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Quiescence is an essential property of meristematic cells, which restrains the cell cycle while retaining the capacity to divide. This crucial process not only facilitates life-long tissue homeostasis and regenerative capacity but also provides protection against adverse environmental conditions, enabling cells to conserve the proliferative potency while minimizing DNA damage. As a survival attribute, quiescence is inherently regulated by the products of aerobic life, in particular reactive oxygen species (ROS) and the redox (reduction/oxidation) mechanisms that plant have evolved to channel these into pervasive signals. Adaptive responses allow quiescent cells to compensate for reduced oxygen tension (hypoxia) in a reversible manner, while the regulated production of the superoxide anion (O2·−) facilitates cell division and the maintenance of stem cells. Here we discuss the role of ROS and redox reactions in the control of the quiescent state in plant meristems, and how this process is integrated with cellular energy and hormone biochemistry. We consider the pathways that sense and transmit redox signals with a focus on the central significance of redox regulation in the mitochondria and nucleus, which is a major regulator of quiescence in meristems. We discuss recent studies that suggest that ROS are a critical component of the feedback loops that control stem cell identity and fate, and suggest that the ROS/hypoxia interface is an important 'outside/in' positional cue for plant cells, particularly in meristems. [ABSTRACT FROM AUTHOR]

Nanozymes present promising alternatives to natural enzymes, but controlling nanozymes' performance and employing them for selectively removing antibiotics are extremely challenging. Employing theoretical calculations to design the coordination environments of mental and coordination atoms for directing single‐atom nanozymes synthesis emerges as a promising strategy to enhance their efficiency and selectivity in antibiotic elimination. In this study, the peroxidase‐like specificity of iron single‐atom nanozymes (FeSA‐Nx, x = 2,3, and 4) with specific Fe–N coordination numbers is demonstrated based on theoretical calculations. These calculations guide the synthesis of corresponding ultra‐thin FeSA‐Nx, achieving a high degree of consistency between theoretical predictions and experimental results. FeSA‐N3 with a Fe─N3 coordination number proves to be the most effective. The efficient electron transfer from Fe─N3 site to H2O2 reduces the free energy required for •OH generation. Quantitative structure‐activity relationship (QSAR) analysis reveals a strong positive correlation between degradation efficiency of cephalosporins and their electron‐donating capabilities (R2 = 0.820–0.929), realizing selectively eliminating cephalosporins. Integration FeSA‐N3 into ceramic membrane (FeSA‐N3/CM) improves hydrophilicity, achieving continuous and stable removal of cephalosporin. This study provides valuable insights into coordination number regulating nanozyme properties for selective antibiotics removal and offers novel perspectives for FeSA‐N3 application in integrated systems. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Methods Results Conclusion Clinical Significance Tooth bleaching procedures on nonvital teeth have been performed for crown discoloration caused by regenerative endodontic therapy (RET). However, leakage of bleaching agents across the root canal can be detrimental. This study aimed to assess and compare the penetration levels of hydrogen peroxide (HP) from different bleaching agents across calcium silicate‐based coronal barriers in immature permanent teeth.Fifty extracted single‐rooted human teeth were randomly divided into four groups (n = 10): Group I (HH)–35% hydrogen peroxide (HP); Group II (SS)−a mixture of sodium perborate (SP) powder and saline; Group III (SH)−a mixture of SP powder and 30% HP liquid; Group IV (CP)–10% carbamide peroxide gel. The control group (Group V, CC) was treated with distilled water. The bleaching agent was replaced on the 4th day, and penetration analysis was performed on the 7th day using ferro thiocyanate (FTC) method and a UV‐spectrophotometer at a wavelength of 480 nm.Compared with the control group, the SH group (SP mixed with HP) showed a significant difference, indicating substantial HP penetration across the root canal space (p value < 0.0001). Intergroup comparisons also revealed a significant difference between the SS and SH groups (p value < 0.0001), suggesting that the SS group had less penetration.Compared with other bleaching agents, SP mixed with saline/water resulted in the lowest HP penetration in the pulp canals of the RET‐simulated tooth models.This study is the first to investigate HP penetration from different bleaching agents in teeth that have undergone RET, identifying the safest bleaching agent for use in these cases. This study also provides a foundation for further research to develop precise guidelines for nonvital tooth bleaching protocols in RET‐treated teeth. [ABSTRACT FROM AUTHOR]

The photocatalytic oxygen reduction reaction (ORR) is a key pathway for producing hydrogen peroxide (H2O2). While most previous studies have focused on the two‐step 2e− ORR process, the one‐step two‐electron ORR route offers thermodynamic and kinetic advantages that can significantly enhance 2e− ORR activity and selectivity. In this study, a photocatalyst design is reported by incorporating cadmium into vacancy‐rich Zn3In2S6 (Cd‐SV/ZIS). This catalyst enables H2O2 production via a one‐step 2e− ORR process without the use of sacrificial agents, achieving a high H2O2 yield of 39.42 µmol g−1 min−1 under UV–vis light irradiation, outperforming most reported ZIS‐based photocatalysts. Theoretical simulations and experimental results demonstrate that Cd doping improves the carrier kinetics of the catalyst, broadens its light absorption range, and promotes the Yeager adsorption configuration of O2, leading to highly active and selective H2O2 generation. This study provides insights into the design of efficient ZIS‐based photocatalysts for H2O2 production. [ABSTRACT FROM AUTHOR]

SUMMARY Polyamines act as protective compounds directly protecting plants from stress‐related damage, while also acting as signaling molecules to participate in serious abiotic stresses. However, the molecular mechanisms underlying these effects are poorly understood. Here, we utilized metabolome genome‐wide association study to investigate the polyamine content of wild and cultivated tomato accessions, and we discovered a new gene cluster that drove polyamine content during tomato domestication. The gene cluster contains two polyphenol oxidases (SlPPOE and SlPPOF), two BAHD acyltransferases (SlAT4 and SlAT5), a coumaroyl‐CoA ligase (Sl4CL6), and a polyamine uptake transporter (SlPUT3). SlPUT3 mediates polyamine uptake and transport, while the five other genes are involved in polyamine modification. Further salt tolerance assays demonstrated that SlPPOE, SlPPOF, and SlAT5 overexpression lines showed greater phenolamide accumulation and salt tolerance as compared with wild‐type (WT). Meanwhile, the exogenous application of Spm to SlPUT3‐OE lines displayed salt tolerance compared with WT, while having the opposite effect in slput3 lines, confirms that the polyamine and phenolamide can play a protective role by alleviating cell damage. SlPUT3 interacted with SlPIP2;4, a H2O2 transport protein, to maintain H2O2 homeostasis. Polyamine‐derived H2O2 linked Spm to stress responses, suggesting that Spm signaling activates stress response pathways. Collectively, our finding reveals that the H2O2‐polyamine‐phenolamide module coordinately enhanced tomato salt stress tolerance and provide a foundation for tomato stress‐resistance breeding. [ABSTRACT FROM AUTHOR]

The current study was conducted to mitigate salt stress on Calendula officinalis L. plants using Streptomyces (Sm) bacteria alone or in combination with potassium nanoparticles (K NPs). Based on the results, morphometric characters, leaf SPAD and relative water content in plants treated with Sm bacteria and K NPs increased compared to the nontreated control under salinity stress. However, leaf ionic leakage, malondialdehyde (MDA) and hydrogen peroxide (H2O2) content decreased considerably in these treated plants. Also, under salt stress, the activity of antioxidant enzymes was higher in Sm bacteria + K NPs -treated plants than in controls. In all plants, endogenous indole acetic acid (IAA) content increased compared to plants grown in non-saline conditions. Inoculated plants reflected a relative increase in IAA by about 28% over the uninoculated plants. The highest amount of abscisic acid (ABA) and putrescine (Put) was related to those plants treated with Sm bacteria + K NPs, which the amounts were 43% and 47% higher than in control plants, respectively. Application of Sm bacteria + K NPs had a helpful outcome on both macronutrients (N-NO-3, P, K and Mg) and micronutrients (Fe, Zn, and Mn) of vines leaves. In general, the inoculation of Sm bacteria + K NPs application by improving the uptake of nutrients, regulating phytohormones and increasing the antioxidant enzymes activity resulted in salinity tolerance improvement in calendula plants. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) in plants is produced in relatively large amounts and plays a universal role in plant defense and physiological responses, including the regulation of growth and development. In the Rhizobium–legume symbiosis, hydrogen peroxide plays an important signaling role throughout the development of this interaction. In the functioning nodule, H2O2 has been shown to be involved in bacterial differentiation into the symbiotic form and in nodule senescence. In this study, the pattern of H2O2 accumulation in pea (Pisum sativum L.) wild-type and mutant nodules blocked at different stages of the infection process was analyzed using a cytochemical reaction with cerium chloride. The observed dynamics of H2O2 deposition in the infection thread walls indicated that the distribution of H2O2 was apparently related to the stiffness of the infection thread wall. The dynamics of H2O2 accumulation was traced, and its patterns in different nodule zones were determined in order to investigate the relationship of H2O2 localization and distribution with the stages of symbiotic nodule development in P. sativum. The patterns of H2O2 localization in different zones of the indeterminate nodule have been partially confirmed by comparative analysis on mutant genotypes. [ABSTRACT FROM AUTHOR]

Water electro-oxidation to form H2O2 is an important way to produce H2O2 which is widely applied in industry. However, its mechanism is under debate and HO(ads), hydroxyl group adsorbed onto the surface of the electrode, is regarded as an important intermediate. Herein, we study the mechanism of water oxidation to H2O2 at Pt electrode using in-situ Raman spectroscopy and differential electrochemical mass spectroscopy and find peroxide bond mainly originated from the coupling of two CO32- via a C2O62- intermediate. By quantifying the 18O isotope in the product, we find that 93% of H2O2 was formed via the CO32- coupling route and 7% of H2O2 is from OH(ads)-CO3•− route. The OH(ads)-OH(ads) coupling route has a negligible contribution. The comparison of various electrodes shows that the strong adsorption of CO3(ads) at the electrode surface is essential. Combining with a commercial cathode catalyst to produce H2O2 during oxygen reduction, we assemble a flow cell in which the cathode and anode simultaneously produce H2O2. It shows a Faradaic efficiency of 150% of H2O2 at 1 A cm−2 with a cell voltage of 2.3 V. Electrosynthesis via two electron water reactions offers a promising method for decentralized H2O2 production, yet its mechanism remains unclear. Here, the authors address the challenge by using in-situ Raman and DEMS, and demonstrate 93% of H2O2 forms via the carbonate coupling route through a C2O62− intermediate. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to investigate the mechanism of action of our newly developed green sanitizer formulation comprising a natural phenolic compound, gallic acid (GA), strengthened by the Generally Recognized as Safe (GRAS) materials hydrogen peroxide (H2O2) and DL-lactic acid (LA). Combining 8 mM GA with 1 mM H2O2 resulted in an abundant generation of reactive oxygen species (ROS) and a bactericidal effect towards Gram-negative (Escherichia coli, Pseudomonas syringae, and Pectobacterium brasiliense) and Gram-positive (Bacillus subtilis) bacteria (4 to 8 log CFU mL−1 reduction). However, the exposure to this dual formulation (DF) caused only a modest 0.7 log CFU mL−1 reduction in the Gram-positive L. innocua population. Amending the DF with 20 mM LA to yield a triple formulation (TF) resulted in the efficient synergistic control of L. innocua proliferation without increasing ROS production. Despite the inability to grow on plates (>7 log CFU mL−1 population reduction), the TF-exposed L. innocua maintained high intracellular ATP pools and stable membrane integrity. The response of L. innocua to TF could be qualified as a "viable but nonculturable" (VBNC) phenomenon, while with the other species tested this formulation caused cell death. This research system may offer a platform for exploring the VBNC phenomenon, a critical food safety topic. [ABSTRACT FROM AUTHOR]

Ultrasound (US) washing has been verified to improve the quality of postharvest blueberry fruit. However, its physiological and molecular mechanisms remain largely unknown. In the present study, an US with a frequency of 25 kHz and a power density of 400 W for 2 min was performed to investigate its role in impacting the quality of blueberries. The results showed that US washing improved the quality of blueberries, with a higher firmness and lignin content (p < 0.05) than the control. Moreover, US washing inhibited the levels of superoxide radical (O2·−) production rate and hydrogen peroxide (H2O2) content while stimulating the superoxide dismutase (SOD) and catalase (CAT) activities of the blueberry fruit. Transcriptomic analysis screened 163 differentially expressed genes (DEGs), and the key DEGs were mainly enriched in phenylpropanoid biosynthesis, flavonoid biosynthesis, and plant–pathogen interaction pathways. Furthermore, the transcription factors and the structural genes associated with lignin biosynthesis were also identified from the DEGs. More importantly, the correlation analysis revealed that firmness and lignin content were positively correlated with the expression of C4H, COMT1, and POD52 in blueberry fruit, indicating that these genes might be involved in the regulation of US-mediated lignin synthesis. The findings provide new insight into the US-enhanced quality of blueberry fruits. [ABSTRACT FROM AUTHOR]

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The objective of this study was to determine the effect of ionising and ultraviolet radiation on stimulating melanin secretion in Tetrahymena pyriformis. Cell cultures were exposed to different doses of radiation for 48, 72 and 96 h. After incubation, melanin was extracted and analysed. Our results showed that melanin concentration increased with increasing irradiation dose and exposure duration. Melanin was insoluble in water and organic solvents but soluble in alkaline and acidic solutions. A linear correlation between the logarithm of melanin absorbance and wavelength ranging from 400 to 600 nm was observed. The HPLC chromatograms of melanin degradation products by the alkaline hydrogen peroxide oxidation method revealed the existence of four peaks. The natural melanin standard extracted from the cuttlefish Sepia officinalis was used as a reference compound of eumelanin markers. These markers were detected in control cells, irradiated cells and black human hair but with different intensities. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) attract significant attention due to their ordered, crystalline, porous, metal‐free, and predictable structures. These unique characteristics offer great opportunities for the diffusion and transmission of photogenerated charges during photocatalysis. Currently, a considerable number of COFs are used as metal‐free organic semiconductor photocatalysts. This review aims to understand the relationships between the structure and photocatalysis performance of COFs and provides in‐depth insight into the synthetic strategy to improve photocatalysis performance. Subsequently, the review focuses on the structural motif of COFs in sustainable photocatalytic hydrogen evolution, carbon dioxide reduction, hydrogen peroxide generation, and organic compound transformations. Last, in conjunction with the significant progress achieved and the challenges yet to be overcome, a candid discussion is undertaken regarding the challenges and opportunities in the field of COF photocatalysis, accompanied by the presentation of potential research avenues and future directions. This review seeks to provide readers with a comprehensive understanding of the pivotal role of COFs in the field of photocatalysis, to offer robust guidance for the innovative utilization of COFs in future sustainable photocatalysis. [ABSTRACT FROM AUTHOR]

Ti‐MWW zeolite is a promising catalyst for partial oxidation reactions. In the present work, a Ti‐MWW sample with high TiO2 loading was synthesized. It was revealed that the Ti insertion in the purely siliceous MWW framework mainly occurs during the post treatment washing with HNO3, when the double structure directing agent synthetic method is used. By exploiting carbon monoxide, acetonitrile, pyridine and ammonia as probe molecules in infrared spectroscopy and diffuse reflectance ultraviolet spectroscopy, the acidic behavior of the Ti sites and the interaction of the Ti sites with hydrogen peroxide (H2O2) were revealed. The Ti Lewis acid sites showed stronger acidity than the one observed in Titanium Silicalite‐1 (TS‐1), with MFI framework. This is coherent with previously reported results, suggesting that a significative fraction of the Ti sites in Ti‐MWW are TiOH(SiO)3 instead of Ti(OSi)4. The Ti‐peroxo and ‐hydroperoxo complexes formed upon H2O2 were shown to be more labile than in TS‐1 and they were shown to be completely reversible upon calcination. [ABSTRACT FROM AUTHOR]

Background Methods Key results Conclusions & inferences Chronic constipation is a gastrointestinal functional disorder which affects patient quality of life. Therefore, many studies were oriented to search herbal laxative agents. In this study, we investigated the phytochemical composition of beetroot juice (BJ) and its laxative potential in an experimental model of constipation and colonic dysmotility induced by loperamide (LOP) in Wistar rats.Animals were concurrently pretreated with LOP (3 mg/kg, b.w., i.p.) and BJ (5 and 10 mL/kg, b.w., p.o.), or yohimbine (2 mg/kg, b.w., i.p.), during 1 week. The laxative activity was determined based on the weight, frequency, and water content of the feces matter. The gastric‐emptying test and intestinal transit were determined. Colon histology was examined, and oxidative status was evaluated using biochemical‐colorimetric methods.The in vivo study revealed that LOP induced a significant inhibition of gastrointestinal motility, negative consequences on defecation parameters, oxidative stress, and colonic mucosa lesions. Conversely, administration of BJ reestablished these parameters and restored colonic oxidative balance. Importantly, BJ treatment protected against LOP‐induced inflammatory markers (pro‐inflammatory cytokines and WBC) and the increase in intracellular mediators such as hydrogen peroxide, free iron, and calcium levels.This study demonstrated that the bioactive compounds in BJ provided an anti‐constipation effect by modulating intestinal motility and regulating oxidative stress and inflammation induced by LOP intoxication. [ABSTRACT FROM AUTHOR]

The direct production of hydrogen peroxide (H2O2) through photocatalytic reaction via H2O and O2 is considered as an ideal approach. However, the efficiency of H2O2 generation is generally limited by insufficient charge and mass transfer. Covalent organic framework (COFs) offer a promising platform as metal‐free photocatalyst for H2O2 production due to their potential for rational design at the molecular level. Herein, we integrated the multipolar structures and carboxyl groups into COFs to enhance the efficiency of photocatalytic H2O2 production in pure water without any sacrificial agents. The introduction of octupolar and quadrupolar structures, along with an increase of molecular planarity, created efficient oxygen reduction reaction (ORR) sites. Meanwhile, carboxyl groups could not only boost O2 and H2O2 movement via enhancement of pore hydrophilicity, but also promote proton conduction, enabling the conversion to H2O2 from ⋅O2−, which is the crucial intermediate product in H2O2 photocatalysis. Overall, we demonstrate that TACOF‐1‐COOH, consisting of optimal octupolar and quadrupolar structures, along with enrichment sites (carboxyl groups), exhibited a H2O2 yield rate of 3542 μmol h− 1 g−1 and a solar‐to‐chemical (SCC) efficiency of 0.55 %. This work provides valuable insights for designing metal‐free photocatalysts for efficient H2O2 production. [ABSTRACT FROM AUTHOR]

Breast cancer, the most common malignant tumor in the world, seriously threatens human life and health. Early diagnosis of breast cancer may help enhance the survival rate. In this work, a colorimetric and fluorescent dual-mode biosensor based on the CRISPR-Cas12a system was constructed to detect the breast cancer biomarker BRCA1. The intact G4 DNA, with the assistance of K+ and hemin, catalyses the oxidation of o-phenylenediamine (OPD) with the assistance of hydrogen peroxide (H2O2), generating the oxidation product 2,3-diaminophenazine (DAP), which has distinct absorption and fluorescence peaks. The presence of the target BRCA1 activates the trans-cleavage activity of CRISPR-Cas12a, leading to the cleavage of G4 DNA and inhibiting the catalytic oxidation of OPD. Target BRCA1 was quantitatively determined by measuring both the absorbance and fluorescence intensity of DAP. The detection limits were calculated to be 0.615 nM for the colorimetric method and 0.289 nM for the fluorescence method. The dual-mode biosensor showed good selectivity and reliability for BRCA1 and can resist interference from complex substrates, and it has great potential in biomedical detection. [ABSTRACT FROM AUTHOR]

Barium titanate (BTO) is well-known (as a photo- or sono/piezo-catalyst) to produce hydrogen peroxide via 2-electron reduction of oxygen in the presence of a sacrificial quencher, such as isopropanol. While barium titanate nanoparticles with a tetragonal crystal structure (piezoelectric) are particularly reactive, the recovery and reuse of these nano-catalysts from reactions can be difficult. Here, barium titanate nanoparticles of typically 200 nm to 600 nm diameter are embedded into a host film of a polymer of intrinsic microporosity (PIM-EA-TB). Due to molecular rigidity of the polymer, there is no capping effect, and the surface catalytic reaction occurs effectively with a catalyst embedded in the polymer. In this exploratory work, the catalytic formation of H2O2 in the presence of isopropanol is investigated via kinetic studies and by electron paramagnetic resonance (EPR). Perhaps surprisingly, at a neutral pH the rate of the catalytic reaction is substantially increased when barium titanate is embedded into the polymer host and when the polymer is protonated. This is attributed here to a "kinetic cage effect" which exploits the tertiary amine in the polymer backbone with anodic and cathodic processes coupled into a pH neutral reaction. [ABSTRACT FROM AUTHOR]

The abuse of tetracycline (TC) has led to serious threats to human health and the environment. Therefore, the rapid and sensitive detection of tetracycline is of particular importance. Herein, we successfully synthesised a bimetallic nanozyme D-Fe/Co-MOF with oxidase activity and established a colourimetric sensor. The complex of Fe2+ in D-Fe/Co-MOF and TC can release hydroxyl radicals (˙OH) and promote the oxidation of TMB. As a result, the colour of the detection system significantly changes, enabling the sensitive colourimetric detection of TC. Compared with the existing Fe/Co-MOF sensor, D-Fe/Co-MOF can effectively reduce the detection error caused by hydrogen peroxide decomposition, improving the accuracy of TC detection. Under the optimal conditions, the absorbance at 652 nm showed a good linear relationship with TC concentration in the range of 0.35–220 μg mL−1. The detection limit was as low as 0.0719 μg mL−1, considerably lower than the national safety standard. The proposed colourimetric sensor was also successfully used for the detection of TC in actual milk samples, and the results were in good agreement with those obtained via liquid chromatography. The proposed strategy for the detection of TC in food is expected to contribute to ensuring food safety and human health. [ABSTRACT FROM AUTHOR]

The extensive utilization of chlorpyrifos and cypermethrin in agriculture raises concerns regarding the accumulation of pesticide residues in human food, posing a threat to human health. This study aimed to investigate the effect of ozonation on cauliflower to decrease the level of pesticides. Cypermethrin and organophosphate chlorpyrifos were applied to cauliflower at specific doses. High-performance liquid chromatographic techniques were employed to detect pesticide residues in cauliflower. The effects of common oxidizers (hydrogen peroxide, chlorine, and ozone) on the reduction of pesticide residues were investigated. Solutions of hydrogen peroxide (10 and 100 ppm), chlorine (10 and 100 ppm), and ozone (10 and 100 ppm) were prepared, and the cauliflower sample was immersed for 20 min. The immersion in 10 ppm hydrogen peroxide solution reduced chlorpyrifos and cypermethrin by 68 and 65%, respectively. Meanwhile, at 100 ppm hydrogen peroxide solution, the reduction rates of chlorpyrifos and cypermethrin residues were 72 and 75%, respectively. Immersion in ozone solution at 10 ppm concentration reduced chlorpyrifos and cypermethrin by 58 and 57%, respectively. At 100 ppm ozone, chlorpyrifos was reduced up to 64%, and cypermethrin reduction was 74%. Chlorine immersion at 10 ppm reduced chlorpyrifos residues by 68% and cypermethrin residues by 81%, while a 100 ppm chlorine solution reduced chlorpyrifos residues by 100% and cypermethrin residues by 84%. From these results, it was concluded that chlorine was the most effective of all the cleaning solutions to remove pesticides from vegetables. [ABSTRACT FROM AUTHOR]

The document "Advanced Oxidation Catalysts—Innovative Approaches and Emerging Trends" discusses the development and application of novel oxidation catalysts for water treatment and purification. The Special Issue brings together 17 articles that explore the use of advanced oxidation technologies to eliminate organic pollutants and disinfect water. Various studies highlight the effectiveness of different catalysts in breaking down pollutants, emphasizing the importance of developing innovative materials for environmental remediation. The research presented in the document aims to inspire further advancements in advanced oxidation catalysts to contribute to a cleaner and safer ecological environment. [Extracted from the article]

Understanding how pathogens defend themselves against host defence mechanisms, such as hydrogen peroxide (H2O2) production, is crucial for comprehending fungal infections. H2O2 poses a significant threat to invading fungi due to its potent oxidizing properties. Our research focuses on the hemibiotrophic fungal wheat pathogen Zymoseptoria tritici, enabling us to investigate host–pathogen interactions. We examined two catalase‐peroxidase (CP) genes, ZtCpx1 and ZtCpx2, to elucidate how Z. tritici deals with host‐generated H2O2 during infection. Our analysis revealed that ZtCpx1 was up‐regulated during biotrophic growth and asexual spore formation in vitro, while ZtCpx2 showed increased expression during the transition from biotrophic to necrotrophic growth and in‐vitro vegetative growth. Deleting ZtCpx1 increased the mutant's sensitivity to exogenously added H2O2 and significantly reduced virulence, as evidenced by decreased Septoria tritici blotch symptom severity and fungal biomass production. Reintroducing the wild‐type ZtCpx1 allele with its native promoter into the mutant strain restored the observed phenotypes. While ZtCpx2 was not essential for full virulence, the ZtCpx2 mutants exhibited reduced fungal biomass development during the transition from biotrophic to necrotrophic growth. Moreover, both CP genes act synergistically, as the double knock‐out mutant displayed a more pronounced reduced virulence compared to ΔZtCpx1. Microscopic analysis using fluorescent proteins revealed that ZtCpx1 was localized in the peroxisome, indicating its potential role in managing host‐generated reactive oxygen species during infection. In conclusion, our research sheds light on the crucial roles of CP genes ZtCpx1 and ZtCpx2 in the defence mechanism of Z. tritici against host‐generated hydrogen peroxide. [ABSTRACT FROM AUTHOR]

In order to explore the possibilities of increasing the hydrophilicity of carbon-based adsorbents, catalysts, or electrode materials in aqueous solutions, the oxidation of wood-based activated biochar using H2O2 was investigated. The properties of oxidized activated biochar obtained at different activation temperatures (600, 700, and 800 °C) and H2O2 oxidized for 15–180 min were investigated using the characteristics of surface functionality, elemental composition, porous structure, contact angle measurements, FTIR spectroscopy, and immersion calorimetry. It was observed that the optimal oxidation time was different for each sample depending on activation temperature, and the degree of oxidation can be tailored by changing the oxidation time. The course of oxidation depends on the degree of graphitization and functionalization, determined by the activation temperature. It was established that the highest degree of oxidation and increase in wettability is observed for samples with the lowest degree of activation obtained at a temperature of 600 °C. [ABSTRACT FROM AUTHOR]

Simple Summary: This research investigates the potential therapeutic applications of Quercus glauca acorn seed coat water extract (QGASE) in the context of wound healing. The results indicate that QGASE significantly enhances wound closure in human dermal fibroblasts by upregulating critical markers associated with the wound-healing process. Furthermore, QGASE demonstrates antioxidant properties that mitigate oxidative stress and promote recovery from injuries induced by hydrogen peroxide, thereby providing evidence of its anti-inflammatory effects. In vivo experiments further corroborate the efficacy of QGASE in facilitating wound healing. The results of our study enhance the existing body of literature regarding phytotherapy and its potential applications in the field of wound care. This research seeks to identify a promising candidate for the development of innovative therapeutic strategies, thereby addressing the urgent need for safe and effective wound-healing therapies. The skin, recognized as the largest organ in the human body, serves a vital function in safeguarding against external threats. Severe damage to the skin can pose significant risks to human health. There is an urgent requirement for safe and effective therapies for wound healing. While phytotherapy has been widely utilized for various health conditions, the potential of Quercus glauca in promoting wound healing has not been thoroughly explored. Q. glauca is a cultivated crop known for its abundance of bioactive compounds. This study examined the wound-healing properties of Quercus glauca acorn seed coat water extract (QGASE). The findings from the study suggest that QGASE promotes wound closure in HF cells by upregulating essential markers related to the wound-healing process. Additionally, QGASE demonstrates antioxidant effects, mitigating oxidative stress and aiding in recovery from injuries induced by H2O2. In vivo experiments provide additional substantiation supporting the efficacy of QGASE in enhancing wound healing. The collective results indicate that QGASE may be a promising candidate for the development of innovative therapeutic strategies aimed at enhancing skin wound repair. [ABSTRACT FROM AUTHOR]

Phytoplasmas are phytopathogenic bacteria that cause serious damage to agriculture. A quarantine pathogen, the flavescence dorée phytoplasma (FDp), often associated with grapevine yellows disease, affects viticultural production across Europe. However, the mechanisms of FDp pathogenicity are not still elucidated. In this study, symptomatic and asymptomatic grapevine (Vitis vinifera L. var. 'Pinot gris') leaves were sampled. Two different FDp genotypes (M38 and M54) were identified, and genotype-dependent changes to grapevine physiological responses through the development of FDp infection were analysed. Correlation analyses established a potential link between measured physiological parameters and relative FDp DNA abundance. Increased malondialdehyde levels pointed to the oxidative stress in infected leaves, and highly correlated with the activation of L-ascorbic acid synthesis. Levels of hydrogen peroxide were reduced in infected leaves, possibly as an FDp mechanism to avoid plant-derived oxidative damage. Genotype M54 was associated with a lower accumulation of soluble sugars and lower damage to photosynthetic pigments while retaining a higher titre than M38. Therefore, pronounced phytoplasma genotype-dependent changes in grapevine physiology, potentially caused by the differences between M54 and M38 on the level of the efficiency of their effectors should be further investigated. Altogether, results provide data on certain targets of FDp in grapevine and could assist in the identification of potential specific effectors of this phytoplasma to aid the efforts of FDp management in European vineyards. [ABSTRACT FROM AUTHOR]

Objective: This laboratory study aimed to evaluate the effect of different mouthwash solutions on the surface and mechanical properties of NiTi arch wire. Methods: This experimental study was conducted at the Department of Preventive Dental Sciences, College of Dentistry, Princess Nourah bint Abdulrahman University, Saudi Arabia from September 2023 to November 2023. A 30 mm NiTi wires in length with 0.017 × 0.022” in dimensions were selected and equally divided into four groups: Control (G0) group wires were immersed in distilled water (DW); G1 wires were immersed in antiseptic mouthwash; G2 wires were immersed in fluoridated mouthwash; and G3 wires were immersed in therapeutic mouthwash. Surface morphology, nanohardness, and flexural modulus were evaluated at 24-hours, four weeks, and eight weeks’ time points. Data were statistically analyzed using a two-way analysis of variance (P<0.05). Results: The arch wires immersed in DW showed insignificant effects on surface roughness, nanohardness, and flexural modulus at different time points. However, all the experimental groups showed a significant effect of time and immersion solutions on the said properties (P<0.05). At the end of eight weeks, G3 showed the highest surface roughness (0.346 ± 0.032 μm) and the lowest nanohardness (1.350 ± 0.412 GPa) and flexural modulus (3.960 ± 0.140 MPa) compared to other study groups. Conclusions: The efficiency of tooth realignment could be influenced by the detrimental influence of fluoride and hydrogen peroxide mouthwash solutions on superelastic NiTi arch wires. [ABSTRACT FROM AUTHOR]

Solution processing has emerged as a promising technique for the fabrication of oxide thin‐film transistors (TFTs), offering advantages such as low cost, high throughput, and exceptional compositional control. However, achieving reasonable electrical properties typically demands high annealing temperatures in the fabrication process. In addressing this challenge, a novel combination strategy is proposed that involves integrating the H2O2 inducement technique with infrared (IR) irradiation annealing. The study investigates the effects of precursors and IR irradiation annealing temperatures on the electrical properties of In2O3 TFTs. It is found that H2O2 can help accelerate the decomposition of organic residues, while IR irradiation annealing could enhance the film densification. By employing the proposed strategy, metal oxide TFTs consisting of a Zr‐Al‐O dielectric fabricated at 230 °C and an In2O3 channel layer fabricated at 185 °C demonstrated high performance with field‐effect mobility = 31.7 cm2 V−1·s−1, threshold voltage = 1.3 V, subthreshold swing = 0.13 V per decade, and on‐to‐off current ratio = 1.1 × 105. This work demonstrates the proposed combinational strategy is a general method to fabricate not only metal oxide semiconductors but also dielectrics. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) detection as a potential development strategy for hydrogen peroxide and dopamine sensors has received extensive attentions. Herein, BiOI/ZnIn2S4-X (X = n (BiOI)/n(ZnIn2S4)) heterojunction was synthesized using various molar ratios via a two-step method. A series of characterization techniques were employed to analyze the composition, surface structure, valence state, and optical properties of BiOI/ZnIn2S4-X. The results show that BiOI/ZnIn2S4-X perform significantly better than both BiOI and ZnIn2S4. Furthermore, BiOI/ZnIn2S4-9% exhibits superior visible light absorption capacity and photocurrent response among all of the BiOI/ZnIn2S4-X tested. Therefore, a PEC sensor was developed using BiOI/ZnIn2S4-9% for the detection of hydrogen peroxide and dopamine. The linear detection range for hydrogen peroxide spans from to 1 ~ 40,000 µM, with the LOD of 0.036 µM (S/N = 3). For dopamine, the corresponding values are 2 ~ 250 µM for the linear detection range, and 0.017 μM for the LOD, respectively. The sensor exhibits demonstrates excellent stability, reproducibility and resistance to interference, enabling the detection of real samples and thus holds promising application potential. [ABSTRACT FROM AUTHOR]

A novel colorimetric approach specifically designed to effectively identify the presence of 3-aminophenol (3-AP) in environmental water is introduced. Briefly, a nitrogen-doped carbon-supported cobalt nanozyme (Co@CN-1) was synthesized and utilized to improve the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of peroxymonosulfate (PMS). Comparative catalytic reactions confirmed that the performance of PMS as an activator exceeds that of hydrogen peroxide catalytically by a factor of 3.5. The catalytic reaction parameters underwent optimization, further resulting in the derivation of a linear detection equation for 3-AP, expressed as inhibition rate (IR%) = 3.35[3-AP]—4.36 (0–20 μM, R2 = 0.994) and IR% = 1.43[3-AP] + 31.87 (20–36 μM, R2 = 0.992), with the limit of detection (LOD) of 2.84 μM. The linear relationship between 3-AP concentration and the conversion of color to grayscale value (GSV) was established by smartphones, expressed as GSV = 1.28[3-AP] + 147.10 (R2 = 0.972). Density functional theory calculations revealed that Co acts as the preferred active site for donating electrons in PMS activation. This work provides a rapid and accurate approach for monitoring 3-AP concentration, enabling real-time analysis and potentially contributing to environmental and ecological studies. [ABSTRACT FROM AUTHOR]

Based on the peroxidase activity of Cu-hemin metal–organic framework (Cu-hemin MOF) nanozyme, a colorimetric enzyme-linked immunosensor was developed for the detection of furazolidone (FZD). Cu-hemin MOF is a bimetallic nanozyme that exhibited a stronger catalytic effect compared with single-metal organic framework nanoenzymes. Cu-hemin-MOF catalyzes hydrogen peroxide (H2O2) to produce hydroxyl radicals (•OH), which oxidizes the chromogenic substrate 3,3′,5,5′-tetramethylbenzidine (TMB) to blue oxidized TMB (oxTMB). The absorbance change is at 650 nm. The content of AOZ in animal food can be quickly and accurately determined by changes in absorbance. The linear range of the colorimetric biosensor for detecting FZD was 0.01 ~ 62.52 ng/mL, and the limit of detection was as low as 0.01 ng/mL. The recovery of spikes samples was in the range 94.2-108.0 % and reproducibility was less than 4.8%. In addition, the cross-reaction rate was less than 0.1% when detecting other metabolites except AOZ, indicating that the sensor has good applicability and specificity. This study not only provides a better understanding of the relationship between the dispersion of nanoenzymes and enzyme-like activity but also offers a general method for detecting antibiotics using the nanoenzyme colorimetric method. [ABSTRACT FROM AUTHOR]

Background: Ultrahigh dose‐rate radiation (UHDR) produces less hydrogen peroxide (H2O2) in pure water, as suggested by some experimental studies, and is used as an argument for the validity of the theory that FLASH spares the normal tissue due to less reactive oxygen species (ROS) production. In contrast, most Monte Carlo simulation studies suggest the opposite. Purpose: We aim to unveil the effect of UHDR on H2O2 production in pure water and its underlying mechanism, to serve as a benchmark for Monte Carlo simulation. We hypothesized that the reaction of solvated electrons (eaq−${\mathrm{e}}_{{\mathrm{aq}}}^ - $) removing hydroxyl radicals (•OH), the precursor of H2O2, is the reason why UHDR leads to a lower G‐value (molecules/100 eV) for H2O2 (G[H2O2]), because: 1, the third‐order reaction between eaq−${\mathrm{e}}_{{\mathrm{aq}}}^ - $ and •OH is more sensitive to increased instantaneous ROS concentration by UHDR than a two‐order reaction of •OH self‐reaction producing H2O2; 2, eaq−${\mathrm{e}}_{{\mathrm{aq}}}^ - $ has two times higher diffusion coefficient and higher reaction rate constant than that of •OH, which means eaq−${\mathrm{e}}_{{\mathrm{aq}}}^ - $ would dominate the competition for •OH and benefit more from the inter‐track effect of UHDR. Meanwhile, we also experimentally verify the theory of long‐lived radicals causing lower G(H2O2) in conventional irradiation, which is mentioned in some simulation studies. Methods and materials: H2O2 was measured by Amplex UltraRed assay. 430.1 MeV/u carbon ions (50 and 0.1 Gy/s), 9 MeV electrons (600 and 0.62 Gy/s), and 200 kV x‐ray tube (10 and 0.1 Gy/s) were employed. For three kinds of water (real hypoxic: 1% O2; hypoxic: 1% O2 and 5% CO2; and normoxic: 21% O2), unbubbled and bubbled samples with N2O, the scavenger of eaq−${\mathrm{e}}_{{\mathrm{aq}}}^ - $, were irradiated by carbon ions and electrons with conventional and UHDR at different absolute dose levels. Normoxic water dissolved with sodium nitrate (NaNO3), another scavenger of eaq−${\mathrm{e}}_{{\mathrm{aq}}}^ - $, and bubbled with N2O was irradiated by x‐ray to verify the results of low‐LET electron beam. Results: UHDR leads to a lower G(H2O2) than conventional irradiation. O2 and CO2 can both increase G(H2O2). N2O increases G(H2O2) of both UHDR and conventional irradiation and eliminates the difference between them for carbon ions. However, N2O decreases G(H2O2) in electron conventional irradiation but increases G(H2O2) in the case of UHDR, ending up with no dose‐rate dependency of G(H2O2). Three‐spilled carbon UHDR does not have a lower G(H2O2) than one‐spilled UHDR. However, the electron beam shows a lower G(H2O2) for three‐spilled UHDR than for one‐spilled UHDR. Normoxic water with N2O or NaNO3 can both eliminate the dose rate dependency of H2O2 production for x‐ray. Conclusions: UHDR has a lower G(H2O2) than the conventional irradiation for both high LET carbon and low LET electron and x‐ray beams. Both scavengers for eaq−${\mathrm{e}}_{{\mathrm{aq}}}^ - $, N2O and NaNO3, eliminate the dose‐rate dependency of G(H2O2), which suggests eaq−${\mathrm{e}}_{{\mathrm{aq}}}^ - $ is the reason for decreased G(H2O2) for UHDR. Three‐spilled UHDR versus one‐spilled UHDR indicates that the assumption of residual radicals reducing G(H2O2) of conventional irradiation may only be valid for low LET electron beam. [ABSTRACT FROM AUTHOR]

In this study, we demonstrate the electrodeposition of copper nanoparticles (NPs) on pencil graphite electrodes (PGEs) utilizing sodium dodecyl sulphate (SDS) as a soft template. The utilization of the surfactant had an impact on both the physical arrangement and electrochemical characteristics of the modified electrodes. The prepared Cu-SDS/PGE electrodes had hierarchical dendritic structures of copper NPs, thereby increasing the surface area and electrochemical catalytic activity in comparison with Cu/PGE electrodes. The Cu-SDS/PGE electrode showed excellent catalytic activity in reducing hydrogen peroxide, resulting in the sensitive and selective detection of hydrogen peroxide. The electrode exhibited a good sensitivity of 21.42 µA/µM/cm2, a lower limit of detection 0.35, and a response time of less than 2 s over a wide range spanning 1 µM to 1 mM of hydrogen peroxide concentrations. The electrodes were also highly selective for H2O2 with minimal interference from other analytes even at concentrations higher than that of H2O2. The approach offers the benefit of electrode preparation in just 5 min, followed by analysis in 10 min, and enables for the quantitative determination of hydrogen peroxide within 30 min. This can be achieved utilizing a newly prepared, cost-effective electrode without the need for complex procedures. [ABSTRACT FROM AUTHOR]

The demetallation reaction of sulfanyl magnesium(II) porphyrazine with N-ethylphthalimide substituents, followed by remetallation with manganese(II) salts, yields the corresponding manganese(III) derivative (Pz3) with high efficiency. This novel manganese(III) sulfanyl porphyrazine was characterized by HPLC and analyzed using UV-Vis, MS, and FT-IR spectroscopy. Electrochemical experiments of Pz3 conducted in dichloromethane revealed electrochemical activity of the new complex due to both manganese and N-ethylphthalimide substituents redox transitions. Subsequently, Pz3 was deposited on multiwalled carbon nanotubes (MWCNTs), and this hybrid material was then applied to glassy carbon electrodes (GC). The resulting hybrid electroactive electrode material, combining manganese(III) porphyrazine with MWCNTs, showed a significant decrease in overpotential of H2O2 oxidation compared to bare GC or GC electrodes modified with only carbon nanotubes (GC/MWCNTs). This improvement, attributed to the electrocatalytic performance of Mn3+, enabled linear response and sensitive detection of H2O2 at neutral pH. Furthermore, a glucose oxidase (GOx)-containing biosensing platform was developed by modifying the prepared GC/MWCNT/Pz3 electrode for the electrochemical detection of glucose. The bioelectrode incorporating the newly designed Pz3 exhibited good activity in the presence of glucose, confirming effective electronic communication between the Pz3, GOx and MWCNT surface. The linear range for glucose detection was 0.2–3.7 mM. [ABSTRACT FROM AUTHOR]

The development of high-performance hydrogen peroxide (H2O2) sensors is critical for various applications, including environmental monitoring, industrial processes, and biomedical diagnostics. This study explores the development of efficient and selective H2O2 sensors based on bismuth oxide/bismuth oxyselenide (Bi2O3/Bi2O2Se) nanocomposites. The Bi2O3/Bi2O2Se nanocomposites were synthesized using a simple solution-processing method at room temperature, resulting in a unique heterostructure with remarkable electrochemical characteristics for H2O2 detection. Characterization techniques, including powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM), confirmed the successful formation of the nanocomposites and their structural integrity. The synthesis time was varied to obtain the composites with different Se contents. The end goal was to obtain phase pure Bi2O2Se. Electrochemical measurements revealed that the Bi2O3/Bi2O2Se composite formed under optimal synthesis conditions displayed high sensitivity (75.7 µA µM−1 cm−2) and excellent selectivity towards H2O2 detection, along with a wide linear detection range (0–15 µM). The superior performance is attributed to the synergistic effect between Bi2O3 and Bi2O2Se, enhancing electron transfer and creating more active sites for H2O2 oxidation. These findings suggest that Bi2O3/Bi2O2Se nanocomposites hold great potential as advanced H2O2 sensors for practical applications. [ABSTRACT FROM AUTHOR]

In recent years, the health benefits of lactic acid bacteria have garnered attention, but their antioxidant activity remains relatively underexplored. We have been analyzing the antioxidant activities of various dietary phytochemicals by assessing their ability to mitigate oxidative stressor-induced toxicity in zebrafish larvae through pretreatment. In this study, the antioxidant activities of 24 strains of heat-killed lactic acid bacteria from various origins were examined using this zebrafish assay system. The results revealed that all 24 strains possessed antioxidant activity that reduces hydrogen peroxide toxicity. Further detailed analysis using the H61 strain, which exhibited the strongest activity, showed that no direct antioxidant activity was observed in the assay system, suggesting that the detected antioxidant activity was entirely indirect. Moreover, it was found that pretreatment of zebrafish larvae with the H61 strain for more than 6 h was required to exert its antioxidant activity. This duration was similar to that required by dietary antioxidants that activate the Keap1-Nrf2 pathway, suggesting potential involvement of this pathway. However, analysis using Nrf2-knockout zebrafish revealed that the antioxidant activity of strain H61 is independent of Nrf2, indicating that it represents a novel indirect antioxidant activity that does not involve the Keap1-Nrf2 pathway. To further characterize this activity, the ability to mitigate the toxicity of oxidative stressors other than hydrogen peroxide was examined. The results indicated that while the toxicity of tert-butyl hydroperoxide was reduced, unlike with the Keap1-Nrf2 pathway, it was not effective in counteracting the toxicity of paraquat or arsenite, which generate superoxide radicals. In conclusion, we have identified a novel indirect antioxidant activity in lactic acid bacteria. [ABSTRACT FROM AUTHOR]

Introduction: Surgical guides are commonly used to assist with dental implant placement. This study investigated the effects of five sterilization and disinfection methods on the accuracy of implant guides. Methods: Thirty surgical guides (five in each group) were designed and printed (with digital light processing technology) using different sterilization or disinfection methods categorized into six groups: hydrogen peroxide sterilization (group one); glutaraldehyde sterilization (group two); autoclaving (group three); plasma sterilization (group four); iodophor disinfection (group five); and blank group (group six). Verification was determined using three methods: distance and angle between the cross‐shaped marks, deformation after superimposing the guides, and displacement and axial changes in the virtual implant. Results: After disinfection and sterilization, the guides in the autoclaving and iodophor groups showed a more pronounced color change and the guide in the autoclaving group had visible cracks. More significant changes were observed in the H2O2, glutaraldehyde, autoclaving, and iodophor groups regarding deformation after superimposing the guides and the distance and angle between the cross‐shaped marks. The average labial deformation values (mm) of the first through fifth groups of guides were 0.283, 0.172, 0.289, 0.153, and 0.188, respectively. All groups were statistically different from the blank group for displacement and axial changes of the virtual implant (p < 0.05). Conclusion: The sizes of almost all surgical guides changed after sterilization and disinfection treatments, with between‐group differences. Plasma sterilization was more suitable for surgical guide sterilization because of the smaller deformations after treatment. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the influence of air‐abrasion of enamel with three different desensitizing powders on the whitening effect of a bleaching gel containing 40% H2O2, which was used for in‐office tooth bleaching. Materials and Methods: Forty human incisors, extracted and prepared, were acquired for this study and subsequently randomized into four groups (n = 10). The control group specimens underwent no pretreatment prior to the bleaching procedure, whereas the remaining three groups underwent air abrasion using distinct desensitizing powders; (a) Sylc, which contains bioglass 45S5; (b) BioMinF, which contains calcium phospho‐fluoro‐silicate glass; and (c) MI Pearls, which contains nano‐hydroxyapatite, 1 h preceding the Opalescence Boost PF 40% bleaching procedure. Color measurements were conducted using a double‐beam UV–Vis spectrophotometer at four distinct time points (prior to bleaching, 24 h, 15 days, and 30 days post‐bleaching). Results: Tooth color change outcomes revealed that there were no statistically significant results with respect to the interaction of the two criteria (treatments and time) (p = 0.990). Additionally, there were no statistically significant results with respect to the main effects of treatments (p = 0.385), while there were statistically significant effects with respect to the time criterion (p = 0.013). Conclusions: The use of the tested desensitizing powders prior the bleaching procedure did not affect the tooth color change induced by the tested bleaching agent. Clinical Significance: Tooth color change and whiteness are not affected by air‐abrasion desensitizing treatments when applied prior to in‐office bleaching procedures. [ABSTRACT FROM AUTHOR]

Aim: This study evaluated the efficacy and cytotoxicity of 35% hydrogen peroxide (HP) gel incorporated with 10% (w/w) biosilicate (BioS) on sound enamel and early‐stage enamel erosion lesions. Methods: Discs of enamel/dentin were selected, subjected to erosive cycles (0.3% citric acid, pH 2.6), and treated with (n = 8): HP (35% HP, positive control); HP_BioS [carboxymethyl cellulose (CMC) + HP + BioS]; BioS (CMC + BioS); CMC (negative control). The discs were adapted to artificial pulp chambers with the enamel exposed for bleaching, and the dentin facing toward the culture medium (Dulbecco's modified Eagle's medium [DMEM]). Bleaching was performed in three 30‐min sessions at 7‐day intervals. After bleaching, the diffusion product (DMEM extract + diffused HP) was pipetted onto MDPC‐23 odontoblastic cell line and inoculated. Color parameters (ΔL, Δa, Δb), color change (ΔE00), and changes in whiteness index (ΔWID) were determined before (T0) and after the last bleaching session (T3). Cell viability (MTT, %), H2O2 diffusion (μg/mL), oxidative cell stress (OxS), and cell fluorescence (live/dead assay, in confocal microscopy) were assessed (ANOVA/Tukey; α = 0.05). Results: No difference in ΔL, Δa, Δb, ΔE00, and ΔWID were found between HP and HP_BioS (p > 0.05). The incorporation of BioS decreased the HP diffusion into the substrates and mitigated oxidative stress in early‐stage eroded enamel (p < 0.05). HP_BioS presented significantly higher cell viability compared with HP under erosion conditions. Live/dead assay indicated that BioS_HP maintained viability with larger clusters of viable cells. Conclusion: Incorporating BioS into HP maintained bleaching effectiveness, favored cell viability, reduced the oxidative stress, and the cytotoxicity in teeth with early‐stage erosion. Clinical Significance: BioS formulation showed promising results for reducing cytotoxicity in patients seeking tooth bleaching and presenting undetectable early‐stage erosion. [ABSTRACT FROM AUTHOR]

To gain insight on chemical sterilization processes, the influence of temperature (up to 70 °C), intense green light, and hydrogen peroxide (H2O2) concentration (up to 30% in aqueous solution) on microbial spore inactivation is evaluated by in‐situ Raman spectroscopy with an optical trap. Bacillus atrophaeus is utilized as a model organism. Individual spores are isolated and their chemical makeup is monitored under dynamically changing conditions (temperature, light, and H2O2 concentration) to mimic industrially relevant process parameters for sterilization in the field of aseptic food processing. While isolated spores in water are highly stable, even at elevated temperatures of 70 °C, exposure to H2O2 leads to a loss of spore integrity characterized by the release of the key spore biomarker dipicolinic acid (DPA) in a concentration‐dependent manner, which indicates damage to the inner membrane of the spore. Intensive light or heat, both of which accelerate the decomposition of H2O2 into reactive oxygen species (ROS), drastically shorten the spore lifetime, suggesting the formation of ROS as a rate‐limiting step during sterilization. It is concluded that Raman spectroscopy can deliver mechanistic insight into the mode of action of H2O2‐based sterilization and reveal the individual contributions of different sterilization methods acting in tandem. [ABSTRACT FROM AUTHOR]

The membrane‐integrated NADPH oxidases DUOX1 and DUOX2 are recruited to the apical plasma membrane in epithelial cells to release hydrogen peroxide, thereby playing crucial roles in various functions such as thyroid hormone synthesis and host defense. However, it has remained unknown about the molecular mechanism for apical sorting of DUOX1 and DUOX2. Here we show that DUOX1 and DUOX2 are correctly sorted to the apical membrane via the membrane‐spanning DUOX maturation proteins DUOXA1 and DUOXA2, respectively, when co‐expressed in MDCK epithelial cells. Impairment of N‐glycosylation of DUOXA1 results in mistargeting of DUOX1 to the basolateral membrane. Similar to DUOX1 complexed with the glycosylation‐defective DUOXA1, the naturally non‐glycosylated oxidase NOX5, which forms a homo‐oligomer, is targeted basolaterally. On the other hand, a mutant DUOXA2 deficient in N‐glycosylation is less stable than the wild‐type protein but still capable of recruiting DUOX2 to the apical membrane, whereas DUOX2 is missorted to the basolateral membrane when paired with DUOXA1. These findings indicate that DUOXA2 is crucial but its N‐glycosylation is dispensable for DUOX2 apical recruitment; instead, its C‐terminal region seems to be involved. Thus, apical sorting of DUOX1 and DUOX2 is likely regulated in a distinct manner by their respective partners DUOXA1 and DUOXA2. [ABSTRACT FROM AUTHOR]

The basis of most neurological syndromes is the accumulation of free radical molecules. Quercetin is a polyphenolic bioflavonoid molecule and it has a very strong antioxidant effect by maintaining oxidative balance. There are many difficulties in the clinical use of quercetin due to its hydrophobic structure, low solubility, instability, poor oral bioavailability, and limited tissue-barrier penetration. Its synergistic use in complex with gold nanoparticles (AuNPs) could overcome these problems. AuNPs have recently emerged as an attractive candidate for delivery applications of various biomolecules and drugs. The aim of this study was to synthesize two different sized gold nanoparticles (AuNP 20 and AuNP 50) modified with polyethyleneimine (PEI) and quercetin, evaluate their potential neuroprotective effects on the in vitro oxidative stress model using DRG primary sensory neurons. It was shown that the antioxidant and anti-apoptotic ability of the bioflavonoid was preserved after exposure to the designed quercetin modified AuNPs. The PEI surface coating increased the stability and biocompatibility of the AuNPs in both sizes. It also potentially enables additional surface functionalization. This study indicates that designed nanoparticles (AuNP-Q-PEI) with different sizes could be a useful potential platform for the treatment of neurodegenerative syndromes or cancer diseases. Quercetin/PEI modified and two different sized (AuNP 20 and AuNP 50) gold nanoparticles were successfully synthesized. Designed nanoplatform (AuNPs-Q-PEI) increased stability and biocompatibility. After nanomaterial exposure in the oxidative stress model of the DRG sensory neurons, the level of ROS and apoptosis was significantly reduced. [Display omitted] • Quercetin/PEI modified and two different sized (AuNP 20 and AuNP 50) gold nanoparticles were successfully synthesized. • The antioxidant property of the bioflavonoid was preserved after exposure to designed Q-coated AuNPs in the DRG neurons. • The PEI surface coating increased the stability and biocompatibility of the AuNPs in both sizes. • The designed gold nanoconjugates could be a useful potential nanoplatform for the treatment of neurodegenerative syndromes. [ABSTRACT FROM AUTHOR]

The hypoxic environment of deep tissue and the weak energy of microwave (MW) are still the major limitations of MW catalytic therapy. In this work, an MW‐responsive nano‐platform consisting of an Mn‐doped porphyrin metal–organic framework loaded with calcium peroxide (Mn0.1PCC) is designed to regulate the microenvironment of the injection site and enhance the generation of reactive oxygen species. The excellent MW absorbing properties of Mn0.1PCC improve the Fenton reaction between hydrogen peroxide formed by the hydrolysis of calcium peroxide and released Mn2+ generating more hydroxyl radicals under MW. This process does not consume the oxygen substrate and even produces oxygen to improve the hypoxic environment. Therefore, at a low and safe concentration (125 µg mL−1), the antibacterial rate of Mn0.1PCC against 4 × 108 CFU mL−1 of methicillin‐resistant Staphylococcus aureus (MRSA) after MW irradiation for 15 min is 99.71% ± 0.18%. Mn0.1PCC, upon exposure to MW, prevents the recurrence of bacterial infections and overcomes drug resistance by inhibiting quorum sensing and the two‐component system of MRSA. It can also induce macrophage M1 polarization, up‐regulate the pro‐inflammatory factor tumor necrosis factor‐α, and enhance the phagocytosis of macrophage to bacteria. This strategy provides insights into the development of high‐performance MW‐responsive nanocomposites for the treatment of infections in deep tissues. [ABSTRACT FROM AUTHOR]

Rechargeable alkaline zinc–air batteries (ZAB) hold great promise as a viable, sustainable, and safe alternative energy storage system to the lithium‐ion battery. However, the practical realization of ZABs is limited by their intrinsically low energy trip efficiency, stemming from a large charge and discharge potential gap. This overpotential is attributed to the four‐electron oxygen evolution and reduction reactions and their sluggish kinetics. Here, a new concept based on two‐electron generation and consumption of hydrogen peroxide at the air electrode is introduced. The O2/peroxide chemistry, facilitated by a newly developed Ni‐based bifunctional electrocatalyst, enables fast peroxide generation/consumption, exceptional energy efficiency, high durability, and high capacity. Hence, this new design offers substantial progress toward the commercialization of high energy density metal–air batteries. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the influence of H2O2‐based and H2O2‐free in‐office bleaching on the surface and mechanical attributes of CAD/CAM composite blocks. CAD/CAM composite blocks from five different composite materials (CC1, CC2, CC3, CC4, and CC5) were randomly divided into two groups according to bleaching application (H2O2‐based and H2O2‐free). The surface topography, morphology, nanohardness, elastic modulus, flexural strength, and fracture toughness were measured. A paired and unpaired sample t‐tests gauged the effect of pre‐ and post‐bleaching on the substrates. The estimated mean differences (before‐after bleaching) suggested an increase in surface roughness for two materials CC2 and CC4, and a significant decrease in nanohardness for material CC4 and in elastic modulus for materials CC2 and CC4 with H2O2‐based bleaching, whereas H2O2‐free bleaching resulted in changes compatible with no change in these properties. Flexural strength and fracture toughness showed no evidence of changes, irrespective of the bleaching gel used. Scanning electron microscopic analysis revealed erosive effects and micropore formation due to H2O2‐based bleaching. H2O2‐based bleaching deteriorates the surface of CAD/CAM composite materials while H2O2‐free bleaching gel had an insignificant effect on both surface and bulk properties. The clinician should carefully evaluate the potential effects of H2O2‐based bleaching on the surface properties of CAD/CAM composites. [ABSTRACT FROM AUTHOR]

This study evaluated the changes in surface properties of three resin‐based restorative materials after two laser‐assisted, in‐office tooth bleaching protocols using erbium, chromium: yttrium‐scandium‐gallium‐garnet (Er,Cr:YSGG) or diode (980 nm) lasers. A nanohybrid composite (Enamel Plus HRi), a Bis‐GMA‐free composite (Enamel Plus HRi Bio Function), and a resin‐matrix CAD‐CAM ceramic (Shofu Block HC) were tested. Forty specimens for each material were prepared and divided into four groups (n = 10/group). The control specimens did not undergo any bleaching treatment, whereas group 2 received bleaching with 40% hydrogen peroxide (H2O2), while groups 3 and 4 underwent the same bleaching procedure with the use of diode (980 nm) or Er,Cr:YSGG lasers, respectively. Surface microhardness and roughness measurements were conducted using a Vickers tester and an optical profilometer. Microhardness was lower in bleached specimens, with the nanohybrid composite exhibiting the largest difference from the no bleaching group. For the Bis‐GMA‐free composite the microhardness difference between no bleaching and laser‐assisted bleaching were smaller than seen for the conventional bleaching technique. Surface roughness was higher in bleached specimens, with nanohybrid composite showing the largest differences from the control specimens. The examined laser‐assisted tooth bleaching protocols were found not to impact surface microhardness and roughness of the tested resin‐based specimens and they are deemed suitable for clinical use. [ABSTRACT FROM AUTHOR]

Photocatalytic production of hydrogen peroxide (H2O2) has the advantages of safety, non-polluting operation and energy savings. Molecular-designed covalent organic frameworks (COFs) are an ideal material for achieving efficient photosynthesis of H2O2. However, the current COFs photocatalyst systems have various issues. Most of them harness only ultraviolet light and a small portion of visible light, unable to utilize 52% of the infrared (IR) light in the solar spectrum. Additionally, there are drawbacks such as the need for sacrificial agents and insufficient activity for large-scale production of H2O2. In this study, H2O2 production of 7.6 μmol h−1 was achieved using IR light irradiation without a sacrificial agent, and this photocatalyst ensured 6-times H2O2 production over Pristine COFs. The apparent quantum yield (AQY) under 900 nm light was 3.2%, which is 1.2-times higher than that when using Pristine COFs. This research outcome will contribute to the development of efficient and stable organic polymer photocatalysts for IR-driven H2O2 photocatalysis. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) transport by aquaporins (AQP) is a critical feature for cellular redox signaling. However, the H2O2 permeation mechanism through these channels remains poorly understood. Through functional assays, two Plasma membrane Intrinsic Protein (PIP) AQP from Medicago truncatula, MtPIP2;2 and MtPIP2;3 have been identified as pH-gated channels capable of facilitating the permeation of both water (H2O) and H2O2. Employing a combination of unbiased and enhanced sampling molecular dynamics simulations, we investigated the key barriers and translocation mechanisms governing H2O2 permeation through these AQP in both open and closed conformational states. Our findings reveal that both H2O and H2O2 encounter their primary permeation barrier within the selectivity filter (SF) region of MtPIP2;3. In addition to the SF barrier, a second energetic barrier at the NPA (asparagine-proline-alanine) region that is more restrictive for the passage of H2O2 than for H2O, was found. This behavior can be attributed to a dissimilar geometric arrangement and hydrogen bonding profile between both molecules in this area. Collectively, these findings suggest mechanistic heterogeneity in H2O and H2O2 permeation through PIPs. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the efficacy and cytotoxicity of experimental 6% and 35% hydrogen peroxide gels (HP6 or HP35) incorporated with titanium dioxide nanoparticles (NP) co-doped with nitrogen and fluorine and irradiated with a violet LED light (LT). Methods: Bovine enamel-dentin disks adapted to artificial pulp chambers were randomly assigned to bleaching (n = 8/group): NC (negative control), NP, HP6, HP6 + LT, HP6 + NP, HP6 + NP + LT, HP35, HP35 + LT, HP35 + NP, HP35 + NP + LT, and commercial HP35 (COM). Color (ΔE00) and whiteness index (ΔWID) changes were measured before and 14 days after bleaching. The extracts (culture medium + diffused gel components) collected after the first session were applied to odontoblast-like MDPC-23 cells, which were assessed concerning their viability, oxidative stress, and morphology. The amount of HP diffused through the disks was determined. Data were analyzed by generalized linear models or Kruskal Wallis Tests (α = 5%). Results: HP6 + NP + LT exhibited ΔE00 and ΔWID higher than HP6 (p < 0.05) and similar to all HP35 groups. HP6 + NP + LT showed the lowest HP diffusion, and the highest cell viability (%) among bleached groups, preserving cell morphology and number of living cells similar to NC and NP. HP6 + LT, HP6 + NP, and HP6 + NP + LT exhibited the lowest cell oxidative stress among bleached groups (p < 0.05). HP35, HP35 + LT, and HP35 (COM) displayed the lowest cell viability. Conclusion: HP6 achieved significantly higher color and whiteness index changes when incorporated with nanoparticles and light-irradiated and caused lower cytotoxicity than HP35 gels. The nanoparticles significantly increased cell viability and reduced the hydrogen peroxide diffusion and oxidative stress, regardless of HP concentration. Clinical Significance: Incorporation of co-doped titanium dioxide nanoparticles combined with violet irradiation within the HP6 gel could promote a higher perceivable and acceptable efficacy than HP6 alone, potentially reaching the optimal esthetic outcomes rendered by HP35. This approach also holds the promise of reducing cytotoxic damages and, consequently, tooth sensitivity. [ABSTRACT FROM AUTHOR]

In the search for new leads capable of interacting with multiple targets involved in NDD pathogenesis, a series of pyrazine-linked isoxazoline scaffolds were designed, synthesized and evaluated for their acetylcholinesterase and tyrosinase inhibitory potency and antioxidant activity. Isoxazolines 4a, 4d and 4h exhibited better molecular interaction with cholinesterases, tyrosinases and peroxiredoxin enzymes. Isoxazolines 4a, 4d and 4h interacted with acetylcholinesterase with the highest docking score of −9.083, −8.68 and −7.87 kcal/mol, respectively. Compound 4h ranked top when interacting with butyrylcholinesterase with a docking score of −7.926 kcal/mol, followed by 4a (−6.327 kcal/mol). 4a exhibited a robust interaction with 1HD2 with a docking score of −3.103 kcal/mol followed by 4d and 4h. 4a, 4d and 4h exhibited better docking scores of −5.47 kcal/mol, −4.63 kcal/mol and −5.157 kcal/mol with the enzyme tyrosinase. Based on the in-silico data, we have proceeded further to synthesis and in-vitro studies. Chalcones were synthesized by the Claisen-Schmidt reaction, which was cyclised to isoxazolines by the cycloaddition of hydroxylamine HCl. FTIR, 1HNMR, 13CNMR, and mass spectral studies further characterized the compounds. The prediction of pharmacokinetic parameters also supports the study, and all the compounds passed the screening. In-vitro studies were performed to evaluate acetylcholinesterase and tyrosinase inhibition. Compound 4h displayed excellent action against acetylcholinesterases and tyrosinase enzymes. Hydrogen peroxide assay determined the antioxidant effect, which found that 4h and 4d compounds exhibited higher strength as peroxide scavengers. Thus, the study shows that pyrazine-based isoxazolines with electron-withdrawing groups can be used as leads to develop a drug of choice for NDD, as it has excellent acetylcholinesterase and tyrosinase inhibitory action and tremendous peroxide scavenging effect. [ABSTRACT FROM AUTHOR]

Modulating the electronic state of multicomponent covalent organic framework (COF) electrocatalysts is crucial for enhancing catalytic activity. However, the effect of dimensionality on their physicochemical functionalities is still lacking. Herein, we report an interlaced unsaturated 2D and saturated 3D strategy to develop multicomponent‐regulated COFs with tunable gradient dimensionality for high selectivity and activity electrocatalysis. Compared with the two‐component 2D and 3D model COFs, the 2D/3D framework interlaced COFs with locally irregular dimensions and electronic structures are more practical in optimizing the intrinsic electrode surface reaction and mass transfer. Remarkably, the unsaturated 2D‐inserted 3D TAE‐COF regulates the adsorption mode of OOH* species to supply a favorable dynamic pathway for the H2O2 process, thereby achieving an excellent production rate of 8.50 mol gcat−1 h−1. Moreover, utilizing theoretical calculation and in situ ATR‐FTIR experiment, we found that the central carbon atom of the tetraphenyl‐based unit (site‐1 and site‐6) are potential active sites. This strategy of operating the adsorption ability of reactants with dimensionality‐interconnected building blocks provides an idea for designing durable and efficient electrocatalysts. [ABSTRACT FROM AUTHOR]