Search Results (22,403)

The North China Craton hosts abundant skarn iron resources, yet the regional large-scale mineralization mechanism remains incompletely understood. The Litun deposit is a newly discovered skarn iron deposit in the North China Craton. Integrated field geological investigations, petrographic observations, fluid inclusion microthermometry and stable isotope geochemistry are applied to constrain evaporite contributions to metallogenic processes. Four mineralization stages are identified: skarn, oxide, sulfide, and carbonate. Early skarn-stage fluids are iron-rich magmatic hydrothermal fluids with high temperatures (498 to >550 °C), high salinities (18.6 to 59.4 wt% NaCl eqv.), and magmatic δ¹⁸O values of 8.3 to 10.8‰. Subsequent oxide to late carbonate stages record continuous infiltration of meteoric water, supported by H–O isotopic trends of rising meteoric water proportions. Pyrite from the magnetite ores has δ³⁴S_V-CDT values between 12.0 and 15.0‰, significantly higher than those of pyrite in the Litun diorite (−0.8 to 1.1‰), indicating the contributions of sulfur from evaporites (δ³⁴S_V-CDT 26.9 to 28.6‰) in the mineralization process. Moreover, vein pyrite formed in later stages displays even higher δ³⁴S values (17.3 to 20.9‰), demonstrating progressive enrichment of evaporite-derived sulfur as hydrothermal activity evolves. Synchronous rises in meteoric water fraction and evaporite sulfur proportion indicate evaporites are delivered into the ore-forming system via meteoric water mixing. The mixing of meteoric water containing dissolved evaporites and iron-rich magmatic-hydrothermal fluids may be the major mechanism of magnetite precipitation in the Litun deposit. Full article

The development of efficient, low-cost hydrodeoxygenation (HDO) catalysts is essential for converting renewable lipids into sustainable aviation fuels. Here, we report a series of sulfided bimetallic NiFe/γ-Al₂O₃ catalysts and systematically investigate the promotional role of Fe in the HDO of methyl decanoate, a model lipid compound. Using complementary characterization together with fixed-bed reactor kinetic measurements, we elucidate the influence of the Ni/Fe ratio on catalyst structure, sulfidation behavior, electronic properties, and reaction pathway. Fe incorporation promotes Ni sulfidation and induces electron transfer from Fe to Ni, as directly evidenced by a red shift in the CO stretching frequency (from 2094 cm⁻¹ for Ni-only to 2090 cm⁻¹ for NiFe), indicating increased electron density on Ni sites and enhanced π-backdonation. Among the catalysts tested, N5F5 (Ni/Fe mass ratio = 1:1) exhibits the highest Ni sulfidation degree, the highest turnover frequency (32.1 h⁻¹), and the lowest apparent activation energy (E_a ≈ 92 kJ/mol). At 360 °C, it achieves 52.9% methyl decanoate conversion, far exceeding that of monometallic Ni and Fe catalysts. Product selectivity analysis reveals that sulfided Ni sites predominantly promote the decarboxylation/decarbonylation (DCOx) pathway, whereas Fe sites contribute only marginally to direct deoxygenation (DDO). This work provides the first direct spectroscopic evidence for Fe-to-Ni electron transfer in sulfided NiFe catalysts and establishes a clear structure-performance correlation, offering a rational design strategy for low-cost, high-performance HDO catalysts for lipid upgrading. Full article

To support the achievement of the carbon peaking and carbon neutrality goals and promote the resource utilization of industrial solid waste, a ternary solid waste composite cementitious material was prepared by blending ground granulated blast-furnace slag (GGBFS), fly ash (FA), and carbide slag (CS) with cement. The optimal mix ratio was determined through single-factor experiments and response surface methodology. The synergistic hydration mechanism was elucidated using microstructural characterization techniques, including XRD, FTIR, TG-DTG, and SEM. The composite material was then applied to a semirigid base course, and its mechanical properties and durability were systematically evaluated. The results indicate that the optimal levels of FA, GGBFS, and CS investigated in the single-factor experiments are 20–40%, 30–50%, and 2–6%, respectively. The optimal mix ratio of the ternary solid waste composite is 21.0% FA, 36.3% GGBFS, and 5.7% CS. The underlying microstructural mechanism is that carbide slag creates a highly alkaline environment, which activates the pozzolanic activity of GGBFS and fly ash, leading to the formation of hydration products dominated by C-(A)-S-H gel. With increasing curing age, the gel structure evolves from a loose and disordered state to a dense and ordered state, ultimately forming a compact microstructure based on a highly polymerized C-(A)-S-H gel matrix. The 7-day unconfined compressive strength of the stabilized gravel using the solid waste-based composite cementitious material reached 5.93 MPa, and the 28-day drying shrinkage coefficient was reduced by 18.3% compared with that of cement-stabilized gravel. After 18 freeze–thaw cycles, the compressive strength increased by 2.4%, with the pore structure characterized by a “macropores decreasing, micropores increasing” refinement pattern. After 18 wetting–drying cycles, the cumulative strength loss was 11.26%, outperforming cement-stabilized gravel. Combined with SEM observations, these performance improvements are attributed to the densely intertwined hydration products, particularly C-S-H gel, which effectively fill the voids between aggregate particles and significantly enhance the volume stability, freeze–thaw resistance, and wetting–drying durability of the stabilized gravel. The application of this cementitious material in a semirigid base course demonstrates excellent mechanical and durability properties, providing a theoretical basis and technical support for the widespread application of industrial solid waste in road engineering. Full article

Hydroxyapatite (HAp) is a widely used bioceramic in bone tissue engineering due to its biocompatibility and osteoinductive capacity; however, sustainable low-cost synthesis routes remain a challenge. This study evaluated HAp-polysaccharide composite synthesis from nejayote, the alkaline wastewater of maize nixtamalization, via chemical precipitation with (NH₄)₃PO₄ under controlled and uncontrolled pH, followed by calcination at 550 °C for 2 or 4 h. Controlled pH synthesis yielded higher solid recovery (89.8% vs. 76.4%), better calcium removal (99.8% vs. 87.4%), and smaller particle sizes (423.6 nm vs. 715.0 nm). XRD and FTIR confirmed HAp formation in both conditions, with crystallinity increasing upon calcination. Monomeric composition analysis revealed co-precipitation of amylose and arabinoxylan-derived polysaccharides in uncalcined samples, progressively eliminated by thermal treatment. Cell viability assays with human fetal osteoblasts (hFOB 1.19) confirmed non-cytotoxicity at all concentrations tested (10–633 μg/mL). Uncalcined composites synthesized without pH control achieved 126% cell viability at 633 μg/mL, surpassing pH-controlled and calcined counterparts (90–100%), suggesting active promotion of osteoblast proliferation, further supported by fluorescence imaging. These results establish nejayote as a viable dual source of calcium and polysaccharides for sustainable HAp composite synthesis with biomedical potential. Full article

Water-soluble blue microbial pigments with antioxidant activity remain rare, and their host-level protective mechanisms are poorly understood. Here, we identified the genetic basis of blue pigment biosynthesis in the glacier-derived strain Arthrobacter antioxidans QL17. Heavy-ion mutagenesis yielded a hyperpigmented mutant (M157) and a pigment-deficient mutant (M186), and pigment yield was positively associated with hydrogen peroxide (H₂O₂) tolerance. Genome mining identified MWM45_RS16760 as the sole core biosynthetic gene in a candidate nonribosomal peptide synthetase (NRPS)-like cluster. The encoded protein displayed an adenylation–peptidyl carrier protein–thioesterase (A-PCP-TE) architecture with a predicted L-glutamine-specific A domain, and its transcript abundance paralleled pigment production across the three strains. Phylogenetic analysis placed MWM45_RS16760 in a distinct actinomycete-associated indigoidine-like lineage separated from the characterized BpsA and IndC branches. Heterologous expression in Escherichia coli reconstructed a blue-pigment-producing phenotype, increased H₂O₂ tolerance, and was accompanied by enhanced extracellular DPPH and ABTS radical-scavenging activities in the culture supernatant. Comparative transcriptomics further revealed coordinated activation of oxidative-stress and proteostasis responses alongside repression of tryptophan biosynthesis and flagellar assembly. These findings identify MWM45_RS16760 as a candidate indigoidine-like NRPS associated with blue pigment biosynthesis and oxidative-stress resistance, with heterologous expression linked to enhanced radical scavenging and coordinated transcriptional reprogramming, expanding the phylogenetic and functional diversity of indigoidine-like systems. Full article

Artemisia annua contains artemisinin, a sesquiterpene lactone endoperoxide; artemether is a semisynthetic derivative of artemisinin that may offer potential advantages due to its redox-modulating and antimicrobial activities. These compounds have been associated with oxidative-stress modulation and microbial inhibition, making them promising candidates for experimental evaluation in nutritional and post-harvest quality studies. This study evaluated the effect of dietary supplementation with A. annua powder, artemisinin, and artemether on the refrigerated quality of Nile tilapia (Oreochromis niloticus) fillets. A total of 160 Nile tilapia were randomly assigned to four treatments: control (no additive), 1% A. annua powder, artemisinin (9.6 mg/kg feed), or artemether (9.6 mg/kg feed). After 30 days of feeding, 320 fillets were collected and stored under refrigeration at 4 °C. Samples were analyzed immediately after slaughter (day 0) and on days 7, 15, and 30. For each treatment group and sampling time, 20 fillets were used: 10 for microbiological evaluations, including counts of mesophilic and psychrotrophic bacteria, molds and yeasts, sulfite-reducing Clostridium, Enterobacteriaceae, coagulase-positive staphylococci, and coliforms; and 10 for physicochemical analyses, including pH, colorimetry, lipid oxidation through TBARS, and sensory evaluation. All supplemented treatments demonstrated improved microbial stability and lower TBARS values when compared with the control. Spoilage indicators such as discoloration, texture loss, and odor deterioration were also delayed. Artemether showed the most pronounced benefits, with lower microbial loads and oxidation indices for several evaluated parameters. These findings suggest that dietary supplementation with A. annua and its derivatives may help delay post-harvest quality deterioration of tilapia fillets during refrigerated storage. Full article

This study explores an innovative approach based on deep eutectic solvent (DES)-synergistic ultrasonic-assisted extraction (UAE) of anthocyanins from blueberry pomace (BP). Choline chloride–lactic acid (ChCl-LA, 1:2) was identified as the most efficient DES and provided the highest anthocyanin recovery. The optimal conditions for ChCl-LA-synergistic UAE (ChCl-LA-UAE) were obtained as follows: ultrasonic power of 270 W, extraction time of 30 min, liquid-to-solid ratio of 35:1, and water content in ChCl-LA of 40%, achieving a total anthocyanin content (TAC) of 3.5168 mg/g, with R² = 0.9860. This value was significantly higher than those obtained with 70% ethanol (3.1962 mg/g) and pure water (1.9137 mg/g). SEM images revealed that ChCl-LA-UAE disrupted the surface structure of the samples, thereby promoting anthocyanin release. COSMO-RS simulations confirmed that ChCl-LA significantly enhanced the interaction between the solvent and the representative anthocyanin (cyanidin-3-O-glucoside, C3G), resulting in higher extraction efficiency. In vitro antioxidant assays further demonstrated that the synergistic system exhibited stronger antioxidant activity. Overall, ultrasonic-synergistic DES extraction could be an eco-friendly method for recovering high-value compounds from blueberry and its byproducts. Full article

Epilepsy is a common chronic neurological disorder characterized by recurrent seizures. Gastrodia elata, the dried tuber of G. elata Bl. (Orchidaceae), is a valuable medicinal and edible botanical resource. This study optimized the preparation of Yellow Rice Wine-Processed G. elata (YPGE) and investigated its antiepileptic effects and underlying mechanisms in a pentylenetetrazol (PTZ)-kindled rat model. Processing parameters were optimized using single-factor experiments combined with an analytic hierarchy process (AHP)-entropy weight method (EWM) weighting strategy and Box–Behnken design–response surface methodology. The optimal parameters were determined as 18% alcohol by volume, 72 °C drying temperature, and 32 h drying time. Compared with unprocessed G. elata (GE), YPGE exhibited 0.54-, 0.13-, 1.87-, and 3.58-fold increases in the contents of gastrodin (GAS), G. elata polysaccharides (GEPs), p-hydroxybenzyl alcohol (p-HBA), and total parishins (TP), respectively, and demonstrated significantly enhanced in vitro antioxidant activity (IC50 values of 2.604, 2.719, and 4.046 mg/mL for DPPH, ABTS, and hydroxyl radicals). In vivo, both GE and YPGE significantly reduced seizure severity, decreased inflammatory cytokines (TNF-α, IL-1β), alleviated oxidative stress (increased SOD and GSH-Px, decreased MDA), and modulated neurotransmitter balance (reduced Glu, increased GABA) in brain tissues. YPGE also upregulated P-glycoprotein expression and reduced neuronal apoptosis in the hippocampal CA1 region by upregulating Bcl-2 and downregulating Bax. These findings suggest that YPGE exerts multi-target antiepileptic effects through synergistic anti-inflammatory, antioxidant, and anti-apoptotic actions, providing experimental evidence for the development of novel antiepileptic therapies based on processed G. elata. Full article

Phenylglycine (Phg) is a nonproteinogenic α-amino acid found in various bioactive molecules. The C-terminal activation of N-acyl Phg is often accompanied by oxazolone-mediated racemization, arising from the direct attachment of the phenyl ring to the α-carbon. After peptide bond formation with another chiral amino acid, this stereochemical erosion is observed as Phg-site epimerization and diastereomer formation. N-acyl activated esters, particularly N-hydroxysuccinimide (OSu) esters, are widely used for peptide bond formation with proteinogenic α-amino acids. Our previous study on N-trifluoroacetyl phenylglycine (TFA-Phg-OH) revealed that Phg-site epimer formation could still occur when TFA-Phg-OSu was employed as an acyl donor for coupling with amino acid ester hydrochlorides (AA–OMe·HCl) in the presence of a soluble organic base. To address these issues, in this study, we report a base-limited one-pot coupling of TFA-Phg-OH with α-amino acid ester hydrochlorides (AA–OR·HCl; R = Me or tert-Bu) using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (WSCD·HCl), which effectively suppresses Phg epimerization. The resulting TFA-Phg–AA–OR dipeptides (AA = Ala, Val, Leu, Met, Phg) were all obtained at a >60% yield with a diastereomeric excess (de) ≥ 98.5%. Notably, reducing the amount of triethylamine further minimized epimer formation, while Ba(OH)₂·8H₂O and trifluoroacetic acid enabled stereoretentive deprotection of the N-TFA group and tert-butyl ester, respectively. This workflow provides practical access to both protected and deprotected Phg–AA motifs, thereby facilitating the preparation of unprotected Phg-containing peptide building blocks. Full article

The extent to which cricket frass placement and rate regulate fertility restoration and crop response in tropical acidic sandy soil remains insufficiently resolved. This greenhouse bioassay tested whether incorporated or surface-applied cricket frass differentially improved soil fertility and Chinese kale biomass, and whether these responses were rate-dependent. Cricket frass was applied by incorporation or surface placement at 3.125, 6.25, and 12.5 Mg (tonnes) ha⁻¹ and compared with an unamended control. The frass had pH of 6.95, EC 19.6 mS cm⁻¹, 10.7 g N kg⁻¹, 8446 mg P kg⁻¹, and 12,425 mg K kg⁻¹ and a C:N ratio of 16.8. At 12.5 Mg ha⁻¹, incorporation produced the greatest shoot dry biomass (7.16 g plant⁻¹), exceeding surface placement (4.78 g plant⁻¹) and the control (1.70 g plant⁻¹). High-rate incorporation increased NH₄⁺–N, net ammonification, available P, and microbial activity, reduced exchangeable acidity, and promoted greater nutrient uptake. Pearson correlation analysis showed that shoot biomass was strongly associated with plant nutrient uptake, soil P, pH, CEC, NH₄⁺–N, and net ammonification, and was negatively associated with soil Al and exchangeable acidity. Both placement methods improved fertility and yield relative to the control, but incorporation was superior at the high rate. Surface placement remains useful where soil disturbance must be minimized, although field validation with larger soil volumes and rainfall-driven processes is required. Full article

Protea venus, a hybrid of Protea repens and Protea aristata, is a commonly found flower in the South African market. To date, there are no reported chemical or biological studies on this hybrid. This study presents the first investigation of the chemical composition and preliminary biological activity of the methanolic extract of P. venus. Phytochemical analysis of the methanolic extract led to the isolation of nine known phenolic compounds (2–10) and one new compound, p-coumaroyl calleryanin (1). The identified known constituents include calleryanin derivatives (2–4), lacticolorin (5), quercetin derivatives (6–8), protocatechuic acid (9), and p-hydroxybenzoic acid (10). Notably, calleryanin (2), protocatechuoyl calleryanin (3), kaempferol-3-O-rhamnoside (6), and quercetin-3-O-rhamnoside (7) are reported for the first time in the genus Protea. Compounds 3 and 9 exhibited strong antioxidant activity in the ferric reducing antioxidant power (FRAP) assay, with 9 exceeding vitamin C. Molecular docking studies suggest that the isolated compounds may interact with Kelch-like ECH-associated protein 1 (KEAP1). In H9c2 cardiomyocytes exposed to high glucose (40 mM) and palmitate (0.15 mM), the extract and compound 6 were non-cytotoxic (≤100 µg/mL) and produced a moderate restoration of ATP levels under glucolipotoxic conditions. These findings expand the phytochemical profile of P. venus and provide preliminary insight into its biological activity under metabolic stress. Full article

Hydrophobic silica aerogels are widely used as thermal-insulation materials, but the thermal decomposition of their organic surface groups may affect their stability and safety during high-temperature service. In this study, ambient-pressure-dried silica aerogels modified with trimethylsilyl, dimethylsilyl, and methylsilyl groups were prepared and denoted as TSA, DSA, and MSA, respectively, to clarify how the degree of methyl substitution in the surface modifier controls the pyrolysis behavior of hydrophobic silica aerogels. Thermogravimetric analysis at different heating rates was combined with TG-FTIR, a model-free kinetic analysis, a model-fitting analysis and thermodynamic calculation. With decreasing methyl substitution from TSA to MSA, the aerogel framework became denser, the specific surface area decreased, and the contribution of solid-phase heat transfer increased slightly. The main pyrolysis process occurred at 250–800 °C and involved multiple overlapping reactions. The average activation energies of TSA, DSA, and MSA were 241.4, 246.6, and 285.5 kJ/mol according to the Kissinger–Akahira–Sunose (KAS) method and 243.0, 248.2, and 289.0 kJ/mol according to the Flynn–Wall–Ozawa (FWO) method, respectively. The higher activation energy of MSA indicates that the more condensed silica-rich framework and lower organic methyl content improves its resistance to the main degradation process. The model-fitting analysis further suggested an A1/2 mechanism for TSA and A2/5 mechanisms for DSA and MSA. TG-FTIR further confirmed the evolution of CO₂, H₂O, CH₄, and C₂H₄ and revealed distinct gas-release behaviors among the three samples. These results demonstrate that the surface methyl-substitution structure governs the balance between hydrophobic modification, pore-structure preservation, pyrolysis resistance, and volatile-product release, providing a basis for selecting surface modifiers for thermally stable silica-aerogel insulation materials under oxygen-limited high-temperature conditions. Full article

The hormonal vitamin D metabolite, 1,25-dihydroxyvitamin D (1,25D), produced primarily in the kidney, acts in numerous end-organs via the nuclear vitamin D receptor (VDR) to trigger molecular events that orchestrate bone mineral homeostasis, immune responsiveness, and aspects of behavior. Tyrosine hydroxylase (TH) encodes a neuronally expressed enzyme that catalyzes the initial, rate-limiting step in the production of several catecholamine neurotransmitters and hormones, including dopamine, norepinephrine, and epinephrine. Herein we report that TH mRNA is significantly induced (2.5-fold) and NURR1 mRNA is induced 9.3-fold by 10 nM 1,25D in differentiated human SH-SY5Y neuroblastoma cells. Similar results were observed in human U87 glioblastoma cells (TH, 2.6-fold; NURR1, 3.6-fold). Comparative analysis of TH gene promoter-proximal sequences from human, mouse, and rat identifies candidate NURR1-responsive elements (NBREs) at the following positions: −35, −855, −1470, and −2343 bp in the human gene; −34 and −961 bp in the mouse gene; and −34, −350, and −873 bp in the rat gene, consistent with NURR1 acting as a recurring regulatory factor at TH promoters across mammalian species. Furthermore, by interrogating VDR ChIP-seq/cistrome datasets, we identified candidate vitamin D-responsive elements (VDREs) at the human NURR1 locus that provide a plausible genomic framework for direct regulation of NURR1 by 1,25D/VDR. We propose that 1,25D-liganded VDR acts as a primary inducer of NURR1, which in turn secondarily activates expression of the TH gene, thereby defining a transcriptional route through which 1,25D/VDR signaling may influence TH-linked dopaminergic gene programs. Retinoid X receptor (RXR) may facilitate both NURR1-dependent and -independent potentiation of TH transcription because the rexinoid, bexarotene, significantly enhances TH mRNA in human U87 cells, either alone (2.0-fold) or in combination with 1,25D (4.1-fold). In addition, bexarotene and its novel analogs, A41 and A55, induce NURR1 mRNA expression in U87 cells by 2.8-, 3.1-, and 4.8-fold, respectively, with A55 outperforming the parent compound at matched concentration. Because Parkinson’s disease is characterized by the selective degeneration of dopaminergic neurons and impaired NURR1-dependent transcriptional programs, our findings identify a 1,25D/VDR–NURR1–RXR transcriptional axis as a previously underappreciated regulatory framework for studying TH gene expression and dopaminergic gene regulation in Parkinson’s disease-relevant neural contexts. Full article

This study aims to demonstrate the feasibility of transferring alkali activation technology to the ceramic tile production by developing tiles based on metakaolin and ceramic tile waste by uniaxial pressing. Optimization of the tile formulations was achieved by adjusting precursor composition (metakaolin or combination of metakaolin and ceramic tile waste), NaOH molarity, and overall water content. After uniaxial pressing at 50 MPa, alkali-activated tiles were consolidated at 50 °C for 24 h. Physical and mechanical properties were assessed following ISO test methods for ceramic tiles, allowing direct comparison with the ISO classification requirements. The more promising formulations highlight a water absorption by vacuum test method (ISO 10545-3) equal to 15%, thus allowing a BIII classification according to ISO 13006. Finally, thermal stability up to 850 °C was determined, thus allowing alkali-activated tiles to be industrially glazed. Full article

Andrographolide-loaded microparticles with an aqueous-based carrier system were developed with the aim of pulmonary drug delivery. Five formulations of andrographolide (0.6–5.8% w/w) loaded on mixed-polymer carriers containing chitosan (CHS), hydroxyethyl cellulose (HEC), Poloxamer 188, and PEG 20,000, with various ratios were produced under various spray-drying parameters: solution viscosity (5–20 cP), atomization air pressure (0.8–1.5 bar) and solution feed rate (3–6 mL/min). The physiochemical properties of the microparticles were strongly affected by carrier composition and atomization air pressure. The optimal formulation: andrographolide 0.6% w/w, CHS 62.2% w/w, HEC 15.5% w/w and Poloxamer 188 21.7% w/w, spray dried using solution viscosity 15 cP, atomization air pressure 1.1 bar and feed rate 3 mL/min, was selected according to its particle sizes (3–5 µm) with rough morphology, encapsulation efficiency (54.47%) and release behaviors (22.31%/h and 89.23% within 4 h). Good physical, chemical, and thermal stabilities under room storage condition (28 ± 2 °C, 50% relative humidity) were also proven. Importantly, it demonstrated potent antiviral activity against Influenza A/H1N1, achieving a 3.3-log₁₀ reduction in viral titer with 99.95% inhibition. Overall, this aqueous-based carrier approach and spray-drying technique offer a stable and effective inhalable formulation for localized treatment of influenza infections. Full article