Ozone Research Articles

Praseodymium-Doped Cr2O3 Prepared by In Situ Pyrolysis of MIL-101(Cr) for Highly Efficient Catalytic Oxidation of 1,2-Dichloroethane.

The development of economical catalysts that exhibit both high activity and durability for chlorinated volatile organic compounds (CVOCs) elimination remains a challenge. The oxidizing and acidic sites play a crucial role in the oxidation process of CVOCs; herein, praseodymium (Pr) was introduced into CrOx catalysts via in situ pyrolysis of MIL-101(Cr). With the decomposition of the ligand, a mixed micro-mesoporous structure was formed within the M-Cr catalyst, thereby reducing the contact resistance between catalyst active sites and the 1,2-dichloroethane molecule. Moreover, the synergistic interaction between chromium and praseodymium facilitates Oβ species and acidic sites, significantly enhancing the low-temperature catalytic performance and durability of the M-PrCr catalyst for 1,2-dichloroethane (1,2-DCE) oxidation. The M-30PrCr catalyst possess enhanced active oxygen sites and acid sites, thereby exhibiting the highest catalytic activity and stability. This study may provide a novel and promising strategy for practical applications in the elimination of 1,2-DCE.

Effect of transition metal (M=Cr, Mn, Fe, Co) doping on catalytic combustion of chlorobenzene over Ce − Y composite oxide

Transition metal (Cr, Mn, Fe, Co)-doped CeYOx catalysts were prepared by a co-precipitation method and applied for chlorobenzene elimination. Metal doping caused significant changes in physical properties and chemical environment of CeY solid solution. Intrinsic activity of metals and their interaction with CeY significantly improved the redox performance and oxygen mobility, thus enhancing the catalytic activity and chlorine poisoning resistance. The enhanced concentration and mobility of reactive oxygen can effectively control chlorinated by-products. MnCeYOx can achieve 90 % chlorobenzene conversion at 235 °C, attributing to the promotion of the redox dynamic cycle by the enhanced mobility of active oxygen.

Фотосинтез, минеральное питание и продуктивность лиственных и хвойных видов дендрофлоры центральной части Русской равнины

An ecological and physiological retrospective transformation of the data from the dry mass tables obtained by V.A. Usoltsev has been carried out for 7 coniferous and deciduous species (Larix sukaczewii, Picea abies, Pinus sylvestris, Betula alba, Quercus robur, Tilia cordata and Fraxinus excelsior) in the central part of the Russian Plain. In the age range from 5–20 to 80–200 years, the indicators of net photosynthetic productivity, net mineral productivity, net primary production, carbon sequestration, free oxygen emission and biological productivity have been determined at the organism level. When establishing these parameters, plants have been considered from the standpoint of ecology and the structure of a modular organism. The calculation of net mineral productivity has been carried out according to I.A. Muromtsev and V.M. Lebedev, and the net productivity of photosynthesis has been calculated according to A.A. Nichiporovich. A decrease in all physiological parameters with age has been recorded at a simultaneous increase in the ratio of root to photosynthetic potential (as an adaptive response to a decrease in the availability of nutrients). In all species, upon reaching the age of 20–30 years, a sharp decrease in the absorption activity of the roots has been revealed, which has stabilized at an extremely low level by the age of 50–60 years. The relationship between the listed plant indicators and their age for the studied species has been negative, and the relationship between mineral and biological productivity has been characterized as highly positive. In comparable age periods (30, 60 and 90 years), the studied species differed in nitrogen absorption by the root system by 21.7–28.0 times, in net photosynthetic productivity – by 4.4–7.0 times, in the value of net primary production – by 1.8–6.2 times, in nitrogen absorption – by 3.2– 6.1 times, in carbon sequestration and free oxygen emission – by 1.8–6.2 times, and in the mass of the whole plant – by 2.4–3.9 times. According to the accumulated dry mass, tree species at 90 years of age have been arranged in the following descending order: oak, spruce, larch, pine, linden, ash and birch.

Synthesis and reaction mechanism of high injected electron concentration and low work function [Ca24Al28O64]4+:(4e-) by Sol-gel method combined with spark plasma sintering

The high injected electron concentration and low work function C12A7:e- was successfully prepared by the sol-gel method combined with spark plasma sintering(SPS) using calcium nitrate, aluminum nitrate, citric acid, and ethylene glycol as raw materials. By analyzing the morphology of carbon and its role in the reactive synthesis, we reveal the reaction synthesis mechanism of C12A7:e- under the SPS. The analysis shows that C12A7:e- started to be generated at 800 °C. During the SPS reaction sintering process, carbon atoms from citric acid and ethylene glycol were excited by a pulsed current at high temperature, forming the carbon ions C22- and C (gas). Both act as reducing agents and react with the free oxygen ions O2- in the C12A7 cage cavity to form gaseous CO or CO2, enabling electrons to be injected into the cage cavity, thus generating C12A7:e-. Meanwhile, the graphene oxide (GO) formed on the surface of C12A7:e- grain is produced by the precursor of sol-gel synthesis in the high temperature oxidation environment, which will be conducive to improving the stability of C12A7: e- in air and high temperature oxidation resistance.

Interlinking the Fe doping concentration, optoelectronic properties, and photocatalytic performance of ZnO nanostructures

Doping is one of the effective strategies to modulate the optoelectronic properties and photocatalytic activity of photocatalysts. In this study, the effect of Fe doping (0–10 %) on morphology, optical and electronic properties, and photocatalytic activity of ZnO nanostructures is studied. The X-ray diffraction analysis shows that >5 % Fe doping, ZnFe2O4 is segregated as a secondary phase. The crystalline size decreases from 50.8 nm to 21.4 nm and the micro-strain increases with increasing the Fe concentration. The Fe doping-induced electronic restructuring facilitates visible light absorption through the O 2p → Fe 3d transition and the suppression of charge recombination by efficiently trapping conduction band electrons. Density functional theory (DFT) calculations are employed to unravel the underlying electronic changes induced by Fe doping in ZnO. The formation of shallow donor levels below the conduction band originates from the Fe 3d state. Photoluminescence spectra of pristine and Fe-doped ZnO nanostructures show characteristic emission peaks at approximately 384 nm and 570 nm, indicating the recombination of free excitons and oxygen interstitial defects, respectively. The results of the photocatalytic activity tests confirm that the 1 % Fe-doped ZnO nanostructures can exhibit the highest efficiency compared to the heavily doped ZnO nanostructures. The high efficiency in photocatalytic activity of 1 % Fe-doped ZnO nanostructures is ascribed to the modulated electronic structure and defect density. The adsorption affinity of methylene blue and water molecules to the surfaces of pristine and Fe-doped ZnO is simulated using the Monte-Carlo method. This study emphasizes the importance of controlling the dopant concentration to enhance the photocatalytic activity of various photocatalysts.

Neutrophil-Mimicking Nanozyme with Cascade Catalytic Releasing Nitric Oxide and Signet Oxygen Property for Synergistic Bimodal Therapy of Methicillin-Resistant Staphylococcus Aureus Infections.

Recently, chloroperoxidase (CPO)-mediated enzyme dynamic therapy (EDT) by mimicking the antipathogen function of neutrophils via generating highly active signet oxygen (1O2) has attracted great interest in biomedical applications. However, the therapeutic efficiency of EDT is largely restricted by the low CPO delivery efficiency and insufficient hydrogen peroxide (H2O2) supply. In the present work, a neutrophil-mimicking nanozyme of MGBC with high CPO delivery efficiency, H2O2 self-supply, and enzyme-cascade catalytic properties is designed for high-efficient treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. In the infection microenvironment, MGBC can effectively catalyze glucose to self-supply substantial H2O2, which enables long-lasting 1O2 generation via the CPO-mediated catalytic reaction. At the meantime, MGBC can also catalyze H2O2 to sustainably release NO for gas therapy (GT), which synergistically strengthens the therapeutic effect of EDT. As a result, MGBC displayed effective MRSA-killing and MSRA biofilms-eradicating properties, and high efficiency in treating both MRSA infected full-thickness excision wounds and subcutaneous MRSA infection by exerting the synergistic bimodal EDT/GT therapeutic effects. In-depth mechanism study revealed that the synergistic EDT/GT antibacterial effects of MGBC can attenuate the drug resistance and toxicity of MRSA by significantly downregulating quorum sensing, multidrug efflux, virulence, and biofilm formation-related genes.

Association between iron intake with diet and diabetes and impaired fasting glucose among PURE Poland study participants

Abstract Introduction Different studies results show that higher iron intake and increased iron stores in the body are significantly associated with a higher risk of diabetes mellitus (DM), a risk factor for cardiovascular diseases. Iron metabolism in the body is associated with the production of free oxygen radicals, which, combined with the stressful effect of glycation end products in pre-diabetes, increases the risk of diabetes and cardiovascular events. The purpose of the study was to assess the relationship between iron intake with diet and diabetes and impaired fasting glucose among PURE Poland study participants. Methods Study group consisted of 1889 individuals (1185 women and 704 men, aged 35-70 years, from urban and rural area), who were participants of the Polish arm of the Prospective Urban Rural Epidemiology (PURE) study. The study was approved by the Ethics Committee. The data were collected between 2007-2009, in the first stage of the PURE Poland study. Diabetes was diagnosed when fasting glucose level was ≥ 126 mg/dl or there was a declaration about DM occurrence in the medical interview. Diagnosis of impaired fasting glucose (IFG) was made when fasting glucose level was between 100-125 mg/dl with no statement about DM in the interview. Analysis were conducted for DM+IFG in three models: 1. crude data, 2. adjusted for energy intake, 3. adjusted for energy intake, age, body mass index and smoking. Food Frequency Questionnaire (FFQ) was used to assess food intake. FFQ was developed and validated for this population within the PURE study. Iron intake with diet was calculated based on the data from FFQ. For further analysis the study group was divided into tertiles based on the daily iron intake with diet, separately for men and women. Results The prevalence of DM+IFG in each tertile (T) of iron intake with diet was: 27.6% (T1), 37.0% (T2) and 38.7% (T3) among women, and 30.3% (T1), 40.9% (T2) and 37.9% (T3) among men. Taking into account crude data the OR (95% CI) for DM+IFG among women was 1.54 (1.14-2.08) in T2 and 1.66 (1.23-2.24) in T3 when comparing with T1. In model 2 the OR (95% CI) for DM+IFG among women was 1.63 (1.16-2.28) in T2 and 1.88 (1.21-2.94) in T3 when comparing with T1. In model 3 in the group of women the OR (95% CI) for DM+IFG was 1.52 (1.07-2.16) and 1.62 (1.02-2.56) when comparing T2 vs T1 and T3 vs T1, respectively. In the group of men in model 1 the OR (95% CI) for DM+IFG prevalence was 1.59 (1.08-2.32) in T2 vs T1 and 1.40 (0.95-2.05, p>0.05) in T3 vs T1. In the group of men in model 2 and 3 the results were not statistically significant, both in T2 vs T1 and T3 vs T1. Taking into account the whole study group the risk of DM+IFG was significantly higher in T2 vs T1 (model 1, 2 and 3) and in T3 vs T1 (model 1 and 2). Conclusions Higher iron intake with diet was associated with a higher risk of diabetes and impaired fasting glucose in the study group, especially among women.

Environmental and Genetic Determinants of Ankylosing Spondylitis.

Exposure to heavy metals and lifestyle factors like smoking contribute to the production of free oxygen radicals. This fact, combined with a lowered total antioxidant status, can induce even more damage in the development of ankylosing spondylitis (AS). Despite the fact that some researchers are looking for more genetic factors underlying AS, most studies focus on polymorphisms within the genes encoding the human leukocyte antigen (HLA) system. The biggest challenge is finding the effective treatment of the disease. Genetic factors and the influence of oxidative stress, mineral metabolism disorders, microbiota, and tobacco smoking seem to be of great importance for the development of AS. The data contained in this review constitute valuable information and encourage the initiation and development of research in this area, showing connections between inflammatory disorders leading to the pathogenesis of AS and selected environmental and genetic factors.

Design of an intelligent Near-Infrared responsive antibacterial Nano-Platform based on MoS2/Cu3Mo2O9

In this era of high drug resistance, there is an urgent need for novel antimicrobial agents and strategies to achieve smarter sterilization effects. However, developing an environmentally friendly, controllable, and self-cleaning smart antimicrobial material remains a formidable challenge. In this work, a smart antimicrobial nanoplatform composed of Cu3Mo2O9 and MoS2 has been successfully designed and synthesized. The computational findings reveal that, owing to the interfacial coupling between the two substances at the solid junction, this architecture can effectively absorb near-infrared light, significantly reduce migration resistance, and improve carrier separation efficiency. Empirical observations demonstrate that with a sample concentration of 100 μg/mL, under near-infrared (NIR) laser irradiation, the microenvironmental temperature proximal to the bacteria can be swiftly elevated from 28.6 °C to in excess of 50 °C within a mere 6 min. The overall photothermal conversion efficiency is 32.6 %, and it exhibits an active oxygen level nearly 5 times higher than that of Cu3Mo2O9. Furthermore, the permeability of the cell membrane was greatly improved with the increased temperature, which is beneficial for the generated reactive oxygen species (ROS) entering the bacterial cells. After synergistic antimicrobial treatment, the antibacterial rate against Escherichia coli can reach over 99 %. More importantly, this nano-platform features a unique ’activation’ mechanism that uses NIR as an ’activation switch’ to selectively toggle between ’passive defense,’ ’secondary sterilization,’ and ’active attack’ antibacterial modes as needed. Upon interaction with aqueous environments, its reusability and favorable biocompatibility with terrestrial and aquatic life promise to facilitate the intelligent eradication of deleterious microorganisms in aquatic systems via the diurnal cycle of sunrise and sunset. This is highly significant for the ongoing management and maintenance of public resources such as amusement parks, artificial fish ponds, and urban water features.

Facile preparation of alkali metal‐modified hollow nanotubular manganese‐based oxide catalysts and their excellent catalytic soot combustion performance

AbstractThe soot emitted during the operation of diesel engine exhaust seriously threatens the human health and environment, so treating diesel engine exhaust is critical. At present, the most effective method for eliminating soot particles is post‐treatment technology. Preparation of economically viable and highly active soot combustion catalysts is a pivotal element of post‐treatment technology. In this study, different single‐metal oxide catalysts with fibrous structures and alkali metal‐modified hollow nanotubular Mn‐based oxide catalysts were synthesized using centrifugal spinning method. Activity evaluation results showed that the manganese oxide catalyst has the best catalytic activity among the prepared single‐metal oxide catalysts. Further research on alkali metal modification showed that doping alkali metals is beneficial for improving the oxidation state of manganese and generating a large number of reactive oxygen species. Combined with the structural effect brought by the hollow nanotube structure, the alkali metal‐modified Mn‐based oxide catalysts exhibit superior catalytic performance. Among them, the Cs‐modified Mn‐based oxide catalyst exhibits the best catalytic performance because of its rich active oxygen species, excellent NO oxidation ability, abundant Mn4+ ions (Mn4+/Mnn+ = 64.78%), and good redox ability. The T10, T50, T90, and CO2 selectivity of the Cs‐modified Mn‐based oxide catalyst were 267°C, 324°C, 360°C, and 97.8%, respectively.

Rutile‐Structured Ru0.48Mn0.52O2 Solid Solution for Highly Active and Stable Oxygen Evolution at Large Current Density in Acidic Media

AbstractThe development of active, stable, and cost‐effective electrocatalysts for the oxygen evolution reaction (OER) in acidic media is crucial for proton‐exchange‐membrane water electrolysis. Inspired by theoretical screening on a series of transition metal incorporated RuO2 systems, a low Ru‐content solid solution oxide (Ru0.48Mn0.52O2) achieved is fabricated by a simple two‐step synthesis method through the combination of rutile RuO2 and β‐MnO2. The Ru0.48Mn0.52O2 catalyst exhibits an exceptionally low overpotential of 154 mV at 10 mA cm−2 and maintains a high stability under a high current of 100 mA cm−2 for 50 h in 0.5 m H2SO4 electrolyte. Furthermore, the obtained catalyst exhibits sustained stability at a large current of 0.5 A cm−2 for at least 50 h when loaded onto a Ti felt. The in‐situ characterization results indicate that Ru0.48Mn0.52O2 preferably followed the adsorbate evolution mechanism rather than the lattice oxygen oxidation mechanism during the OER process, contributing to its high activity and stability at large current densities in acidic media.

Efficient enzymatic hydrolysis of active oxygen and solid alkali/dilute sulfuric acid-pretreated corn cob

This work proposed a two-step pretreatment method of cooking with active oxygen and solid alkali (CAOSA) followed by dilute sulfuric acid treatment (DA), to contribute enzymatic hydrolysis of corn cob. The first step, CAOSA pretreatment, removed 83.16 % of the lignin, while the second step, a milder pretreatment with DA further eliminated hemicellulose. After the two-step pretreatment, the cellulose content of the residue reached 66.74 %, and with a solid loading of 5 %, the glucose yield was remarkably high at 98.35 % with a concentration of 36.47 g/L. The optimal conditions of the process were determined as follows: DA with 1 % H2SO4 at a solid-to-liquid ratio of 1:10, a temperature of 110 ℃, and a pretreatment time of 60 min. To confirm the efficacy of the two-step pretreatment, we characterized the samples treated with different methods using X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The developed method proposes an effective pretreatment and results in the complete enzymatic hydrolysis of corn cob.

Chitosan boosts ginger disease resistance: Insights from transcriptomic and metabolomic analyses

Chitosan exhibits efficacy in controlling ginger diseases, yet its systemic regulatory mechanisms remain unknown. This study explored the potential mechanisms underlying chitosan-regulated resistance by conducting physiological, comparative transcriptome, and metabolome analyses in Fusarium solani-inoculated ginger rhizomes with and without chitosan treatment. Chitosan treatment decreased decay severity and water loss, and reduced reactive oxygen species accumulation by enhancing antioxidant enzyme activities. Chitosan increased PAL, C4H, and CHI activities, along with elevated levels of lignin, total phenolic, total flavonoid, and the accumulation of suberin polyphenolic. RNA-seq analysis identified 1158 differentially expressed genes, predominantly involved in active oxygen and phenylpropanoid metabolism. Metabolomics identified 226 differential metabolites, including numerous phenylpropanoids and flavonoids. Integrated RNA-seq and metabolome analyses revealed chitosan's regulatory impact on gene expression and metabolite accumulation in the phenylpropanoid metabolism. These findings provide novel insights into chitosan's mechanisms against Fusarium solani.

Structure and molecular-level transformation for oxidation of effluent organic matters by manganese oxides

As important organic components in water environments, effluent organic matters (EfOMs) from wastewater treatment plants are widely present in Mn-rich environments or engineered treatment systems. The redox interaction between manganese oxides (MnOx) and EfOMs can lead to their structural changes, which are crucial for ensuring the safety of water environments. Herein, the reactivities of MnOx with EfOMs were evaluated, and it was found that MnOx with high specific surface area, active high-valent manganese content and lattice oxygen content (i.e., amorphous MnO2) possessed stronger oxidizing ability towards EfOMs. Accompanying by EfOMs oxidation, Mn(IV) and Mn(III) were reduced into Mn(II), with Mn(III) as the significant active species. Through molecular-level transformation analysis by ultrahigh mass spectrometry (FT-ICR MS), the highly reactive compounds in EfOMs were clearly determined to be that with more aromatic and unsaturated structures, especially lignin-like compounds (the highest content in EfOMs (over 60 %)). EfOMs were oxidized by amorphous MnO2 into products with lower humification index (0.60 vs. 0.46), smaller apparent molecular weight (386.94 Da vs. 368.68 Da), and higher biodegradability (BOD5/COD: 0.12 vs. 0.78). This finding suggested that redox reactions between MnOx and EfOMs might alter their abiotic and biotic behaviors in receiving water environments.

Hesperidin Alleviated Intestinal Barrier Injury, Mitochondrial Dysfunction, and Disorder of Endoplasmic Reticulum Mitochondria Contact Sites under Oxidative Stress.

As primary flavonoids extracted from citrus fruits, hesperidin has been attracting attention widely for its capacity to act as antioxidants that are able to scavenge free radicals and reactive oxygen species (ROS). Many factors have made oxidative stress a risk factor for the occurrence of intestinal barrier injury, which is a serious health threat to human beings. However, little data are available regarding the underlying mechanism of hesperidin alleviating intestinal injury under oxidative stress. Recently, endoplasmic reticulum (ER) mitochondria contact sites (ERMCSs) have aroused increasing concerns among scholars, which participate in mitochondrial dynamics and Ca2+ transport. In our experiment, 24 piglets were randomly divided into 4 groups. Piglets in the diquat group and hesperidin + diquat group received an intraperitoneal injection of diquat (10 mg/kg), while piglets in the hesperidin group and hesperidin + diquat group received hesperidin (300 mg/kg) with feed. The results indicated that hesperidin alleviated growth restriction and intestinal barrier injury in piglets compared with the diquat group. Hesperidin ameliorated oxidative stress and restored antioxidant capacity under diquat exposure. The mitochondrial dysfunction was markedly alleviated via hesperidin versus diquat group. Meanwhile, hesperidin alleviated ER stress and downregulated the PERK pathway. Furthermore, hesperidin prevented the disorder of ERMCSs by downregulating the level of ERMCS proteins, decreasing the percentage of mitochondria with ERMCSs/total mitochondria and the ratio of ERMCSs length/mitochondrial perimeter. These results suggested hesperidin could alleviate ERMCS disorder and prevent mitochondrial dysfunction, which subsequently decreased ROS production and alleviated intestinal barrier injury of piglets under oxidative stress.

Orchestrating Stress Responses in Multiple Sclerosis: A Role for Astrocytic IFNγ Signaling.

Multiple sclerosis (MS) is an inflammatory and neurodegenerative disease that is characterized by the infiltration of peripheral immune cells into the central nervous system (CNS), secretion of inflammatory factors, demyelination, and axonal degeneration. Inflammatory mediators such as cytokines alter cellular function and activate resident CNS cells, including astrocytes. Notably, interferon (IFN)γ is a prominent pleiotropic cytokine involved in MS that contributes to disease pathogenesis. Astrocytes are dynamic cells that respond to changes in the cellular microenvironment and are highly responsive to many cytokines, including IFNγ. Throughout the course of MS, intrinsic cell stress is initiated in response to inflammation, which can impact the pathology. It is known that cell stress is pronounced during MS; however, the specific mechanisms relating IFNγ signaling to cell stress responses in astrocytes are still under investigation. This review will highlight the current literature regarding the impact of IFNγ signaling alone and in combination with other immune mediators on astrocyte synthesis of free oxygen radicals and cell death, and cover what is understood regarding astrocytic mitochondrial dysfunction and endoplasmic reticulum stress.

Monte Carlo simulations of microdosimetry and radiolytic species production at long time post proton irradiation using GATE and Geant4-DNA.

Radiobiological effectiveness of radiation in cancer treatment can be studied at different scales (molecular till organ scale) and different time post irradiation. The production of free radicals and reactive oxygen species during water radiolysis is particularly relevant to understand the fundamental mechanisms playing a role in observed biological outcomes. The development and validation of Monte Carlo tools integrating the simulation of physical, physico-chemical and chemical stages after radiation is very important to maintain with experiments. Therefore, in this study, we propose to validate a new Geant4-DNA chemistry module through the simulation of water radiolysis and Fricke dosimetry experiments on a proton preclinical beam line. In this study, we used the GATE Monte Carlo simulation platform (version 9.3) to simulate a 67.5 MeV proton beam produced with the ARRONAX isochronous cyclotron (IBA Cyclone 70XP) at conventional dose rate (0.2Gy/s) to simulate the irradiation of ultra-pure liquid water samples and Fricke dosimeter. We compared the depth dose profile with measurements performed with a plane parallel Advanced PTW 34045 Markus ionization chamber. Then, a new Geant4-DNA chemistry application proposed from Geant4 version 11.2 has been used to assess the evolution of , , , , , , and reactive species along time until 1-h post-irradiation. In particular, the effect of oxygen and pH has been investigated through comparisons with experimental measurements of radiolytic yields for and Fe3+. GATE simulations reproduced, within 4%, the depth dose profile in liquid water. With Geant4-DNA, we were able to reproduce experimental radiolytic yields 1-h post-irradiation in aerated and deaerated conditions, showing the impact of small changes in oxygen concentrations on species evolution along time. For the Fricke dosimeter, simulated G(Fe3+) is 15.97±0.2 molecules/100eV which is 11% higher than the measured value (14.4±04 molecules/100 eV). These results aim to be consolidated by new comparisons involving other radiolytic species, such as or to further study the mechanisms underlying the FLASH effect observed at ultra-high dose rates (UHDR).

Resveratrol Modulates Diabetes-Induced Neuropathic Pain, Apoptosis, and Oxidative Neurotoxicity in Mice Through TRPV4 Channel Inhibition

Diabetic peripheral neuropathy (DPN) is caused by several factors, including reactive free oxygen radicals (ROS)-induced excessive Ca2+ influx. Transient receptor potential (TRP) vanilloid 4 (TRPV4) is a member of the Ca2+-permeable TRP superfamily. Resveratrol (RESV) has been extensively utilized in TRP channel regulation due to its pharmacological properties, which include antioxidant and TRP inhibitory effects. The protective function of RESV and the contribution of TRPV4 to streptozotocin (STZ)-induced neuropathic pain in mice are still unclear. Here, we evaluated the effects of RESV through the modulation of TRPV4 on Ca2+ influx, ROS-mediated pain, apoptosis, and oxidative damage in the mouse dorsal root ganglion (DRGs). From the 32 mice, four groups were induced: control, RESV, STZ, and STZ + RESV. We found that the injection of RESV reduced the changes caused by the STZ-induced stimulation of TRPV4, which in turn increased mechanical/thermal neuropathic pain, cytosolic Ca2+ influx, TRPV4 current density, oxidants (lipid peroxidation, mitochondrial ROS, and cytosolic ROS), and apoptotic markers (caspase-3, -8, and -9). The RESV injection also increased the STZ-mediated reduction of viability of DRG and the amounts of glutathione, glutathione peroxidase, vitamin A, β-carotene, and vitamin E in the brain, erythrocytes, plasma, liver, and kidney. All of these findings suggest that TRPV4 stimulation generates oxidative neurotoxicity, neuropathic pain, and apoptosis in the STZ-induced diabetic mice. On the other hand, neurotoxicity and apoptosis were reduced due to the downregulation of TRPV4 carried out through the RESV injection.Graphical An overview of how resveratrol (RESV) inhibits TRPV4 in mice to modulate the effects of diabetes mellitus-induced diabetic peripheral neuropathy (DPN). Ruthenium red (RuR) inhibits TRPV4, while GSK1016790A (GSK) and reactive free oxygen radicals (ROS) activate it. In the mitochondria of DRGs, the glucose oxidation brought on by diabetes mellitus (STZ) causes an intracellular free Ca2+ and Zn2+ influx excess that is dependent on TRPV4. The administration of STZ leads to the DRG becoming more depolarized (ΔΨm), which in turn causes an increase in mitochondrial ROS, apoptosis, and caspases (caspase-3, caspase-8, and caspase-9) by downregulating enzymatic (glutathione peroxidase, GSH-Px) and non-enzymatic (glutathione (GSH), vitamin A, and vitamin E) antioxidants. The mice’s molecular pathways were diminished by the RESV injections. (Increase (↑); diminish (↓))

Surface oxygen vacancies induced by cu-doping in hexagonal ZnMn2O4 nanoplates for high efficiency photothermocatalytic oxidation of toluene

The exploitation of efficient and stable photothermal catalyst for the deep mineralization of volatile organic compounds (VOCs) is crucial and challenging. Herein, a photothermal catalyst with abundant oxygen defects was prepared for the first time via Cu-doped ZnMn2O4 hexagonal nanoplate. Experimental characterization results reveal that Cu doping enhances not only the ZnMn2O4 defect contents but also the light absorption and thermal conversion ability of ZnMn2O4. Compared to the undoped ZnMn2O4 (ZMO), the ZnMn2O4 with optimal Cu doping amount (ZMO-4Cu) exhibits excellent photothermal catalytic performance (94% toluene conversion and 87% toluene mineralization) and good resistance to low concentration SO2 under full-spectrum light irradiation. Experimental characterizations and theoretical calculations jointly demonstrated that the oxygen vacancies of ZMO-4Cu surface are more conducive to the adsorption of O2, effectively reduce the oxygen dissociation energy of ZMO-4Cu, thus generating abundant active oxygen species and improving the photothermal catalytic activity for toluene oxidation. In situ IR experiments disclosed that photothermal catalysis is more conducive to the toluene deep oxidation than thermal catalysis. This work provides new insights for the design of high efficiency photothermal catalysis for the deep oxidation of VOCs.

NaHS immersion alleviates the stress effect of chromium(III) on alfalfa seeds by affecting active oxygen metabolism

ABSTRACT Objective This study aimed to investigate the regulatory effects of exogenous hydrogen sulfide (H2S) on seed germination, seedling growth, and reactive oxygen species (ROS) homeostasis in alfalfa under chromium (Cr) ion (III) stress. Methods The effects of 0–4 mM Cr(III) on the germination and seedling growth of alfalfa were first assessed. Subsequently, following seed NaHS immersion, the influence of H2S on alfalfa seed germination and seedling growth under 2 mM Cr(III) stress was investigated, and the substance contents and enzyme activities associated with ROS metabolism were quantified. Results Compared to the control group, alfalfa plant germination was delayed under 2 mM Cr(III) stress for up to 48 h (p < 0.05). At 120 h, the total seedling length was approximately halved, and the root length was roughly one-third of the control. Treatment with 0.02–0.1 mM NaHS alleviated the delay in germination and root growth inhibition caused by 2 mM Cr(III) stress, resulting in an increased ratio of root length to hypocotyl length from 0.57 to 1 above. Additionally, immersion in 0.05 mM NaHS reduced hydrogen peroxide (H2O2) and oxygen-free radicals (O2 · –) levels (p < 0.05), boosted glutathione (GSH) levels (p < 0.05), and notably enhanced catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) activities (p < 0.05) compared to the 2 mM Cr(III) stress treatment group. Conclusion Seed immersion in NaHS mitigated the delay in germination and inhibition of root elongation under 2 mM Cr(III) stress. This effect is likely attributed to the regulation of intracellular ROS homeostasis and redox balance through enzymatic and non-enzymatic systems; thus, providing a potential mechanism for combating oxidative stress.