching energy. Typical thermal fluids used in TES systems include molten salts, such as solar salt (a KNO₃–NaNO₃ eutectic), as well as other inorganic salts currently under consideration. While these molten nitrate, chloride, sulfate, and carbonate salts offer favourable thermal properties, they can induce significant corrosion of metallic containment materials, leading to reduced system efficiency and component lifetime. Despite extensive post-exposure studies, in situ electrochemical understanding of corrosion mechanisms in molten solar salt remains limited, particularly for emerging alloys such as FeCrAl. In this study, the in situ corrosion behaviour of structural alloys in molten solar salt was investigated using electrochemical impedance spectroscopy (EIS). Complementary post-exposure characterization was performed using destructive techniques, including scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), to assess microstructural and chemical changes. The materials evaluated were stainless steel SS316 and comparatively underexplored Kanthal FeCrAl alloys, exposed to molten solar salt (40 wt% KNO₃–60 wt% NaNO₃) at 545 °C. The electrochemical and microstructural analyses indicate that FeCrAl exhibits superior corrosion resistance associated with the formation of a more stable and protective oxide scale, compared to SS316 under the investigated conditions. This study provides new electrochemical evidence supporting the suitability of FeCrAl alloys for TES applications, while also indicating that SS316 may develop improved corrosion resistance over extended exposure durations, highlighting the importance of long-term performance assessment. Full article

Background/Objectives: Bacterial conjunctivitis is a common ocular infection requiring prompt treatment, particularly in vulnerable patients, and may influence perioperative outcomes. This study aimed to characterize conjunctival bacterial isolates phenotypically and genotypically, to evaluate their biofilm-forming capacity, and to investigate the relationship between resistance gene carriage, resistance phenotypes, and biofilm-associated antimicrobial resistance (AMR). Methods: A prospective, single-center, cross-sectional study was conducted on bacterial isolates from conjunctival samples of patients examined in an ophthalmology department. Antimicrobial susceptibility testing (AST) was performed to determine the minimum inhibitory concentrations (MICs). Resistance genes were detected by quantitative PCR. Biofilm-forming capacity was assessed using the microtiter plate assay, and biofilm susceptibility to amikacin (AK) and levofloxacin (LEV) was evaluated using a biofilm susceptibility assay. Results: A total of 78 isolates were analyzed; Gram-positive cocci prevailed (GPC, 84.6%), being significantly more frequent than Gram-negative bacilli (GNB, p < 0.001). Among GPC, 65.2% were multidrug-resistant, with Staphylococcus epidermidis emerging as the most frequent species (p < 0.001). Resistance gene carriage was detected in 33.3% of GNB. Strong biofilm formation was observed in 22.7% of GPC versus 58.3% of GNB. It should be noted that the relatively small number of GNB may limit the statistical robustness of comparisons between Gram-positive and Gram-negative groups. A statistically significant association between resistance genes and biofilm capacity was found only in Staphylococcus aureus (p = 0.027). Biofilm-embedded bacteria showed increased antimicrobial tolerance, particularly for AK in S. aureus and for both AK and LEV in S. epidermidis (p < 0.001). Conclusions: The prevalence of multidrug-resistant conjunctival isolates and their biofilm-forming capacity highlights the clinical importance of biofilm-related resistance and support integrating AMR profiling with biofilm assessment to optimize empirical therapy in bacterial conjunctivitis. Full article

Osteoporosis is a metabolic disease of the skeleton characterized by a low bone mass and deterioration of bone tissue structure, leading to increased fragility and susceptibility to fractures. It is often referred to as the “silent killer of bones” because it progresses without symptoms until a bone fracture occurs. Osteoporosis is a serious health problem, especially in aging societies, leading to fractures, limited mobility, and a decreased quality of life. Osteoporosis prevention through dietary modification should be the first step in protecting bone health before implementing any form of pharmacotherapy. The composition of the diet and nutritional patterns are considered the most important factors influencing the shaping of gut microbiota and its metabolites, which in turn affect the regulation of bone tissue metabolism. Mushrooms, as a source of vitamin D, can play a significant role in the prevention of osteoporosis. Additionally, the application of UV irradiation can rapidly increase the vitamin D₂ content in mushrooms. A review of currently available studies reveals that many mushroom species contain substances (Ca, P, Se) that support bone formation by promoting remineralization. Mushrooms also induce bone regeneration after osteoporosis by balancing their reconstruction. This review systematically integrates the latest research on the use of mushrooms in the prevention of osteoporosis. The most promising species in the prevention of osteoporosis include: Lentinula edodes, Ganoderma lucidum, Ophiocordyceps sinensis, Pleurotus eryngii, Antrodia camphorata, Auricularia auricula, Agaricus bisporus, and Grifola frondosa. Full article

5-Methoxymethyl-2-furfural (MMF) serves as a crucial biobased platform molecule that can be transformed into various high-value chemicals and biobased polyester monomers. However, the current production of MMF still faces several challenges, such as low yield and prolonged reaction time. In this study, we prepared a series of amide-modified strongly acidic resin catalysts and discovered that they have a higher efficiency in converting fructose to prepare MMF in 1-Butyl-3-methylimidazolium chloride ([BMIM]Cl) and methanol. Among the synthesized catalysts, DB757-NMP demonstrated superior performance, achieving an MMF yield of approximately 61.5% under the optimized conditions, with a combined yield of HMF and MMF reaching about 66.6%. The catalyst formation mechanism was analyzed using FTIR, and NMR, confirming the transformation of proton between NMP and the sulfonic acid groups of the resin, which collectively promoted the conversion of fructose to MMF. In addition, we investigated main reasons for catalyst deactivation and successfully restored catalytic activity through regeneration. The regenerated catalyst could be reused for three times with only a slight decrease in MMF yield. The results suggested that DB757-NMP is a more sufficient and recyclable catalyst for the production of MMF from fructose. This work presented a simple and environmentally benign approach for the synthesis of MMF. Full article

Plants have a remarkable ability to regenerate tissues and organs from single cells, a property that underpins in vitro protoplast regeneration. Efficient protoplast-to-plant regeneration remains a major bottleneck for genome engineering in many crop species, including broccoli (Brassica oleracea var. italica). In this study, we established and optimized a regeneration system for broccoli cv. Claremont by evaluating enzyme composition, light quality, and culture media at successive stages of development. Among the tested enzyme mixtures, 1.5% Cellulase R-10 combined with 0.4% Macerozyme R-10 yielded the highest protoplast viability and recovery. Alginate-embedded protoplasts were cultured under control (dark), blue, and red + far-red LED illumination. Red + far-red treatment significantly enhanced microcolony formation, plating efficiency, and shoot regeneration compared with blue light, whereas blue illumination consistently reduced regenerative performance. The inclusion of activated charcoal in the regeneration medium further increased shoot production. The generalized linear model analyses identified light quality as a significant predictor of both shoot number and regeneration. To our knowledge, this study provides one of the first demonstrations of LED-assisted enhancement of protoplast regeneration in broccoli. The optimized protocol enables whole-plant recovery within approximately 5 months and offers a practical platform for CRISPR-based genome editing and advanced breeding applications in B. oleracea. Full article

Inflammatory bowel disease (IBD) is triggered by genetic predisposition and chronic inflammation, with aberrant activation of the innate immune complex NLRP3 inflammasome playing a pivotal role in its pathogenesis. In this study, we investigated the effects of a hot water extract from the brown alga Endarachne binghamiae (EB-WE) on the inhibition of NLRP3 inflammasome activation, with a focus on its antioxidant properties, in various inflammation models. In bone marrow-derived macrophages (BMDMs), NLRP3 inflammasome activation was induced using LPS and ATP, and EB-WE pretreatment (100, 200 µg/mL) significantly reduced the secretion of IL-1β and IL-18. Confocal immunofluorescence analysis further confirmed that EB-WE suppressed the formation of the NLRP3-ASC/caspase-1 complex. Furthermore, the in vivo anti-IBD efficacy of EB-WE was assessed using a DSS-induced mouse model, in which colonic inflammation and NLRP3-mediated responses were prominent. Oral administration of EB-WE (2 or 5 mg/day) markedly ameliorated clinical symptoms, such as weight loss, diarrhea, and rectal bleeding, and significantly reduced the disease activity index (DAI). EB-WE also decreased serum pro-inflammatory cytokine levels and the expression of NLRP3 inflammasome-related molecules in colon tissue at both the gene and protein levels. In both BMDMs and the IBD mouse model, we further analyzed the upstream regulatory pathway involving NOX2-iNOS. EB-WE efficiently inhibited the activation of the NOX-iNOS axis and NF-κB phosphorylation, thereby alleviating inflammasome activation associated with DSS-induced oxidative stress and neutrophil/macrophage infiltration. Collectively, these results demonstrate that EB-WE effectively suppresses the formation and activation of the NLRP3 inflammasome by modulating the NOX-iNOS axis and the NF-κB pathway via antioxidant mechanisms. These findings suggest that EB-WE holds promise as a novel marine-derived natural therapeutic agent for the treatment of chronic inflammatory diseases. Full article

In this study, a novel material was obtained by functionalizing shredded maize stalk (MS) with Alizarine Red S (ArS), a complexing agent that contains −OH and −C=O groups in its structure (MS-ArS). The obtained MS-ArS was employed in adsorption studies for Mn²⁺, Pb²⁺, Cu²⁺, Cr³⁺, Zn²⁺, and Fe³⁺ (Mⁿ⁺) removal from mixed aqueous matrices. Initially, complex formation between (Mⁿ⁺) and ArS in buffer solution at pH 4 and 10 was investigated using the UV-Vis spectrometric method. Continuous, the functionalization process of MS with ArS was tested at several pH values (2, 4, 6, 8, and 10) using a batch technique. It was observed that the best functionalization of MS with ArS was obtained at pH = 2. Subsequently, Mⁿ⁺ adsorption onto the MS-ArS mass was tested separately at pH 4 and 10. The study achieved that Mⁿ⁺ adsorption proved to be pH dependent. The results confirmed that at pH = 10, Mⁿ⁺ adsorption was increased, compared with pH = 4. MS-ArS has affinity for Mⁿ⁺ in the following order Fe³⁺ > Cu²⁺ > Zn²⁺ > Mn²⁺ > Pb²⁺ > Cr³⁺. Experimental data revealed remarkable desorption rates when 0.5 M HCl was used. After five adsorption/desorption cycles of Mⁿ⁺, the removal capability of MS-ArS was preserved. Overall, the potential of MS-ArS for effective Mⁿ⁺ removal/reuse makes it a sustainable polymer for wastewater treatment applications. Full article

Arsenic (As) pollution has become a global concern, and the search for effective and sustainable As remediation methods has attracted much attention. Sustainable and cost-effective technologies for As remediation are essential to protect public health. This study aligns with the United Nations Sustainable Development Goals (SDGs), specifically SDG 6 (Clean Water and Sanitation) and SDG 12 (Responsible Consumption and Production), by transforming agricultural waste into value-added biochar for environmental remediation. Currently, studies on the remediation of As pollution using iron-modified biochar (Fe-BC) and cerium-modified biochar (Ce-BC) have demonstrated promising application potential. Although there is an established research foundation regarding their remediation performance and mechanisms, comparative studies evaluating their performance and mechanisms under unified experimental conditions remain limited. As in this study, Fe-BC and Ce-BC were prepared and systematically investigated. The As remediation performance and mechanisms of the two biochars were compared and analyzed through material characterization, aqueous adsorption experiments, and soil remediation assessments. The results showed that the specific surface areas of Fe-BC and Ce-BC were 94.380 m²·g⁻¹ and 36.388 m²·g⁻¹, respectively, both higher than that of the original biochar (BC). The Langmuir and Freundlich models adequately fitted the As adsorption processes of all three materials. Fe-BC and Ce-BC exhibited a tendency toward monolayer adsorption for As(III). The Freundlich distribution coefficient K_F of Fe-BC was 0.1604, which was higher than that of BC and Ce-BC, indicating superior adsorption performance for As(III). In the pot experiment, when Fe-BC and Ce-BC were applied at 5%, the As content in ryegrass decreased by 78.38% and 77.15%, respectively. Fe-BC reduced the available As content in soil by 63.1% and decreased As accumulation in ryegrass by 78.38%. The reduction in available As content achieved by Fe-BC was greater than that achieved by Ce-BC. Fe(III) oxides supported on Fe-BC immobilized As through complexation and precipitation mechanisms. Fe⁰ and Fe₃O₄ in the materials altered the redox potential of the local microenvironment, affecting the transformation and stabilization of As species. Ce-BC primarily oxidized As(III) to As(V), and Ce⁴⁺ facilitated the formation of CeAsO₄ precipitates due to its high redox potential. Full article

Thermal modification is widely applied to improve the durability and dimensional stability of wood; however, it alters the emission profile of volatile organic compounds (VOCs), which may affect indoor air quality. This study evaluated the effect of accelerated aging on VOC emissions from thermally modified Norway spruce (Picea abies) wood. Untreated and thermally treated samples (160, 180, and 210 °C) were subjected to accelerated aging in a xenon test chamber for 600 h. VOC emissions were analyzed using headspace gas chromatography–mass spectrometry (HS-GC-MS), and total VOC emissions (TVOC) were calculated from peak areas. Thermal modification significantly reduced TVOC compared to untreated wood, with samples treated at 210 °C showing up to a 376-fold decrease. Increasing modification temperature reduced the amount and variability of emitted VOCs and altered their chemical composition. Terpenes dominated in untreated wood, particularly α-pinene (51%), whereas thermally treated samples showed lower terpene content and higher proportions of carbonyl compounds such as furfural. Accelerated aging further affected VOC emissions, including a 42% decrease in TVOC for the 160 °C sample and compositional shifts characterized by the disappearance or formation of specific compounds. Thermal modification and subsequent aging substantially modify VOC emission profiles and improve emission stability of thermally treated spruce wood. Full article

This work focused on the investigation of sulfonated lignin as a novel and sustainable reinforcing filler for polyamide 6 (PA6) composites. Different formulations were thus prepared by melt compounding, varying the lignin content (5, 10, and 20 wt%). The interaction between lignin and PA6 was systematically studied through rheological, structural, morphological, thermo-mechanical, and flammability tests. Rheological measurements showed an increase in the complex viscosity and viscoelastic moduli with increasing lignin content, suggesting restricted polymer chain mobility and the formation of strong physical interactions between the molten PA6 and the lignin particles. Microstructural observations through FESEM highlighted a good dispersion of lignin particles and efficient filler–matrix interfacial adhesion. Moreover, the addition of lignin significantly increased the tensile stiffness of the composites (up to 3.4 GPa), and a lignin content of 10 wt% enhanced the tensile strength up to 58.4 MPa (i.e., +45% compared to neat PA6) without compromising the ductility. Finally, UL-94 tests revealed an improvement in flame retardancy at higher lignin contents due to the intrinsic char-forming ability of this filler. These results demonstrated that lignin could be an effective multifunctional bio-based filler that can improve the thermo-mechanical performance of PA6 without the need for compatibilizing agents. Full article