Search Results (4,896)

Acute myocardial infarction (AMI) results from a lack of oxygen supply to the myocardium, leading to the loss of cardiomyocytes and their replacement with fibrotic scar tissue. This process is closely associated with the development of heart failure. Regenerative medicine has emerged as a promising strategy to enhance treatment outcomes in severe cases of heart failure. This study aimed to evaluate myocardial regeneration after AMI using a biomaterial composed of mononuclear stem cells and human amniotic membrane. A total of 120 Wistar rats were subjected to experimentally induced AMI. On the 7th day post-infarction, rats with an ejection fraction of <50% on echocardiography were randomized into four groups: (1) control; (2) stem cells; (3) amniotic membrane; and (4) amniotic membrane combined with stem cells. On the 30th day, the surviving animals underwent a second echocardiographic evaluation and were subsequently euthanized. The group treated with the combination of amniotic membrane and stem cells showed reduced systolic and diastolic ventricular volumes. Histological analysis revealed that these animals exhibited less fibrosis and a lower percentage of type I collagen. Based on the results of the study, it was concluded that the combination of human amniotic membrane and mononuclear stem cells decreased ventricular volumes and myocardial fibrosis, suggesting more favorable ventricular remodeling in this experimental model. Full article

Nucleoside diphosphate kinase (NDPK) is a ubiquitous enzyme that maintains cellular nucleotide balance by catalyzing the transfer of phosphate groups between nucleoside diphosphates and triphosphates. Although the evolutionary conservation of NDPK is well established, several aspects of its diversification and functional adaptation remain unclear. The central question of this work is how NDPK evolved across plant species, focusing on the Solanaceae family and how its evolutionary history relates to the diversification of its cellular functions. Phylogenetic and molecular dating analyses showed that the division between NDPK groups 1 and 2 predates the divergence of plants and animals, whereas plant-specific NDPK types (I–IV) originated early in streptophyte evolution. Solanaceae species retain a conserved set of NDPK genes, including a type III isoform with features consistent with mitochondrial targeting. Functional assays in isolated potato tuber mitochondria revealed high NDPK activity in the intermembrane space, sustaining ADP supply to oxidative phosphorylation. Activation of mitochondrial NDPK induced a phosphorylative respiratory state, which partially dissipated the mitochondrial membrane potential and significantly reduced reactive oxygen species (ROS) production. GDP and UDP were preferentially phosphorylated, conferring a stronger antioxidant effect than other nucleotides. Consistently, the mitochondrial isoform StNDPK3 was upregulated during tuber development. Together, our results demonstrate that NDPKs are evolutionarily conserved yet functionally diversified enzymes in plants and identify mitochondrial NDPK as a key modulator of mitochondrial redox homeostasis. By linking nucleotide metabolism to Δψ_m control and ROS suppression, this study highlights a previously underappreciated antioxidant mechanism that integrates mitochondrial energy metabolism with developmental and stress-related processes in plants. Full article

Ferroptosis is an iron-dependent cell death driven by lipid peroxidation and failure of cellular antioxidant defenses. It is triggered by oxidative stress and can be aggravated by aging, inflammation, and dysregulation of iron homeostasis. In the central nervous system, iron dyshomeostasis, mitochondrial dysfunction, and membrane lipid remodeling can amplify oxidative injury and increase susceptibility to ferroptotic damage, particularly in vulnerable neurons. There is growing evidence that ferroptosis-related processes are linked to Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and Amyotrophic Lateral Sclerosis. This review addresses novel approaches to track ferroptosis in vivo, such as imaging and biomarker techniques, and important molecular mechanisms linking iron metabolism, reactive oxygen species, and PUFA-driven lipid peroxidation to neuronal damage. We also explore upstream transcriptional control via NRF2, iron chelation and iron-handling modulation, inhibition of lipid peroxidation, and reinforcement of the System Xc-GSH-GPX4 and CoQ10-linked defense pathways. Subsequently, we highlight translational issues that need attention to further progress ferroptosis-targeted therapies for neurodegenerative disease. Full article

Bovine mastitis is a multifactorial inflammatory disease primarily characterized by inflammatory cell infiltration and the destruction of mammary alveoli. It is a major cause of reduced milk yield and quality. The imbalance between antioxidant defenses and the generation of reactive oxygen species (ROS), which occurs due to the high metabolic activity of the mammary gland during the periparturient period, increases the incidence of mastitis. During early lactation, especially in high-yielding dairy cows, the massive synthesis and secretion of milk increase the energy demand of mammary tissue, leading to excessive ROS accumulation. This results in cell membrane disruption and, ultimately, antioxidant dysfunction in the mammary tissue. This study established an in vitro oxidative stress model by treating bovine mammary epithelial cells (BMECs) with 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH). The optimal concentration of 1000 μmol/L AAPH was determined using the CCK-8 assay. Model validation showed that, compared to the control group, ROS levels were significantly elevated (p < 0.001) and mitochondrial membrane potential was significantly decreased (p < 0.001) in the AAPH-treated group. Transmission electron microscopy (TEM) analysis revealed that AAPH treatment caused ultrastructural damage, including reduced microvilli, mitochondrial swelling, disappearance of cristae, and vacuolization. Mechanistic studies demonstrated that AAPH treatment significantly upregulated the mRNA and protein expression of AMPK, HMOX-1, mTOR, NOS, and SOD (p < 0.001), while significantly downregulating CYP1A1 expression (p < 0.001). Pretreatment with N-acetylcysteine (NAC) effectively alleviated the oxidative stress damage caused by AAPH. This study successfully established an in vitro AAPH-induced oxidative stress model in BMECs and revealed its molecular mechanism of cellular damage. The damage occurs through modulation of the AMPK/mTOR signaling pathway and the regulation of antioxidant-related gene expression. Full article

The increasing prevalence of multidrug-resistant (MDR) pathogens, particularly avian pathogenic Escherichia coli (APEC) and methicillin-resistant Staphylococcus aureus (MRSA), poses a severe threat to the breeding industry and human health. To develop novel antibiotic alternatives, we adopted a “converting virulence into therapy” strategy by leveraging the type VI secretion system (T6SS) of the APEC strain ACN17-20. Guided by the structural analysis of T6SS Protein 00145, we rationally designed a series of amphipathic α-helical polypeptides. Among them, polypeptide A7 emerged as a lead candidate, exhibiting potent broad-spectrum antibacterial activity with negligible cytotoxicity against mammalian cells. Mechanistic studies revealed that A7 exerts a rapid bactericidal effect through a dual mode of action: physical disruption of bacterial membrane integrity leading to cytoplasmic leakage, and induction of lethal oxidative stress via reactive oxygen species (ROS) accumulation. Furthermore, A7 demonstrated excellent efficacy in eradicating pre-formed bacterial biofilms, addressing the challenge of persistent infections in breeding environments. In a mouse sepsis model induced by APEC and MRSA, A7 treatment significantly improved survival rates (60–80%), reduced bacterial loads in vital organs, and attenuated the systemic cytokine storm (TNF-α and IL-1β), thereby alleviating immune-mediated tissue damage. In conclusion, this study identifies polypeptide A7 as a safe therapeutic agent with a dual mechanism of action, providing a promising strategy to combat MDR infections and reduce antibiotic dependence. Full article

Proton exchange membrane fuel cells (PEMFCs) have considerable potential for frequency support in grid-forming applications. However, their transient dispatchable power is nonlinearly influenced by operating conditions, such as the oxygen excess ratio and stack temperature, thereby weakening frequency support performance by delaying power compensation during disturbances. To address this issue, a coordinated control strategy for inertia support and active power compensation is proposed that explicitly accounts for operating-state effects. Based on a dynamic PEMFC model, the effects of the oxygen excess ratio and stack temperature on transient output capability are analyzed, and a jointly corrected inertia coefficient is introduced into the virtual synchronous generator (VSG) rotor motion equation to achieve adaptive adjustment of virtual inertia under varying operating conditions. In addition, model predictive control (MPC) is incorporated into the VSG control framework, and a performance index is formulated using weighted quadratic terms of frequency variation and input power, thereby enabling the compensation power to be determined online and the PEMFC power reference to be updated accordingly. Simulation results show that the proposed strategy can effectively suppress frequency fluctuations under disturbance conditions. Compared with Conventional PI-VSG, the maximum frequency deviation and the peak rate of change of frequency (ROCOF) are reduced by 49.1% and 62.1%, respectively. Full article

Low-temperature polymer electrolyte membrane fuel cell systems can achieve higher efficiency than diesel engines, but heat rejection remains a major challenge in class-8 heavy-duty fuel cell trucks. For the same rated power, the radiator heat load is greater than that in a diesel engine, while the allowable operating temperatures are lower. This work proposes and evaluates 400 kW_e fuel cell–battery hybrid (FCH) platforms and operating strategies that manage heat rejection without enlarging the radiator frontal area. Three FCH platforms are identified, each varying in fuel cell system (FCS) rated power, battery energy storage system (ESS) capacity, and maximum stack coolant exit temperature ($T_{h1}$). All three satisfy key system and vehicle requirements, including 175 kW_e FCS power at top sustained speed, 400 kW_e FCH power on a 6% grade climb, a target stack power density (PD) of 750 mW_e/cm², and heat rejection constraints. The first FCH has the smallest FCS, the largest ESS, and a $T_{h1}$ of 90 °C. The second achieves the highest PD of 840 mW_e/cm² at a $T_{h1}$ of 95 °C. The third has the largest FCS, the smallest ESS, and a $T_{h1}$ of 102 °C. At a $T_{h1}$ of 115 °C, the platform can be configured as a stand-alone 400 kW_e(net) FCS without hybridization, but the achievable PD drops to 460 mW_e/cm². Full article

Sweet potato (Ipomoea batatas (L.) Lam) is an important food and energy crop. Soil salinization is a major abiotic stress that limits agricultural productivity and severely reduces yield of crops. Protein hydrolysates, as a class of natural biostimulants, have gained increasing attention for their potential to improve crop yield, quality and stress tolerance. This study investigated the effects of peptides from swine blood (PSB) on high salinity stress tolerance in sweet potato. Application of PSB promoted the growth of both aerial and underground parts of sweet potato under normal and high-salinity conditions. Further analysis revealed that, under high salinity stress, exogenous PSB up-regulated the expression of genes associated with stress responses, increased the accumulation of organic osmotic adjustment compounds such as free amino acids, promoted K⁺ uptake to elevate the K⁺/Na⁺ ratio, and enhanced the activity of key antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) involved in the reactive oxygen species-scavenging system. These biochemical responses contributed to maintaining cellular osmotic balance and redox homeostasis, protecting the cell membrane from damage while preserving its structural integrity and normal physiological functions, and improving photosynthetic efficiency, thereby enhancing high salinity stress tolerance in sweet potato. Thus, PSB holds significant potential as an effective natural biostimulant for sweet potato cultivation in saline soils. Full article

This study elucidates the mechanism enabling the low-voltage electrolysis of black liquor (BL) for integrated resource recovery. The process simultaneously generates protons at the anode via the oxidation of organics (OOR), which occurs at a lower potential than the oxygen evolution reaction (OER), and induces lignin precipitation. Concurrently, hydrogen and hydroxide ions are produced at the cathode through the hydrogen evolution reaction (HER). Driven by the electric field, sodium ions migrate from the anode to the cathode chamber, combining with hydroxide ions to form sodium hydroxide, thereby achieving the synchronous production of acid, alkali, hydrogen, and modified lignin in a single process. Using a platinum electrode, we conducted a mechanistic investigation through linear sweep voltammetry (LSV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and detailed product analysis. The results show that overall efficiency is controlled by competition at the anode between OOR and OER, which directly determines proton yield. A critical trade-off exists between anodic proton generation and cathodic alkali recovery, driven by the competitive migration of protons and sodium ions across the cation-exchange membrane. The proton yield was highly dependent on the initial BL composition, with a characteristic peak observed under specific conditions. Conversely, the sodium hydroxide recovery rate was maximized when the anolyte pH remained high, minimizing competitive proton migration. This work provides fundamental insights into the interfacial mechanisms of BL electrocatalytic, establishing it as a versatile electrochemical biorefinery platform for simultaneous proton and alkali production from a renewable waste stream, beyond its role as a hydrogen source and lignin recovery. Full article

Deoxynivalenol (DON) is a common mycotoxin linked to ovarian oxidative stress, toxicity, and reduced reproductive performance. Fermented Chinese chive is known for its antioxidant properties and potential reproductive benefits, but their individual and combined effects on ovarian function remain unclear in post-pubertal mice. In this study, a 21-day oral gavage model in female Kunming mice was used to evaluate the effects of DON (2 mg/kg/day), fermented Chinese chive extract (LEEK; 0.2 mL/day), and their combined exposure (LKDON) on ovarian physiology, oocyte quality, and ovarian transcriptomic responses. The results showed that DON exposure significantly reduced the zygote cleavage rate, increased intracellular reactive oxygen species levels, and disrupted oocyte mitochondrial membrane potential. While histological examination revealed disturbed follicular architecture. Transcriptomic hub gene analysis showed that DON exposure down-regulate the key associated with innate immune responses and motile cilia/axonemal structure, including Rsph4a, Drc1, Zmynd10, Hydin, and Tmem212. In contrast, LEEK alone was associated with immunomodulatory upregulated genes, including Il5, Cd27, and Crp. Interestingly, LKDON and DON comparison revealed upregulation of a motile cilia/axoneme gene network (Dnah5, Dnah11, Tekt1, Zmynd10, Cfap44, and Spag6l), rather than a global reversal of DON-induced changes. Overall, finding suggest that DON disrupts ovarian immune and structural pathways, while fermented Chinese chive provides partial protection by modulating specific biological processes. Further studies are needed to confirm the underlying mechanisms. Full article

Apis cerana is widely managed in apiculture in Southern China but experiences substantial colony losses during prolonged summer heat. Developing effective strategies to support colony over-summering is therefore critical. This study demonstrates that dietary supplementation with melatonin significantly enhances thermal tolerance and extends worker lifespan in A. cerana under heat stress. Laboratory bioassays revealed that melatonin supplementation (20 µg/mL) markedly improved worker survival at both 35 °C and 37 °C, with the most pronounced effect at 37 °C, where mortality was significantly reduced. Consistently, field trials demonstrated that melatonin supplemented colonies gained significantly more weight during summer heatwaves than colonies without melatonin supplementation. Mechanistically, melatonin orchestrates a biphasic adaptive response. In an early phase (day 4), melatonin rapidly upregulates heat shock proteins (HSC70-4, CRYAA, l(2)efl) and detoxification enzymes (GST-like), accompanied by reduced reactive oxygen species (ROS) accumulation and enhanced proboscis extension response (PER), indicative of preserved sensory function. This is followed by a later maintenance phase (day 11), characterized by sustained upregulation of fatty acyl-CoA reductases (FAR1, FAR11-like, FARwat) and peroxisomal components (PMP34), which promote lipid remodeling and membrane stabilization. RNA-seq analysis identified differentially expressed genes (DEGs) significantly enriched in pathways related to redox homeostasis, lipid metabolism, detoxification (GSTs, CarEs, CYP450s), and longevity. These molecular responses were associated with enhanced antioxidant capacity, reduced oxidative damage, and sustained foraging activity under thermal stress. Collectively, these results indicate that melatonin serves as a potent nutritional intervention that reprograms redox metabolic networks to mitigate heat-induced damage, extend worker longevity, and enhance colony productivity under climate warming. These findings highlight melatonin’s potential as a practical tool to reduce summer colony losses in apiculture. Full article

Sulfamethoxazole (SMX) is one of the most frequently detected antibiotics in aquatic environments and is difficult to remove by conventional biological treatment because of its persistence, potential toxicity to microbial communities, and associated risk of antibiotic resistance selection. Aerobic granular sludge membrane bioreactors (AGMBRs), which combine the compact and stratified structure of aerobic granular sludge with membrane-based solid–liquid separation, have emerged as a promising platform for SMX-contaminated wastewater treatment because they provide high biomass retention, decoupled sludge retention time (SRT) and hydraulic retention time (HRT), and stable effluent quality. This review systematically summarizes recent advances in AGMBRs for SMX removal, with emphasis on how operating parameters (e.g., dissolved oxygen, hydraulic retention time, organic loading rate, C/N ratio, and sludge retention time) and membrane-related factors (e.g., membrane flux, aeration-induced shear, membrane type, and pore size) affect treatment performance and process stability. The main SMX attenuation pathways in AGMBRs are discussed from three perspectives: sorption and partitioning within granules and extracellular polymeric substances (EPSs), microbial biodegradation and co-metabolism, and membrane retention that prolongs effective contact time and shapes microbial ecology. Particular attention is given to the dual role of EPS and soluble microbial products (SMPs), which contribute to granule stability and SMX tolerance but also accelerate membrane fouling through cake-layer formation, pore blocking, and transmembrane pressure increase. Current challenges include incomplete understanding of transformation products, ARG- and MGE-related risks, long-term fouling–biodegradation interactions, and the lack of pilot-scale validation. Future research should therefore focus on mechanism clarification, integrated control of removal and fouling, energy-efficient operation, and scale-up of AGMBRs for practical antibiotic wastewater treatment. Full article

Curcumin, a natural polyphenol derived from Curcuma longa, is widely recognized for its therapeutic properties. However, its clinical utility is limited because of poor solubility, rapid degradation and hence low bioavailability. To overcome these issues, nanoformulation approaches, especially PEGylated liposomes, have been explored as advanced delivery systems. PEGylation, which involves attaching polyethylene glycol (PEG) to the liposomal surface, enhances circulation time by creating a steric shield that reduces protein interactions and clearance by the mononuclear phagocyte system (MPS). However, PEG can alter lipid membrane properties, which may in turn affect curcumin’s solubility and distribution within the liposomal bilayer, ultimately reducing its loading efficiency. To ensure that PEG-modified liposomes can be effectively loaded with curcumin, we investigated curcumin–membrane interactions in saturated (DMPC) and unsaturated (POPC) liposomes, both in the presence and absence of PEG. Based on dissociation constants (K_d) obtained from fluorescence spectroscopy measurements, we found that PEGylated DMPC liposomes exhibit the strongest binding affinity for curcumin. Fluorescence quenching experiments showed that curcumin adopts a transbilayer orientation in all membranes examined. Curcumin’s location within PEGylated and non-PEGylated liposomal membranes was further confirmed by examining its effects on membrane properties, including fluidity, polarity, and oxygen transport. These effects were investigated using electron paramagnetic resonance (EPR) spectroscopy with spin labels. The results indicate that PEG does not impose major changes on membrane properties. Curcumin, however, was found to reinforce the liposomal membranes, increase their polarity, and reduce oxygen availability. Overall, the findings suggest that liposomes, particularly those composed of PEGylated DMPC, are effective vehicles for curcumin delivery. Full article

Developing active and robust catalysts for the acidic oxygen evolution reaction (OER) with reduced Ir loading is still a challenge in the industrial production of green H₂. In this work, several catalysts ranging from single metal oxides (e.g., IrO₂) to high-entropy oxides (IrNiMnFeCoCuVO_x) were synthesised through thermal decomposition in air to study the effect of the mixed-oxide composition in terms of activity and stability towards the acidic OER. Catalysts were named MOx-n, with n being the number of metal elements in the mixture. The results show that the activity of rutile IrO₂ can be improved by introducing other elements into the composition. The best performance was obtained for MOx-4 to MOx-5, which delivered a current density of 10 mA cm⁻² at an overpotential (η₁₀) of 279 ± 4 mV; approx. 100 mV lower than IrO₂ at a comparable Ir loading and with better stability. Nevertheless, further increasing the complexity of the mixed oxide resulted in an evident degradation in terms of activity and stability. It is worth noting that surface dissolution and reconstruction occurred with all mixed-oxide catalysts, including high-entropy configurations. Full article

Background: Gumming disease caused by Fusarium tricinctum severely threatens Zanthoxylum bungeanum production. This study investigated the antifungal potential of volatile organic compounds (VOCs) produced by an endophytic fungus, Schizophyllum commune, isolated from Z. bungeanum. Methods: A dual-culture assay evaluated VOCs inhibition against F. tricinctum. Compounds were identified using headspace solid-phase microextraction gas chromatography-mass spectrometry, and the antifungal mechanism of this component was explored. Results: VOCs from S. commune significantly inhibited mycelial growth and sporulation of the pathogen. Among 53 identified compounds, 1-octen-3-ol (mushroom alcohol) was the most abundant (35.98% relative content) and exhibited strong antifungal activity with an EC₅₀ of 0.15 µL/mL against F. tricinctum. Mechanistically, 1-octen-3-ol disrupted cell membrane integrity by increasing alkaline phosphatase and β-1,3-glucanase activities, leading to enhanced permeability and content leakage. It also induced oxidative stress by promoting reactive oxygen species accumulation via elevated NADPH oxidase and superoxide dismutase activities, while suppressing antioxidant enzymes. Conclusions: 1-octen-3-ol inhibits F. tricinctum through membrane disruption and oxidative stress, offering a promising eco-friendly strategy for controlling gumming disease. Full article