Superoxide Radical Production Research Articles

Role of sulfide anion in the development of chronic alcoholic hepatitis under the conditions of modulation of adenosine monophosphate kinase – a correlational study

Introduction and aim. Hydrogen sulfide (H 2 S) has attracted the attention of researchers as a novel signaling molecule that affects vascular metabolism, immune function, stress and inflammation. It plays an important role in pathophysiological disorders under the conditions of the development of obesity, diabetes, non-alcoholic fatty liver disease and cardiovascular diseases. The purpose of this work is to establish correlation ratios of H 2 S concentration with markers of oxidative-nitrosative stress and extracellular matrix metabolism of the liver during chronic alcoholic hepatitis modeling and AMPK modulation by phenformin and doxorubicin. Material and methods. The experiments were performed on 36 white, sexually mature male Wistar rats, weighing 180-220 g. Alcoholic hepatitis was modelled by alcohol administration, on the background of alcoholic hepatitis animals received phenformin orally at a dose of 10 mg/kg or doxorubicin at a dose of 1.25 mg/kg intraperitoneally. Statistical processing of the results of biochemical studies was carried out using the non-parametric method of Spearman to determine correlations. Results. H 2 S during alcoholic hepatitis inversely proportionally strongly correlates with the concentration of nitrites, oxyproline and arginase activity. Phenformin administration during alcoholic hepatitis leads to formation of inversely proportionally strongly correlation of H 2 S with the production of superoxide anion radical, the concentration of malondialdehyde, activities of constitutive NO-synthases, nitrite reductases, nitrate reductases, and arginase. Doxorubicin administration during alcoholic hepatitis leads to formation of directly proportional strongly correlation of H 2 S with the activity of constitutive NO-synthases, nitrite reductases, nitrate reductases. Conclusion. Administration of phenformin or doxorubicin expands correlations between H 2 S and indicators of oxidative-nitrosative stress.

A new multimodal magnetic nanozyme and a reusable peroxymonosulfate oxidation catalyst: Manganese oxide coated-monodisperse-porous and magnetic core-shell microspheres

Monodisperse-porous, polydopamine and manganese oxide coated, core-shell type, magnetic SiO2 (MagSiO2@PDA@MnO2) microspheres 6.4 μm in size were synthesized for the first time, using magnetic, monodisperse-porous SiO2 (MagSiO2) microspheres 6.2 μm in size as the starting material. MagSiO2 microspheres were obtained by a recently developed method namely “staged shape templated hydrolysis and condensation protocol”. In the synthesis, MagSiO2 microspheres were consecutively coated by polydopamine (PDA) and then by a MnO2 layer in the aqueous medium. The pore volume and the specific surface area of monodisperse-porous MagSiO2@PDA@MnO2 microspheres were measured as 0.59 cm3 g−1 and 154 m2 g−1, respectively. Their Mn and Fe contents were determined as 66 ± 1 mg g−1 and 165 ± 5 mg g−1 respectively. MagSiO2@PDA@MnO2 microspheres exhibited multimodal enzyme mimetic behavior with highly superior catalase-like, oxidase-like and peroxidase-like activities. The effective production of singlet oxygen (1O2) and superoxide anion (O2−*) radicals in MagSiO2@PDA@MnO2-peroxymonosulfate (PMS) system was demonstrated by ESR spectroscopy. By evaluating this property, MagSiO2@PDA@MnO2 microspheres were tried as a reusable catalyst for dye removal via peroxymonosulfate (PMS) activation in batch experiments for the first time. The degradation runs were made with, rhodamine B (Rh B), methyl orange (MO) and methylene blue (MB) as the pollutant. The core-shell type design allowing the deposition of porous MnO2 layer onto a large surface area provided very fast, instant removals with all dyes, via both physical adsorption and degradation via PMS activation. In the reusability experiments, the removal yields of MO and Rh B decreased 1.8% and 8.9% over five consecutive runs in batch fashion. MagSiO2@PDA@MnO2 microspheres exhibited very good functional and structural stability in consecutive dye degradations. No significant change was observed in Fe content of microspheres while Mn content exhibited a decrease of 7.4% w/w over 5 consecutive degradation runs.

Natural tourmaline for pyroelectric dye decomposition under 25–60 °C room-temperature cold-hot fluctuation

Tourmaline is a typical natural pyroelectric material. In this work, the pyroelectric property of tourmaline micro-powder is used to chemically deal with dyes wastewater under room-temperature cold-hot alternation. Under 25–60 °C heating-cooling cycles excitation, the decomposition ratio of Rhodamine B wastewater can achieve 84.7%. In the dye decomposition process, dissolved oxygen and hydroxide in the solution react with pyroelectrically induced positive and negative charges, respectively. This reaction triggers the production of superoxide radicals (O2–) and hydroxyl radicals (OH), which possess highly potent oxidation capabilities towards dye molecules. This work highlights the potential application of tourmaline mineral for dye decomposition in harvesting the environmental cold-hot alternation heat energy in future.

Synthesis of germanium/germanium phosphide in-plane heterostructure with efficient photothermal and enhanced photodynamic effects in the second near-infrared biowindow

Inspired by the bifunctional phototherapy agents (PTAs), constructing compact PTAs with efficient photothermal therapy (PTT) and photodynamic therapy (PDT) effects in the near-infrared (NIR-II) biowindow is crucial for high therapeutic efficacy. Herein, none-layered germanium (Ge) is transformed to layered Ge/germanium phosphide (Ge/GeP) structure, and a novel two-dimensional sheet-like compact S-scheme Ge/GeP in-plane heterostructure with a large extinction coefficient of 15.66 L/g cm−1 at 1,064 nm is designed and demonstrated. In addition to the outstanding photothermal effects, biocompatibility and degradability, type I and type II PDT effects are activated by a single laser. Furthermore, enhanced reactive oxygen species generation under longer wavelength NIR laser irradiation is achieved, and production of singlet oxygen and superoxide radical upon 1,064 nm laser irradiation is more than double that under 660 nm laser irradiation. The S-scheme charge transfer mechanism between Ge and GeP, is demonstrated by photo-irradiated Kelvin probe force microscopy and electron spin resonance analysis. Thus, the obtained S-scheme Ge/GeP in-plane heterostructure shows synergistic therapeutic effects of PTT/PDT both in vitro and in vivo in the NIR-II biowindow and the novel nanoplatform with excellent properties has large clinical potential.

Free zinc ions, as a major factor of ZnONP toxicity, disrupts free radical homeostasis in CCRF-CEM cells

Nanotechnology has become a ubiquitous part of our everyday life. Besides the already-known nanoparticles (NPs), plenty of new nanomaterials are being synthesized every day. Here, we explain the mechanism of the zinc oxide nanoparticles (ZnONPs) cytotoxicity in a cellular model of acute lymphoblastic leukaemia (CCRF-CEM). To do so, we investigated both possible hypotheses about the ZnONPs mechanism of toxicity: a free zinc ions release and/or reactive oxygen species (ROS) generation. Presented here results show that:A)EDTA protects the cells, whereas a common antioxidant agent (NAC) enhances the cytotoxic effect induced by ZnONPs,B)ZnONPs release zinc ions in vitro,C)ZnONPs upregulate the activity of antioxidative defence enzymes, which are Nrf2 transcription factor-dependent,D)The upregulation of ROS generation is correlated with the upregulation of reductive stress markers,E)ZnONPs treatment induces NADPH oxidases that cause excessive production of superoxide radicals in tested cellular model.Our results support the hypothesis that the mechanism of ZnONPs cytotoxicity is based on the release of free zinc ions. Nevertheless, both previously quoted hypotheses incompletely described the mechanism of action of ZnONPs. In this paper, we show that the mechanism of cytotoxicity of ZnONPs is based on the induction of reductive stress in CCRF-CEM cells, which is caused by free zinc ions released from ZnONPs. Therefore, the increase of oxidative stress markers is most likely a secondary response of the cells towards the Zn2+. These results provide a crucial expansion of the zinc ion hypothesis and thus explain the biphasic cellular response of CCRF-CEM cells treated with ZnONPs.

Exploring the potential of graphene oxide nanocomposite as a highly efficient photocatalyst for antibiotic degradation and pathogen inactivation

The widespread use of antibiotics in human and veterinary medicine makes them an emerging contaminant in the aquatic environment. The degradation of antibiotics is essential for environmental remediation and requires low-cost, high-performance photocatalysts. In this work, water-dispersible, highly efficient Yttrium oxide/Nickel Oxide anchored Graphene Oxide (GO/Y2O3/NiO) ternary composites were fabricated via a facile hydrothermal procedure and photocatalytically active for the degradation of the antibiotics ciprofloxacin (CIP) and + amoxicillin (AMOX) under visible light illumination. The formation of GO/Y2O3/NiO was confirmed by a variety of spectroscopic and microscopic techniques. GO/Y2O3/NiO ternary composite material exhibits 94.03 % degradation efficiency for CIP and 78 % for AMOX, associated with a faster reaction rate and a longer response to visible light. In addition, the presence of GO in the ternary nanocomposite served as an electron conductor, leading to the production of superoxide and hydroxy radicals that have reduced band gap of 2.8 eV. A unique combination of GO /Y2O3/NiO nanocubes, nanorods and nanosheets enhanced the photocatalytic activity. In addition, GO/Y2O3/NiO exhibits high antibacterial and concentration-dependent cytotoxic properties. These studies demonstrated that GO/Y2O3/NiO nanocomposite photocatalysts have unique potential as both antibacterial and eco- friendly photocatalysts, which has great potential for use in photo nanotechnology.

Efficient removal of aqueous organic pollutants by well-ordered layered manganese oxide nanocomposites: Impacts of interlayer spacing and nanoconfinement

Although manganese oxide is able to spontaneously oxidize organic contaminants in nature, the slow kinetics limit its application in engineered water treatment processes. Herein, we prepared well-ordered layered manganese oxides (LMOs) with adjustable interlayer distances using cetyltrimethylammonium bromine as a guest molecule, which were applied to degrade 3-chlorophenol as an example of organic pollutants. The ordering of the layered structure was found to be highly dependent on the molar ratio of cetyltrimethylammonium ion (CTA+) to Mn in the solutions (range 0–1.2). The maximum interlayer spacing (11.27 Å) was obtained at a molar ratio was 1.0 (LMO-1.0), which reduces the steric hindrance for 3-chlorophenol entering the interlayers. Additionally, the surface of the LMOs becomes more hydrophobic as their molar ratio increased, further favors adsorption of 3-chlorophenol on the LMO-1.0. The LMO-1.0 provides a constrained reaction environment, which increases the probability of 3-chlorophenol interacting with the active species as well as promotes the production and enrichment of superoxide radical (O2•−). Consequently, the degradation rate constant of 3-chlorophenol (0.446 min−1) is two orders of magnitude higher compared to the unconfined bulk phase (0.004 min−1). These findings provide useful insights into the development of Mn-based layered materials for water purification.

Enhanced mechanism of copper doping in magnetic biochar for peroxymonosulfate activation and sulfamethoxazole degradation

Magnetic biochar is excellent for separation and peroxymonosulfate (PMS) activation. Copper doping could improve the catalytic capability of magnetic biochar significantly. In this study, cow dung biochar is applied to investigate the effects of copper doping on the magnetic biochar, focusing on the specific influence on the consumption of active sites, the production of oxidative species and the toxicity of degradation intermediates. The results showed that copper doping promoted the uniform distribution of iron sites on the biochar surface and reduced iron aggregation. At the same time, copper doping interpreted the biochar with larger specific surface area, which was beneficial to the adsorption and degradation of sulfamethoxazole (SMX). The SMX degradation kinetic constant with copper-doped magnetic biochar was 0.0403 min−1, which was 1.45 times than that of magnetic biochar. Besides, copper doping might accelerate the consumption of CO, Fe0, Fe2+ sites and hinder the activation of PMS at copper-related sites. Furthermore, copper doping promoted the PMS activation by magnetic biochar through accelerated electron transfer. For the oxidative species, copper doping accelerated the production of hydroxyl radicals, singlet oxygen, and superoxide radicals in solution and inhibited the generation of sulfate radicals. In addition, SMX could be directly decomposed into less toxic intermediates in the copper-doped magnetic biochar/PMS system. In conclusion, this paper provides insight and analysis of the advantages of copper doping on the magnetic biochar, which helps to facilitate the design and practical application of bimetallic biochar.

Boosting VOCs photodegradation performance of Co-doped WO3 nanofibers through efficient oxygen activation and localized electric field construction

Exploring efficient photocatalysts for degrading hazardous volatile organic compounds (VOCs) is gaining increasing popularity. Herein, we developed Co-doped WO3 nanofibrous photocatalysts by incorporating Co dopant into the WO3 lattice, where hexavalent W(VI) is replaced with divalent Co(II). This heterovalent substitution causes significant charge rearrangement around the Co dopant, resulting in a localized electric field (LEF) that enhances oxygen adsorption and activation. Such an electric field drives photoexcited electrons to gather at the Co dopant, thereby achieving spatial charge separation. Both the efficient oxygen activation and LEF forming contribute to the production of superoxide radicals. The Co0.8-WO3 nanofibers demonstrated improved photocatalytic oxidation of gaseous HCHO and CH3COCH3 compared to WO3. This study highlights the significant promotion of dopant-induced oxygen adsorption and LEF-induced efficient carrier separation. These findings offer a new direction for developing more efficient photocatalysts using unique doping approaches.

Susceptibility of the Most Popular Soybean Cultivars in South-East Europe to Macrophomina phaseolina (Tassi) Goid.

Oxidative stress in soybean seedlings and the length of the soybean stem lesions infected with the fungus Macrophomina phaseolina (Tassi) Goid were evaluated to determine the most tolerant soybean cultivar to this pathogen. The level of superoxide anion radical (O2•-) production, the activity of the antioxidant enzyme superoxide-dismutase (SOD), and the intensity of lipid peroxidation (LP) were measured in four soybean cultivars: Favorit, Atlas, Victoria, and Rubin. Results showed that O2•- radical production and SOD activity were the most elevated in the cv. Favorit inoculated with M. phaseolina, while the level of lipid peroxidation intensity was the lowest compared to the control. This indicates that the soybean cv. Favorit has managed to prevent infection with M. phaseolina. Furthermore, higher O2•- radical production and lower SOD enzyme activity were measured in cv. Victoria, with enhanced lipid peroxidation. This means that the cv. Victoria was infected with M. phaseolina, and was the most sensitive. None of the tested oxidative stress parameters showed a significant difference in the cvs. Atlas and Rubin compared to the control. Furthermore, the highest lesion length was measured in the cv. Victoria, followed by cv. Favorit, while the lowest lesion length was measured in the cv. Atlas followed by the cv. Rubin; and thus, the cv. Atlas followed by the cv. Rubin, were the most tolerant soybean cultivars to this pathogen.

Bioinspired Single-Atom Sites Enable Efficient Oxygen Activation for Switching Anodic/Cathodic Electrochemiluminescence.

Exploring advanced co-reaction accelerators with superior oxygen reduction activity that generate rich reactive oxygen species (ROS) has attracted great attention in boosting luminol-O2 electrochemiluminescence (ECL). However, tuning accelerators for efficient and selective catalytic O2 activation to switch anodic/cathodic ECL is very challenging. Herein, we report that enzyme-inspired Fe-based single-atom catalysts with axial N/C coordination structures (FeN5, FeN4(C) SACs) can generate specific ROS for cathodic/anodic ECL conversion. Mechanistic studies reveal that FeN5 sites prefer to produce highly active hydroxyl radicals and afford direct cathodic luminescence by promoting the cleavage of O-O bonds through N-induced electron redistribution. In contrast, FeN4(C) sites tend to produce superoxide radicals, resulting in inefficient anodic ECL. Benefiting from the enhanced cathodic ECL, FeN5 SAC-based immunosensor was constructed for the sensitive detection of cancer biomarkers.

Bioinspired Single‐Atom Sites Enable Efficient Oxygen Activation for Switching Anodic/Cathodic Electrochemiluminescence

AbstractExploring advanced co‐reaction accelerators with superior oxygen reduction activity that generate rich reactive oxygen species (ROS) has attracted great attention in boosting luminol‐O2 electrochemiluminescence (ECL). However, tuning accelerators for efficient and selective catalytic O2 activation to switch anodic/cathodic ECL is very challenging. Herein, we report that enzyme‐inspired Fe‐based single‐atom catalysts with axial N/C coordination structures (FeN5, FeN4© SACs) can generate specific ROS for cathodic/anodic ECL conversion. Mechanistic studies reveal that FeN5 sites prefer to produce highly active hydroxyl radicals and afford direct cathodic luminescence by promoting the cleavage of O−O bonds through N‐induced electron redistribution. In contrast, FeN4© sites tend to produce superoxide radicals, resulting in inefficient anodic ECL. Benefiting from the enhanced cathodic ECL, FeN5 SAC‐based immunosensor was constructed for the sensitive detection of cancer biomarkers.

White-rot fungi scavenge reactive oxygen species, which drives pH-dependent exo-enzymatic mechanisms and promotes CO2 efflux.

Soil organic matter (SOM) decomposition mechanisms in rainforest ecosystems are governed by biotic and abiotic procedures which depend on available oxygen in the soil. White-rot fungi (WRF) play an important role in the primary decomposition of SOM via enzymatic mechanisms (biotic mechanism), which are linked to abiotic oxidative reactions (e.g., Fenton reaction), where both processes are dependent on reactive oxygen species (ROS) and soil pH variation, which has yet been studied. In humid temperate forest soils, we hypothesize that soil pH is a determining factor that regulates the production and consumption of ROS during biotic and abiotic SOM decomposition. Three soils from different parent materials and WRF inoculum were considered for this study: granitic (Nahuelbuta, Schizophyllum commune), metamorphic (Alerce Costero, Stereum hirsutum), and volcanic-allophanic (Puyehue, Galerina patagonica). CO2 fluxes, lignin peroxidase, manganese peroxidase, and dye-decolorizing peroxidase levels were all determined. Likewise, the production of superoxide anion (O2•-), hydrogen peroxide (H2O2), and hydroxyl radicals (•OH) were assessed in soils microcosms after 36 days of anaerobic incubation with WRF inoculum and induced Fenton reaction under pH variations ranging from 2.5 to 5.1. ROS significantly increased biotic and abiotic CO2 emissions in all tested soils, according to the findings. The highest values (217.45 mg C kg-1) were found during the anaerobic incubation of sterilized and inoculated soils with WRF at a natural pH of 4.5. At pH 4.0, the lowest levels of C mineralization (82 mg C kg-1) were found in Nahuelbuta soil. Enzyme activities showed different trends as pH changed. The Fenton reaction consumed more H2O2 between pH 3 and 4, but less between pH 4.5 and 2.5. The mechanisms that oxidized SOM are extremely sensitive to variations in soil pH and the stability of oxidant radical and non-radical compounds, according to our findings.

Synthesis of Bi-Metallic-Sulphides/MOF-5@graphene Oxide Nanocomposites for the Removal of Hazardous Moxifloxacin

The development of new and advanced materials for various environmental and energy applications is a prerequisite for the future. In this research, the removal of hazardous moxifloxacin (MOX) is accomplished by synthesizing new hybrids of MOF-5 i.e., Ni/Mo.S2/MOF-5/GO, Ni.S2/MOF-5/GO, Mo.S2/MOF-5/GO, and Ni/Mo.S2/MOF-5 nanocomposites by using a metal-organic framework (MOF-5) and graphene oxide (GO) as a precursor. The introduction of NixMoxS2 facilitates the unique interfacial charge transfer at the heterojunction, demonstrating a significant improvement in the separation effectiveness of the photochemical electron-hole pairs. To evaluate equilibrium adsorption capacity, time, pH, and concentration of organic pollutants were used as experimental parameters. The adsorption kinetics data reveals pseudo-first-order (R2 = 0.965) kinetics when Ni/Mo.S2/MOF-5/GO photocatalyst was irradiated under light for 90 min against MOX degradation. This led to a narrow energy band gap (2.06 eV in Ni/Mo.S2/MOF-5/GO, compared to 2.30 eV in Ni/Mo.S2/MOF-5), as well as excellent photocatalytic activity in the photodegradation of moxifloxacin (MOX), listed in order: Ni/Mo.S2/MOF-5/GO (95%) > Ni.S2/MOF-5/GO (93%) > Mo.S2/MOF5/GO (90%) > Ni/Mo.S2/MOF-5 (86%) in concentrations up to 2.0 mgL−1, caused by the production of superoxide (O2•−) and hydroxide (OH•) radicals, which encouraged the effective photocatalytic activities of the heterostructure. After five successive tests demonstrating its excellent mechanical stability, the impressive recyclability results for the Ni/Mo.S2/MOF-5/GO revealed only a tiny variation in efficiency from 95% (for the first three runs) to 93% (in the fourth run) and 90% (in the fifth run). These findings show that the heterostructure of Ni/Mo.S2/MOF-5/GO is an effective heterojunction photocatalyst for the quick elimination of moxifloxacin (MOX) from aqueous media.

Differences in Physiological Responses of Two Tomato Genotypes to Combined Waterlogging and Cadmium Stresses.

Waterlogging and heavy mental (e.g., cadmium) stress are two primary threats to crop growth. The combination of abiotic stresses was common and frequent, especially in the field condition. Even though the effects of individual waterlogging and cadmium on tomato plants have been widely investigated, the response of tomatoes under combined waterlogging and cadmium stress remains unclear. This study aimed to clarify and compare physiological, biochemical characteristics and plant growth of two tomato genotypes under individual and combined stress. Two tomato genotypes ('MIX-002' and 'LA4440') were treated under control, waterlogging, cadmium stress and their combination. The results showed that chloroplast ultrastructure of tomatoes under individual and combined stress was damaged with disordered stroma and grana lamellae. The H2O2 (hydrogen peroxide) content and O2·- (superoxide anion radical) production rate of plants under all the three stresses was not significantly higher than the control except for 'LA4440' under the combined stress. Antioxidant enzymes actively responded in the two tomato genotypes, as shown by significant increase in SOD activity from 'MIX-002' under waterlogging and combined stress and from 'LA4440' under cadmium. Meanwhile, CAT activity of 'MIX-002' under waterlogging and 'LA4440' under combined stress significantly decreased, and the POD activity of 'MIX-002' under combined stress significantly increased as compared with the respective control. The APX activity of 'MIX-002' and 'LA4440' under combined stress was significantly lower and higher than the respective controls. This indicated that tomato plants were able to secure redox homeostasis and protect plants from oxidative damage through the synergetic regulation of antioxidant enzymes. Plant height and biomass of the two genotypes under individual and combined stress significantly decreased, which could be a direct result from the chloroplast alteration and resource re-allocation. Overall, the effects of combined waterlogging and cadmium stress were not simply the sum of individual effects on two tomato genotypes. Distinct ROS (reactive oxygen species) scavenging systems of two tomato genotypes under stresses suggest a genotype-dependent antioxidant enzymes regulation.

Assessing the Rheological, Mechanical, and Photocatalytic Properties of Niobium Oxide-Incorporated White Cement Pastes.

Niobium oxide (Nb2O5) is a semiconductor that exhibits photocatalytic properties, making it potentially valuable in addressing air pollution, self-cleaning, and self-disinfection in cement-based materials (CBMs). Therefore, this study aimed to evaluate the impact of different Nb2O5 concentrations on various parameters, including rheological characteristics, hydration kinetics (measured using isothermal calorimetry), compressive strength, and photocatalytic activity, specifically in the degradation of Rhodamine B (RhB) in white Portland cement pastes. The incorporation of Nb2O5 increased the yield stress and viscosity of the pastes by up to 88.9% and 33.5%, respectively, primarily due to the larger specific surface area (SSA) provided by Nb2O5. However, this addition did not significantly affect the hydration kinetics or the compressive strength of the cement pastes after 3 and 28 days. Tests focusing on the degradation of RhB in the cement pastes revealed that the inclusion of 2.0 wt.% of Nb2O5 was insufficient to degrade the dye when exposed to 393 nm UV light. However, an interesting observation was made concerning RhB in the presence of CBMs, as it demonstrated a degradation mechanism that was not dependent on light. This phenomenon was attributed to the production of superoxide anion radicals resulting from the interaction between the alkaline medium and hydrogen peroxide.

OXIDATIVE MECHANISMS UNDERLYING BRAIN CELL DAMAGE IN RATS UNDER CHANGES IN DURATION OF THE LIGHTDARK CYCLES

One of the main mechanisms underlying cell damage is lipid peroxidation, which is characterized by increased levels of free radical, products of lipid peroxidation chain reactions, and alterations in the activity of the antioxidant system in tissues. Therefore, the objective of this study is to investigate the proand antioxidant balance in rat brain homogenate under conditions of disrupted "light-dark" cycles. The study involved 28 white Wistar rats weighing 150-200 gm, divided into two groups: control (15) and the group of animals exposed to acute desynchronosis simulation (13). To simulate desynchronosis, a normal "light-dark" cycle of 12 hours of light and 12 hours of darkness was initially established for three weeks, followed by a shift of the "light-dark" phases backward by six hours over the next three days. The animals were kept in standard conditions with a balanced diet in the vivarium, and the study adhered to the principles of biomedical ethics.
 The results obtained indicate a significant increase in the activity of superoxide anion radical production in the brain tissues of the rats with modelled desynchronosis by 75.8% compared to the control group. This increase is attributed to the NADPH-oxidase mechanism by 20.2% and to xanthine oxidase mechanisms by 28%. The concentration of TBA-active products increased by 36.8%, the growth of TBA-active products elevated by 30%, and the activity of the key antioxidant enzymes, superoxide dismutase and catalase, decreased by 53% and 14%, respectively, in the second group of animals. Furthermore, in the brain tissues of rats with disrupted "light-dark" cycles, there were found elevated levels of nitrites by 23.8%, nitrosothiols by 19%, and peroxynitrites by 69%, along with a reduction in the activity of total NO-synthase by 59.1%, inducible NO-synthase by 61.1%, and constitutive NO-synthase by 9% compared to the control group. The activity of ornithine decarboxylase increased by 26.5% in the brain tissues of the rats with simulated desynchronosis compared to the control group.
 In conclusion, the disruption of "light-dark" cycles leads to the development of oxidative stress in brain tissues of animals and is characterized by increased production of reactive oxygen species and diminished antioxidant protection. Acute desynchronosis decreases nitric oxide production through the NO-synthase pathway, while increasing the accumulation of toxic nitric oxide metabolites in the brain tissues of rats, thereby posing a potential risk of nitrosative stress. Furthermore, alterations in the normal light regimen of the day activate the arginase pathway of L-arginine metabolism and result in increased glutamate production in the brain tissues of rats, potentially leading to oxidative stress.

The role of reactive oxygen species and redoxsensitive protein kinases in the infarction-limiting effect of opioid peptide deltorphin II in cardiac reperfusion in rats

Background. Mortality from acute myocardial infarction with ST-segment elevation in cardiac hospitals ranges from 4.5 to 7 %, and these data has not decreased in recent years. The most common cause of death in patients is cardiogenic shock, the likelihood of which directly depends on infarct size. It is quite clear that there is an urgent need to create drugs to limit the size of infarction and prevent the occurrence of cardiogenic shock.The aim. To evaluate the role of reactive oxygen species and redox-sensitive protein kinases in the infarction-limiting effect of opioid peptide deltorphin II in cardiac reperfusion in rats.Materials and methods. Coronary occlusion (45 min) and reperfusion (120 min) were performed in rats anesthetized with α-chloralose. The selective δ2-opioid receptor agonist deltorphin II, a hydroxyl radical scavenger 2-mercaptoprpionyl glycine (2-MPG), a superoxide radical scavenger tempol, the protein kinase Cδ (PKCδ) inhibitor rottlerin, the PI3-kinase inhibitor wortmannin, the inhibitor of ERK1/2 kinase PD98059 were injected before of reperfusion of the heart.Results. Deltorphin II contributed to a two-fold decrease in infarction size. Injection of 2-MPG, tempol, rottlerin, wortmannin, PD98059 alone had no effect on infarction size in rats. 2-MPG and tempol did not affect the infarction-reducing effect of deltorphin II. Rottlerin, wortmannin, and PD98059 eliminated the cardioprotective effect of deltorphin II.Conclusion. The infarction-reducing effect of deltorphin II does not depend on the production of superoxide radical and hydroxyl radical. Superoxide radical and hydroxyl radical do not play a significant role in reperfusion injury of the heart after coronary occlusion (45 min). PKCδ, PI3-kinase, and ERK1/2 kinase are involved in the infarction-limiting effect of deltorphin II in myocardial reperfusion.

Custom-Made Piezoelectric Solid Solution Material for Cancer Therapy.

Piezoelectric material-mediated sonodynamic therapy (SDT) has received considerable research interest in cancer therapy. However, the simple applications of conventional piezoelectric materials do not realize the full potential of piezoelectric materials in medicine. Therefore, the energy band structure of a piezoelectric material is modulated in this study to meet the actual requirement for cancer treatment. Herein, an elaborate PEGylated piezoelectric solid solution 0.7BiFeO3 -0.3BaTiO3 nanoparticles (P-BF-BT NPs) is synthesized, and the resultant particles achieve excellent piezoelectric properties and their band structure is tuned via band engineering. The tuned band structure of P-BF-BT NPs is energetically favorable for the synchronous production of superoxide radicals (•O2 - ) and oxygen (O2 ) self-supply via water splitting by the piezoelectric effect. Besides, the P-BF-BT NPs can initiate the Fenton reaction to generate hydroxyl radical (•OH), and thus, chemodynamic therapy (CDT) can be augmented by ultrasound. Detailed in vitro and in vivo research has verified the promising effects of multimodal imaging-guided P-BF-BT NP-mediated synergistic SDT/CDT by the piezo-Fenton process in hypoxic tumor elimination, accompanied by high therapeutic biosafety. The current demonstrates a novel strategy for designing and synthesizing "custom-made" piezoelectric materials for cancer therapy in the future.

Enhanced degradation of carbamazepine by electrochemical activation of peroxymonosulfate with PTFE/black carbon as cathode

Sulfate radical (SO4•−)-based advanced oxidation processes (AOPs), such as the electro-activated peroxymonosulfate (E-PMS) process, have shown great potential for environmental remediation. As oxygen competes with PMS for electrons at the cathode in the E-PMS process, oxygen was proposed to be one of the negative factors reducing the generation of SO4•− in previous studies. Surprisingly, our preliminary experiment found that polytetrafluoroethylene-black carbon (PBC), which could efficiently produce H2O2 in the E-PMS process as a cathode, could produce an 18.4 times greater steady-state concentration of SO4•− than Pt cathodes with nearly no production of H2O2. In addition, the generation of SO4•− in the E-PMS process with a Pt cathode can also be significantly enhanced by dosing H2O2 in the system. Quenching experiments and electron paramagnetic resonance (EPR) analysis demonstrated that H2O2 could react with PMS at the cathode to produce superoxide radicals (O2•−). Furthermore, O2•− reacted with PMS in solution to generate SO4•−. In addition, the influence of various water matrices on carbamazepine (CBZ) removal was also discussed. Finally, the degradation pathways of CBZ were proposed and corresponding toxicity of products was analyzed by ecological structure activity relationships (ECOSAR) analysis. This study may present novel and fundamental insights into the E-PMS process and a simple and convenient approach to regulate the generation of SO4•− during PMS activation.