Search Results (4,862)

Electrospun sulfonated polyketone (PK) nanofiber membranes were prepared to investigate the sulfonation-time-dependent structure–property relationships of hydrocarbon-based polymer electrolyte membranes for PEMFC (Polymer Electrolyte Membrane Fuel Cell) applications. NaCl addition to the electrospinning solution increased solution conductivity and enabled the formation of uniform PK nanofibers with an average diameter of approximately 270 nm. Subsequent sulfonation introduced sulfonic-acid-related groups into the PK nanofiber framework, and the resulting membrane properties were strongly governed by sulfonation time. Among the tested membranes, PK-NC16 exhibited the highest proton conductivity of 0.107 ± 0.031 S cm⁻¹ and an ion exchange capacity of 2.82 m_eq g⁻¹, exceeding or comparable to those of Nafion 115 under the tested conditions. FTIR-based analysis indicated that the relative sulfonation index increased up to 16 h, whereas extended sulfonation for 24 h generated additional sulfone/sulfonate-related bands, suggesting possible side reactions or structural changes under prolonged acid treatment. The high water uptake of PK-NC16 enhanced proton transport but also revealed a hydration-sensitive polymer network, as reflected by a voltage degradation rate of approximately −590 μV h⁻¹ during a 100 h short-term stability constant-current test. These results demonstrate that sulfonation time is a key parameter controlling the balance among ionic functionality, hydration, mechanical response, proton conductivity, and PEMFC-relevant single-cell performance in electrospun PK nanofiber membranes. Full article

This study investigates numerically a Coupled Solar Ventilation Evaporative Cooling system for hot and arid climates. The system uses a solar wall chimney to produce natural ventilation and generate hot and dry airflow, which is then directed through a roof-mounted humid hay packed bed to enhance evaporative air conditioning. The resulting cold is transferred via a thermally conductive inner roof plate while a membrane condenser recovers moisture for reusing. A mathematical model was developed to describe heat and mass transfer in the hay packed bed, including solar chimney airflow, pressure drop and the evaporation energy balance. Parametric simulations were carried out for inlet air temperature of 40–60 °C, airflow rates of 0.25–0.45 m³/s, hay moisture contents of 0.006–0.014 kg/kg dry basis and air humidity ratio of 0.002–0.006 kg/kg dry air. Results show that evaporative cooling becomes effective only above certain inlet temperature. Increasing airflow from 0.25 to 0.45 m³/s reduced hay temperature from 30 to 26.8 °C when inlet air temperature exceeded 43.5 °C. Higher hay moisture content enhanced cooling performance, reaching about 26 °C, while higher inlet air humidity reduced evaporation and limited cooling. The operating maps obtained from the numerical simulations provide practical guidance for preliminary system sizing and for optimal operating parameters selection in solar-driven evaporative cooling systems. The mathematical model treats the solar chimney, the evaporative packed bed, the conditioned room and the membrane condenser within the same steady state calculation. The solar energy balance and the pressure balance are used to relate the inlet air temperature and the airflow rate to solar irradiance, ambient temperature and chimney geometry. The model also includes the heat transferred from the room through the roof plate, the sensible heat of the supplied water and the mass transfer and pressure drop effects of the membrane condenser. Full article

Oscillating water column (OWC) wave energy converters equipped with dielectric elastomer generators (DEGs) represent a promising technology for harnessing ocean wave energy. This study emphasises the critical role of functional specifications in guiding the development of these devices from initial concept to full-scale deployment. A comprehensive analysis of key design parameters that influence the performance and efficiency of flexible OWCs with DEG-based power take-off systems is presented. This investigation focuses on the effects of draft, membrane diameter, deformation characteristics, number of layers, and membrane thickness on power output. Utilising a combination of analytical tools, including Wave Venture software, MATLAB, and Abaqus, detailed simulations and analyses are conducted to optimise these parameters. Our results demonstrate that increasing the DEG diameter significantly enhances power output, with diameters between 5 and 12 m showing optimal efficiency. A critical strain threshold of approximately 32% is identified, beyond which power output efficiency diminishes. Furthermore, the study reveals that multi-layer DEG configurations can substantially increase energy production, with thinner membranes generally yielding higher outputs. These findings provide valuable insights for developing functional specifications that balance performance, manufacturability, and long-term reliability in marine environments. This research advances OWC technology by offering a parameter-screening framework to guide device design towards optimised configurations and to accelerate the path to commercial viability in the wave energy sector. Full article

Background: Stroke significantly increases morbidity and mortality in patients receiving extracorporeal membrane oxygenation (ECMO). This study evaluates the prognostic impact of stroke subtypes, acute ischemic stroke (AIS) and hemorrhagic stroke (HS), and neurologic injury severity in a contemporary adult population. Methods: We conducted a retrospective cohort study using the TriNetX federated electronic health record network, including adult patients who underwent ECMO between 1 October 2015 and 31 December 2025. Stroke was defined as a first-instance diagnosis of AIS, HS, or unspecified cerebrovascular event occurring within 24 h of ECMO cannulation during the index hospitalization. Propensity score matching (1:1 nearest neighbor) was performed to balance baseline demographics, comorbidities, anticoagulant use, and ECMO modality between the stroke and non-stroke cohorts. Primary outcomes included all-cause mortality at 30 days, 90 days, and 1 year. Secondary outcomes included cardiac arrest, seizures, palliative care utilization, and hospital readmission. Kaplan–Meier survival analysis and multivariable Cox proportional hazards modeling were performed. Results: Among 18,981 ECMO patients, 1481 (7.8%) developed a stroke within 24 h of ECMO cannulation, including 814 AIS (54.9%), 454 HS (30.6%), and 213 unspecified cerebrovascular events (14.4%). After propensity score matching, stroke was associated with significantly higher all-cause mortality at 30 days (RR 1.16), 90 days (RR 1.18), and 1 year (RR 1.18), all p < 0.05. Stroke was also associated with higher rates of cardiac arrest, seizures, hospital readmission, and palliative care utilization (all p < 0.001). AIS was associated with significantly lower mortality than HS at 30 days, 90 days, and 1 year (all p < 0.0001). In multivariable Cox regression, only HS was independently associated with increased 30-day mortality compared with no stroke. Markers of neurologic injury severity, including cerebral edema, brain compression, and coma, were among the strongest independent predictors of mortality. Conclusions: Stroke occurring early after ECMO cannulation is associated with substantially worse short- and long-term survival, with hemorrhagic subtype and markers of neurologic injury severity driving the strongest prognostic signals. These findings support early stroke recognition and subtype-informed prognostic discussions in ECMO patients. Full article

Growing demand for greener and more sustainable materials in cultural heritage conservation has prompted the investigation of bio-based alternatives for cleaning applications. This study presents a preliminary evaluation of bacterial nanocellulose (BNC) membranes for the removal of acrylic resins from mural paintings, comparing commercial medical-grade and laboratory-produced BNC with conventional gel systems under simulated application conditions. Both BNC types were characterized in terms of composition, pH, electrical conductivity, Water Holding Capacity and Water Retention Rate. Acetone loading via solvent exchange was assessed by thermogravimetric analysis (TGA), while mechanical behavior before and after solvent loading was evaluated through tensile testing and optical density measurements of the immersion media. The performance of BNCs and reference delivery systems was comparatively assessed in terms of solvent retention, solvent penetration depth into the substrate and residue release. Cleaning performance was investigated through FTIR spectroscopy and semi-quantitative image analysis as indirect indicators of residual resin content, on both mock-up samples and in situ applications. Under the tested conditions, both BNC membranes were compatible with acetone loading and maintained mechanical integrity after solvent exposure. FTIR analysis showed a reduction in the acrylic carbonyl band after treatment with acetone-loaded BNC, which exhibited greater solvent diffusion depth; the underlying removal mechanism, including the possible contribution of solvent-driven redistribution phenomena, remains to be clarified. Differences in reproducibility were observed between medical-grade and laboratory-produced BNC. Overall, the study provides experimental data contributing to the assessment of BNC membranes as bio-based solvent delivery systems for conservation practice. Full article

To elucidate the pollution status and spatial distribution patterns of microplastics in representative deep-sea regions of China, the Qiongdongnan sea area has emerged as a key focus area for microplastic research. A comprehensive assessment of microplastic contamination across the water column (0–1500 m) was conducted using CTD-integrated water sampling coupled with 0.2 μm membrane filtration. Results revealed that polypropylene (PP), polyethylene (PE), and polyamide (PA) were the dominant polymer types. Granular microplastics constituted the overwhelming majority (95.3%) of identified particles, while size analysis showed that those in the 20–50 μm range accounted for the largest fraction (80.5%). The average microplastic abundance across all sampled depths was 3.47 particles/L. Comparative analysis with other prominent marine environments globally and domestically indicates minimal vertical differences in the characteristics of microplastics. Comparative analysis with other prominent marine environments globally and domestically indicates that microplastic pollution in the South China Sea is relatively moderate. This study delivers foundational empirical data critical for environmental risk assessment and source apportionment of microplastics in the South China Sea. This study provides key basic data for assessing the environmental risk of microplastics in the South China Sea and tracing their sources. Full article

Background: Extracorporeal cardiopulmonary resuscitation (ECPR) can improve outcomes following refractory out-of-hospital cardiac arrest (OHCA); however, access is constrained by geography and resources. This study compared two strategies against the current system in Nara Prefecture, Japan: a two-stage hospital model using chest-pain network hospitals as ECPR-initiation sites, and a prehospital ECPR model using physician-staffed ambulances from two extracorporeal membrane oxygenation (ECMO)-ready hospitals. Methods: A geographic information system (GIS)-based simulation was conducted using emergency medical service (EMS) records of witnessed cardiac-origin OHCA cases (2017–2022). Isochrone analyses estimated areas reachable within a 60 min arrest-to-ECMO target. In the two-stage hospital model, patients located within a 15 min transport radius from chest-pain network hospitals were considered geographically covered. In the prehospital ECPR model, a physician-staffed ambulance was assumed to reach arrest sites within a 25 min travel-time radius from ECMO-ready hospitals. The study outcome was geographic coverage, defined as the proportion of cases within each service area; the two strategies were compared using McNemar’s test for paired proportions. Results: Among 1476 included cases, the coverage rate was as follows: current system, 28.7%; two-stage hospital model, 65.2%; prehospital model, 70.4% (p < 0.001). Certain eastern and southern mountainous regions remained outside both coverage areas. Conclusions: Using real-world EMS data, a mobility-focused prehospital ECPR strategy provided broader potential geographic access without requiring additional fixed hospital infrastructure than expanding hospital-based initiation sites. Optimization of prehospital deployment may represent a geographically feasible approach to expanding ECPR access in mixed urban–rural regions, though operational feasibility and cost-effectiveness require further evaluation. Full article

Salinity stress severely inhibits crop growth and reduces yield. Exogenous selenium (Se) enhances plant abiotic stress tolerance, but how different selenium forms exert their impacts and pathways in mitigating salinity remains ambiguous. Under salt stress, this work compared two Se forms, selenate [Se(VI)] and selenite [Se(IV)], regarding their impacts on development, photosynthetic performance, antioxidative system, osmotic regulators, Se buildup, and stress-related gene expression in Nicotiana tabacum L. Both Se species significantly promoted tobacco growth. (1) Under 150 mmol/L NaCl stress, biomass, net photosynthetic rate and antioxidant enzyme activities decreased significantly, while soluble sugar, free proline, Na⁺/K⁺, Na⁺/Ca²⁺, H₂O₂, MDA contents and NtROS2a, NtLEA5 expression increased significantly. (2) Exogenous Se increased biomass, photosynthetic parameters; antioxidant enzyme activities and NtNAC2, NtCDPK12, NtROS2a expression; elevated Se deposition in roots and leaves; and reduced oxidative damage, ion imbalance and NtLEA5 expression in salt-stressed tobacco, suggesting that Se may improve salt tolerance by regulating these physiological processes and stress-related gene expression. (3) Compared with Se(IV), Se(VI) significantly increased root length, chlorophyll content, stomatal conductance, K⁺ content, SOD/CAT activities, leaf and root Se accumulation as well as and NtNAC2, NtCDPK12 expression, while Se(IV) resulted in higher root diameter, free proline content, Na⁺/K⁺ ratio and NtROS2a expression. In conclusion, both sodium selenate and sodium selenite effectively enhanced tobacco salt tolerance. The salt stress alleviation effect of Se(VI) may be associated with upregulating NtNAC2 and NtCDPK12 to improve antioxidant capacity and photosynthesis, thereby potentially maintaining cell membrane integrity and ion balance, while Se(IV) may exert its effect through upregulating NtROS2a to promote root thickening, reactive oxygen species scavenging and osmotic adjustment. At the tested concentrations, selenate was more effective. Full article

Phosphoric acid-doped polybenzimidazole membranes are a leading fluorine-free electrolyte platform for high-temperature proton exchange membrane fuel cells, enabling proton transport under anhydrous conditions. However, recent evidence shows that conductivity, mechanical stability, and acid retention are intrinsically coupled, preventing independent optimization of these properties. This review establishes a unified framework in which membrane performance is governed by a multidimensional design space defined by acid doping level, activation energy (E_a), hydrogen-bond network topology, and mechanical confinement. Conductivity is shown to scale with both carrier density and hopping energetics, while mechanical stability decays with increasing ADL due to acid-induced plasticization, described through a semi-empirical relationship. Analysis across molecular architectures, including molecular weight control, crosslinking, backbone modification, topological design, and free-volume engineering, demonstrates that performance emerges from a balance between transport efficiency and structural stability. Device-level benchmarking further reveals that similar conductivity values can correspond to orders-of-magnitude differences in voltage decay rate, confirming that durability is governed primarily by mechanical confinement and acid mobility rather than σ alone. A multivariate stability corridor is identified, within which phosphoric acid-doped polybenzimidazole membranes achieve σ ≈ 0.14–0.20 S·cm⁻¹ while maintaining low degradation rates under realistic high temperature proton exchange membrane conditions. Based on this framework, quantitative design rules are derived linking acid doping level, activation, topology, and mechanical properties. This work shifts membrane design from conductivity-driven optimization toward predictive structure–property–durability engineering, providing a basis for the development of next-generation HT-PEM fuel cells with sustained long-term performance. Full article

Metabolically dysfunction-associated steatotic liver disease (MASLD) complicated by type 2 diabetes mellitus (T2DM) represents a clinically aggressive phenotype associated with accelerated hepatic fibrosis progression. The interplay among oxidative stress, systemic inflammation, and the risk of hepatic fibrosis in this context remains incompletely characterised. We conducted a single-centre observational study enrolling 110 adult MASLD patients, stratified into two groups: Group 1 (G1, n = 20), patients with concurrent T2DM, followed longitudinally at three successive time points, and Group 2 (G2, n = 90), non-diabetic controls. Serum oxidative stress biomarkers were assessed using malondialdehyde (MDA) and 8-isoprostaglandin F2α (8-iso-PGF2α). Systemic inflammatory status was quantified through the neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR). Hepatic fibrosis risk was estimated using the FIB-4 index. Diabetic MASLD patients exhibited significantly elevated levels of 8-iso-PGF2α (p = 0.014) and NLR (p = 0.016) compared with controls, indicating greater oxidative membrane damage and systemic neutrophilic inflammation. A robust inverse correlation between PLR and FIB-4 was observed across all analytical strata (combined cohort: Spearman r = −0.680, p < 0.001). MLR emerged as the only independent predictor of MDA in G1 (β = 841.78, p = 0.013). Longitudinal analysis demonstrated biomarker stability over time, except for a significant increase in ALT from T1 to T2 (p_adj = 0.014). These findings support the clinical utility of routinely available haematological inflammatory ratios and lipid peroxidation biomarkers for phenotypic characterisation of MASLD in the diabetic context, highlighting the need for larger prospective studies with histological validation. Full article

Background and Objectives: Trauma-associated auditory dysfunction, encompassing tinnitus and hearing loss, represents a frequent yet underrecognized sequela of acoustic overexposure, blast injury, and head trauma. Despite increasing clinical awareness, the published literature exhibits substantial heterogeneity in reported prevalence estimates and recovery outcomes across different injury mechanisms. This narrative review aims to synthesize available evidence on the prevalence, clinical characteristics, recovery patterns, and prognostic factors of tinnitus and hearing loss following traumatic injury, with a particular focus on comparing outcomes across distinct trauma mechanisms and evaluating the impact of early intervention. Materials and Methods: A comprehensive literature search was conducted in PubMed, Embase, Scopus, and Web of Science for studies published between January 2010 and December 2025. The search strategy combined terms related to traumatic injury (e.g., “acoustic trauma,” “blast injury,” “traumatic brain injury,” “head trauma”) with terms related to auditory dysfunction (e.g., “tinnitus,” “hearing loss,” “auditory dysfunction”). Eligible studies included observational studies (cohort, cross-sectional, case–control) reporting original data on tinnitus and/or hearing loss prevalence, recovery outcomes, or prognostic factors in adult or mixed populations exposed to traumatic injury. A narrative synthesis was organized thematically around the key research questions. Results: The available evidence consistently indicates that tinnitus and hearing loss are frequent consequences of blast injury, acute acoustic trauma, and traumatic brain injury, although reported prevalence estimates vary considerably across studies due to differences in populations, injury mechanisms, and diagnostic criteria. Blast injury is associated with mixed hearing loss (conductive and sensorineural components), while acute acoustic trauma typically causes sensorineural hearing loss, often with a characteristic high-frequency notch. Traumatic brain injury can lead to central auditory processing deficits even when pure-tone thresholds are normal. Recovery is variable and often incomplete; tympanic membrane perforations frequently heal spontaneously, but sensorineural components often persist. Early treatment (within days to two weeks) is associated with better recovery outcomes. Conclusions: Trauma-associated tinnitus and hearing loss are highly prevalent and frequently result in persistent disability. The strong association between early treatment and improved recovery outcomes supports the implementation of prompt audiological evaluation and intervention following traumatic injury. These findings underscore the need for routine audiological screening in at-risk populations and for continued research into preventive strategies, standardised assessment protocols, and optimised treatment regimens. Full article

Pt-based catalysts remain the premier hydrogen evolution reaction (HER) electrocatalysts for anion-exchange membrane water electrolyzers. Faced with insufficient abundance and high cost, developing low-Pt electrocatalysts that can accelerate the Volmer step while maintaining high durability is critically important yet challenging. Herein, we propose niobium nitrides with excellent conductivity and stability as supports for Pt to enhance the alkaline HER. A polyoxoniobate-based molecular self-assembly strategy was ingeniously designed to fabricate Nb₄N₅ nanospheres, on which ultrafine Pt nanoparticles (NPs) were successfully immobilized, forming Pt/Nb₄N₅ heterostructures (denoted as Pt/Nb₄N₅). The rich interface structures with metal–support interactions drive charge transfer from Pt to Nb₄N₅, which modulates the electronic structure of Pt and Nb sites, collectively lowering interfacial charge transfer resistance, generating abundant active sites, and improving catalyst durability. Consequently, the Pt/Nb₄N₅ catalyst achieves exceptional HER performance, including a low overpotential (22 mV@10 mA cm⁻²), a small Tafel slope (26 mV dec⁻¹), an 11.5-fold higher mass activity at 150 mV, and remarkable durability, drastically surpassing the commercial Pt/C catalyst. Notably, the Pt/Nb₄N₅-based electrolyzer requires only 1.508 V to drive 10 mA cm⁻². This work offers a viable pathway to engineer highly active and durable low-Pt electrocatalysts for energy-related applications. Full article

This study investigates graphene oxide/carboxymethyl cellulose composite membranes containing 3 wt.% graphene oxide. The influence of the carboxymethyl cellulose content on the structural organization, mechanical properties, electrical resistivity, and humidity-dependent conductivity was systematically analyzed using Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, tensile testing, and electrical measurements. Fourier transform infrared spectroscopy indicated intermolecular interactions between graphene oxide and carboxymethyl cellulose functional groups. X-ray diffraction analysis showed gradual inter-layer expansion from 0.71 to 0.87 nm together with crystallite size reduction after polymer incorporation. Scanning electron microscopy observations demonstrated the increasing structural uniformity and polymer encapsulation of graphene oxide sheets with the increasing carboxymethyl cellulose content. Mechanical testing revealed improvement in the tensile strength from 6.6 to 17.8 MPa with the increasing carboxymethyl cellulose concentration. Simultaneously, the dry-state electrical resistivity increased from 5.8 × 10⁶ to 2.32 × 10⁷ Ω·m due to increasing dielectric separation between graphene oxide domains. Humidity-sensing experiments demonstrated reversible resistance changes in the 20–90% relative humidity range, associated with proton-assisted conduction through adsorbed water layers. The obtained results demonstrate that polymer incorporation strongly influences both the structural organization and electrophysical behavior of graphene oxide/carboxymethyl cellulose composite membranes. Full article

Liquid electrolytes in conventional lithium-ion batteries pose safety risks associated with flammability, leakage, and explosion, whereas solid polymer electrolytes are generally limited by insufficient ionic conductivity at ambient temperature, restricting the development of high-energy lithium batteries. To address these issues, flexible poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)-based gel polymer electrolyte membranes (GPEs) were prepared via a slit-coating process combined with UV curing. NASICON-type lithium aluminum titanium phosphate (Li_1.3Al_0.3Ti_1.7P₃O₁₂, LATP) and garnet-type tantalum-doped lithium lanthanum zirconate (Li_6.4La₃Zr_1.4Ta_0.6O₁₂, LLZTO) were introduced as inorganic ceramic fillers to improve the ion-transport and interfacial properties of the GPE. Among the investigated samples, the PVDF-HFP-based GPE containing 10 wt% LLZTO exhibited the best overall performance, with an ionic conductivity of 3.40 × 10⁻⁴ S·cm⁻¹ at ambient temperature and a Li⁺ transference number of 0.77. Cyclic voltammetry results showed that the LLZTO-modified electrolyte membrane exhibited sharper and more symmetric redox peaks, higher peak current response, and better curve overlap during repeated cycles, indicating improved electrochemical reversibility and interfacial stability. In addition, LLZTO incorporation enhanced the mechanical strength, broadened the electrochemical stability window, and improved the flame-retardant behavior of the membrane. The LiFePO₄/GPE/Li cell assembled with the optimized membrane delivered an initial discharge capacity of 160 mAh·g⁻¹ at 0.1 C and maintained 80 mAh·g⁻¹ at 1 C, demonstrating good rate capability. Moreover, a capacity retention of 96% was maintained after 100 cycles at 0.1 C, confirming excellent cycling stability. Therefore, this work provides an effective strategy for the structural optimization and scalable preparation of high-performance gel polymer electrolyte membranes for lithium battery applications. Full article

Background/Objectives: Cyclotides are plant-derived macrocyclic peptides distinguished by their head-to-tail cyclized backbone and cystine knot motif, which confer remarkable stability against thermal, enzymatic, and chemical degradation. These features, combined with a compact and rigid structure, position cyclotides as promising scaffolds for future antibacterial agents in response to the escalating threat of multidrug-resistant (MDR) pathogens and the stagnation of conventional antibiotic discovery pipelines. This review summarizes the structural features, antibacterial mechanisms, bioengineering strategies, and translational potential of cyclotides against MDR infections. Methods: A narrative review of the literature was conducted using recent original research articles and reviews on cyclotide structure, antibacterial activity, bioengineering, computational modeling, and pharmaceutical applications. Results: Cyclotides exhibit potent antimicrobial activity, primarily through membrane disruption mediated by amphipathic surfaces and affinity for anionic bacterial membranes. Some variants also demonstrate anti-virulence and antibiofilm properties, broadening their therapeutic relevance for difficult-to-treat infections. Bioengineering approaches, including epitope grafting and rational design, have improved selectivity and potency while reducing cytotoxicity. Advances in computational modeling, molecular dynamics, and artificial intelligence have accelerated the prediction and optimization of antimicrobial activity, toxicity, and pharmacokinetic properties. Conclusions: Innovations in synthesis, including recombinant expression and enzymatic ligation, are helping overcome translational barriers related to cost and scalability. Although challenges remain in oral bioavailability and systemic delivery, strategies such as lipidation and scaffold modification support the development of cyclotide-based therapeutics as adaptable platforms for peptide drug discovery. Full article