Susceptibility To Oxidation Research Articles

Perfect Ultraviolet Absorbers via Disordered Polarizonic Metasurfaces for Multiband Camouflage and Stealth Technologies

AbstractAchieving multiband camouflage through the integration of ultraviolet (UV) absorption, visible light camouflage, and infrared signature modulation has long posed a challenge in material science. Leveraging the polarizonic concept, the study demonstrates, for the first time, the broadband camouflage system that adheres to the golden rule by achieving near‐perfect UV absorption (99.96%) across the UV‐A, UV‐B, and UV‐C ranges. This system is also visibly colored to blend with its environment and leaves no thermal signature in the IR. Traditionally, earth‐abundant metals, such as iron, are not considered viable for plasmonic color applications due to their high optical losses and oxidation susceptibility that degrade their optical properties. However, contrary to conventional assumptions, the study introduces a sustainable color palette derived from transparent and grey earth‐abundant materials, offering novel approaches to color, stealth, and energy‐harvesting metasurface‐driven technologies. The simple, cost‐effective, and environmentally friendly co‐sputtering fabrication method highlights the impact of the polarizonic concept and its novel dipolar image interference phenomena on flexible substrates therefore passivating the way for scalable and sustainable solutions in next‐generation camouflage systems with potential applications in UV‐protective coatings, photolithography, and anti‐counterfeiting technologies.

Exploring the Correlation Between Salt Tolerance and Seed Nutritional Value of Different Quinoa Genotypes Grown Under Saharan Climatic Conditions.

Quinoa is an annual pseudocereal highly adapted to extreme environments and has become, at this point in time, an extremely popular food due to its exceptional and high nutritional quality. This study aims to investigate the association of quinoa salt tolerance at an early developmental stage with its grain nutritional value under the effect of severe climatic hurdles. The current findings revealed a significant variability between genotypes in salt response attributes at the first development stage, where genotypes Amarilla Sacaca (thereafter, A. Sacaca) and QQ57 exhibited high salt tolerance thresholds with a low salt sensitivity index (SI), and a high capacity for Na+ sequestration into vacuoles. A significant positive association was detected between salt tolerance degree and yield parameters, saponins (SAPs), and minerals contents, where genotype A. Sacaca exhibited the highest SAP content with 3.84 mg.g-1 and the highest amounts of K, Ca, P, and Fe. The analysis of fatty acid composition demonstrated a high significant negative correlation between crude fat content and salt SI, and between yield parameters. Despite its low harvest index (HI) and low seed oil content, the salt-tolerant genotype A. Sacaca showed a high nutritional quality for seed oil according to its lowest ω6/ω3 ratio (5.6/1) and lowest level of atherogenicity index (AI). The genotype 115R, defined as the most sensitive to salt stress, exhibited a high seed oil quality due to its low lipid peroxidation susceptibility as reflected by its oxidative susceptibility and peroxidizability indexes. The significance of this study includes the identification of valuable quinoa genotypes showing high efficiency in growth and yield under severe stress accompanied by a high nutritional value satisfying the market requirements for healthy, nutritious, and safe food products.

Origin of Oxidation Variations in Ambient-Stable β-InSe.

Understanding and controlling the oxidation of layered materials remain critical issues in the final stages of their practical application in devices. Layered materials achieve a band gap by removing inversion symmetry. However, the oxidation process becomes complex, and the oxidation of these materials is not yet fully understood. As a representative example, InSe has attracted considerable attention due to its high charge mobility and Si-like band gap. However, conflicting observations such as oxidation by Se and In have been reported, including contrasting assessments of the oxidation susceptibility. In this study, we report in situ spectroscopy results detailing the origins of various oxidation pathways. We observed that at low defect densities the reduced reaction barrier of InSe due to Se vacancies leads to oxygen adsorption, while as defects increase, the lower electronegativity of In rises as a new pathway for oxidation. At low defect density, the bulk layer was more energetically favored for oxygen adsorption, allowing oxygen to diffuse to a depth sufficient to form pseudoheterojunctions and making the surface layer seemingly resistant to oxidation. Our results provide an answer to why the resulting diversity of optical responses is expected to increase as well as strategies to achieve gas stability.

A novel mutation in HNF1B promotes ferroptosis-mediated renal mesangial cells fibrosis

Maturity onset diabetes of the young type 5(MODY5) is typically attributed to mutations in the HNF1B gene, which encodes transcription factors that play a significant role in kidney development and function maintenance. In this study, we identified a novel HNF1B gene mutation (c.445C > A) in a young male MODY5 patient exhibiting elevated serum creatinine levels and albuminuria. Through transfection of wild type and mutant HNF1B plasmids into mouse mesangial cells (MMCs), we investigated the impact on molecular indicators related to proliferation, fibrosis and oxidative stress. The results revealed that the HNF1B novel mutation promoted the expression of fibronectin, type 1 collagen, and CyclinD1, as well as increasing cellular oxidative stress and susceptibility to ferroptosis in MMCs. Our findings established a novel association between HNF1B mutant diseases and mesangial cell proliferation and fibrosis, suggesting that mutations of HNF1B may contribute to the progression of renal function in MODY5 patients. Additionally, our results implicate potential therapeutic targets for restraining fibrosis.

Alginate's ability to prevent metabolic illnesses, the degradation of the gut's protective layer, and alginate-based encapsulation methods.

The gut serves as the body's main immunological and digestive system. Furthermore, host immunity is mostly managed there. Nutrients are further broken down and absorbed here. Numerous research investigations have shown evidence that inflammation, oxidative stress, impairment of the intestinal barrier, and imbalance in the gut microbiota can all contribute to a variety of intestinal illnesses and other issues, underscoring the growing significance of intestinal health concerns. Because of their high biological activity and lack of negative side effects, the organic food-derived chemicals known as brown algal polysaccharides-mainly fucoidan, laminaran, and alginate-have attracted a lot of attention from academics. Because of its many benefits, sodium alginate is one of the biopolymers that has garnered the greatest attention, research, and application. Carotenoids, which are found in our food, have several positive health effects. Their low solubility in water, oxidation susceptibility, chemical instability, accessibility, and restricted solubility in water, however, restrict their use in food and medicine. In this review and in overcoming these constraints, encapsulation might be helpful. Furthermore, the primary goal of our study is to provide a fresh perspective into the control and avoidance of intestinal diseases. It provides more potent alternatives to this system, clarifies the function of alginates in enhancing the encapsulation of carotenoids, and functions as a model for the synthesis of the intestinal protective agent fucoidan.

Optimization of Non-Alloyed Backside Ohmic Contacts to N-Face GaN for Fully Vertical GaN-on-Silicon-Based Power Devices.

In the framework of fully vertical GaN-on-Silicon device technology development, we report on the optimization of non-alloyed ohmic contacts on the N-polar n+-doped GaN face backside layer. This evaluation is made possible by using patterned TLMs (Transmission Line Model) through direct laser writing lithography after locally removing the substrate and buffer layers in order to access the n+-doped backside layer. As deposited non-alloyed metal stack on top of N-polar orientation GaN layer after buffer layers removal results in poor ohmic contact quality. To significantly reduce the related specific contact resistance, an HCl treatment is applied prior to metallization under various time and temperature conditions. A 3 min HCl treatment at 70 °C is found to be the optimum condition to achieve thermally stable high ohmic contact quality. To further understand the impact of the wet treatment, SEM (Scanning Electron Microscopy) and XPS (X-ray Photoelectron Spectroscopy) analyses were performed. XPS revealed a decrease in Ga-O concentration after applying the treatment, reflecting the higher oxidation susceptibility of the N-polar face compared to the Ga-polar face, which was used as a reference. SEM images of the treated samples show the formation of pyramids on the N-face after HCl treatment, suggesting specific wet etching planes of the GaN crystal from the N-face. The size of the pyramids is time-dependent; thus, increasing the treatment duration results in larger pyramids, which explains the degradation of ohmic contact quality after prolonged high-temperature HCl treatment.

Enhanced oxidation resistance and electrochemical performance of PEMFC gas diffusion layer through [EMIM][TFSI] ionic liquid coating

The performance and durability of Proton Exchange Membrane Fuel Cells (PEMFCs) are critically hindered by the oxidation susceptibility of graphite felt gas diffusion layers (GDLs). This study addresses this challenge by employing a protective coating of 1-Ethyl-3-methylimidazolium Bis(trifluoromethyl sulfonyl)imide ([EMIM][TFSI]) on the GDL through a dip-coating method, followed by thermal curing to ensure uniform distribution and strong adherence. Comprehensive characterization, including Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and Fourier-Transform Infrared Spectroscopy (FTIR), confirmed the homogeneous coating, adhesion, and maintained porosity and gas diffusion properties of the GDL. The coated GDL exhibited a substantial increase in oxidation resistance, resulting in higher hydrophobicity with a contact angle of approximately 131°, compared to 96° for the uncoated GDL. Electrochemical analyses revealed that the [EMIM][TFSI]-coated GDL achieved a current density of 27 mA cm−2 at 0.925 V, surpassing the 19 mA cm−2 of the uncoated GDL at 0.91 V during cyclic voltammetry (CV) analysis. This study is limited by the short-term stability tests and the specific environmental conditions under which the experiments were conducted. Future work will focus on optimizing the coating process for varied environmental conditions and exploring the scalability of this technique for practical applications.

Inter-tissue differences in oxidative stress susceptibility reveal a less stable endothelial barrier in the brain than in the retina

Oxidative stress can impair the endothelial barrier and thereby enable autoantibody migration in Neuromyelitis optica spectrum disorder (NMOSD). Tissue-specific vulnerability to autoantibody-mediated damage could be explained by a differential, tissue-dependent endothelial susceptibility to oxidative stress. In this study, we aim to investigate the barrier integrity and complement profiles of brain and retinal endothelial cells under oxygen-induced oxidative stress to address the question of whether the pathomechanism of NMOSD preferentially affects the brain or the retina.Primary human brain microvascular endothelial cells (HBMEC) and primary human retinal endothelial cells (HREC) were cultivated at different cell densities (2.5*104 to 2*105 cells/cm2) for real-time cell analysis. Both cell types were exposed to 100, 500 and 2500 μM H2O2. Immunostaining (CD31, VE-cadherin, ZO-1) and Western blot, as well as complement protein secretion using multiplex ELISA were performed.HBMEC and HREC cell growth phases were cell type-specific. While HBMEC cell growth could be categorized into an initial peak, proliferation phase, plateau phase, and barrier breakdown phase, HREC showed no proliferation phase, but entered the plateau phase immediately after an initial peak. The plateau phase was 7 h shorter in HREC. Both cell types displayed a short-term, dose-dependent adaptive response to H2O2. Remarkably, at 100 μM H2O2, the transcellular resistance of HBMEC exceeded that of untreated cells. 500 μM H2O2 exerted a more disruptive effect on the HBMEC transcellular resistance than on HREC. Both cell types secreted complement factors H (FH) and I (FI), with FH secretion remaining stable after 2 h, but FI secretion decreasing at higher H2O2 concentrations.The observed differences in resistance to oxidative stress between primary brain and retinal endothelial cells may have implications for further studies of NMOSD and other autoimmune diseases affecting the eye and brain. These findings may open novel perspectives for the understanding and treatment of such diseases.

Oil/water (O/W) nanoemulsions developed from essential oil extracted from wildly growing Calotropis gigantea (Linn.) Aiton F.: synthesis, characterization, stability and evaluation of anti-cancerous, anti-oxidant, anti-inflammatory and anti-diabetic activities

Calotropis gigantea essential oil is utilized in outmoded medicine, therapeutics, and the cosmetic industries. However, the extreme volatility, oxidation susceptibility, and instability of this oil restricts its application. Thus, encapsulation is a more effective method of shielding this oil from unfavorable circumstances. The creation of oil/water (O/W) nanoemulsions based on Calotropis gigantea essential oil (CEO), known as CNE (Calotropis gigantea essential oil nanoemulsions), and an assessment of its biological potential were the goals of this work. UV, fluorescence, and FT-IR methods were used for physiological characterization. Biological activities, including anti-inflammatory, anti-diabetic, and anti-cancer effects. Studies on the pharmacokinetics of CNE were conducted. CNEs encapsulation efficiency was found to be 92%. The CNE nanoemulsions had a spherical shape with polydispersity index of 0.531, size of 200 nm, and a zeta potential of −35.9 mV. Even after being stored at various temperatures for 50 days, CNE nanoemulsions remained stable. Numerous tests were used to determine the antioxidant capacity of CNE, and the following IC50 values (µl/mL) were found: iron chelating assay: 18, hydroxyl radical scavenging: 37, and nitric oxide radical scavenging activity: 58. The percentage of HeLa cells that remained viable after being treated with CNE was 41% at a higher dose of 1 µl. CNE inhibited α-amylase in a dose-dependent manner, with 72% inhibition at its higher dose of 250 µL. Research on the kinetics of drugs showed that nanoemulsions showed Higuchi pattern. This research showed potential use of Calotropis gigantea oil-based nanoemulsions in the food, cosmetic, and pharmaceutical industries.

Oxidative stability and nutritional quality of stored Linum usitatissmium L. and Argania spinosa L., oil blends: Chemical compositions, properties and nutritional value

Identification of the chemical compositions of fatty acids and tocopherols shows the high content of linum usitatissimum oil (LO) by linolenic acid 55.3735% and γ-tocopherol 570.927 mg/kg, while argania spinosa oil (AO) is known by the dominance of oleic acid 47.77% followed by linoleic acid 31.08% as well as tocopherols by γ-tocopherols 687.485 mg/kg and δ-tocopherols 51.035 mg/kg. This difference in compositions enables us to enrich the low-stability oil and monitor its behavior during storage at a specific time and under specific conditions. In this study, pure linum usitatissimum and argania spinosa oils extracted by cold pressing as well as their formulations at proportions of (LO: AO) respectively: (80:20; 60:40, 50:50; 40:60; 20: 80) were oxidized at 60 °C for 28 days of storage, during which time the pure oils and blends were assessed for oxidative stability by studying their different fatty acid and tocopherol profiles and physicochemical characteristics such as acidity, peroxide value and chlorophyll and carotenoid pigments, as well as nutritional indexes such as the atherogenic index (AI), the thrombogenic index (TI), and the hypocholesterolemic: hypercholesterolemic ratio (HH), ω3:ω6 ratio, also the oxidative susceptibility (OS), and oxidazability value (Cox), and total phenolic compounds (TPC).

Phytochemical characterization and nutritional value of vegetable oils from ripe berries of Schinus terebinthifolia raddi and Schinus molle L., through extraction methods

The aims of this study are the phytochemical exploration and food valorization of Schinus molle L. (S. molle) and Schinus terebinthifolia Raddi (S. terebinthifolia) from the Rabat, Morocco. Gas chromatography (GC) and high-performance liquid chromatography (HPLC) were used to analyze the chemical composition of the oils extracted from both species by soxhlet and maceration. Moreover, physicochemical characteristics such as lipid quality indexes such as thrombogenic index (TI), atherogenic index (AI), oxidation susceptibility (OS), and calculated oxidability (Cox) were determined. These characteristics included percentage acidity, peroxide, saponification, iodine, specific extinction values, chlorophyll, and carotenoid pigments. As results, the oil yields varied from 7% (S. molle) to 13% (S. terebinthifolia). In addition, unsaturated fatty acids represented the major fraction for S. terebinthifolia (79%) and S. molle (81%). However, S. terebinthifolia contains more saturated fatty acids (20%) than S. molle (16%) with a predominance of linoleic acid (59.53% and 55%, C18,2), oleic acid (19.29% and 21.69%, C18,1), and palmitic acid (12.56% and 15.48%, C16,0) in S. molle and S. terebinthifolia, respectively. Moreover, the main sterols are β-sitosterol followed by campesterol and then Δ-5-avenasterol, while β-sitosterol varies according to the species and the extraction method. Results revealed also that campesterol is influenced by the extraction results in a content of 179.66 mg/kg (soxhlet) and 63.48 mg/kg (maceration) for S. molle, while S. terebinthifolia yeilds concentrations of 170 mg/kg and 138 mg/kg, then Δ-5-avenasterol, which present with (117 mg/kg and 136 mg/kg), (34 mg/kg and 80 mg/kg) of the total amount of sterols for the oils extracted by soxhlet and maceration, respectively. In addition, there are favorable physicochemical properties for all oils, such as chlorophylls (0.4 to 0.8 mg/kg) and carotenoids (0.7 to 2 mg/kg). However, further investigations are needed to determine other chemical compounds of both extracts as well as to evaluate their biological and health benefits.

Revolutionizing Cardiovascular Health with Nano Encapsulated Omega-3 Fatty Acids: A Nano-Solution Approach.

Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) offer diverse health benefits, such as supporting cardiovascular health, improving cognitive function, promoting joint and musculoskeletal health, and contributing to healthy aging. Despite their advantages, challenges like oxidation susceptibility, low bioavailability, and potential adverse effects at high doses persist. Nanoparticle encapsulation emerges as a promising avenue to address these limitations while preserving stability, enhanced bioavailability, and controlled release. This comprehensive review explores the therapeutic roles of omega-3 fatty acids, critically appraising their shortcomings and delving into modern encapsulation strategies. Furthermore, it explores the potential advantages of metal-organic framework nanoparticles (MOF NPs) compared to other commonly utilized nanoparticles in improving the therapeutic effectiveness of omega-3 fatty acids within drug delivery systems (DDSs). Additionally, it outlines future research directions to fully exploit the therapeutic benefits of these encapsulated omega-3 formulations for cardiovascular disease treatment.

Development of a high throughput oxidation profiling strategy for monoclonal antibody products

Oxidation is one of the most common degradation pathways of biopharmaceutics, potentially leading to altered product stability, pharmacokinetics, reduced biological activity and/or an increased immunogenicity. However, it is often insufficiently assessed in early development stages, leaving potential molecule liabilities undiscovered. Aim of the present work was the development of a high throughput oxidation profiling strategy, applicable throughout various stages of biopharmaceutical development. The study demonstrates that the combination of multiple stress assays, including peroxide-based, visible light, and metal-catalyzed oxidation (MCO), enables a comprehensive understanding of a mAb's oxidation susceptibility. The most effective parameters to evaluate oxidation in a high-throughput screening workflow are aggregation, tryptophan oxidation and changes in the hydrophobicity profile of the Fc and Fab subunit measured via Size Exclusion Chromatography, Intrinsic Tryptophan Fluorescence Emission spectroscopy and Reversed-Phase Chromatography subunit analysis, respectively. This oxidation profiling approach is valuable tool to systematically characterize the oxidation susceptibility under relevant conditions, time effective and with minimal sample consumption.

Dual preservative effects of SnO2-chitosan on Cu1+-doped boehmite composites for stable CO adsorption properties

In the realm of environment and energy sectors, the strategic designing of adsorbents utilizing active Cu1+-based composite materials stands as a pivotal initiative for effective CO removal. However, the commercial viability of these composites was hindered by oxidation tendency of active Cu1+ species during ambient storage, leading to a gradual decline in activity. Concurrently, selectivity constraints pose challenges to the practical utility of Cu1+-based CO adsorbents. In this study, a synergistic dual inorganic–organic stabilization system was introduced to address inherent stabilization and selectivity constraints. The SnO2-chitosan coupled stabilizer was employed to exploit dual chemical stabilization interactions which involved synergistic redox behavior within active Cu2O-SnO2 interface stemming from strong Sn-O interaction in contrast to that of Cu–O and coordinated chelation facilitated by the unsaturated nitrogen sourced from chitosan in conjunction with Cu1+ species. These mechanisms effectively preserved the oxidative susceptibility of active Cu1+ ions and impeded their gradual deactivation. The stable structural formation and complexation effects were validated through TEM, XPS, and in-situ FTIR analyses. Remarkably, incorporating a small quantity of SnO2 with organic chitosan stabilizer within the composite maintained ∼ 99 % stability of the initial adsorption uptake (∼24 cm3/g) even after 30-day storage under ambient conditions, surpassing the adsorption stability performance of the adsorption composite with only organic chitosan stabilizer. Furthermore, inclusion of SnO2 attenuated the surface basicity stemming from nitrogen-doping which favors the CO2 adsorption over CO, and due to the enhanced surface acidity as confirmed through NH3-TPD and in-situ FTIR analyses, a higher CO selectivity of 7.1 over CO2 was achieved. In conclusion, this study highlighted the advantageous potential of an inorganic–organic stabilizing system, specifically SnO2-chitosan combination, offering a viable approach to address stability and selectivity challenges associated with the Cu1+-based CO adsorption, presenting a viable pathway for the development of practical CO adsorbents.

Organic-inorganic hybrid ZIF-8/MXene/cellulose-based textiles with improved antibacterial and electromagnetic interference shielding performance

Despite the tremendous efforts on developing antibacterial wearable textile materials containing Ti3C2Tx MXene, the singular antimicrobial mechanism, poor antibacterial durability, and oxidation susceptibility of MXene limits their applications. In this context, flexible multifunctional cellulosic textiles were prepared via layer-by-layer assembly of MXene and the in-situ synthesis of zeolitic imidazolate framework-8 (ZIF-8). Specifically, the introduction of highly conductive MXene enhanced the interface interactions between the ZIF-8 layer and cellulose fibers, endowing the green-based materials with outstanding synergistic photothermal/photodynamic therapy (PTT/PDT) activity and adjustable electromagnetic interference (EMI) shielding performance. In-situ polymerization formed a MXene/ZIF-8 bilayer structure, promoting the generation of reactive oxygen species (ROS) while protecting MXene from oxidation. The as-prepared smart textile exhibited excellent bactericidal efficacy of >99.99 % against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) after 5 min of NIR (300 mW cm−2) irradiation which is below the maximum permissible exposure (MPE) limit. The sustained released Zn2+ from the ZIF-8 layer achieved a bactericidal efficiency of over 99.99 % within 48 h without NIR light. Furthermore, this smart textile also demonstrated remarkable EMI shielding efficiency (47.7 dB). Clearly, this study provides an elaborate strategy for designing and constructing multifunctional cellulose-based materials for a variety of applications.

Review on " Current Advancements in Niosomes"

Non-ionic surfactants self-assemble into vesicular systems called niosomes in aqueous solutions with the help of physical agitation or high temperatures. Nonionic surfactants, as opposed to phospholipids, are used as the constituents of the membrane, which circumvents many of the drawbacks of liposomes, including inadequate chemical stability, phospholipids' oxidation susceptibility, high production costs, and the need for particular handling and storage conditions. Because of their unique shape, which consists of an inner aqueous compartment encircled by a hydrophobic membrane, hydrophilic and hydrophobic drug molecules can be incorporated and delivered, respectively. In addition, niosomes are biocompatible, biodegradable, nontoxic, and osmotically active. Niosomes were first proposed as a workable solution for the cosmetics industry in the 1970s, and in the 1980s, L'Oreal filed for patents on the ingredient. Their advantageous qualities establish theIn recent times, there has been a dramatic shift in the treatment of infectious diseases and vaccination strategies. Along with the creation of many biologicals targeted at specific diseases, biotechnology and genetic engineering have also brought attention to the effective delivery of these biologicals. Niosomes, which are vesicles made of non-ionic surfactants and less expensive than liposomes, are biodegradable, harmless, stable, and less expensive than liposomes. This article summarizes various studies that have examined the effectiveness of using niosomes for various diseases.

Abstract 1562: HMGA2 regulates GPX4 expression and oxidative stress

Abstract Prostate cancer (PCa) is a leading cause of mortality, primarily due to its ability to metastasize to the bone. The High Mobility Group AT-Hook 2 (HMGA2) plays a crucial role in regulating gene expression and has been implicated in tumorigenesis and the metastatic process. Our recent study revealed that overexpression of the wild-type/full-length HMGA2 isoform in PCa cells promotes cancer progression by triggering epithelial mesenchymal transition (EMT), whereas truncated HMGA2 isoform promotes progression through oxidative stress signaling. We hypothesize that HMGA2 regulates GPX4 expression and oxidative stress in PCa. We studied the expression of HMGA2 and GPX4 in various PCa cell lines including enzalutamide resistant cell line (C4-2B MDVR), LNCaP cells overexpressing HMGA2 isoforms (wild type and truncated HMGA2). Our analysis of HMGA2 and GPX4 expression in diverse PCa cell lines, shows an inverse relationship between HMGA2 and GPX4 levels. Elevated HMGA2 expression coincides with reduced GPX4 expression, leading to heightened oxidative stress and susceptibility to ferroptosis. Moreover, treatment of enzalutamide resistant cell line C4-2B MDVR with ferroptosis inducer RSL3, further suppresses GPX4 expression, resulting in decreased cell proliferation. Our results unveils the intricate relationship between HMGA2, GPX4 regulation and oxidative stress in the context of prostate cancer progression. Exploiting this oxidative stress pathway offers a promising therapeutic approach for cancer treatment, especially for enzalutamide-resistant cancer cells. Acknowledgements: These studies were supported by NIH/NIGMS/RISE SR25GM060414 and NIH/NIMHD 2U54MD007590; 5U54MD013376. Citation Format: Precious Elechi Dike, Taaliah Campbell, Mojisoluwa Awolowo, Valerie Odero-Marah. HMGA2 regulates GPX4 expression and oxidative stress [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1562.

TNFRSF1B Signaling Blockade Protects Airway Epithelial Cells from Oxidative Stress.

Progressive respiratory airway destruction due to unresolved inflammation induced by periodic infectious exacerbation episodes is a hallmark of cystic fibrosis (CF) lung pathology. To clear bacteria, neutrophils release high amounts of reactive oxygen species (ROS), which inflict collateral damage to the neighboring epithelial cells causing oxidative stress. A former genome-wide small interfering RNA (siRNA) screening in CF submucosal gland cells, instrumental for mucociliary clearance, proposed tumor necrosis factor receptor superfamily member 1B (TNFRSF1B; TNFR2) as a potential hit involved in oxidative stress susceptibility. Here, we demonstrate the relevance of TNFRSF1B transcript knock-down for epithelial cell protection under strong oxidative stress conditions. Moreover, a blockade of TNFR signaling through its ligand lymphotoxin-α (LTA), overexpressed in airway epithelial cells under oxidative stress conditions, using the anti-tumor necrosis factor (TNF) biologic etanercept significantly increased the viability of these cells from a toxic oxidizing agent. Furthermore, bioinformatic analyses considering our previous RNA interference (RNAi) screening output highlight the relevance of TNFRSF1B and of other genes within the TNF pathway leading to epithelial cell death. Thus, the inhibition of the LTα3-TNFR2 axis could represent a useful therapeutic strategy to protect the respiratory airway epithelial lining from the oxidative stress challenge because of recurrent infection/inflammation cycles faced by CF patients.

Local Chemical Environment Dependent Nitrate-Reduction-to-Ammonia Performance on Cu-Based Electrocatalysts.

The active component of copper-based materials for electrocatalytic nitrate reduction to ammonia (NRA) remains unclear due to the susceptibility of oxidation of copper. Using density functional theory calculations, NRA pathways are evaluated on low-index crystal surfaces Cu2O (111), CuO (111), and Cu (111) at different pH. Cu2O (111), with abundant undercoordinated Cu atoms on the surface, shows easier adsorption of NO3- than Cu (111) or CuO (111). NRA on CuO (111) is hindered by the large ΔG of adsorption of NO3- and hydrogenation of *NO. Thus, Cu (111) and Cu2O (111) contribute most to the NRA activity while CuO (111) is inert. Three key steps of NRA on copper-based catalysts are identified: adsorption of NO3-, *NO → *NOH/*NHO, and *NH3 desorption, as the three can be rate-determining steps depending on the local environment. Moreover, previous experimentally detected NH2OH on copper-based catalysts may come from the NRA on Cu2O (111) as the most probable pathway on Cu2O (111) is NO3- → *NO3 → *NO2 → *NO → *NHO → *NHOH → *NH2OH → *NH2 → *NH3 → *NH3(g). At high reduction potential, CuOx would be reduced into Cu, so the effective active substance for NRA in a strong reduction environment is Cu.

Thermogravimetric/Thermal-Mass Spectroscopy Insight into Oxidation Propensity of Various Mechanochemically Made Kesterite Cu2ZnSnS4 Nanopowders.

Thermogravimetry coupled with thermal analysis and quadrupole mass spectroscopy TGA/DTA-QMS were primarily used to assess the oxidation susceptibility of a pool of nanocrystalline powders of the semiconductor kesterite Cu2ZnSnS4 for prospective photovoltaic applications, which were prepared via the mechanochemically assisted synthesis route from two different precursor systems. Each system, as confirmed by XRD patterns, yielded first the cubic polytype of kesterite with defunct semiconductor properties, which, after thermal annealing at 500 °C under neutral gas atmosphere, was converted to the tetragonal semiconductor polytype. The TGA/DTA-QMS determinations up to 1000 °C were carried out under a neutral argon Ar atmosphere and under a dry, oxygen-containing gas mixture of O2:Ar = 1:4 (vol.). The mass spectroscopy data confirmed that under each of the gas atmospheres, a distinctly different, multistep evolution of such oxygen-bearing gaseous compounds as sulfur oxides SO2/SO3, carbon dioxide CO2, and water vapor H2O was taking place. The TGA/DTA changes in correlation with the nature of evolving gases helped in the elucidation of the plausible chemistry linked to kesterite oxidation, both in the stage of nanopowder synthesis/storage at ambient air conditions and during forced oxidation up to 1000 °C in the dry, oxygen-containing gas mixture.