Amount Of Peroxide Research Articles

A novel [1,2,4]triazolo[1,5-a]pteridine framework: Synthesis, photophysical properties and material studies

The synthesis of novel [1,2,4]triazolo[1,5-a]pteridine (TPt) derivatives was carried out starting from [1,2,4]triazolo[1,5-a]pyrimidine-6,7-diamines and 1,2-dicarbonyl compounds. For obtained TPt DFT/TD-DFT calculations were performed with subsequent complex photophysical and electrochemical studies. The substituent in the pyrazine ring of TPt framework proved to have a higher effect on photophysical properties than that in the triazole ring. The fluorescence quantum yields of studied compounds were generally low (3–23%). However, it was shown that some of TPt was sensitive to trace amounts of organic peroxides (about 100 ppm), which will make it possible to create test systems based on them. On the other hand, low-lying HOMO energy levels and the energy gap values of TPt (2.63 eV < E0-0 < 2.97 eV) as well as the electron mobility in solid-state films measured by the conventional CELIV technique (approximately 10−4 cm2 V−1 s−1) make these materials promising for the further use in organic electronic devices.

Process research on the preparation of high-purity cobalt chloride by chemical precipitation

As the precursor of high-purity cobalt, the purity of cobalt chloride has an important influence on the properties of the cobalt target prepared subsequently. In recent years, in addition to ion exchange and extraction, chemical precipitation is a promising method for the purification of cobalt chloride. High-purity cobalt chloride was prepared by chemical precipitation with ammonium hydroxide and dimethylglyoxime as precipitants. The purification mechanism of high-purity cobalt chloride and the depletion mechanism of the main element Co were studied. Inductively coupled plasma-mass spectrometry (ICP-MS) and X-ray diffraction (XRD) were used to characterize the ion concentration, precipitate phase, and depletion products of the main element Co in the solution. The results show that the concentration of impurity elements Al, Cu, and Cr in cobalt chloride solution can be reduced to less than 0.5 mg/L and the concentration of Fe can be reduced to less than 2 mg/L after removing impurities with ammonia. When a small amount of hydrogen peroxide is added to the solution, the concentration of impurity Fe can be reduced to less than 0.82ug/L. In an alkaline environment where nickel dimethylglyoxime is generated, the main element Co is mainly depleted in the form of [Co(NH3)5Cl]Cl2.

Ch1 (Vitis vinifera L.) Rootstock Control of Scion Response to Water Stress in Some Commercial Grapevine Cultivars

Drought stress is the most important environmental factor limiting the growth, development and yield of crop plants and horticulture. In this study, the induction of drought resistance in commercial cultivars (as scion) by the Ch1 rootstock was evaluated based on physiological and biochemical responses. Factorial experiment was performed in a completely randomised design (CRD) with three replications in the greenhouse. Plant materials consisted of five commercial grapevine cultivars (own-rooted plants of Black seedless, Flame seedless, Turkman seedless, Sultana and Shahani, and the scion of these cultivars grafted onto Ch1 rootstock). Drought stress treatment comprised stopping irrigation for 30 days from July to August, and not stopping irrigation was the control. Drought stress significantly reduced the membrane stability index (MSI) and the relative water content (RWC), and increased electrolyte leakage (EL), catalase, hydrogen peroxide, proline, ascorbic acid, guaiacol peroxidase, protein, sodium and potassium levels (P &lt; 0.05). The EL and MSI in the Ch1 rootstock under drought stress decreased by 18.38% and 14.86% respectively. The Ch1 rootstock significantly increased the amount of proline, total protein and enzyme activity of guaiacol peroxidase and catalase in cultivars in a drought stress environment. The amount of hydrogen peroxide decreased in all cultivars grafted on Ch1 in both drought stress and non-drought stress environments, by 14.3% and 18.9% respectively. Sultana cultivar grafted on Ch1 rootstock showed the highest drought resistance. Therefore, it can be concluded that the Ch1 rootstock is recommended as a rootstock for inducing drought resistance in grapevine cultivar scions.

Antimicrobial Effects of Lactic Acid Bacteria on Food-Borne Pathogens Isolated from Some Fruits Sold in Ibadan, Nigeria

This study was conducted to determine the antimicrobial effect of Lactic acid bacteria on food-borne pathogens isolated from some fruits sold in Ibadan, Nigeria. Lactobacillus species isolated from healthy fruits include L. casei, L. brevis, L. desidosus, L. jenseni, Lactiplantibacillus plantarum and Fructilactobacillus spp. while Aeromonas hydrophylia, Enterobacter aerogene, Escherichia coli, Salmonella typhii, Shigella dysentriae, Pseudomonas fluorescens, Bacillus megaterium, Candida valida, Saccharomyces cerevisiae, Rhizopus stolonifer were isolated from spoilt fruits using pour plate technique and biochemical test. Gram-negative isolates were 100% resistant to Cefuroxime, Amoxycillin/Clauvulanate, and Ampicillin while 93.75% of the isolates were highly sensitive to Ofloxacin. Gram-positive isolates were 100% resistant to Cloxicillin and highly sensitive to Ofloxacin and Gentamycin using an antibiotic disc. Lactiplantibacillus plantarum had the highest amount of Lactic acid (5.6 g/l) while L. casei had the lowest yield (3.6 g/l) at 48 hours. L. casei had the highest amount of hydrogen peroxide (0.00036 g/l) while Lactiplantibacillus plantarum. and Fructilactobacillus spp. had the lowest yield (0.00021 g/l) at 48 hours. The highest amount of diacetyl (3.01 g/l) was produced by L. jenseni while the lowest amount was observed in L. brevis (0.43 g/l) at 48 hours. The maximum inhibitory activity was observed in L. brevis against B. megaterum with a diameter of 18mm zone of inhibition while the minimum activity by L. desidosus, L. jenseni, Fructilactobacillus spp. was observed against B. subtilis and Lactiplantibacillus plantarum against K. pneumoniae with diameter 8 mm zone of inhibition. The antimicrobial compounds produced by the Lactic Acid Bacterial had antimicrobial effects on food-borne pathogens.

Modulation of nutritional and biochemical status of hydroponically grown Cucurbita pepo L. by Calcium Nitrate under saline conditions

Salinity is one of the critical environmental factors that decreases the water availability and induces nutritional imbalance in crops. In order to study the effect of calcium nitrate [(Ca(NO3)2] in the nutrient solution under salinity conditions, an experiment was designed with different salinity (0, 50, and 100 mM) and Ca(NO3)2 (2, 3, and 4 mM) levels on Cucurbita pepo (zucchini). Based on the results, an increase in the salinity from 0 to 100 mM caused a decrease in the leaf potassium and calcium concentration, whereas the iron, magnesium and zinc concentrations increased. The most effective Ca(NO3)2 level in increasing the nutritional quality and yield of zucchini was 3 and 4 mM. Salinity at 50 and 100 mM significantly increased the leaf sodium concentration and leaf area as well as the leaf number per plant, while the application of both Ca(NO3)2 levels modulated the harmful effects of salinity. The amount of malondialdehyde (MDA), proline and hydrogen peroxide (H2O2) as well as the catalase (CAT) activity increased under the severe salinity conditions, whereas the application of 4 mM Ca(NO3)2 had the potential of removing the negative effects of severe salinity. The catalase activity increased along with the increase in the Ca(NO3)2 concentration, which was independent from the salinity level. However, the amount of proline, MDA and H2O2 decreased in plants fed with 3 and 4 mM Ca(NO3)2 compared to the control in the presence of salinity. These findings suggest that both the 3 and 4 mM concentrations of Ca(NO3)2 under 50 mM salinity could be used to improve the zucchini performance by maintaining the ion homeostasis and inducing the antioxidant defence system.

A versatile supramolecular nanoagent for three-pronged boosting chemodynamic therapy

Chemodynamic therapy (CDT) utilizing toxic hydroxyl radicals (·OH) to kill cancer cells exhibits huge potentiality in antitumor treatment. However, inadequate acidity, insufficient hydrogen peroxide (H2O2) amount, and overexpressed reduced glutathione (GSH) inside cancer cells severely restrict the efficacy of CDT. Although numerous efforts have been made, fabricating a versatile CDT material for surmounting these obstacles simultaneously is still a great challenge, especially for supramolecular materials owing to lacking an active metal unit for the Fenton reaction. Here, we intriguingly proposed a powerful supramolecular nanoagent (GOx@GANPs) based on the host–guest interaction between pillar[6]arene and ferrocene for all-sided boosting CDT efficacy via in situ cascade reactions. GOx@GANPs could stimulate intracellular glucose conversion into H+ and H2O2 to optimize the in situ Fenton reaction conditions and continuously produce sufficient •OH. Meanwhile, consumption of the original intracellular GSH pool and inhibition of GSH regeneration were synchronously achieved through the GSH-responsive gambogic acid prodrug and cutting off adenosine triphosphate (ATP) supply for GSH resynthesis, respectively. This complete GSH exhausting characteristic of GOx@GANPs effectively suppressed •OH elimination, ultimately resulting in a superior CDT effect. Furthermore, GOx@GANPs also produced synergistic effects of starvation therapy, chemotherapy, and CDT, exhibiting low toxicity toward normal tissues. Thus, this work introduces a valuable way for optimizing and elevating CDT efficiency and synergistic treatment of tumors.

Synergistic Effects of Kaolin and Silicon Nanoparticles for Ameliorating Deficit Irrigation Stress in Maize Plants by Upregulating Antioxidant Defense Systems.

Water deficit is a significant environmental stress that has a negative impact on plant growth and yield. In this research, the positive significance of kaolin and SiO2 nanoparticles in moderating the detrimental effects of water deficit on maize plant growth and yield is investigated. The foliar application of kaolin (3 and 6%) and SiO2 NPs (1.5 and 3 mM) solutions increased the growth and yield variables of maize plants grown under normal conditions (100% available water) and drought stress conditions (80 and 60% available water (AW)). In addition, plants treated with SiO2 NPs (3 mM) demonstrated increased levels of important osmolytes, such as proline and phenol, and maintained more of their photosynthetic pigments (net photosynthetic rate (PN), stomatal conductance (gs), intercellular CO2 concentration (Ci), and transpiration rate (E)) than with other applied treatments under either stress or non-stress conditions. Furthermore, the exogenous foliar application of kaolin and SiO2 NPs also reduced the amounts of hydroxyl radicals (OH), superoxide anions (O2), hydrogen peroxide (H2O2), and lipid peroxidation in maize plants experiencing a water deficit. In contrast, the treatments led to an increase in the activity of antioxidant enzymes such as peroxidase (POX), ascorbate peroxidase (APX), glutathione peroxidase (GR), catalase (CAT), and superoxide dismutase (SOD). Overall, our findings indicate the beneficial impact of the application of kaolin and silicon NPs, particularly the impact of SiO2 NPs (3 mM) on managing the negative, harmful impacts of soil water deficit stress in maize plants.

Mild-temperature responsive nanocatalyst for controlled drug release and enhanced catalytic therapy

Owing to the advantages of the in situ production of toxic agents through catalytic reactions, nanocatalytic therapy has arisen as a highly potential strategy for cancer therapeutics in recent years. However, the insufficient amount of endogenous hydrogen peroxide (H2O2) in the tumor microenvironment commonly limits their catalytic efficacy. Here, we employed carbon vesicle nanoparticles (CV NPs) with high near-infrared (NIR, 808 nm) photothermal conversion efficiency as carriers. Ultrafine platinum iron alloy nanoparticles (PtFe NPs) were grown in situ on the CV NPs, where the highly porous nature of the resultant CV@PtFe NPs was employed to encapsulate a drug, β-lapachone (La), and phase-change material (PCM). As a multifunctional nanocatalyst CV@PtFe/(La-PCM) NPs can exhibit a NIR-triggered photothermal effect and activate cellular heat shock response, which upregulates the downstream NQO1 via HSP70/NQO1 axis to facilitate bio-reduction of the concurrently melted and released La. Moreover, sufficient oxygen (O2) is supplied by CV@PtFe/(La-PCM) NPs catalyzed at the tumor site to reinforce the La cyclic reaction with abundant H2O2 generation. This promotes the bimetallic PtFe-based nanocatalysis, which breaks H2O2 down into highly toxic hydroxyl radicals (•OH) for catalytic therapy. Our results show that this multifunctional nanocatalyst can be used as a versatile synergistic therapeutic agent with NIR-enhanced nanocatalytic tumor therapy by tumor-specific H2O2 amplification and mild-temperature photothermal therapy, which holds promising potential for targeted cancer treatment. Statement of significanceWe present a multifunctional nanoplatform with mild-temperature responsive nanocatalyst for controlled drug release and enhanced catalytic therapy. This work aimed at not only reduce the damage to normal tissues caused by photothermal therapy, but also improves the efficiency of nanocatalytic therapy by stimulating endogenous H2O2 production through photothermal heat. In vitro and in vivo confirmed that CV@PtFe/(La-PCM) NPs exhibited powerful and overall antitumor effects. This formulation may provide an alternative strategy for the development of the mild- photothermal enhanced nanocatalytic therapy effect in solid tumor.

Mammalian Animal and Human Retinal Organ Culture as Pre-Clinical Model to Evaluate Oxidative Stress and Antioxidant Intraocular Therapeutics.

Oxidative stress (OS) is involved in the pathogenesis of retinal neurodegenerative diseases such as age-related macular degeneration (AMD) and diabetic retinopathy (DR) and an important target of therapeutic treatments. New therapeutics are tested in vivo despite limits in terms of transferability and ethical concerns. Retina cultures using human tissue can deliver critical information and significantly reduce the number of animal experiments along with increased transferability. We cultured up to 32 retina samples derived from one eye, analyzed the model's quality, induced OS, and tested the efficiency of antioxidative therapeutics. Bovine, porcine, rat, and human retinae were cultured in different experimental settings for 3-14 d. OS was induced by a high amount of glucose or hydrogen peroxide (H2O2) and treated with scutellarin, pigment epithelium-derived factor (PEDF), and/or granulocyte macrophage colony-stimulating factor (GM-CSF). The tissue morphology, cell viability, inflammation, and glutathione level were determined. The retina samples showed only moderate necrosis (23.83 ± 5.05 increased to 27.00 ± 1.66 AU PI-staining over 14 d) after 14 days in culture. OS was successfully induced (reduced ATP content of 288.3 ± 59.9 vs. 435.7 ± 166.8 nM ATP in the controls) and the antioxidants reduced OS-induced apoptosis (from 124.20 ± 51.09 to 60.80 ± 319.66 cells/image after the scutellarin treatment). Enhanced mammalian animal and human retina cultures enable reliable, highly transferable research on OS-triggered age-related diseases and pre-clinical testing during drug development.

Non thermal 2.45 GHz electromagnetic exposure causes rapid changes in Arabidopsis thaliana metabolism

Numerous studies report different types of responses following exposure of plants to high frequency electromagnetic fields (HF-EMF). While this phenomenon is related to tissue heating in animals, the situation is much less straightforward in plants where metabolic changes seem to occur without tissue temperature increase. We have set up an exposure system allowing reliable measurements of tissue heating (using a reflectometric probe and thermal imaging) after a long exposure (30 min) to an electromagnetic field of 2.45 GHz transmitted through a horn antenna (about 100 V m−1 at the plant level). We did not observe any heating of the tissues, but we detected rapid increases (60 min) in the accumulation of transcripts of stress-related genes (TCH1 and ZAT12 transcription factor) or involved in ROS metabolism (RBOHF and APX1). At the same time, the amounts of hydrogen peroxide and dehydroascorbic acid increased while glutathione (reduced and oxidized forms), ascorbic acid, and lipid peroxidation remained stable. Therefore, our results unambiguously show that molecular and biochemical responses occur rapidly (within 60min) in plants after exposure to an electromagnetic field, in absence of tissue heating.

Engineered Biomimetic Copper Sulfide Nanozyme Mediates "Don't Eat Me" Signaling for Photothermal and Chemodynamic Precision Therapies of Breast Cancer.

The rapid development of nanomedicine has brought hope and confidence to the precise treatment of tumors. However, the efficacy of nanoparticle-mediated therapy is severely limited due to phagocytosis and clearance by macrophages. CD47 is a well-documented ″don't eat me″ signaling molecule that binds to the SIRPα receptor on the macrophage surface, inhibiting the phagocytic behavior of the macrophages. In this study, CD47-overexpressing cancer cell membranes were used to coat hollow copper sulfide nanoparticles. The nanoparticles were shown to have an extended circulatory half-life and to actively target breast cancer, leading to increased accumulation in the tumor tissue. An excellent photothermal therapeutic effect was produced by near-infrared laser irradiation. At the same time, β-lapachone within the nanoparticles generated large amounts of hydrogen peroxide in the tumor environment, which was then catalyzed by the copper sulfide nanozyme to cytotoxic hydroxyl radicals, exerting a chemodynamic therapeutic effect. This engineered biomimetic nanozyme, through the mediation of the ″don't eat me″ signal, achieved both photothermal and chemodynamic precision treatments of breast cancer, creating a new mode of safe and effective tumor treatment.

Functionalized Poly(ethylene-octene)/Linear Low-Density Polyethylene Prepared by Melt Free-radical Grafting Reaction and Its Potential in Toughening Poly(butylene terephthalate) Resins

Glycidyl methacrylate (GMA) and styrene (St) were used as the graft monomer and co-graft monomer, respectively, and grafted onto poly(ethylene-octene) (POE) and linear low-density polyethylene (LLDPE) to prepare a series of GMA-functionalized (POE/LLDPE)-g-(GMA-co-St) graft copolymers. The copolymers were then blended with poly(butylene terephthalate) (PBT) to produce PBT/(POE/LLDPE)-g-(GMA-co-St) blends. The effects of grafting factors and copolymer content on the mechanical properties, thermal properties, rheology, morphology, and deformation mechanism of the blends were studied in detail. The results showed that GMA and St were successfully grafted onto the molecular chains of POE and LLDPE. In the grafting reaction, the best grafting degree and comprehensive performance were achieved when the amounts of dicumyl peroxide and GMA were 0.3 and 5 wt %, respectively, the mass ratio of GMA to St was 1:2, and the screw rotation speed was 60 rpm. By introducing graft copolymers into the PBT matrix, the toughness and thermal stability of the blends were improved. At the same time, the crystallinity and fluidity decreased, and the blends possessed the best mechanical properties when the copolymer content was 20 wt %, with the elongation at break and notched impact strength increasing to 409.98% and 945.90 J/m, respectively. Scanning electron microscopy analysis showed that the copolymers were uniformly dispersed in the PBT matrix. The principal toughening mechanisms were the shear-yielding properties of the PBT matrix and cavitation of (POE/LLDPE)-g-(GMA-co-St) phases.

In Situ Fabrication of Silver Peroxide Hybrid Ultrathin Co-Based Metal-Organic Frameworks for Enhanced Chemodynamic Antibacterial Therapy.

Bacterial-induced infectious diseases have always caused an unavoidable problem and lead to an increasing threat to human health. Hence, there is an urgent need for effective antibacterial strategies to treat infectious diseases. Current methods are often ineffective and require large amounts of hydrogen peroxide (H2O2), with harmful effects on normal healthy tissue. Chemodynamic therapy (CDT) provides an ideal infection microenvironment (IME)-activated paradigm to tackle bacterial-related diseases. To take full advantage of the specificity of IME and enhanced CDT for wounds with bacterial infection, we have designed an intelligent antibacterial system that exploits nanocatalytic ZIF-67@Ag2O2 nanosheets. In this system, silver peroxide nanoparticles (Ag2O2 NPs) were grown on ultrathin zeolitic imidazolate framework-67 (ZIF-67) nanosheets by in situ oxidation, and then, ZIF-67@Ag2O2 nanosheets with the ability to self-generate H2O2 were triggered by the mildly acidic environment of IME. Lamellar ZIF-67 nanosheets were shown to rapidly degrade and release Co2+, allowing the conversion of less reactive H2O2 into the highly toxic reactive oxygen species hydroxyl radicals (•OH) for enhanced CDT antibacterial properties. In vivo results revealed that the ZIF-67@Ag2O2 nanosheet system exhibits excellent antibacterial performance against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The proposed hybrid strategy demonstrates a promising therapeutic strategy to enable antibacterial agents with IME-responsive nanocatalytic activity to circumvent antibiotic resistance against bacterial infections.

Biosynthesis, characterization, and determination of trace hydrogen peroxide of Organo-Cr(III) nanoparticles by Lysinibacillus sp. 4H

The mechanism of microbial reduction of Cr(VI) has been widely reported; however, only a few studies have focused on Cr(VI) reduction products. In this study, a green synthetic pathway for the biosynthesis of Organo-Cr(III) nanoparticles using Lysinibacillus sp. 4H was investigated, and some properties of these nanoparticles were characterized, based on analysis using X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy, among other techniques. The analyses revealed that the reduction product induced by Lysinibacillus sp. 4H may be amorphous Organo-Cr(III) nanoparticles with an irregular spherical structure (20–90 nm). Thermal characterization of the nanoparticles showed that they maintain a high residual mass (50.45%) at 700 °C, indicating high stability. In addition, the nanoparticles were capable of detecting trace amounts of hydrogen peroxide (H2O2), owing to their redox properties, such that the corresponding H2O2 concentrations could be accurately determined in a range of concentrations. This study provided novel insights and strategies regarding the use of nanoparticles to detect trace hydrogen peroxide concentrations in multiple fields.

Cerebrovascular function is protected in hepatic xanthine oxidase knockout mice under chronic stress

Americans have been facing a mental health crisis that is predicted to impact and yield long-term psychological and physiological consequences negatively. We have shown that exposure to chronic stress can induce a pro-oxidative environment leading to cerebrovascular dysfunction and cognitive impairment. Xanthine oxidoreductase (XOR) is an enzyme that generates xanthine oxidase (XO) and xanthine dehydrogenase (XDH). Under hypoxic or pro-inflammatory conditions, XO produces excessive amounts of hydrogen peroxide and superoxide, which plays an important role in this stress-induced cerebrovascular dysfunction. Pharmacologically inhibiting XO with Febuxostat (50 mg/L) prevented stress-induced cerebrovascular dysfunction. XO is found in multiple tissues/organs; however, the liver is the major source of XO. Thus, this study aimed to understand how XO produced from the liver impacted cerebrovascular function during chronic stress. We hypothesize that liver XO production mediates stress-induced cerebrovascular dysfunction. To test our hypothesis, we exposed wild-type (WT) and hepatic XO knockout mice (HXO) to eight weeks of unpredictable chronic mild stress (UCMS) with or without Febuxostat (Feb). Groups were separated by HXO-control, HXO-UCMS, HXO-UCMS+Feb, WT-con, WT-UCMS, and WT-UCMS+Feb. During terminal procedures, the middle cerebral artery (MCA) was isolated and assessed using pressure myography to test the endothelial-dependent (EDD) and endothelium-independent dilation (EID) to acetylcholine (ACh) and sodium nitroprusside (SNP). The isolated MCA was kept under physiological conditions (pH 7.4±0.2; 70±2 mmHg, 37±1℃). In WT mice, UCMS decreased by 50% EDD (p&lt;0.0001) and did not affect EID compared to WT-con, whereas the WT-UCMS+Feb group was fully protected, with similar EDD and EID values compared to WT-con. In contrast, HXO mice were partially protected from UCMS, reflected by only a 24% decrease (p&lt;0.0001) in EDD and no change in EID. However, the HXO-UCMS+Feb group was fully protected with similar EDD and EID values to control mice. Our data shows that the liver significantly contributes to stress-induced cerebrovascular dysfunction. However, additional sources of XO circulation within the cerebrovasculature need further investigation. NIH, NINDS BINP R01 NS1117754, Psychosocial Stress-Induced Vascular Contributions to Cognitive Impairment and Alzheimer's. Disease: The Role of Xanthine Oxidase, NIH F31 Diversity Award, US DHHS-NIH-National Institute on Aging, Role of Xanthine Oxidase on Vascular Contributions to Cognitive Impairment This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Characterization of selenium nanoparticles extracted from Bacillus subtilis and its antibacterial effects in Onychostoma macrolepis: Insight into ferroptosis

Selenium nanoparticles (SeNPs) were often used as growth and antioxidant capacity promoter. In this study, we found selenium nanoparticles (SeNPs) could improve the survival rate of Onychostoma macrolepis (O. macrolepis) fry as a feed additive after a challenged by Aeromonas hydrophila (A. hydrophila). To further explore the mechanism of SeNPs against bacterial infection, we examined the changes before and after bacterial infection, and the results showed that large amounts of peroxide were produced under A. hydrophila infection in O. macrolepis fry, and then the excessive accumulation of peroxides led to a large amount of ferroptosis in the liver. Interestingly, we found supplementing 0.9 mg/kg biogenic SeNPs decreased MDA, iron content, and enhanced T-AOC levels in the liver of O. macrolepis fry after a challenged by Aeromonas hydrophila (P˂0.01). Especially, the diet with 0.9 mg/kg biogenic SeNPs could significantly increase the expression level of Glutathione peroxidase-4 (GPX4), nuclear factor erythroid2-related factor 2 (Nrf2), and Ferroportin 1 (FPN1) in the liver of O. macrolepis after infection with A. hydrophila. In summary, the results of this research suggested that the diet with 0.9 mg/kg biogenic SeNPs was an optimal additive dose to improve the survival rate of O. macrolepis fry by increasing antioxidant capacity and inhibiting ferroptosis, which sheds a new light on the mechanism of antibacterial infection in fish from the perspective of ferroptosis.

Hypoxia Enhances Oxidative Stress in Neutrophils from ZZ Alpha-1 Antitrypsin Deficiency Patients.

Alpha-1 antitrypsin deficiency (AATD) is a neutrophilic inflammatory disorder that may result in local hypoxia, reactive oxygen and nitrogen species (ROS/RNS) production, and increased damage in adjacent tissues. This study aims to determine the impact of hypoxia on neutrophil oxidative stress profile in AATD patients. Neutrophils were isolated from AATD patients and control volunteers and exposed to hypoxia (1% O2 for 4 h), ROS/RNS, mitochondrial parameters, and non-enzymatic antioxidant defenses measured by flow cytometry. The expression of enzymatic antioxidant defenses was determined by qRT-PCR. Our results indicate that ZZ-AATD neutrophils produce higher amounts of hydrogen peroxide, peroxynitrite, and nitric oxide and decreased levels of the antioxidant enzymes catalase, superoxide dismutase, and glutathione reductase. Likewise, our results show a decrease in mitochondrial membrane potential, indicating that this organelle could be involved in the production of the reactive species observed. No decrease in glutathione and thiol levels were observed. The accumulation of substances with high oxidative capacity would explain the greater oxidative damage observed in proteins and lipids. In conclusion, our results indicate that, compared to MM control individuals, ZZ-AATD neutrophils show increased ROS/RNS production under hypoxic conditions opening a new rationale for using antioxidant therapies to treat the disease.

Güney Marmara Bölgesi’nde Tüketime Sunulan Tahin Helvalarının Kimyasal Kalitesi ve Standartlara Uygunluğu

In this study, three different tahini halva types (plain, cocoa and pistachio) from 15 different brands were obtained from various manufacturers or commercial markets in the Southern Marmara Region provinces of Balikesir, Bilecik, Bursa, and Canakkale. For each manufacturer, samples were obtained from two different lot numbers. The results of chemical analysis in tahini halva samples were as follows; the total amount of sugar was 39.45-43.78%, the total amount of tahini was 51.88-76.84%, the amount of oil was 33.1-38.9%, the amount of peroxide in the extracted oil was 0-3.67 meq/kg, the amount of copper was 5.88-7.98 mg/kg, the amount of iron varied between 6.98 and 22.33 mg/kg, the amount of tin ranged between 0 and 1.12 mg/kg, the amount of lead was 0.019 mg/kg, and the amount of salt was between 0 and 0.96 g/100g. Arsenic was not detected in halva samples. When the fatty acid composition of oils extracted from tahini halva was analyzed using gas chromatography, a profile high in oleic acid (43%) and linoleic acid (40%) was found. When all of these results were taken into consideration, tahini halva from one of the examined enterprises was inconsistent with the Turkish Food Codex Communique on Tahini Halva (2015/28) in terms of the total amount of tahini.

Effective and Efficient Porous CeO2 Adsorbent for Acid Orange 7 Adsorption.

A porous CeO2 was synthesized following the addition of guanidine carbonate to a Ce3+ aqueous solution, the subsequent addition of hydrogen peroxide and a final hydrothermal treatment. The optimal experimental parameters for the synthesis of porous CeO2, including the amounts of guanidine carbonate and hydrogen peroxide and the hydrothermal conditions, were determined by taking the adsorption efficiency of acid orange 7 (AO7) dye as the evaluation. A template-free hydrothermal strategy could avoid the use of soft or hard templates and the subsequent tedious procedures of eliminating templates, which aligned with the goals of energy conservation and emission reduction. Moreover, both the guanidine carbonate and hydrogen peroxide used in this work were accessible and eco-friendly raw materials. The porous CeO2 possessed rapid adsorption capacities for AO7 dye. When the initial concentration of AO7 was less than 130 mg/L, removal efficiencies greater than 90.0% were obtained, achieving a maximum value of 97.5% at [AO7] = 100 mg/L and [CeO2] = 2.0 g/L in the first 10 min of contact. Moreover, the adsorption-desorption equilibrium between the porous CeO2 adsorbent and the AO7 molecule was basically established within the first 30 min. The saturated adsorption amount of AO7 dye was 90.3 mg/g based on a Langmuir linear fitting of the experimental data. Moreover, the porous CeO2 could be recycled using a NaOH aqueous solution, and the adsorption efficiency of AO7 dye still remained above 92.5% after five cycles. This study provided an alternative porous adsorbent for the purification of dye wastewater, and a template-free hydrothermal strategy was developed to enable the design of CeO2-based catalysts or catalyst carriers.

Testing of yeast cells damage using hydrogen peroxide spiking and Pd-NPs-based electrodes and impact of oxidoreductase presence on electrochemical read-out

Herein, a rapid electrochemical approach for testing of yeast cells damage using hydrogen peroxide spiking and Pd-NPs-based electrodes was proposed. The approach is based on the analyzing of electrochemical interactions between the droplets of yeast suspension spiked with hydrogen peroxide solutions (H2O2) and the surface of screen printed electrode modified by palladium nanoparticles (Pd-NPs). For the intact cells the characteristic anodic electrochemical signal recorded at 0.28 – 0.3 V remains at a constant level due to self-regulation processes regardless the spiked amount of hydrogen peroxide. In contrast, the increase of the anodic current corresponding to the added H2O2 concentration reflects the damage of yeast cells. Significantly, by introduction of peroxide-sensitive oxidoreductase in the design of Pd-NPs, which led to the formation of hybrid oxidoreductase-Pd-NPs electrodes, it was possible to modify the electrochemical read-out of the proposed approach.