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32 pages, 995 KiB  
Case Report
Phytotoxic Effects and Agricultural Potential of Nanofertilizers: A Case Study Using Zeolite, Zinc Oxide, and Titanium Dioxide Under Controlled Conditions
by Ezequiel Zamora-Ledezma, Glenda Leonela Loor Aragundi, Willian Stalyn Guamán Marquines, Michael Anibal Macías Pro, José Vicente García Díaz, Henry Antonio Pacheco Gil, Julián Mauricio Botero Londoño, Mónica Andrea Botero Londoño and Camilo Zamora-Ledezma
J. Xenobiot. 2025, 15(4), 123; https://doi.org/10.3390/jox15040123 (registering DOI) - 1 Aug 2025
Abstract
Nanofertilizers (NFs) and engineered nanoparticles (NPs) are increasingly used in agriculture, yet their environmental safety remains poorly understood. This study evaluated the comparative phytotoxicity of zinc oxide (ZnO), titanium dioxide (TiO2), and clinoptilolite nanoparticles, three commercial nanofertilizers, and potassium dichromate (K [...] Read more.
Nanofertilizers (NFs) and engineered nanoparticles (NPs) are increasingly used in agriculture, yet their environmental safety remains poorly understood. This study evaluated the comparative phytotoxicity of zinc oxide (ZnO), titanium dioxide (TiO2), and clinoptilolite nanoparticles, three commercial nanofertilizers, and potassium dichromate (K2Cr2O7) using Lactuca sativa seeds under adapted OECD-208 protocol conditions. Seeds were exposed to varying concentrations of each xenobiotic material (0.5–3% for NFs; 10–50% for NPs), with systematic assessment of seedling survival, root and hypocotyl length, dry biomass, germination index (GI), and median effective concentration (EC50) values. Nanofertilizers demonstrated significantly greater phytotoxicity than engineered nanoparticles despite lower application concentrations. The toxicity ranking was established as NF1 > NF3 > NF2 > NM2 > NM1 > NM3, with NF1 being most toxic (EC50 = 1.2%). Nanofertilizers caused 45–78% reductions in root length and 30–65% decreases in dry biomass compared with controls. GI values dropped to ≤70% in NF1 and NF3 treatments, indicating concentration-dependent growth inhibition. While nanofertilizers offer agricultural benefits, their elevated phytotoxicity compared with conventional nanoparticles necessitates rigorous pre-application safety assessment. These findings emphasize the critical need for standardized evaluation protocols incorporating both physiological and ecotoxicological endpoints to ensure safe xenobiotic nanomaterial deployment in agricultural systems. Full article
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16 pages, 1141 KiB  
Article
Coordinated Roles of Osmotic Adjustment, Antioxidant Defense, and Ion Homeostasis in the Salt Tolerance of Mulberry (Morus alba L. ‘Tailai Sang’) Seedlings
by Nan Xu, Tiane Wang, Yuan Wang, Juexian Dong and Yu Shaopeng
Forests 2025, 16(8), 1258; https://doi.org/10.3390/f16081258 (registering DOI) - 1 Aug 2025
Abstract
Soil salinization severely limits plant growth and productivity. Mulberry (Morus alba L.), an economically and ecologically important tree, is widely cultivated, yet its salt-tolerance mechanisms at the seedling stage remain insufficiently understood. This study investigated the physiological and biochemical responses of two-year-old [...] Read more.
Soil salinization severely limits plant growth and productivity. Mulberry (Morus alba L.), an economically and ecologically important tree, is widely cultivated, yet its salt-tolerance mechanisms at the seedling stage remain insufficiently understood. This study investigated the physiological and biochemical responses of two-year-old mulberry (‘Tailai Sang’) seedlings subjected to six NaCl treatments (0, 50, 100, 150, 200, and 300 mmol L−1) for 28 days. Results showed that growth parameters and photosynthetic gas exchange exhibited dose-dependent declines. The reduction in net photosynthetic rate (Pn) was attributed to both stomatal limitations (decreased stomatal conductance) and non-stomatal limitations, as evidenced by a significant decrease in the maximum quantum efficiency of photosystem II (Fv/Fm) under high salinity. To cope with osmotic stress, seedlings accumulated compatible solutes, including soluble sugars, proteins, and proline. Critically, mulberry seedlings demonstrated effective ion homeostasis by sequestering Na+ in the roots to maintain a high K+/Na+ ratio in leaves, a mechanism that was compromised above 150 mmol L−1. Concurrently, indicators of oxidative stress—malondialdehyde (MDA) and H2O2—rose significantly with salinity, inducing the activities of antioxidant enzymes (SOD, CAT, APX, and GR), which peaked at 150 mmol L−1 before declining under extreme stress. A biomass-based LC50 of 179 mmol L−1 NaCl was determined. These findings elucidate that mulberry salt tolerance is a coordinated process involving three key mechanisms: osmotic adjustment, selective ion distribution, and a robust antioxidant defense system. This study establishes an indicative tolerance threshold under controlled conditions and provides a physiological basis for further field-based evaluations of ‘Tailai Sang’ mulberry for cultivation on saline soils. Full article
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15 pages, 3882 KiB  
Article
Performance of Low-Cost Energy Dense Mixed Material MnO2-Cu2O Cathodes for Commercially Scalable Aqueous Zinc Batteries
by Gautam G. Yadav, Malesa Sammy, Jungsang Cho, Megan N. Booth, Michael Nyce, Jinchao Huang, Timothy N. Lambert, Damon E. Turney, Xia Wei and Sanjoy Banerjee
Batteries 2025, 11(8), 291; https://doi.org/10.3390/batteries11080291 (registering DOI) - 1 Aug 2025
Abstract
Zinc (Zn)-based batteries have attracted significant interest for applications ranging from electric bikes to grid storage because of its advantageous properties like high abundance, non-toxicity and low-cost. Zn offers a high theoretical capacity of two electrons per atom, resulting in 820 mAh/g, making [...] Read more.
Zinc (Zn)-based batteries have attracted significant interest for applications ranging from electric bikes to grid storage because of its advantageous properties like high abundance, non-toxicity and low-cost. Zn offers a high theoretical capacity of two electrons per atom, resulting in 820 mAh/g, making it a promising anode material for the development of highly energy dense batteries. However, the advancement of Zn-based battery systems is hindered by the limited availability of cathode materials that simultaneously offer high theoretical capacity, long-term cycling stability, and affordability. In this work, we present a new mixed material cathode system, comprising of a mixture of manganese dioxide (MnO2) and copper oxide (Cu2O) as active materials, that delivers a high theoretical capacity of ~280 mAh/g (MnO2 + Cu2O active material) (based on the combined mass of MnO2 and Cu2O) and supports stable cycling for >200 cycles at 1C. We further demonstrate the scalability of this novel cathode system by increasing the electrode size and capacity, highlighting its potential for practical and commercial applications. Full article
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31 pages, 1295 KiB  
Review
The Oral–Gut Microbiota Axis Across the Lifespan: New Insights on a Forgotten Interaction
by Domenico Azzolino, Margherita Carnevale-Schianca, Luigi Santacroce, Marica Colella, Alessia Felicetti, Leonardo Terranova, Roberto Carlos Castrejón-Pérez, Franklin Garcia-Godoy, Tiziano Lucchi and Pier Carmine Passarelli
Nutrients 2025, 17(15), 2538; https://doi.org/10.3390/nu17152538 (registering DOI) - 1 Aug 2025
Abstract
The oral–gut microbiota axis is a relatively new field of research. Although most studies have focused separately on the oral and gut microbiota, emerging evidence has highlighted that the two microbiota are interconnected and may influence each other through various mechanisms shaping systemic [...] Read more.
The oral–gut microbiota axis is a relatively new field of research. Although most studies have focused separately on the oral and gut microbiota, emerging evidence has highlighted that the two microbiota are interconnected and may influence each other through various mechanisms shaping systemic health. The aim of this review is therefore to provide an overview of the interactions between oral and gut microbiota, and the influence of diet and related metabolites on this axis. Pathogenic oral bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, can migrate to the gut through the enteral route, particularly in individuals with weakened gastrointestinal defenses or conditions like gastroesophageal reflux disease, contributing to disorders like inflammatory bowel disease and colorectal cancer. Bile acids, altered by gut microbes, also play a significant role in modulating these microbiota interactions and inflammatory responses. Oral bacteria can also spread via the bloodstream, promoting systemic inflammation and worsening some conditions like cardiovascular disease. Translocation of microorganisms can also take place from the gut to the oral cavity through fecal–oral transmission, especially within poor sanitary conditions. Some metabolites including short-chain fatty acids, trimethylamine N-oxide, indole and its derivatives, bile acids, and lipopolysaccharides produced by both oral and gut microbes seem to play central roles in mediating oral–gut interactions. The complex interplay between oral and gut microbiota underscores their crucial role in maintaining systemic health and highlights the potential consequences of dysbiosis at both the oral and gastrointestinal level. Some dietary patterns and nutritional compounds including probiotics and prebiotics seem to exert beneficial effects both on oral and gut microbiota eubiosis. A better understanding of these microbial interactions could therefore pave the way for the prevention and management of systemic conditions, improving overall health outcomes. Full article
(This article belongs to the Special Issue Exploring the Lifespan Dynamics of Oral–Gut Microbiota Interactions)
16 pages, 24404 KiB  
Article
Oxidation of HfB2-HfO2-SiC Ceramics Modified with Ti2AlC Under Subsonic Dissociated Airflow
by Elizaveta P. Simonenko, Aleksey V. Chaplygin, Nikolay P. Simonenko, Ilya V. Lukomskii, Semen S. Galkin, Anton S. Lysenkov, Ilya A. Nagornov, Artem S. Mokrushin, Tatiana L. Simonenko, Anatoly F. Kolesnikov and Nikolay T. Kuznetsov
Corros. Mater. Degrad. 2025, 6(3), 35; https://doi.org/10.3390/cmd6030035 (registering DOI) - 1 Aug 2025
Abstract
Ultrahigh-temperature ceramic composites based on hafnium diboride have a wide range of applications, including as components for high-speed aircraft and energy generation and storage devices. Consequently, developing methodologies for their fabrication and studying their properties are of paramount importance, in particular in using [...] Read more.
Ultrahigh-temperature ceramic composites based on hafnium diboride have a wide range of applications, including as components for high-speed aircraft and energy generation and storage devices. Consequently, developing methodologies for their fabrication and studying their properties are of paramount importance, in particular in using them as an electrode material for energy storage devices with increased oxidation resistance. This study investigates the behavior of ceramic composites based on the HfB2-HfO2-SiC system, obtained using 15 vol% Ti2AlC MAX-phase as a sintering component, under the influence of subsonic flow of dissociated air. It was determined that incorporating the modifying component (Ti2AlC) altered the composition of the silicate melt formed on the surface during ceramic oxidation. This modification led to the observation of a protective antioxidant function. Consequently, liquation was observed in the silicate melt layer, resulting in the formation of spherical phase inhomogeneities in its volume with increased content of titanium, aluminum, and hafnium. It is hypothesized that the increase in the high-temperature viscosity of this melt prevents it from being carried away in the form of drops, even at a surface temperature of ~1900–2000 °C. Despite the established temperature, there is no sharp increase in its values above 2400–2500 °C. This is due to the evaporation of silicate melt from the surface. In addition, the electrochemical behavior of the obtained material in a liquid electrolyte medium (KOH, 3 mol/L) was examined, and it was shown that according to the value of electrical conductivity and specific capacitance, it is a promising electrode material for supercapacitors. Full article
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26 pages, 7374 KiB  
Article
Copper-Enhanced NiMo/TiO2 Catalysts for Bifunctional Green Hydrogen Production and Pharmaceutical Pollutant Removal
by Nicolás Alejandro Sacco, Fernanda Albana Marchesini, Ilaria Gamba and Gonzalo García
Catalysts 2025, 15(8), 737; https://doi.org/10.3390/catal15080737 (registering DOI) - 1 Aug 2025
Abstract
This study presents the development of Cu-doped NiMo/TiO2 photoelectrocatalysts for simultaneous green hydrogen production and pharmaceutical pollutant removal under simulated solar irradiation. The catalysts were synthesized via wet impregnation (15 wt.% total metal loading with 0.6 wt.% Cu) and thermally treated at [...] Read more.
This study presents the development of Cu-doped NiMo/TiO2 photoelectrocatalysts for simultaneous green hydrogen production and pharmaceutical pollutant removal under simulated solar irradiation. The catalysts were synthesized via wet impregnation (15 wt.% total metal loading with 0.6 wt.% Cu) and thermally treated at 400 °C and 900 °C to investigate structural transformations and catalytic performance. Comprehensive characterization (XRD, BET, SEM, XPS) revealed phase transitions, enhanced crystallinity, and redistribution of redox states upon Cu incorporation, particularly the formation of NiTiO3 and an increase in oxygen vacancies. Crystallite sizes for anatase, rutile, and brookite ranged from 21 to 47 nm at NiMoCu400, while NiMoCu900 exhibited only the rutile phase with 55 nm crystallites. BET analysis showed a surface area of 44.4 m2·g−1 for NiMoCu400, and electrochemical measurements confirmed its higher electrochemically active surface area (ECSA, 2.4 cm2), indicating enhanced surface accessibility. In contrast, NiMoCu900 exhibited a much lower BET surface area (1.4 m2·g−1) and ECSA (1.4 cm2), consistent with its inferior photoelectrocatalytic performance. Compared to previously reported binary NiMo/TiO2 systems, the ternary NiMoCu/TiO2 catalysts demonstrated significantly improved hydrogen production activity and more efficient photoelectrochemical degradation of paracetamol. Specifically, NiMoCu400 showed an anodic peak current of 0.24 mA·cm−2 for paracetamol oxidation, representing a 60% increase over NiMo400 and a cathodic current of –0.46 mA·cm−2 at –0.1 V vs. RHE under illumination, nearly six times higher than the undoped counterpart (–0.08 mA·cm−2). Mott–Schottky analysis further revealed that NiMoCu400 retained n-type behavior, while NiMoCu900 exhibited an unusual inversion to p-type, likely due to Cu migration and rutile-phase-induced realignment of donor states. Despite its higher photosensitivity, NiMoCu900 showed negligible photocurrent, confirming that structural preservation and surface redox activity are critical for photoelectrochemical performance. This work provides mechanistic insight into Cu-mediated photoelectrocatalysis and identifies NiMoCu/TiO2 as a promising bifunctional platform for integrated solar-driven water treatment and sustainable hydrogen production. Full article
(This article belongs to the Section Electrocatalysis)
25 pages, 5020 KiB  
Review
Research Progress on Tribological Properties of High-Entropy Alloys
by Shuai Zhang, Zhaofeng Wang, Wenqing Lin and Haoyu Guo
Lubricants 2025, 13(8), 342; https://doi.org/10.3390/lubricants13080342 (registering DOI) - 1 Aug 2025
Abstract
As a new type of alloy system composed of five or more principal components, high-entropy alloys demonstrate outstanding comprehensive performance in the field of friction and wear through the synergistic effects of the high-entropy effect, lattice distortion effect, hysteresis diffusion effect and cocktail [...] Read more.
As a new type of alloy system composed of five or more principal components, high-entropy alloys demonstrate outstanding comprehensive performance in the field of friction and wear through the synergistic effects of the high-entropy effect, lattice distortion effect, hysteresis diffusion effect and cocktail effect. This paper systematically reviews the research progress on the friction and wear properties of high-entropy alloys. The mechanisms of metal elements such as Al, Ti, Cu and Nb through solid solution strengthening, second-phase precipitation and oxide film formation were analyzed emphatically. And non-metallic elements such as C, Si, and B form and strengthen the regulation laws of their tribological properties. The influence of working conditions, such as high temperature, ocean, and hydrogen peroxide on the friction and wear behavior of high-entropy alloys by altering the wear mechanism, was discussed. The influence of test conditions such as load, sliding velocity and friction pair matching on its friction coefficient and wear rate was expounded. It is pointed out that high-entropy alloys have significant application potential in key friction components, providing reference and guidance for the further development and application of high-entropy alloys. Full article
(This article belongs to the Special Issue Tribological Performance of High-Entropy Alloys)
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20 pages, 6929 KiB  
Article
Protective Effects of Sodium Copper Chlorophyllin and/or Ascorbic Acid Against Barium Chloride-Induced Oxidative Stress in Mouse Brain and Liver
by Salma Benayad, Basma Es-Sai, Yassir Laaziouez, Soufiane Rabbaa, Hicham Wahnou, Habiba Bouchab, Hicham El Attar, Bouchra Benabdelkhalek, Loubna Amahdar, Oualid Abboussi, Raphaël Emmanuel Duval, Riad El Kebbaj and Youness Limami
Molecules 2025, 30(15), 3231; https://doi.org/10.3390/molecules30153231 (registering DOI) - 1 Aug 2025
Abstract
Barium chloride (BaCl2), a known environmental pollutant, induces organ-specific oxidative stress through disruption of redox homeostasis. This study evaluated the protective effects and safety profile of sodium copper chlorophyllin (SCC) and ascorbic acid (ASC) against BaCl2-induced oxidative damage in [...] Read more.
Barium chloride (BaCl2), a known environmental pollutant, induces organ-specific oxidative stress through disruption of redox homeostasis. This study evaluated the protective effects and safety profile of sodium copper chlorophyllin (SCC) and ascorbic acid (ASC) against BaCl2-induced oxidative damage in the liver and brain of mice using a two-phase experimental protocol. Animals received either SCC (40 mg/kg), ASC (160 mg/kg), or their combination for 14 days prior to BaCl2 exposure (150 mg/L in drinking water for 7 days), allowing evaluation of both preventive and therapeutic effects. Toxicological and behavioral assessments confirmed the absence of systemic toxicity or neurobehavioral alterations following supplementation. Body weight, liver and kidney indices, and biochemical markers (Aspartate Aminotransferase (ASAT), Alanine Aminotransferase (ALAT), creatinine) remained within physiological ranges, and no anxiogenic or locomotor effects were observed. In the brain, BaCl2 exposure significantly increased SOD (+49%), CAT (+66%), GPx (+24%), and GSH (+26%) compared to controls, reflecting a robust compensatory antioxidant response. Although lipid peroxidation (MDA) showed a non-significant increase, SCC, ASC, and their combination reduced MDA levels by 42%, 37%, and 55%, respectively. These treatments normalized antioxidant enzyme activities and GSH, indicating an effective neuroprotective effect. In contrast, the liver exhibited a different oxidative profile. BaCl2 exposure increased MDA levels by 80% and GSH by 34%, with no activation of SOD, CAT, or GPx. Histological analysis revealed extensive hepatocellular necrosis, vacuolization, and inflammatory infiltration. SCC significantly reduced hepatic MDA by 39% and preserved tissue architecture, while ASC alone or combined with SCC exacerbated inflammation and depleted hepatic GSH by 71% and 78%, respectively, relative to BaCl2-exposed controls. Collectively, these results highlight a differential, organ-specific response to BaCl2-induced oxidative stress and the therapeutic potential of SCC and ASC. SCC emerged as a safer and more effective agent, particularly in hepatic protection, while both antioxidants demonstrated neuroprotective effects when used individually or in combination. Full article
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22 pages, 1563 KiB  
Review
Managing Spinal Muscular Atrophy: A Look at the Biology and Treatment Strategies
by Arianna Vezzoli, Daniele Bottai and Raffaella Adami
Biology 2025, 14(8), 977; https://doi.org/10.3390/biology14080977 (registering DOI) - 1 Aug 2025
Abstract
Since its discovery in the late 19th century, spinal muscular atrophy (SMA) has had a significant medical and societal impact, primarily affecting newborns, toddlers, and young adults. While new pharmaceutical strategies are effective in treating SMA in a particular subset of patients, continued [...] Read more.
Since its discovery in the late 19th century, spinal muscular atrophy (SMA) has had a significant medical and societal impact, primarily affecting newborns, toddlers, and young adults. While new pharmaceutical strategies are effective in treating SMA in a particular subset of patients, continued research is necessary to improve the well-being of patients. Treatments are needed for those who do not respond to newly approved drugs and older patients with significantly compromised neuron systems. After summarizing SMA genotypes, phenotypes, and approved pharmacological treatments, this review presents ongoing trials for approved and new molecules, new formulations, and administration methods. Based on the work of our lab, we also discuss nutritional interventions that aim to counteract the oxidative stress present in SMA cells. Finally, we assess rehabilitative interventions, focusing on psychological approaches. Full article
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18 pages, 634 KiB  
Review
Cardiorenal Syndrome: Molecular Pathways Linking Cardiovascular Dysfunction and Chronic Kidney Disease Progression
by Fabian Vasquez, Caterina Tiscornia, Enrique Lorca-Ponce, Valeria Aicardi and Sofia Vasquez
Int. J. Mol. Sci. 2025, 26(15), 7440; https://doi.org/10.3390/ijms26157440 (registering DOI) - 1 Aug 2025
Abstract
Cardiorenal syndrome (CRS) is a multifactorial clinical condition characterized by the bidirectional deterioration of cardiac and renal function, driven by mechanisms such as renin–angiotensin–aldosterone system (RAAS) overactivation, systemic inflammation, oxidative stress, endothelial dysfunction, and fibrosis. The aim of this narrative review is to [...] Read more.
Cardiorenal syndrome (CRS) is a multifactorial clinical condition characterized by the bidirectional deterioration of cardiac and renal function, driven by mechanisms such as renin–angiotensin–aldosterone system (RAAS) overactivation, systemic inflammation, oxidative stress, endothelial dysfunction, and fibrosis. The aim of this narrative review is to explore the key molecular pathways involved in CRS and to highlight emerging therapeutic approaches, with a special emphasis on nutritional interventions. We examined recent evidence on the contribution of mitochondrial dysfunction, uremic toxins, and immune activation to CRS progression and assessed the role of dietary and micronutrient factors. Results indicate that a high dietary intake of sodium, phosphorus additives, and processed foods is associated with volume overload, vascular damage, and inflammation, whereas deficiencies in potassium, magnesium, and vitamin D correlate with worse clinical outcomes. Anti-inflammatory and antioxidant bioactives, such as omega-3 PUFAs, curcumin, and anthocyanins from maqui, demonstrate potential to modulate key CRS mechanisms, including the nuclear factor kappa B (NF-κB) pathway and the NLRP3 inflammasome. Gene therapy approaches targeting endothelial nitric oxide synthase (eNOS) and transforming growth factor-beta (TGF-β) signaling are also discussed. An integrative approach combining pharmacological RAAS modulation with personalized medical nutrition therapy and anti-inflammatory nutrients may offer a promising strategy to prevent or delay CRS progression and improve patient outcomes. Full article
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20 pages, 3586 KiB  
Article
Enhanced NiFe2O4 Catalyst Performance and Stability in Anion Exchange Membrane Water Electrolysis: Influence of Iron Content and Membrane Selection
by Khaja Wahab Ahmed, Aidan Dobson, Saeed Habibpour and Michael Fowler
Molecules 2025, 30(15), 3228; https://doi.org/10.3390/molecules30153228 (registering DOI) - 1 Aug 2025
Abstract
Anion exchange membrane (AEM) water electrolysis is a potentially inexpensive and efficient source of hydrogen production as it uses effective low-cost catalysts. The catalytic activity and performance of nickel iron oxide (NiFeOx) catalysts for hydrogen production in AEM water electrolyzers were [...] Read more.
Anion exchange membrane (AEM) water electrolysis is a potentially inexpensive and efficient source of hydrogen production as it uses effective low-cost catalysts. The catalytic activity and performance of nickel iron oxide (NiFeOx) catalysts for hydrogen production in AEM water electrolyzers were investigated. The NiFeOx catalysts were synthesized with various iron content weight percentages, and at the stoichiometric ratio for nickel ferrite (NiFe2O4). The catalytic activity of NiFeOx catalyst was evaluated by linear sweep voltammetry (LSV) and chronoamperometry for the oxygen evolution reaction (OER). NiFe2O4 showed the highest activity for the OER in a three-electrode system, with 320 mA cm−2 at 2 V in 1 M KOH solution. NiFe2O4 displayed strong stability over a 600 h period at 50 mA cm−2 in a three-electrode setup, with a degradation rate of 15 μV/h. In single-cell electrolysis using a X-37 T membrane, at 2.2 V in 1 M KOH, the NiFe2O4 catalyst had the highest activity of 1100 mA cm−2 at 45 °C, which increased with the temperature to 1503 mA cm−2 at 55 °C. The performance of various membranes was examined, and the highest performance of the tested membranes was determined to be that of the Fumatech FAA-3-50 and FAS-50 membranes, implying that membrane performance is strongly correlated with membrane conductivity. The obtained Nyquist plots and equivalent circuit analysis were used to determine cell resistances. It was found that ohmic resistance decreases with an increase in temperature from 45 °C to 55 °C, implying the positive effect of temperature on AEM electrolysis. The FAA-3-50 and FAS-50 membranes were determined to have lower activation and ohmic resistances, indicative of higher conductivity and faster membrane charge transfer. NiFe2O4 in an AEM water electrolyzer displayed strong stability, with a voltage degradation rate of 0.833 mV/h over the 12 h durability test. Full article
(This article belongs to the Special Issue Water Electrolysis)
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14 pages, 6773 KiB  
Article
MoTiCo Conversion Coating on 7075 Aluminium Alloy Surface: Preparation, Corrosion Resistance Analysis, and Application in Outdoor Sports Equipment Trekking Poles
by Yiqun Wang, Feng Huang and Xuzheng Qian
Metals 2025, 15(8), 864; https://doi.org/10.3390/met15080864 (registering DOI) - 1 Aug 2025
Abstract
The problem of protecting 7075 Al alloy trekking poles from corrosion in complex outdoor environments was addressed using a composite conversion coating system. This system comprised Na2MoO4, NaF, CoSO4·7H2O, ethylenediaminetetraacetic acid-2Na, and H2(TiF [...] Read more.
The problem of protecting 7075 Al alloy trekking poles from corrosion in complex outdoor environments was addressed using a composite conversion coating system. This system comprised Na2MoO4, NaF, CoSO4·7H2O, ethylenediaminetetraacetic acid-2Na, and H2(TiF6). The influences of this system on the properties of the coating layer were systematically studied by adjusting the pH of the coating solution. The conversion temperature and pH were the pivotal parameters influencing the formation of the conversion coating. The pH substantially influenced the compactness of the coating layer, acting as a regulatory agent of the coating kinetics. When the conversion temperature and pH were set to 40 °C and 3.8, respectively, the prepared coating layer displayed optimal performance in terms of compactness and protective properties. Therefore, this parameter combination favours the synthesis of high-performance conversion coatings. Microscopy confirmed the formation of a continuous, dense composite oxide film structure under these conditions, effectively blocking erosion in corrosive media. Furthermore, the optimised process led to substantial enhancements in the environmental adaptabilities and service lives of the components of trekking poles, thus establishing a theoretical foundation and technical reference for use in the surface protection of outdoor equipment. Full article
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21 pages, 2582 KiB  
Article
Photolysis, Photocatalysis, and Sorption of Caffeine in Aqueous Media in the Presence of Chitosan Membrane and Chitosan/TiO2 Composite Membrane
by Juliana Prando, Ingrid Luíza Reinehr, Luiz Jardel Visioli, Alexandre Tadeu Paulino and Heveline Enzweiler
Processes 2025, 13(8), 2439; https://doi.org/10.3390/pr13082439 (registering DOI) - 1 Aug 2025
Abstract
Sorption and advanced oxidative processes (AOPs) are potential strategies for the removal of organic compounds, such as caffeine, from aqueous media. Such strategies tend to be more promising when combined with biopolymeric membranes as sorbents and photocatalyst supports. Therefore, the aim of the [...] Read more.
Sorption and advanced oxidative processes (AOPs) are potential strategies for the removal of organic compounds, such as caffeine, from aqueous media. Such strategies tend to be more promising when combined with biopolymeric membranes as sorbents and photocatalyst supports. Therefore, the aim of the present study was to investigate sorption and AOP parameters in the performance of chitosan membranes and chitosan/TiO2 composite membranes in individual and hybrid systems involving the photolysis, photocatalysis, and sorption of caffeine. Caffeine degradation by photolysis was 19.51 ± 1.14, 28.61 ± 0.05, and 30.64 ± 6.32%, whereas caffeine degradation by photocatalysis with catalytic membrane was 18.33 ± 2.20, 20.83 ± 1.49, and 31.41 ± 3.08% at pH 6, 7, and 8, respectively. In contrast, photocatalysis with the dispersed catalyst achieved degradation of 93.56 ± 2.12, 36.42 ± 2.59, and 31.41 ± 1.07% at pH 6, 7, and 8, respectively. These results indicate that ions present in the buffer solutions affect the net electrical charge on the surface of the composite biomaterial with the change in pH variation, occupying active sorption sites in the structure of the biomaterial, which was characterized by Fourier transform infrared spectrometry, thermogravimetric analysis, differential scanning thermogravimetry, and X-ray diffraction. Thus, it is verified that in a combined process of caffeine removal under UV irradiation and use of chitosan/TiO2 composite membranes in phosphate-buffered medium, the photolysis mechanism is predominant, with little or no contribution from sorption, and that the TiO2 catalyst promotes a significant reduction in the percentage of pollutant in the medium only when used dispersed and at low pH. Full article
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30 pages, 703 KiB  
Review
Fungal Lytic Polysaccharide Monooxygenases (LPMOs): Functional Adaptation and Biotechnological Perspectives
by Alex Graça Contato and Carlos Adam Conte-Junior
Eng 2025, 6(8), 177; https://doi.org/10.3390/eng6080177 - 1 Aug 2025
Abstract
Fungal lytic polysaccharide monooxygenases (LPMOs) have revolutionized the field of biomass degradation by introducing an oxidative mechanism that complements traditional hydrolytic enzymes. These copper-dependent enzymes catalyze the cleavage of glycosidic bonds in recalcitrant polysaccharides such as cellulose, hemicellulose, and chitin, through the activation [...] Read more.
Fungal lytic polysaccharide monooxygenases (LPMOs) have revolutionized the field of biomass degradation by introducing an oxidative mechanism that complements traditional hydrolytic enzymes. These copper-dependent enzymes catalyze the cleavage of glycosidic bonds in recalcitrant polysaccharides such as cellulose, hemicellulose, and chitin, through the activation of molecular oxygen (O2) or hydrogen peroxide (H2O2). Their catalytic versatility is intricately modulated by structural features, including the histidine brace active site, surface-binding loops, and, in some cases, appended carbohydrate-binding modules (CBMs). The oxidation pattern, whether at the C1, C4, or both positions, is dictated by subtle variations in loop architecture, amino acid microenvironments, and substrate interactions. LPMOs are embedded in a highly synergistic fungal enzymatic system, working alongside cellulases, hemicellulases, lignin-modifying enzymes, and oxidoreductases to enable efficient lignocellulose decomposition. Industrial applications of fungal LPMOs are rapidly expanding, with key roles in second-generation biofuels, biorefineries, textile processing, food and feed industries, and the development of sustainable biomaterials. Recent advances in genome mining, protein engineering, and heterologous expression are accelerating the discovery of novel LPMOs with improved functionalities. Understanding the balance between O2- and H2O2-driven mechanisms remains critical for optimizing their catalytic efficiency while mitigating oxidative inactivation. As the demand for sustainable biotechnological solutions grows, this narrative review highlights how fungal LPMOs function as indispensable biocatalysts for the future of the Circular Bioeconomy and green industrial processes. Full article
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21 pages, 3814 KiB  
Article
Features of the Structure of Layered Epoxy Composite Coatings Formed on a Metal-Ceramic-Coated Aluminum Base
by Volodymyr Korzhyk, Volodymyr Kopei, Petro Stukhliak, Olena Berdnikova, Olga Kushnarova, Oleg Kolisnichenko, Oleg Totosko, Danylo Stukhliak and Liubomyr Ropyak
Materials 2025, 18(15), 3620; https://doi.org/10.3390/ma18153620 (registering DOI) - 1 Aug 2025
Abstract
Difficult, extreme operating conditions of parabolic antennas under precipitation and sub-zero temperatures require the creation of effective heating systems. The purpose of the research is to develop a multilayer coating containing two metal-ceramic layers, epoxy composite layers, carbon fabric, and an outer layer [...] Read more.
Difficult, extreme operating conditions of parabolic antennas under precipitation and sub-zero temperatures require the creation of effective heating systems. The purpose of the research is to develop a multilayer coating containing two metal-ceramic layers, epoxy composite layers, carbon fabric, and an outer layer of basalt fabric, which allows for effective heating of the antenna, and to study the properties of this coating. The multilayer coating was formed on an aluminum base that was subjected to abrasive jet processing. The first and second metal-ceramic layers, Al2O3 + 5% Al, which were applied by high-speed multi-chamber cumulative detonation spraying (CDS), respectively, provide maximum adhesion strength to the aluminum base and high adhesion strength to the third layer of the epoxy composite containing Al2O3. On this not-yet-polymerized layer of epoxy composite containing Al2O3, a layer of carbon fabric (impregnated with epoxy resin) was formed, which serves as a resistive heating element. On top of this carbon fabric, a layer of epoxy composite containing Cr2O3 and SiO2 was applied. Next, basalt fabric was applied to this still-not-yet-polymerized layer. Then, the resulting layered coating was compacted and dried. To study this multilayer coating, X-ray analysis, light and raster scanning microscopy, and transmission electron microscopy were used. The thickness of the coating layers and microhardness were measured on transverse microsections. The adhesion strength of the metal-ceramic coating layers to the aluminum base was determined by both bending testing and peeling using the adhesive method. It was established that CDS provides the formation of metal-ceramic layers with a maximum fraction of lamellae and a microhardness of 7900–10,520 MPa. In these metal-ceramic layers, a dispersed subgrain structure, a uniform distribution of nanoparticles, and a gradient-free level of dislocation density are observed. Such a structure prevents the formation of local concentrators of internal stresses, thereby increasing the level of dispersion and substructural strengthening of the metal-ceramic layers’ material. The formation of materials with a nanostructure increases their strength and crack resistance. The effectiveness of using aluminum, chromium, and silicon oxides as nanofillers in epoxy composite layers was demonstrated. The presence of structures near the surface of these nanofillers, which differ from the properties of the epoxy matrix in the coating, was established. Such zones, specifically the outer surface layers (OSL), significantly affect the properties of the epoxy composite. The results of industrial tests showed the high performance of the multilayer coating during antenna heating. Full article
(This article belongs to the Section Metals and Alloys)
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