Search Results (8,866)

Objectives: We aimed to investigate the effects of 6 weeks of leucine supplementation on athletic performance, central fatigue, and serum metabolome in endurance athletes, and to provide valuable insights into nutritional strategies for endurance athletes. Methods: Twenty cross-country skiers were recruited and randomized into 2 groups: the placebo (PLA) group and the leucine (LEU) group. Subjects were given leucine (8.5 g) + sucrose (14 g) or only sucrose (14 g) supplements twice each day from Monday to Saturday for 6 weeks. Test parameters include body composition, aerobic capacity, isokinetic muscle strength, blood biochemistry, and targeted metabolomics. Results: After intervention, compared to the PLA group (1) the ankle muscle strength (p = 0.01), VO₂max (p = 0.01) and valine in serum (p = 0.03) were increased in the LEU group. (2) Targeted metabolomics results showed that the differential metabolites were enriched in the branched chain amino acids (BCAAs) biosynthesis and degradation. (3) The LEU group had a significant increase in α-ketoisovaleric acid (p = 0.03), which can reduce the continuous decomposition of BCAAs. Conclusions: In conclusion, a six-week intervention of leucine supplementation significantly enhanced ankle muscle strength in endurance athletes, likely through a reduction in BCAA catabolism. Additionally, this combined supplementation strategy demonstrated potential benefits in improving aerobic endurance and may contribute to the attenuation of exercise-induced central fatigue. Full article

Achieving sustainable land restoration in southern Chinese ionic rare earth mining areas remains a significant challenge due to the extended duration and low efficiency of conventional remediation approaches. Although the hyperaccumulator Dicranopteris pedata possesses a remarkable capacity for rare earth element (REE) enrichment, a significant knowledge gap exists regarding how to effectively combine exogenous organic acids with agronomic practices like clipping to enhance its remediation efficiency in an environmentally sustainable manner. Crucially, the potential environmental risks associated with such synergistic strategies have not been systematically evaluated, hindering their practical application. To address this, our study focused on Dicranopteris pedata and employed integrated pot and soil column leaching experiments to systematically analyze the effects of different concentrations of citric acid and tartaric acid on REE migration and transformation within the soil–plant system. The results demonstrated that exogenous organic acids significantly reduced soil pH and promoted the conversion of REEs from the residual to the exchangeable fraction. Specifically, the 20 mmol·kg⁻¹ citric acid treatment increased the proportion of exchangeable REEs by 43.46%. Furthermore, organic acid treatments significantly altered the REE uptake patterns in Dicranopteris pedata, inhibiting the translocation and accumulation of REEs in the aboveground tissues. Soil column leaching experiments revealed that citric acid drove the migration of REEs to deeper soil layers, with the concentration peaking at 288.33 mg·kg⁻¹ at a depth of 6–8 cm; concomitantly, the REE content in the leachate reached its maximum on the 5th day. This study demonstrates that the combined application of 20 mmol·kg⁻¹ citric acid and 100% clipping management increased the annual REE accumulation in Dicranopteris pedata to 4.85 g·m⁻², thereby significantly shortening the theoretical remediation period from 25.0 years in the control to 12.1 years. Soil column leaching experiments indicated no significant secondary pollution risk associated with this strategy. These findings provide a feasible, low-risk, and sustainable technical strategy for the synergistically enhanced remediation of REE-contaminated soils, offering a promising path for ecological restoration and sustainable land management in degraded mining ecosystems. Full article

Background: Chronic diabetic wounds, particularly diabetic foot ulcers (DFUs), are prone to recurrent infection and delayed healing, resulting in substantial morbidity, mortality, and economic burden. Multifunctional wound dressings that combine antibacterial, antioxidant, conductive, and self-healing properties may help to address the complex microenvironment of chronic diabetic wounds. Methods: In this study, ε-poly-L-lysine and amino-terminated polyethylene glycol were grafted onto carboxylated single-walled carbon nanotubes (SWCNTs) via amide coupling to obtain ε-PL-CNT-PEG. Aminated chondroitin sulfate (CS-ADH) and a catechol–metal coordination complex of protocatechualdehyde and Fe³⁺ (PA@Fe) were then used to construct a dynamic covalently cross-linked hydrogel network through Schiff-base chemistry. The obtained hydrogels (Gel0–3, Gel4) were characterized for photothermal performance, rheological behavior, microstructure, swelling/degradation, adhesiveness, antioxidant capacity, electrical conductivity, cytocompatibility, hemocompatibility, and antibacterial activity in the presence and absence of near-infrared (NIR, 808 nm) irradiation. Results: ε-PL-CNT-PEG showed good aqueous dispersibility, NIR-induced photothermal conversion, and improved cytocompatibility after surface modification. Incorporation of ε-PL-CNT-PEG into the PA@Fe/CS-ADH network yielded conductive hydrogels with porous microstructures and storage modulus (G′) higher than loss modulus (G′′) over the tested frequency range, indicating stable gel-like behavior. The hydrogels exhibited self-healing under alternating strain and macroscopic rejoining after cutting. Swelling and degradation studies demonstrated pH-dependent degradation, with faster degradation in mildly acidic conditions (pH 5.0), mimicking infected chronic diabetic wounds. The hydrogels adhered to diverse substrates and tolerated joint movements. Gel4 showed notable DPPH• and H₂O₂ scavenging (≈65% and ≈60%, respectively, within several hours). The electrical conductivity was 0.19 ± 0.0X mS/cm for Gel0–3 and 0.21 ± 0.0Y mS/cm for Gel4 (mean ± SD, n = 3), falling within the range reported for human skin. In vitro, NIH3T3 cells maintained >90% viability in the presence of hydrogel extracts, and hemolysis ratios remained below 5%. Hydrogels containing ε-PL-CNT-PEG displayed enhanced antibacterial effects against Escherichia coli and Staphylococcus aureus, and NIR irradiation further reduced bacterial survival, with some formulations achieving near-complete inhibition under low-power (0.2–0.3 W/cm²) 808 nm irradiation. Conclusions: A dynamic, conductive hydrogel based on PA@Fe, CS-ADH, and ε-PL-CNT-PEG was successfully developed. The hydrogel combines photothermal antibacterial activity, antioxidant capacity, electrical conductivity, self-healing behavior, adhesiveness, cytocompatibility, and hemocompatibility. These properties suggest potential for application as a wound dressing for chronic diabetic wounds, including diabetic foot ulcers, although further in vivo studies are required to validate therapeutic efficacy. Full article

Peroxymonosulfate (PMS)-based advanced oxidation is often hindered by pH instability and the lack of post-reaction separation. Herein, commercial magnesium hydroxide (Mg(OH)₂) is introduced as a multifunctional catalyst to address these limitations. Mg(OH)₂ effectively catalyzed PMS decomposition via a nonradical pathway dominated by singlet oxygen (¹O₂) generation, achieving rapid and complete degradation of electron-rich pollutants like bisphenol A (BPA) within 40 min. The system exhibits exceptional pH self-regulation, stabilizing the solution at ~9.8 and maintaining high efficiency across an initial pH range of 3–11. Mechanistic studies confirm ¹O₂ as the primary reactive species with a steady-state concentration of 1.67 × 10⁻¹² M. The catalyst demonstrates strong resistance to common anions and humic acid, along with excellent stability over four cycles. Furthermore, Mg(OH)₂ enables in situ flocculation and removal of degradation products. This work highlights Mg(OH)₂ as an efficient, stable, and multifunctional activator, offering a integrated strategy for practical wastewater treatment. Full article

Background: Chitosan-based hydrogels exhibit excellent temperature-sensitive properties and are widely used as skin dressings. However, several challenges remain, such as long gelation times and difficulties releasing insoluble drugs, which limit their application in skin wound healing. In this study, we developed a novel sulfobutyl-β-cyclodextrin/quercetin@chitosan/hyaluronic acid hydrogel (Qe/SBE@CS/HA Gel). In this gel, SBE not only encapsulates Qe to form inclusion complexes, thereby enhancing the solubility of Qe, but also shortens the gelation time of thermosensitive gels through electrostatic adsorption with chitosan. Methods: Qe/SBE was prepared using the saturated solution method, while Qe/SBE@CS/HA gel was fabricated via electrostatic adsorption. The performance of the gels was evaluated using antibacterial, antioxidant, compatibility, and skin infection damage models. Results: The Qe/SBE@CS/HA Gel exhibits both thermosensitivity and acid sensitivity, releasing 91.9% of Qe in a medium with a pH of 5.0. This gel displays notable antibacterial activity and antioxidant characteristics. Furthermore, it shows excellent biocompatibility, as evidenced by hemolytic and in vivo degradation tests. The gel has the capacity to modulate chronic inflammation and facilitate angiogenesis and collagen synthesis, thereby significantly accelerating wound healing in wound and infection models. Conclusions: This multi-responsive and multifunctional gel shows potential as a therapeutic strategy for bacterial infection wounds. Full article

High-temperature proton exchange membranes (HT-PEMs) are critical components of high-temperature fuel cells, facilitating proton transport and acting as a barrier to fuel and electrons; however, their performance is hampered by persistent issues of phosphoric acid leaching and oxidative degradation. Herein, a novel HT-PEM with abundant hydrogen bond network is constructed by incorporating nanoscale polyhedral oligomeric silsequioxane functionalized with eight pendent sulfhydryl groups (POSS-SH) into poly(4,4′-diphenylether-5,5′-bibenzimidazole) (OPBI) matrix. POSS, a cage-like nanostructured hybrid molecule, features a well-defined silica core and highly designable surface organic groups, offering unique potential for enhancing membrane performance at the molecular level. Through controlled reactions between sulfhydryl groups and allyl glycidyl ether (AGE), two functional POSS crosslinkers—octa-epoxide POSS (OE-POSS) and mixed sulfhydryl-epoxy POSS (POSS-S-E)—were synthesized. These were subsequently used to fabricate crosslinked OPBI membranes (OPBI-OE-POSS and OPBI-POSS-S-E) via epoxy–amine coupling. The OPBI-POSS-S-E membranes demonstrated exceptional oxidative stability, which is attributed to the free radical scavenging ability of the retained sulfhydryl groups on the nano-sized POSS framework. After soaking in Fenton’s reagent at 80 °C for 108 h, the OPBI-POSS-S-E-20% membrane retained 79.4% of its initial weight, significantly surpassing both the OPBI-OE-POSS-20% and pristine OPBI membranes. The PA-doped OPBI-POSS-S-E-20% membrane achieved a proton conductivity of 50.8 mS cm⁻¹ at 160 °C, and the corresponding membrane electrode assembly delivered a peak power density of 724 mW cm⁻², highlighting the key role of POSS as a nano-modifier in advancing HT-PEM performance. Full article

Background/Objectives: MDMA and MDA are among the stimulant drugs most frequently encountered in forensic casework, and oral fluid represents a practical biological matrix for their detection. However, liquid oral fluid requires refrigeration, is susceptible to degradation, and can be logistically demanding for routine laboratories. Dried Oral Fluid Spots (DOFS) offer a low-cost and stable alternative. This study aimed to develop and validate a DOFS-based analytical workflow for quantifying MDMA and MDA using liquid chromatography and a diode-array detector. Methods: Watercolor paper was selected as the substrate and pretreated with diluted nitric acid to improve analyte desorption. DOFS were prepared using 150 µL of pooled oral fluid, dried for 4 h, and extracted with methanol. Chromatographic separation was performed on a phenyl column using aqueous TFA and acetonitrile mobile phase. Method validation followed the ICH M10 criteria. Results: The method showed linear responses between 12.5 and 5000 ng mL⁻¹, with LOD and LLOQ of 6 and 12 ng mL⁻¹ for both analytes, respectively. Precision and accuracy met acceptance criteria across all QC levels. Recoveries ranged from 84% to98%. DOFS samples demonstrated adequate stability under multiple storage and handling conditions. Conclusions: The optimized DOFS–LC–DAD workflow offers a robust, low-cost, and flexible approach for the analysis of MDMA and MDA in oral fluid for laboratory-based or semi-controlled collection environments. Its compatibility with both LC- and GC-based detectors enhances applicability in diverse forensic laboratory settings. Full article

The mechanism of the quality formation of dark tea is not fully clear, particularly under variable fermentation temperatures. In this study, the tea fermented with Aspergillus niger (AN) at 25 (AN25) and 37 °C (AN37) exhibited the highest quality. Different fermentation temperatures primarily influenced the degradation of fatty acids and the hydrolysis of glycosides in the tea, with 37 °C being the most favorable for the release and accumulation of volatile compounds. Eighteen key volatiles were identified. Among these, benzaldehyde (a 120.9% increase compared to CK), α-ionone (957.8%), linalool (172.2%), and nonanal (22.8%) were present at high levels in AN37, and these compounds served as the main aroma contributors. Inoculation with AN and fermentation temperature primarily influences the levels of total polyphenols, organic acids and their derivatives, as well as amino acids and their metabolites in dark tea. Total polyphenols, flavonoids, and nucleotide and its metabolites were more rapidly consumed at 25–37 °C, contributing to the improved taste of the tea infusion. Additionally, EGC, GC, melezitose, and sucrose showed significant negative correlations with the taste quality of the tea infusion (p < 0.05). These results are conducive to further understanding of the quality formation of dark tea. Full article

Hyaluronic acid (HA) injections are commonly employed in the management of osteoarthritis (OA), yet their therapeutic benefits are often limited by oxidative degradation and enzymatic breakdown within the joint. This study investigates whether Resolvin D1, Resolvin D2, and their methyl ester derivatives can enhance the efficacy of HA injections by acting as dual-function agents with both antioxidant and enzyme inhibitory properties. A comprehensive series of in vitro assays—including ORAC, FRAP, DPPH, ABTS, HRS, and SOD—were performed to evaluate antioxidant capacity, using Trolox, Ascorbic acid, β-Carotene, and Quercetin as reference standards. The potential to inhibit HA degradation was assessed through ROS-induced HA fragmentation and hyaluronidase inhibition assay, with epigallocatechin gallate (EGCG) serving as a positive control. The results indicate that Resolvin derivatives, particularly the methyl ester form of Resolvin D1, display mechanism-dependent antioxidant activity, showing pronounced effects in hydrogen atom transfer-based assays (e.g., ORAC and HRS), as well as in ABTS^•+ and superoxide-related systems, along with protection against ROS and enzyme-induced HA degradation. These findings suggest that incorporating Resolvin derivatives may represent a promising strategy to improve HA-based viscosupplementation by enhancing stability and therapeutic persistence in osteoarthritic joints. Full article

Interferon-stimulated genes (ISGs) are classically recognized for their direct antiviral functions, such as viral genome degradation or replication blockade. However, emerging evidence reveals that ISGs orchestrate a broader landscape of host defense by rewiring cellular metabolism. These mechanisms are still not fully understood in the context of antiviral immunity. This review synthesizes recent advances in understanding how ISGs modulate metabolic pathways (e.g., glycolysis, lipid metabolism, amino acids, and nucleotide metabolism) to create an antiviral cellular environment. However, viruses have developed strategies to evade or counteract ISG-encoded proteins, and some even hijack certain ISGs to their advantage. Therefore, we further explore how viruses subvert these ISG-driven metabolic to evade host defenses. Overall, we summarize the current state of knowledge on the interactions between viruses and ISGs and propose that ISGs act as “protective” or “pathogenic” regulators at the dimensions of metabolism, offering new perspectives for targeting host-centered pathways to combat viral infections. Full article

The excessive use of chemical fertilizers raised concerns regarding environmental sustainability and soil degradation, prompting increasing interest in biofertilizers as eco-friendly alternatives. Among these, a compound that is effective in stimulating root and plant growth is indole-3-acetic acid (IAA). In our study, we evaluated IAA production by the halotolerant bacterium Vreelandella titanicae under different and varying nutritional conditions, such as tryptophan availability, temperature, pH, salinity, etc. The bacterium showed significant IAA production under a broad range of conditions and a dependence on the presence of tryptophan for IAA biosynthesis. High salinity (1.0 M NaCl), slightly alkaline pH (8.0–9.0), and temperatures of 34 °C increased IAA production, while optimal growth occurred in the absence of NaCl at a range of temperatures of 25–28 °C, suggesting a stress-responsive regulation of its biosynthesis. Easily metabolizable carbon sources, such as glucose and mannitol, enhanced IAA yield again, whereas additions of 1.0 g L⁻¹ NH₄NO₃ and KH₂PO₄ in the basal medium, poor in these salts, inhibited both the growth of the bacterium and IAA production. Notably, V. titanicae produced relevant amounts of IAA in seawater (24.57 ± 11.28 μg⋅mL⁻¹) when used as growth medium and dairy whey (15.68 ± 2.42 μg⋅mL⁻¹), highlighting its suitability for low-cost and circular bioprocessing strategies. In conclusion, V. titanicae is a promising Plant Growth-Promoting Rhizobacterium (PGPR) candidate for sustainable IAA production and potential application in saline or marginal agricultural soils. Its ability to synthesize IAA in different growth media could allow its exploitation in environmentally friendly bioprocesses. Full article

Cleisthenes herzensteini is a commercially important demersal fish in the Northwest Pacific. However, the resource stock of this species has undergone a drastic decline due to overfishing and habitat degradation. As a representative taxon for benthic adaptation in the order Pleuronectiformes, the molecular mechanisms underlying its specialized phenotypic traits remain poorly elucidated. Furthermore, population-level studies focusing on the mitochondrial genome of Cleisthenes herzensteini are currently scarce. Given that the mitochondrial genome serves as an ideal genetic tool for deciphering species evolution and population genetics, sequencing of its mitogenome will help fill critical gaps in genetic resources and provide essential support for species conservation and phylogenetic research. In this study, we sequenced, assembled, and annotated its complete mitochondrial genome. The circular mitogenome is 17,171 bp in length and exhibits a typical A + T bias (54.04%). Repeat sequence analysis identified 35 dispersed repeats. Codon usage analysis revealed that leucine was the most frequently encoded amino acid, with CUU being the preferred codon. Several protein-coding genes possessed incomplete stop codons (T--/TA-), and a nucleotide preference for A and C was observed at the third codon position. Phylogenetic reconstruction based on mitogenomes from 23 species supported the monophyly of the order Pleuronectiformes. C. herzensteini showed the closest relationship with Dexistes rikuzenius, forming a distinct clade alongside Hippoglossoides dubius and Limanda aspera. These results provide essential genetic resources for understanding the evolution and population genetics of C. herzensteini and related flatfishes. According to the investigation, this study represents the first report on the sequencing and analysis of the complete mitochondrial genome of the Cleisthenes herzensteini. This not only fills the gap in mitochondrial genetic information for this species but also provides a reference for subsequent investigations into the phylogenetic relationships and evolutionary processes within the family Pleuronectidae. Full article

Monoacylglycerols (MAGs) are significant intermediate byproducts in the hydrolysis of oils and fats. The accumulation of MAGs not only reduces the quality and purity of the final products in biodiesel production and edible oil refining but also poses challenges for downstream separation processes. Therefore, the development of efficient biocatalysts for the specific MAG conversion is of great industrial importance. The lipase from Aspergillus oryzae (AOL) has shown potential for lipid modification; however, the wild-type enzyme (WT) suffers from poor solubility, tendency to aggregate, and low specific activity towards MAGs in aqueous systems, which severely restricts its practical application. In this study, a combinatorial protein engineering strategy was employed to overcome these limitations. We integrated fusion protein technology with rational design to enhance both the functional expression and catalytic efficiency of AOL. Firstly, the superfolder green fluorescent protein (sfGFP) was fused to the N-terminus of AOL. The results indicated that the sfGFP fusion tag significantly improved the solubility and stability of the enzyme, preventing the formation of inclusion bodies. The fusion protein sfGFP-AOL exhibited a MAG conversion rate of approximately 65%, confirming the positive impact of the fusion tag on enzyme developability. To further boost catalytic performance, site-directed mutagenesis was performed based on structural analysis. Among the variants, the mutant sfGFP-Y92Q emerged as the most potent candidate. In the MAG conversion, sfGFP-Y92Q achieved a conversion rate of 98%, which was not only significantly higher than that of sfGFP-AOL but also outperformed the widely used commercial immobilized lipase, Novozym 435 (~54%). Structural modeling and docking analysis revealed that the Y92Q mutation optimized the geometry of the active site. The substitution of Tyrosine with Glutamine at position 92 likely enlarged the substrate-binding pocket and altered the local electrostatic environment, thereby relieving steric hindrance and facilitating the access of the bulky MAG substrate to the catalytic center. In conclusion, this work demonstrates that the synergistic application of sfGFP fusion and rational point mutation (Y92Q) can dramatically transform the catalytic properties of AOL. The engineered sfGFP-Y92Q variant serves as a robust and highly efficient biocatalyst for MAG degradation. Its superior performance compared to commercial standards suggests immense potential for cost-effective applications in the bio-manufacturing of high-purity fatty acids and biodiesel, offering a greener alternative to traditional chemical processes. Full article

A novel polysaccharide from Cynanchum auriculatum Royle ex Wight was isolated, structurally characterized, and its antioxidant activity was evaluated. The crude extract was purified by ion exchange and size exclusion chromatography to obtain a homogeneous fraction, CAP2-1. CAP2-1 displayed a weight-average molecular mass of 184.17 kDa and is mainly composed of galactose, arabinose, and galacturonic acid. Structural analysis revealed that CAP2-1 is a highly branched acidic arabinogalactan-type polysaccharide with a backbone of →6)-β-D-Galp-(1→, →3,6)-β-D-Galp-(1→, and →4)-α-D-GalpA-(1→ units, and side chains enriched in α-L-arabino furanose residues. Ultrasonic degradation produced a lower-molecular-weight derivative, UCAP2-1, which exhibited significantly stronger free radical scavenging ability compared with CAP2-1 (p < 0.01). These findings suggest that molecular weight reduction enhances antioxidant properties by improving electron-donating capacity and accessibility to reactive sites. This study reveals the structure–antioxidant relationship of CAP2-1 and UCAP2-1 and highlights UCAP2-1 as a promising natural antioxidant. Full article

Low ethyl caproate and high ethyl lactate contents pose a significant challenge in producing Chinese nong-xiang baijiu. The formation of these esters depends on the metabolism of their precursors—caproic acid and lactic acid—within the pit mud (PM) microbiome. However, the specific taxa driving the metabolic flux from lactate accumulation to caproate synthesis remain unclear. This study aimed to identify potential functional microbes capable of caproate biosynthesis and lactate utilization by systematically analyzing PM samples from the upper, middle, and lower layers of three different pit ages (0, 20, and 50 years). Results showed that 50-year-old PM exhibited significantly higher caproic acid and ammonium nitrogen levels, but lower lactic acid content, compared to the 0- and 20-year-old counterparts. Notably, Petrimonas, Caproiciproducens, and Sedimentibacter were significantly enriched in the 50-year-old PM. Their relative abundances correlated positively with caproic acid and negatively with lactic acid. Furthermore, PICRUSt2 analysis indicated higher abundances of genes associated with caproate synthesis and lactate utilization in the 50-year-old microenvironment. We propose that Petrimonas, Caproiciproducens, and Sedimentibacter are potential functional candidates for lactate degradation and caproate generation. These findings provide a scientific basis for modulating the microbiome for “increasing ethyl caproate and reducing ethyl lactate”, thereby enhancing baijiu quality. Full article