Search Results (105)

Anion exchange membrane water electrolysis (AEMWE) is promising for low-cost hydrogen production, but its progress is limited by the weak mechanical strength and structural instability of polymer membranes. Here, a PPS-PBP/PVA composite membrane was developed using a polyphenylene sulfide (PPS) mesh as the mechanical scaffold, poly(biphenyl piperidinium) (PBP) as the ion-conducting polymer, and poly(vinyl alcohol) (PVA) as an interfacial binder. The membrane shows significantly enhanced tensile strength and puncture resistance, reduced swelling, and improved interfacial integrity. The optimized PPS-PBP/PVA (10 wt%) membrane delivers 6 A cm⁻² at 2.16 V in 1 M KOH at 80 °C and maintains stable operation for 500 h at 1 A cm⁻² with only a slight voltage increase. The results demonstrate that reinforcement coupled with interface regulation is an effective approach to constructing robust and durable composite membranes for AEMWE. Full article

The precision drive industry has seen rapid growth, leading to an increased demand for actuators that are both highly accurate and responsive. Among these, non-resonant piezoelectric motors are particularly noteworthy. These motors are extensively employed in applications such as high-precision manufacturing, precision drug delivery, and cellular puncture, owing to their adaptable drive control and resistance to external disturbances. Given the specific requirements of these applications, it is crucial to quickly determine the relationship between the motor input parameters and output characteristics—a challenging endeavor. In this research, we examine a typical non-resonant piezoelectric motor using multiple sets of experimental data. A machine learning algorithm is employed to swiftly establish the correlation between electromechanical input parameters and output trajectory characteristics. Data are analyzed using a random forest model to understand the underlying influence mechanisms. Based on this analysis, predictions and recommendations are made to achieve optimal operating conditions for the motor. This study demonstrates that machine learning serves as an effective tool for predicting piezoelectric motor performance, facilitating rapid assessment of motor output capabilities. Full article

Mono-material multilayer polypropylene films were developed as light barrier structures through the incorporation of mineral-filled composite layers. Trilayer films with different layer arrangements were fabricated by thermocompression from polypropylene-based films containing 0, 1 and 5 wt.% of talc and kaolinite. A monolayer polypropylene film of equivalent total thickness was used as a control. Structural, thermal, mechanical, optical, and gas barrier properties were evaluated for all films fabricated. A well-defined trilayer structure was confirmed by SEM. FTIR analysis demonstrated negligible thermo-oxidation, with no thermal-degradation during processing. Improved thermal stability and a slight modification in crystallinity were evidenced by TGA and DSC, respectively. XRD revealed the predominance of the α-form crystalline phase and a preferential polymer crystal orientation associated with the particle presence. Regarding mechanical behavior, enhanced stiffness and tensile strength without loss of sealability or puncture resistance were observed. Trilayer films exhibited significantly reduced UV and visible light transmittance, while maintaining adequate translucency, making them suitable for photosensitive packaging applications. Gas permeabilities remained nearly unchanged, confirming that the barrier performances were preserved. Overall, these mono-material multilayer composites films offer a promising and recyclable alternative to conventional multi-material light barrier packaging, combining improved UV protection, mechanical robustness, and environmental compatibility. Full article

Stalk lodging is one of the major constraints limiting global maize yield. Chemical regulation and fertilization are essential agronomic practices that play critical roles in improving maize yield and lodging resistance. This study aimed to investigate the effects of different fertilization methods on maize plant morphology, stem mechanical properties and chemical composition, and yield under spraying chemical regulator (EDAH, consist of 27% ethephon and 3% DA-6). The experiment was conducted from 2023 to 2025, using Jiangyu668 (JY668) and Jiangyu877 (JY877) with different plant heights. Three fertilization methods (no fertilization, N0; conventional fertilization, N15; and slow-release fertilization, SN15) were set up. Chemical regulation and fertilization methods had significant effects on plant morphology, stem mechanical properties and chemical composition, lodging rate, and grain yield. The combination of spraying EDAH and slow-release fertilization optimized ear position coefficient and gravity center, decreased stem–leaf angle, and increased leaf orientation value, which was beneficial for improving leaf photosynthetic capacity. EDAH and slow-release fertilization also increased the stem internode diameter and aerial root layers; enhanced bending resistance and puncture strength; and increased cellulose, hemicellulose, and lignin contents and the lodging resistance index. These changes synergistically increased grain number and weight, ultimately increased maize yield, and decreased the lodging rate. CSN15 had highest yield and lowest lodging rate in different years and varieties. SN15 increased yield by 10.58% compared with N15, and CSN15 increased yield by 10.53% compared with CN15. JY877, as a medium- to high-stem maize variety, had better performance in plant morphology and yield than JY668 (dwarf maize variety) under EDAH and slow-release fertilization. These findings demonstrate that the strategy of combining chemical regulation and slow-release fertilization represents an optimal management approach for enhancing grain yield by optimizing plant morphology and improving stem mechanical properties and stem chemical composition in maize production. This strategy can increase agricultural productivity by enhancing yield and lodging resistance and provide significant environmental benefits and a scientific basis for agronomic practice recommendations. Full article

Background/Objectives: Multidrug-resistant (MDR) Escherichia coli is a critical One Health challenge, with rising resistance in both humans and animals. The present study aimed to compare antimicrobial resistance (AMR) profiles of E. coli isolates from hospitalized patients and food-producing animals in Satu Mare, a county located in northwestern Romania. Methods: Between 2022–2023, 701 samples were collected, leading to 571 non-duplicate E. coli isolates (420 human, 151 animal). Human strains were recovered from 21 hospital departments and originated from feces, urine, blood, sputum, ear secretions, cerebrospinal fluid, purulent wound secretions, and puncture fluids. Animal isolates were obtained from ceca collected at local slaughterhouses serving farms in north-west Romania, including samples from turkeys, broilers, and pigs. Antimicrobial susceptibility testing was performed against eight antimicrobials (amikacin, ampicillin, cefotaxime, ceftazidime, cefepime, ciprofloxacin, gentamicin, sulfamethoxazole/trimethoprim) using standardized methods. Resistance classification followed international definitions of MDR. Statistical associations between host species and resistance were assessed with chi-square tests. Results: Resistance levels were consistently higher in E. coli strains isolated from animals compared with those from humans (p < 0.05). Among human isolates, resistance to ampicillin (41.9%), ciprofloxacin (41.4%), and sulfamethoxazole/trimethoprim (45.7%) approached, but did not exceed 50%. In contrast, E. coli strains recovered from animals showed markedly higher resistance, exceeding 50% for ampicillin (78.8%), ciprofloxacin (65.6%), and cefotaxime (55.0%). Amikacin retained full activity against all animal isolates, whereas 2.8% of human strains were resistant. Overall, multidrug resistance (MDR) was observed in 70.0% of E. coli isolates from humans and 79.7% from animals, with the highest resistance burden in pig-derived isolates. Conclusions: The study underscores the veterinary sector as a key contributor to the maintenance and spread of MDR E. coli. Even in clinically healthy animals, resistance levels exceeded those observed in human isolates. These findings emphasize the need for coordinated One Health monitoring and stricter antimicrobial use policies in livestock to reduce transmission risks across human and animal populations. Full article

Choline salts represent sustainable and safe electrolyte systems. In this study, an aqueous 1 M choline nitrate solution was employed to prepare hydrogel polymer electrolytes (HPE) via in situ photopolymerization. To enhance compatibility between the electrolyte and polymer matrix, choline methacrylate was synthesized and used as a functional monomer alongside HEMA and PEGDA. The photocurable formulation contained 70 wt.% electrolyte and 30 wt.% monomer mixture. Subsequent electrolyte uptake increased the electrolyte fraction in the HPE to 87 wt.%. The use of choline methacrylate enabled the formation of transparent HPE with favorable mechanical performance, showing puncture resistance of 0.33 N and 0.28 N at elongations of 7.9 mm and 4.4 mm for samples with 70 and 87 wt.% electrolyte, respectively. High ionic conductivity was achieved, reaching ~18 mS/cm and ~34 mS/cm for HPE with 70 and 87 wt.% electrolyte. Finally, a capacitor assembled with HPE containing 87 wt.% electrolyte demonstrated good operational parameters, confirming the applicability of this system in energy storage devices. This work highlights the potential of choline-based electrolytes and polymerizable choline derivatives as functional components for the design of efficient, safe, and environmentally friendly gel polymer electrolytes. Full article

Introduction: Brain abscess is defined as a suppurative collection resulting from hematogenous dissemination as an extension from otorhinolaryngologic infectious foci, or secondary to cranial trauma and neurosurgical procedures. Its evolution follows four histopathological stages, the most severe complication being intraventricular rupture, which is associated with extremely high mortality. Central nervous system infections caused by multidrug-resistant (MDR/XDR) Acinetobacter baumannii are rare but severe, significantly limiting therapeutic options due to the reduced penetration of the blood-brain barrier by active antimicrobial agents. Case report: We report the case of a 48-year-old patient with a history of hemorrhagic stroke treated surgically, who was admitted for fever, severe headache, and vomiting. On admission, lumbar puncture confirmed bacterial meningitis, with isolation of A. baumannii susceptible only to colistin. Brain magnetic resonance imaging revealed a postoperative cerebellar abscess. Initial empirical therapy consisted of meropenem and vancomycin, subsequently adjusted according to the susceptibility profile to cefiderocol, intravenous and intrathecal colistin, combined with ampicillin/sulbactam and minocycline. The clinical course was favorable with regard to meningitis, with partial regression of the cerebellar abscess. Follow-up lumbar punctures were sterile, and the patient’s neurological condition stabilized, allowing avoidance of neurosurgical drainage. Conclusions: Meningitis and brain abscess caused by MDRA. baumannii represent rare clinical entities with potentially severe outcomes. Intrathecal administration of colistin, in combination with systemic multidrug therapy, proved decisive in controlling the infection. An interdisciplinary approach and individualized antimicrobial regimens are essential to achieving a favorable prognosis in such complex cases. Full article

Background: Antimicrobial resistance (AMR) is a major public health concern. Urinary tract infections (UTIs) account for up to 85–90% of community-acquired cases. The COVID-19 pandemic disrupted healthcare access and may have influenced resistance patterns. In this context, we retrospectively evaluated the antibiotic resistance dynamics of various bacterial strains isolated between 2019 and 2023 in a hospital unit; Methods: A total of 8217 clinical specimens (urine, wound secretions, sputum, pharyngeal exudate, nasal exudate, tracheal secretions, vaginal and cervical secretions, puncture fluids, purulent secretions, blood, ear secretions, eye secretions) were processed using standard microbiological techniques. Pathogen identification and susceptibility testing were performed with the VITEK 2 Compact system, following CLSI guidelines. Results: Following the analysis of 8217 clinical samples collected over a five-year period (2019–2023), a total of 2900 microorganisms were isolated and identified. Among these, the most frequently encountered were E. coli strains, with 1204 isolates. Urine cultures represented 71.3% of all processed samples. Out of these 5860 urine cultures, 1530 (26%) were positive. The resistance of E. coli strains to ampicillin (48–55.2%), trimethoprim/sulfamethoxazole (22.9–34%), and ciprofloxacin (21.4–31.5%) remained high throughout the period. ESBL-producing strains peaked at 17.6% in 2020, with multidrug resistance rates ranging from 14% to 22.4%. Conclusions: E. coli strains displayed persistently high resistance to ampicillin, trimethoprim/sulfamethoxazole, and ciprofloxacin, with peaks in ESBL production and multidrug resistance during the COVID-19 pandemic. These trends underscore the importance of continuous surveillance and antibiotic stewardship, with direct implications for empirical UTI therapy and broader strategies to mitigate the public health impact of antimicrobial resistance. Full article

Background/Objectives: Sepsis is a life-threatening condition characterized by organ dysfunction due to a dysregulated host response to infection. Mitochondrial dysfunction is considered a key contributor to the pathogenesis of sepsis, but its molecular mechanisms remain unclear. Methods: In this study, we used a cecal ligation and puncture (CLP) model to induce sepsis in wild-type (WT) and cyclophilin D knockout (CypD KO) mice. Liver tissues were collected at 0, 6, and 18 h post-CLP and analyzed using liquid chromatography–tandem mass spectrometry (LC-MS/MS). Results: Metabolomic profiling revealed that lactate levels significantly increased in the WT mice but remained stable in the KO mice. While AMP levels were preserved in the KO mice, these mice had significantly higher glutathione disulfide (GSSG) and spermidine concentrations than the WT mice at 18 h (p < 0.05). The levels of malondialdehyde (MDA), a marker of oxidative stress, were also significantly lower in the KO mice at 18 h (p < 0.05). These findings suggest that CypD deficiency preserves mitochondrial function, enhances resistance to oxidative stress, and mitigates septic liver injury. Conclusions: Our results highlight the potential of targeting mitochondrial permeability transition as a therapeutic strategy for sepsis. Full article

In this study, the preparation and detailed characterization of a chitosan (CHT) impregnation system modified with cellulose nanofibrils (CNFs) and enriched with bioactive compounds—caffeine (CAF) and gallic acid (GA)—applied to the surface of unbleached paperboard were described. Their mechanical properties (tensile strength, elongation at break, and bursting strength), structural features, and surface barrier parameters (water absorption) were evaluated. The antibacterial activity of the formulations comprising 1% chitosan (1% CHT), 1% chitosan with 1% caffeine (1% CHT/1% CAF), and 1% chitosan with 1% gallic acid (1% CHT/1% GA)—applied to enhance the functionality of the coated paperboard—was additionally assessed. The incorporation of cellulose nanofibrils into the coating matrix markedly improved the mechanical performance of the paperboard, particularly in terms of puncture resistance and elongation at break, while all modified coatings retained high burst strength. Impregnations containing gallic acid or caffeine showed similar mechanical characteristics but improved flexibility without compromising structural integrity. Chitosan solutions containing gallic acid and solutions containing caffeine exhibited activity against the tested Gram-positive (S. aureus, L. monocytogenes) and Gram-negative (E. coli, P. aeruginosa) bacterial strains. Antibacterial analysis showed moderate activity against Gram-positive strains and strong inhibition of Gram-negative bacteria, with the 1% CHT/1% GA impregnation giving the largest zone of growth inhibition around the sample—19 mm in the agar diffusion test—indicating the strongest suppression of E. coli. It was found that incorporation of nanocellulose into the chitosan matrix significantly reduces water uptake by treated paperboard surface, which is critical in the context of food packaging. The best result—Cobb₆₀ value of 32.85 g/m²—was achieved for the 1% CHT/1% CNF formulation, corresponding to an 87% reduction in water absorption compared to the uncoated control. The results obtained in this study indicate a promising potential for the use of these impregnation systems in sustainable packaging applications. Full article

Active packaging supports sustainable development by extending food shelf life and reducing spoilage, contributing to global food security. In this study, cellulose dialdehyde was synthesized and blended with polyvinyl alcohol in varying ratios to produce composite films. The incorporation of dialdehyde cellulose into films tended to increase puncture strength and Young’s modulus, decrease elongation, reduce water solubility, and enhance resistance to water vapor transmission because of crosslinking. Carbon quantum dots were subsequently incorporated into composite films to enhance their antibacterial property. This represents a novel combination of a natural bio-based crosslinker and fluorescent nanomaterials in a single packaging system. Carbon quantum dots were synthesized by an electrochemical method and incorporated as functional agents. The addition of carbon quantum dots influenced the mechanical properties of the films due to interactions between polymers and carbon quantum dots. This interaction also slightly reduced the antibacterial effectiveness of the films, consisting of dialdehyde cellulose and PVA in ratios of 3:1 and 4:0. Nevertheless, the composite films maintained sufficient antimicrobial activity against common foodborne bacteria, including Staphylococcus aureus, Escherichia coli, and Salmonella Typhimurium. Overall, the findings demonstrate that multifunctional material made from dialdehyde cellulose, polyvinyl alcohol, and carbon quantum dots are a promising alternative to conventional plastic packaging. Full article

Epoxy resins are widely used as protective coatings in civil infrastructure, yet sulfate-rich environments accelerate their deterioration. This study evaluates the effectiveness of multi-walled carbon nanotubes (MWCNTs) in enhancing the sulfate resistance of epoxy resins. Neat and MWCNT-reinforced epoxy specimens (0.25 wt.% and 0.5 wt.%) were fabricated, heat cured at 100 °C and exposed to a solution of sulfuric acid and sodium chloride maintaining a pH of less than 3 for 0, 30, and 60 days. Analytical techniques, including scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), revealed distinct degradation patterns: the neat epoxy exhibited puncture damage and extensive salt deposition, while the MWCNT-reinforced specimens showed crack propagation mitigated by nanotube bridging. Heat curing introduced micro-voids that exacerbated sulfate ingress. The salt deposition surged to 200 times for the MWCNT-reinforced specimens compared to the neat ones, whereas crack width was higher in the MWCNT reinforced specimen compared to their neat counterparts, given that crack-bridging was observed. These findings highlight the potential of MWCNTs to improve epoxy durability in sulfate-prone environments, though the optimization of curing conditions and dispersion methods is critical. Full article

Quality and mechanical resilience are crucial for reducing losses in fruit production and for supporting food chains. Indeed, integrating empirical data with rheological models bridges gaps in fruit processing equipment design. Therefore, the objective of this research is to analyze the relationship between the mechanical and physical properties of seven economically important fruits—nectarine, kiwi, cherry, apple, peach, pear, and apricot—to assess their mechanical behavior and post-harvest quality. Standardized compression, creep, and puncture tests were conducted to establish mechanical parameters, such as rupture force, elasticity, and deformation energy. Physical characteristics including size, weight, density, and moisture content were also measured. The results indicated significant differences among the various categories of fruits; apples and pears were most suitable for mechanical harvesting and long storage periods, whereas cherries and apricots were least resistant and susceptible to injury. Correlations were high among the physical measurements, tissue firmness, and viscoelastic properties, thereby confirming structural properties’ contribution in influencing fruit quality and handling efficiency. The originality of this research is in its holistic examination of physical and mechanical properties under standardized testing conditions, thus offering an integrated framework for enhancing post-harvest operations. These findings offer practical insights for optimizing harvesting, packaging, transportation, and quality monitoring strategies based on fruit-specific mechanical profiles. Full article

Background/Objectives: This study investigates the impact of high humidity (25 °C, 75% relative humidity) on gelatin and hydroxypropyl methylcellulose (HPMC) capsules used in dry powder inhalers (DPIs), focusing on moisture dynamics, structural responses, and mechanical performance, with an emphasis on understanding how different capsule types respond to prolonged exposure to humid conditions. Methods: Capsules were exposed to controlled humidity conditions, and moisture uptake was measured via thermal analysis. Visual observations of silica bead color changes were performed to assess moisture absorption, while surface wettability was measured using the sessile drop method. Hardness testing, mechanical deformation, and puncture tests were performed to evaluate structural and mechanical changes. Positron annihilation lifetime spectroscopy (PALS) was used to analyze free volume expansion. Results: HPMC capsules exhibited rapid moisture uptake, attributed to their lower equilibrium moisture content and ability to rearrange dynamically, preventing brittleness. In contrast, gelatin capsules showed slower moisture absorption but reached higher equilibrium levels, resulting in plasticization and softening. Mechanical testing showed that HPMC capsules retained structural integrity with minimal deformation, while gelatin capsules became softer and exhibited reduced puncture resistance. Structural analysis revealed greater free volume expansion in HPMC capsules, consistent with their amorphous nature, compared with gelatin’s semi-crystalline matrix. Conclusions: HPMC capsules demonstrated superior humidity resilience, making them more suitable for protecting moisture-sensitive active pharmaceutical ingredients (APIs) in DPI formulations. These findings underline the importance of appropriate storage conditions, as outlined in the Summary of Product Characteristics, to ensure optimal capsule performance throughout patient use. Full article

Sugar Belle^® mandarin is considered tolerant to Huanglongbing (HLB); however, recent reports have raised concerns about its fruit quality, noting issues such as reduced fruit size, thin peel, poor coloration, decreased firmness, and suboptimal juice quality. Two-year field experiments were conducted to improve external and internal fruit characteristics through foliar application of potassium (K) in five-year-old Sugar Belle mandarin grown in Florida sandy soil. The experiment consisted of foliar K supply (17 kg/ha) via Potassium Nitrate (PN, 4.7 kg/ha N), Dipotassium Phosphate (DKP, 12.7 kg/ha P₂O₅), PN with boron (PNB, 0.84 kg/ha B) at different application times (May, July, September), including one-time Gibberellic acid spray (GA@10 mg/L) and control treatments. PN application during July (PN_J) or two applications of PN with B during May and July (PNB_MJ) resulted in a larger fruit size (>65 mm). Results showed that PN application before fall (May or July) resulted in a significantly thicker peel (2.3 mm), 1.15 fold more than the control and GA treatment. Fruit puncture resistance force was significantly higher (33.1 N) with GA treatment (p = 0.07), followed by PNB_MJ (32.6 N). Meanwhile, K spray positively influenced juice qualities and peel color, regardless of application time or source. However, GA treatment significantly reduced juice quality and peel color. These findings highlighted the benefits of foliar K supply as PN to improve fruit qualities in HLB-affected citrus grown in sandy soil. Full article