Search

Conventional strategies for highly selective and active hydrogen peroxide (H2O2) electrosynthesis primarily focus on catalyst design. Electrocatalytic reactions take place at the electrified electrode–electrolyte interface. Well‐designed electrolytes, when combined with commercial catalysts, can be directly applied to high‐efficiency H2O2 electrosynthesis. However, the role of electrolyte components is equally crucial but is significantly under‐researched. In this study, anionic surfactant n‐tetradecylphosphonic acid (TDPA) and its analogs are used as electrolyte additives to enhance the selectivity of the two‐electron oxygen reduction reaction. Mechanistic studies reveal that TDPA assembled over the electrode–electrolyte interface modulates the electrical double‐layer structure, which repels interfacial water and weakens the hydrogen‐bond network for proton transfer. Additionally, the hydrophilic phosphonate moiety affects the coordination of water molecules in the solvation shell, thereby directly influencing the proton‐coupled kinetics at the interface. The TDPA‐containing catalytic system achieves a Faradaic efficiency of H2O2 production close to 100% at a current density of 200 mA cm−2 using commercial carbon black catalysts. This research provides a simple strategy to enhance H2O2 electrosynthesis by adjusting the interfacial microenvironment through electrolyte design. [ABSTRACT FROM AUTHOR]

Unspecific Peroxygenases (UPOs) have emerged as robust biocatalysts for selective oxygenation reactions, as they are easily produced at scale and require only hydrogen peroxide as the external oxidant. UPOs can catalyze the oxygenation of the primary benzylic carbons of toluenes to give alcohol, aldehyde and carboxylic acid products. They can also catalyze hydroxylation at the benzylic position of ethylbenzenes, and the subsequent oxidation of the secondary alcohols to ketones. In this study, we have investigated factors that affect the balance of products in UPO‐catalyzed benzylic oxygenations using a range of functionalised toluenes and ethyl benzenes, and a UPO from Agrocybe aegerita (rAaeUPO‐PaDa‐I‐H variant). The product distribution is dependent upon a mixture of steric and electronic effects and, in selected cases, controlling the reaction conditions permits products from each product series to be generated chemoselectively. In this way, electron poor toluenes were converted directly into carboxylic acids in isolated yields of 36–99 % on preparative scale. [ABSTRACT FROM AUTHOR]

Surface plasmon resonance of precious metal gold nanorods can be tuned by controlling the aspect ratio, and they find widespread applications in biotechnology, imaging, sensing, optoelectronics, photonics, and catalysis. Here, a method is proposed for the controlled etching of gold nanorods within mesoporous silica shells by using a certain concentration of H2O2 at room temperature. In the experiments, the amount of HCl is varied to adjust the acidity and/or change the amount of H2O2 to control the speed of corrosion, achieving controllable adjustment of the aspect ratio of the gold nanorods. The extinction spectra show that under the action of H2O2 and HCl, the longitudinal plasmonic resonance of the gold nanorods shifted to shorter wavelengths, and the intensity of the longitudinal plasmonic resonance decreased. The more hydrochloric acid or hydrogen peroxide added, the faster the corrosion rate of the gold nanorods, and the faster the blue shift of the longitudinal plasmonic resonance. In addition, the intensity of the extinction spectra at 320 nm increased linearly versus time, which can also be used to monitor the etching process. By corroding gold nanorods to control the plasmonic resonances, gold nanorods can find broader applications. [ABSTRACT FROM AUTHOR]

Carbon‐based materials have been utilized as effective catalysts for hydrogen peroxide electrosynthesis via two‐electron oxygen reduction reaction (2e ORR), however the insufficient selectivity and productivity still hindered the further industrial applications. In this work, we report the Fe−O4 motif activated graphitic carbon material which enabled highly selective H2O2 electrosynthesis operating at high current density with excellent anti‐poisoning property. In the bulk production test, the concentration of H2O2 cumulated to 8.6 % in 24 h and the corresponding production rate of 33.5 mol gcat−1 h−1 outperformed all previously reported materials. Theoretical model backed by in situ characterization verified α‐C surrounding the Fe−O4 motif as the actual reaction site in terms of thermodynamics and kinetics aspects. The strategy of activating carbon reaction site by metal center via oxo‐bridge provides inspiring insights for the rational design of carbon materials for heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

For the 2D metal‐free carbon catalysts, the atomic coplanar architecture enables a large number of pz orbitals to overlap laterally, thus forming π‐electron delocalization, and the delocalization degree of the central atom dominates the catalytic activity. Herein, designing sulfur‐doped defect‐rich graphitic carbon nitride (S‐Nv‐C3N4) materials as a model, we propose a strategy to promote localized electron polarization by enhancing the ferromagnetism of ultra‐thin 2D carbon nitride nanosheets. The introduction of sulfur (S) further promotes localized ferromagnetic coupling, thereby inducing long‐range ferromagnetic ordering and accelerating the electron interface transport. Meanwhile, the hybridization of sulfur atoms breaks the symmetry and integrity of the unit structure, promotes electron enrichment and stimulating electron delocalization at the active site. This optimization enhances the *OOH desorption, providing a favorable kinetic pathway for the production of hydrogen peroxide (H2O2). Consequently, S‐Nv‐C3N4 exhibits high selectivity (>95 %) and achieves a superb H2O2 production rate, approaching 4374.8 ppm during continuous electrolysis over 300 hour. According to theoretical calculation and in situ spectroscopy, the ortho‐S configuration can provide ferromagnetic perturbation in carbon active centers, leading to the electron delocalization, which optimizes the OOH* adsorption during the catalytic process. [ABSTRACT FROM AUTHOR]

The majority of previously reported cathodic electrochemiluminescence (ECL) systems often required very negative potential to be carried out, which has greatly limited their applications in the sensing field. Screening high-performance cathodic ECL systems with low triggering potential is a promising way to broaden their applications. In this work, rhenium disulfide nanosheets (ReS2 NS) have been revealed as an efficient co-promoter to realize low-triggering-potential cathodic luminol ECL. One strong cathodic ECL signal appeared at a potential of −0.3 V and one anodic ECL peak was obtained at −0.15 V under the reverse potential scan, which were caused by electrogenerated reactive oxygen species (ROS) from hydrogen peroxide. The generation of strong luminol ECL at low potential was the result of the electrocatalytic effect of ReS2 NS on the reduction of H2O2. The scavenging effect of uric acid (UA) on the ROS could significantly inhibit the cathodic ECL. As a result, an ECL sensor was proposed, which showed outstanding performance for the detection of UA in the range of 10 nM to 0.1 mM with a low detection limit of 1.53 nM. Moreover, the ECL sensor was successfully applied in the sensitive detection of UA in real samples. This work provides a new avenue to establish a low-potential cathodic ECL system, which will sufficiently expand the potential application of cathodic ECL in the sensing field. [ABSTRACT FROM AUTHOR]

Introduction: Neonatal myiasis is a rare condition, with few reports available on the subject. Surgical management is recommended in some cases. In this study, we present the case of a 7-day-old male neonate with larvae in his scrotum who underwent surgery. Case presentation: A full-term 7-day-old male infant (Aryan race) was referred to a children's hospital. On the sixth day after birth, three 3–4 mm long larvae crawled out from his scrotum, with the number increasing over time. He was given intravenous antibiotics and topical mupirocin to combat secondary infections. The surgical treatment involved two steps: first, the larvae were extracted, and then the infection site was washed with betadine and hydrogen peroxide to help remove any possible remaining larvae. Conclusion: Scrotal myiasis is a rare disease that occurs in infants and requires immediate treatment. Surgical treatment is effective in removing dead or decaying larvae from a deep-seated location and washing the infection site to prevent secondary infection. [ABSTRACT FROM AUTHOR]

Reported herein is an ultra-sensitive turn-off fluorescence sensor for hydrogen peroxide based on its reaction with bimane 1. This reaction is highly efficient, resulting in a detection limit of 7.9 pM. It also maintains sensor efficacy when adsorbed on paper and enables both solution-state and vapor-phase detection. [ABSTRACT FROM AUTHOR]

Mechanotransduction is the essential process that cells convert mechanical force into biochemical responses, and electrochemical sensor stands out from existing techniques by providing quantitative and real-time information about the biochemical signals during cellular mechanotransduction. However, the intracellular biochemical response evoked by mechanical force has been poorly monitored. In this paper, we report a method to apply local stretch on single cell and simultaneously monitor the ensuing intracellular biochemical signals. Specifically, a ferromagnetic micropipette was fabricated to locally stretch a single cell labeled with Fe3O4 nanoparticles under the external magnetic field, and the SiC@Pt nanowire electrode (SiC@Pt NWE) was inserted into the cell to monitor the intracellular hydrogen peroxide (H2O2) production induced by the local stretch. As a proof of concept, this work quantitatively investigated the elevated amount of H2O2 levels in single endothelial cell under different stretching amplitudes. This work puts forward a new research modality to manipulate and monitor the mechanotransduction at the single-cell level. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) can destroy tumor cells by generating singlet oxygen (1O2) under light irradiation, which is limited by the hypoxia of the neoplastic tissue. Chemodynamic therapy (CDT) can produce toxic hydroxyl radical (⋅OH) to eradicate tumor cells by catalytic decomposition of endogenous hydrogen peroxide (H2O2), the therapeutic effect of which is highly dependent on the concentration of H2O2. Herein, we propose a BODIPY‐ferrocene conjugate with a balanced 1O2 and ⋅OH generation capacity, which can serve as a high‐efficiency antitumor agent by combining PDT and CDT. The ferrocene moieties endow the as‐prepared conjugates with the ability of chemodynamic killing of tumor cells. Moreover, combined PDT/CDT therapy with improved antitumor efficiency can be realized after exposure to light irradiation. Compared with the monotherapy by PDT or CDT, the BODIPY‐ferrocene conjugates can significantly increase the intracellular ROS levels of the tumor cells after light irradiation, thereby inducing the tumor cell apoptosis at low drug doses. In this way, a synergistic antitumor treatment is achieved by the combination of PDT and CDT. [ABSTRACT FROM AUTHOR]

ABSTRACT Clinical Significance Objective: This study evaluated the color change, surface roughness, mineral content and morphology of enamel bleached with 35% hydrogen peroxide (HP) combined with an experimental gel containing 1% titanium tetrafluoride (TiF4).Materials and Methods: Bovine enamel blocks were treated with (n = 12): (TiF) experimental gel containing 1% TiF4, (HP) 35% HP, (HPT) 35% HP + 1% TiF4 and (CT) control. Bleaching with HP was performed in 3 sessions (3 × 15 min/applications). pH, colorimetric parameters, surface roughness, mineral content and enamel morphology were determined. The pH was evaluated for 45 min. The color parameters were determined before bleaching (T0), and 14 days elapsed from the last bleaching session (T4). Surface roughness was analyzed at T0 and immediately after last bleaching session (T3). Enamel mineral content and morphology were verified at T4. Data were statistically analyzed by one‐way, two‐way ANOVA and Kruskal–Wallis (α = 0.05).Results: TiF increased surface roughness, and no differences between HP and HPT in terms of color and CO32−$$ {\mathrm{CO}}_3^{2-} $$–PO43−$$ {\mathrm{PO}}_4^{3-} $$ mineral content. Ti was detected only on TiF, and slight surface morphology changes were observed in bleached enamel.Conclusions: The combination of TiF4 and 35% HP did not interfere with the enamel bleaching effect, controlled surface roughness, and kept mineral content but promoted a minor surface morphology alteration.Due to the adverse effects of bleaching, titanium tetrafluoride (TiF4) has gained attention for its therapeutic properties, including the ability to reverse mineral loss and neutralize remineralization of mineral structures. Therefore, TiF4's remineralizing capacity may be a good alternative for incorporation into hydrogen peroxide bleaching agents. [ABSTRACT FROM AUTHOR]

This study focuses on the development a green synthesis of epoxy fatty acids (EFAs) which are commonly used as the plasticizer in polymer industries. The intracellular lipases of Candida catenulata cells as a whole-cell biocatalyst (WCB) were examined in the bio-epoxidation of free fatty acids (FFAs) with hydrogen peroxide. The FFAs in soybean soap stock, an industrial by-product of vegetable oil factories, was used as the feedstock of the process. To remove phosphates from soap stock a degumming process was tested before the bio-epoxidation reaction and results revealed that the EFAs yield was improved using the degummed fatty acids (DFAs). The attachments of magnetic Fe 3 O 4 nanoparticles to the surface of WCBs facilitated the recovery of the biocatalyst, and were improved stabilities. The activation energy for the magnetic whole-cell biocatalysts (MWCB) was 48.54 kJ mol−1, which was lower than the WCB system (51.28 kJ mol−1). The EFA yield was about 47.1 % and 33.8 % after 3 h for the MWCBs and 2 h for the WCBs, respectively. The MWCBs displayed acceptable reusability in the repetitious bio-epoxidation reaction with maintaining 59 % of the original activity after 5 cycles whereas the performance of the WCBs was 5.9 % at the same conditions. The effects of influential factors such as reaction time, molar ratio of H 2 O 2 to C C, and batch and semi-batch operations were investigated for both biocatalyst systems. The quality of EFAs was characterized by FTIR and GC-MS analyses. • A novel intracellular lipase of C. catenulata were introduced for epoxidation of free fatty acids. • A oil refinery waste after pretreatment was used as the feedstock of epoxy fatty acid production. • Magnetic whole-cell biocatalyst was developed by loading of Fe 3 O 4 nanoparticles on cell-surface. • The presence of water, organic solvent, and different molar ratios of H 2 O 2 /C C were examined. • The bare whole cells and magnetic whole cells were examined in batch and semi-batch experiments. [ABSTRACT FROM AUTHOR]

Redox metabolism is an integral part of the glutathione system, encompassing reduced and oxidized glutathione, hydrogen peroxide, and associated enzymes. This core process orchestrates a network of thiol antioxidants like thioredoxins and peroxiredoxins, alongside critical thiol-containing proteins such as mercaptoalbumin. Modifications to thiol-containing proteins, including oxidation and glutathionylation, regulate cellular signaling influencing gene activities in inflammation and carcinogenesis. Analyzing thiol antioxidants, especially glutathione, in biological fluids offers insights into pathological conditions. This review discusses the analytical methods for biothiol determination, mainly in blood plasma. The study includes all key methodological aspects of spectroscopy, chromatography, electrochemistry, and mass spectrometry, highlighting their principles, benefits, limitations, and recent advancements that were not included in previously published reviews. Sample preparation and factors affecting thiol antioxidant measurements are discussed. The review reveals that the choice of analytical procedures should be based on the specific requirements of the research. Spectrophotometric methods are simple and cost-effective but may need more specificity. Chromatographic techniques have excellent separation capabilities but require longer analysis times. Electrochemical methods enable real-time monitoring but have disadvantages such as interference. Mass spectrometry-based approaches have high sensitivity and selectivity but require sophisticated instrumentation. Combining multiple techniques can provide comprehensive information on thiol antioxidant levels in biological fluids, enabling clearer insights into their roles in health and disease. This review covers the time span from 2010 to mid-2024, and the data were obtained from the SciFinder® (ACS), Google Scholar (Google), PubMed®, and ScienceDirect (Scopus) databases through a combination search approach using keywords. [ABSTRACT FROM AUTHOR]

Silica (SiO2) particles are widely used in various industries due to their chemical inertness, thermal stability, and wear resistance. The present study describes the preparation and potential use of porous hydrophobic and hydrophilic SiO2 microcapsules (MCs) of a narrow size distribution. First, various layers of SiO2 micro/nano-particles (M/NPs) were grafted onto monodispersed polystyrene (PS) microspheres of a narrow size distribution. Hydrophobic and hydrophilic sintered SiO2 MCs were then prepared by removing the core PS from the PS/SiO2 core–shell microspheres by burning off under normal atmospheric conditions or organic solvent dissolution, respectively. We examined how the size and quantity of the SiO2 M/NPs influence the MC's properties. Additionally, we utilized two forms of hollow SiO2 MC for different applications; one form was incorporated into polymer films, and the other was free-floating. The hydrophobic microcapsules filled with 6% hydrogen peroxide were effective in killing the tomato brown rugose fruit virus (ToBRFV). The hydrophilic microcapsules filled with thymol and thin coated onto polypropylene films were successfully used to prevent mold formation for hay protection. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Materials and Methods Results Conclusion Clinical Relevance Compare the tooth sensitivity (TS) and bleaching efficacy (BE) of in‐office dental bleaching performed with 35% hydrogen peroxide (HP) or 37% carbamide peroxide (CP).Sixty‐six participants were randomly divided into two groups according to the bleaching gel applied to the right hemiarch: 35% HP, or 37% CP. TS was recorded immediately after, up to 1, 24, and 48 h after bleaching, using the VAS and NRS scales. BE was assessed before bleaching and 1 month after using color guide units (ΔSGUs) and a spectrophotometer (ΔEab, ΔE00, and ΔWID). TS was assessed using McNemar's and paired t‐test (VAS) or Wilcoxon signed rank (NRS). The paired t‐test was used to analyze BE (α = 0.05).TS risk and intensity were lower for the 37% CP (p = 0.003 and p < 0.005). Despite significant differences between the groups after 1 month (ΔSGU and ΔE00; p < 0.05), the color measurements of both groups exceeded the 50%:50% perceptibility/acceptability threshold.In‐office dental bleaching using 37% CP resulted in reduced risk and TS intensity, without prejudice to the BE.The use of 37% CP for in‐office dental bleaching could decrease TS risk and intensity without affecting BE.Trial Registration: ClinicalTrials.gov identifier: RBR‐683qhf [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) with stable crystalline porous structures and flexible assembly properties contribute to the direct photocatalytic synthesis of H2O2 to meet the growing global demand. To address the challenges of insufficient redox capacity and photogenerated carrier recombination of COFs, S‐scheme heterojunction is constructed from COFs with quantum dots (QDs) to improve the photocatalytic production of H2O2. Herein, 0D ZnCdS QDs (ZCS) uniformly anchor on the surface of a 2D conjugated tetrathiafulvalene‐based COF (TT‐COF), affording the S‐scheme heterojunction TT‐COF/ZCS. Formation of S‐scheme heterojunction effectively prevents the agglomeration of ZCS, modulates the energy band structure of TT‐COF, and enhances the migration of photogenerated carriers and redox ability. As a total consequence, the optimized heterojunction (TZ‐40) is able to afford H2O2 in the yield up to 5171 µmol g−1 h−1 under visible light irradiation with H2O and O2, much higher than those for TT‐COF, 2520 µmol g−1 h−1, and ZCS, 2647 µmol g−1 h−1. The present result demonstrates the great potential of COFs/QDs‐based S‐scheme heterojunctions for photocatalytic applications including photocatalytic H2O2 production. [ABSTRACT FROM AUTHOR]

• A novel side-aerated reactor for in-situ H 2 O 2 electrosynthesis was designed. • Side-aerated reactor coupled with a composite cathode greatly improved H 2 O 2 production. • Different aeration system and cathodes were evaluated for comparison. • Key factors for in-situ H 2 O 2 electrosynthesis were determined. The active graphite felt (GF) catalytic layer was effectively synthesized through a wet ultrasonic impregnation-calcination method, modified with CB and PTFE, and implemented in a pioneering side-aeration electrochemical in-situ H 2 O 2 reactor. The optimal mass ratio (CB: PTFE 1:4) for the modified cathode catalytic layer was determined using a single-factor method. Operating under optimum conditions of initial pH 5, 0.5 L/min air flow, and a current density of 9 mA/cm2, the system achieved a remarkable maximum H 2 O 2 accumulation of 560 mg/L, with the H 2 O 2 production capacity consistently exceeding 95 % over 6 usage cycles. The refined mesoporous structure and improved three-phase interface notably amplified oxygen transfer, utilization, and H 2 O 2 yield. Side aeration led to an oxygen concentration near the cathode reaching 20 mg/L, representing a five-fold increase compared to the 3.95 mg/L achieved with conventional bottom aeration. In the final application, the reaction system exhibited efficacy in the degradation of landfill leachate concentrate. After a 60-minute reaction, complete removal of chroma was attained, and the TOC degradation rate surpassed 60 %, marking a sixfold improvement over the conventional system. These results underscore the substantial potential of the system in H 2 O 2 synthesis and environmental remediation. [ABSTRACT FROM AUTHOR]

Achyrocline satureioides, popularly called "marcela" in Brazil, is used in traditional medicine in South America. A. satureioides, inflorescences are used for many conditions, including to minimize the Sars-Cov-2 symptoms. Therefore, the aim of this study was to determine the toxicity profile of A. satureioides aqueous extract (ASAE), using the Caenorhabditis elegans (C. elegans) alternative model. Survival, reproduction, development, and transgenerational assays were performed. The effects of ASAE were investigated under conditions of thermal stress and presence of oxidant hydrogen peroxide (H2O2). In addition, C. elegans strains containing high antioxidant enzyme levels and elevated lineages of daf-16, skn-1 and daf-2 regulatory pathways were examined. The ASAE LC50 value was found to be 77.3 ± 4 mg/ml. The concentration of ASAE 10 mg/ml (frequently used in humans) did not exhibit a significant reduction in worm survival at either the L1 or L4 stage, after 24 or 72 hr treatment. ASAE did not markedly alter the body area. In N2 strain, ASAE (10 or 25 mg/ml) reversed the damage initiated by H2O2. In addition, ASAE protected the damage produced by H2O2 in strains containing significant levels of sod-3, gst-4 and ctl − 1,2,3, suggesting modulation in these antioxidant systems by this plant extract. ASAE exposure activated daf-16 and skn-1 stress response transcriptional pathways independently of daf-2, even under extreme stress. Data suggest that ASAE, at the concentrations tested in C. elegans, exhibits a reliable toxicity profile, which may contribute to consideration for safe use in humans. [ABSTRACT FROM AUTHOR]

Although previous studies have demonstrated that methane (CH4) can mitigate the toxicity of cadmium (Cd) in alfalfa seedlings, the CH4-rich water used in these studies may create hypoxic conditions, potentially influencing the experimental outcomes. Therefore, this study aimed to investigate whether CH4 can reduce Cd toxicity in alfalfa seedlings without the interference of hypoxia and to analyze its underlying mechanisms. Here, it was observed that supplementing oxygen with saturated CH4-rich water can significantly alleviate the inhibition of 75 μM CdCl2 on the growth of alfalfa (Medicago sativa L.) seedlings. Less Cd accumulation was also observed in both root and shoot parts, which could be explained by the CH4-altered cell wall components in alfalfa seedling roots, including covalent and ionic soluble pectin, and the degree of demethylation in pectin, thus enabling a higher proportion of Cd binding to the cell walls and reducing the entry of Cd into the cells. The above actions of CH4 were accompanied by an increase in hydrogen peroxide (H2O2) content and NADPH oxidase activity, which could be blocked by the addition of the NADPH oxidase inhibitor diphenylene iodonium (DPI). Taken together, these results implied that exogenously applied CH4 could alleviate Cd toxicity in alfalfa seedlings by enhancing Cd chelation onto the root cell walls, which might be closely associated with NADPH oxidase-dependent H2O2 signals. These findings could provide insight into the mechanism through which CH4 alleviates Cd toxicity in alfalfa plants. [ABSTRACT FROM AUTHOR]

The SnTox1 effector is a virulence factor of the fungal pathogen Stagonospora nodorum (Berk.), which interacts with the host susceptibility gene Snn1 in a gene-for-gene manner and causes necrosis on the leaves of sensitive wheat genotypes. It is known that salicylic acid (SA), jasmonic acid (JA) and ethylene are the key phytohormones involved in plant immunity. To date, effectors of various pathogens have been discovered that can manipulate plant hormonal pathways and even use hormone crosstalk to promote disease development. However, the role of SnTox1 in manipulating hormonal pathways has not been studied in detail. We studied the redox status and the expression of twelve genes of hormonal pathways and two MAPK genes in six bread wheat cultivars sensitive and insensitive to SnTox1 with or without treatment by SA, JA and ethephon (ethylene-releasing agent) during infection with the SnTox1-producing isolate S. nodorum 1SP. The results showed that SnTox1 controls the antagonism between the SA and JA/ethylene signaling pathways. The SA pathway was involved in the development of susceptibility, and the JA/ethylene pathways were involved in the development of wheat plants resistance to the Sn1SP isolate in the presence of a SnTox1-Snn1 interaction. SnTox1 hijacked the SA pathway to suppress catalase activity, increase hydrogen peroxide content and induce necrosis formation; it simultaneously suppresses the JA and ethylene hormonal pathways by SA. To do this, SnTox1 reprogrammed the expression of the MAPK genes TaMRK3 and TaMRK6 and the TF genes TaWRKY13, TaEIN3 and TaWRKY53b. This study provides new data on the role of SnTox1 in manipulating hormonal pathways and on the role of SA, JA and ethylene in the pathosystem wheat S. nodorum. [ABSTRACT FROM AUTHOR]

Well-dispersed MIL-100(Fe) nanoparticles were synthesized under mild conditions and used to construct a photo-Fenton system (VMH system) with the assistance of visible-light irradiation and hydrogen peroxide. In such a VMH system, the MIL-100(Fe) has a high specific surface area and provides numerous Fe3+ active sites, thus accelerating the reaction of Fe3+ with photo-generated electrons under visible-light irradiation and generates Fe2+, and then the acquired Fe2+ can activate H2O2 to generate ⋅OH, accompanying with the oxidation of Fe2+ to Fe3+. Hence, the in-situ recycling of Fe2+/Fe3+ promotes the generation of ·OH, thus making the VMH system exhibits promising photocatalytic activity. The removal rate of ciprofloxacin in the VMH system is as high as 95.2% within 120 min photo-Fenton reaction, which is about 26 times higher than that of the Visible light/MIL-100(Fe) system. Moreover, the VMH system also exhibits strong degradation ability to other typical antibiotics, such as tetracycline, norfloxacin and cephalexin, and maintains high cyclic stability, revealing great practical application potential in the purification of antibiotic wastewater. [ABSTRACT FROM AUTHOR]

In this study, cost-effective alkali-activated materials made from industrial side streams (blast furnace slag and Na-jarosite) were developed for catalytic applications. The catalytic activity of the prepared materials was examined in catalytic wet peroxide oxidation reactions of a bisphenol A in an aqueous solution. All materials prepared revealed porous structure and characterisation expressed the incorporation of iron to the material via ion exchange in the preparation step. Furthermore, the materials prepared exhibited high specific surface areas (over 200 m2/g) and were mainly mesoporous. Moderate bisphenol A removal percentages (35%–37%) were achieved with the prepared materials during 3 h of oxidation at pH 7–8 and 50°C. Moreover, the activity of catalysts remained after four consecutive cycles (between the cycles the catalysts were regenerated) and the specific surface areas decreased only slightly and no changes in the phase structures were observed. Thus, the prepared blast furnace slag and Na-jarosite-based catalysts exhibited high mechanical stability and showed good potential in the removal of bisphenol A from wastewater through catalytic wet peroxide oxidation. [ABSTRACT FROM AUTHOR]

Background: The effect of an immune-boosting beverage (SAM) containing Sambucus Nigra, an energy beverage (ENE), an in-office bleaching (BLE) agent with 25% hydrogen peroxide superior, glazing (GLA) or polishing (POL) methods, and professional dental prophylaxis (PDP) on the color of CAD-CAM restorative materials is unknown. Methods: In total 210 specimens were prepared, consisting of CAD-CAM feldspathic (FC), zirconia-reinforced lithium disilicate ceramic (ZLS) and hybrid ceramic (HC). The ceramic specimens were divided according to the polishing methods of glazing (GLA) and mechanical polishing (POL). All materials were divided into two groups: with and without BLE. A 25% hydrogen peroxide superior (HPS) gel was used for BLE. After the baseline (BAS) measurement, the specimens were immersed in 3 different beverages (distilled water (DIS), SAM, ENE). After 28 days, a fine-grained (RDA 7) prophylaxis paste was applied. Statistical analysis of ∆E00 color difference values was performed by 3-way ANOVA and Bonferroni test (α = 0.05). Results: The effect of all other actions except material-BLE-beverage on color for BAS-Day 28 was statistically different (p < 0.05). The effect of material, material-BLE, beverage on color for Day 28-PDP was statistically different (p < 0.05). After 28 days, the lowest color change was found in FC-GLA and HC immersed in DIS (p = 0.0001) and the highest in FC-POL immersed in ENE (p = 0.0002). PDP was efficient in color recovery in HC immersed to DIS, ENE and SAM (p = 0.0010). For FC, HC and ZLS, BLE caused a higher color change (p < 0.0001). Regardless of the material, the highest color change for BLE-beverage was found in BLE-treated specimens immersed in ENE (p = 0.0496) and the lowest color change was found in non-BLE-treated specimens immersed in SAM (p = 0.0074). Conclusions: In materials pre-exposed to 25% HPS, the effect of PDP on color recovery was lower than in unexposed materials. After 28 days, mechanical polishing produced higher color change in FC than glazing, however, in ZLS effects of glazing and mechanical polishing on color were similar. For material/polishing method, HC was the most effective. ENE caused higher color change than DIS and SAM. PDP was more effective than ENE in restoring color to DIS- and SAM-immersed specimens. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Basella alba has been used in Thai remedies to treat skin disorders, but scientific evidence supporting its efficacy is currently limited. In this study, we investigated the inhibitory effects of B. alba extracts on melanin production using melanoma cells, as well as their impact on oxidative stress and inflammation in keratinocytes. The results demonstrate that B. alba extracts inhibited melanin content and cellular tyrosinase activity in 3-isobutyl-1-methylxanthine (IBMX)-induced melanoma cells by downregulating MITF and the pigmentary genes TYR, TRP-1, and DCT. Interestingly, the MITF regulator gene was inhibited by both the 50% and 95% ethanolic extracts of B. alba with levels of 0.97 ± 0.19 and 0.92 ± 0.09 of the control, respectively, which are comparable to those observed in the arbutin treatment group at 0.84 ± 0.05 of the control. Moreover, after hydrogen peroxide (H2O2) exposure, pretreatment with B. alba reduced lipid peroxidation byproducts and increased the levels of antioxidant-related genes, including SOD-1, GPX-1, and NRF2. Notably, the suppression of the POMC promoter gene in keratinocytes was observed, which may disrupt melanogenesis in melanocytes involving the MC1R signaling pathway. MC1R mRNA expression decreased in the treatments with 50% and 95% ethanolic extracts of B. alba, with relative levels of 0.97 ± 0.18 and 0.90 ± 0.10 of the control, respectively, similar to the arbutin-treated group (0.88 ± 0.25 of control). A significant reduction in nitric oxide was also observed in the B. alba-treated groups, along with a decrease in genes associated with pro-inflammatory cytokines, including IL-1β, IL-6, and COX-2. These findings suggest that B. alba has potential in the prevention of skin-related problems. [ABSTRACT FROM AUTHOR]

In plants, a local infection can lead to systemic acquired resistance (SAR) through increased production of salicylic acid (SA). For many years, the identity of the mobile signal and its direct transduction mechanism for systemic SA synthesis in initiating SAR have been debated. We found that in Arabidopsis thaliana, after a local infection, the conserved cysteine residue of the transcription factor CCA1 HIKING EXPEDITION (CHE) undergoes sulfenylation in systemic tissues, which enhances its binding to the promoter of the SA-synthesis gene ISOCHORISMATE SYNTHASE1 (ICS1) and increases SA production. Furthermore, hydrogen peroxide (H2O2) produced through NADPH oxidases is the mobile signal that sulfenylates CHE in a concentration-dependent manner. Accumulation of SA and the previously reported signal molecules, such as N-hydroxypipecolic acid (NHP), then form a signal amplification loop to establish SAR. [ABSTRACT FROM AUTHOR]

The synthesis of H2O2-activatable small molecules in the second near-infrared (NIR-II) window remains challenging. We present the NIR-II probe Z-1065 for real-time detection of H2O2. Z-1065 demonstrates high sensitivity and selectivity towards H2O2in vitro and effectively monitors H2O2 generation in drug-induced liver injury (DILI) mouse models. [ABSTRACT FROM AUTHOR]

Manganese catalysts that activate hydrogen peroxide have seen increased use in organic transformations, such as olefin epoxidation and alkane C−H bond oxidation. Proposed mechanisms for these catalysts involve the formation and activation of MnIII‐hydroperoxo intermediates. Examples of well‐defined MnIII‐hydroperoxo complexes are rare, and the properties of these species are often inferred from MnIII‐alkylperoxo analogues. In this study, we show that the reaction of the MnIII‐hydroxo complex [MnIII(OH)(6Medpaq)]+ (1) with hydrogen peroxide and acid results in the formation of a dark‐green MnIII‐hydroperoxo species [MnIII(OOH)(6Medpaq)]+ (2). The formulation of 2 is based on electronic absorption, 1H NMR, IR, and ESI‐MS data. The thermal decay of 2 follows a first order process, and variable‐temperature kinetic studies of the decay of 2 yielded activation parameters that could be compared with those of a MnIII‐alkylperoxo analogue. Complex 2 reacts with the hydrogen‐atom donor TEMPOH two‐fold faster than the MnIII‐hydroxo complex 1. Complex 2 also oxidizes PPh3, and this MnIII‐hydroperoxo species is 600‐fold more reactive with this substrate than its MnIII‐alkylperoxo analogue [MnIII(OOtBu)(6Medpaq)]+. DFT and time‐dependent (TD) DFT computations are used to compare the electronic structure of 2 with similar MnIII‐hydroperoxo and MnIII‐alkylperoxo complexes. [ABSTRACT FROM AUTHOR]

Nanomedicine shows promise in the therapy of eradicating bladder tumors and preventing tumor recurrence caused by cancer‐related inflammation. Shell‐core structured BNN6/Z8@ALA/Z67 nanoparticles with sequential release kinetics is designed, aiming to eliminate tumors and curb inflammation, thereby ablating bladder tumors and preventing their recurrence. The shell of this nanoparticle comprises zeolitic imidazolate framework‐67 (Z67) and 5-aminolevulinic acid (ALA), while the core comprises zeolitic imidazolate framework‐8 (Z8) and N,N'‐di‐sec‐butyl‐N,N'‐dinitroso‐1,4‐phenylenediamine (BNN6). Modified with polydopamine‐methoxypolyethylene glycol amine, these nanoparticles efficiently target bladder tumors. In the acidic tumor environment, the outer‐layered Z67 breaks down rapidly, releasing ALA, which transforms into protoporphyrin IX (PpIX) in mitochondria. Additionally, the degraded Z67 triggers the conversion of hydrogen peroxide into oxygen, aiding PpIX to generate reactive oxygen species under ultrasound, facilitating tumor ablation. As Z67 decomposes, the inner‐layered Z8 releases BNN6 in the acidic environment. Ultrasound exposure prompts the release of nitric oxide, effectively reducing inflammation. Under ultrasound, BNN6/Z8@ALA/Z67 showcased outstanding staged anti‐tumor and anti‐inflammatory effects in both in vitro and murine subcutaneous tumor model tests, and effectively prevents tumor recurrence in rat bladder tumor models. These findings underscore the promising potential of the designed shell‐core nanoparticle with staged tumor ablation and inflammation suppression in preventing bladder tumor recurrence. [ABSTRACT FROM AUTHOR]

Currently, there exists conflicting data regarding the biological activity of unmodified fullerene C60. Various sources report its toxicity, geroprotective activity, and potential interaction with DNA. Contradictory findings regarding the toxicity of C60 may arise from the use of toxic solvents, as well as the influence of bioavailability and bioactivity on the preparation conditions of C60 suspensions. Furthermore, the microbiota of experimental animals can impact geroprotective activity results by releasing surfactants that facilitate substance penetration through the cell membrane. In this study, we selected conditions for solubilizing fullerene C60 in a solution of surfactin, a surfactant of bacterial origin, as well as in a 2% aqueous solution of TWEEN 80, employing ultrasound. Through bioluminescent analysis using lux biosensors in Escherichia coli MG1655, we observed that C60 in surfactin reduced induced genotoxic and oxidative stress. Given that surfactin enhances membrane permeability to fullerene C60, suspensions of fullerene in designated concentrations of surfactin can be regarded as a DNA protector and antioxidant, warranting further investigation as a promising component of novel drugs. [ABSTRACT FROM AUTHOR]

ABSTRACT Polyploid varieties have been suggested as an alternative approach to promote drought tolerance in citrus crops. In this study, we compared the responses of diploid and tetraploid Sunki ‘Tropical’ rootstocks to water deficit when grafted onto ‘Valencia’ sweet orange trees and subjected to water withholding in isolation or competition experiments under potted conditions. Our results revealed that, when grown in isolation, tetraploid rootstocks took longer to show drought symptoms, but this advantage disappeared when grown in competition under the same soil moisture conditions. The differences in drought responses were mainly associated with variations in endogenous leaf levels of abscisic acid (ABA), hydrogen peroxide (H₂O₂) and carbohydrates among treatments. Overall, tetraploids were more affected by drought in individual experiments, showing higher H₂O₂ production, and in competition experiments, rapidly increasing ABA production to regulate stomatal closure and reduce water loss through transpiration. Therefore, our results highlight the crucial importance of evaluating diploid and tetraploid rootstocks under the same soil moisture conditions to better simulate field conditions, providing important insights to improve selection strategies for more resilient citrus rootstocks. [ABSTRACT FROM AUTHOR]

Oxygen reduction reaction via the two-electron pathway (2e− ORR) offers a sustainable opportunity for hydrogen peroxide (H2O2) production, but suffers from low selectivity. In this work, indium oxide with oxygen vacancies (In2O3−x) exhibits a H2O2 selectivity close to 98% at 0.6 V vs. RHE. Further, a Faradaic efficiency (FE) of around 95% at 0.4–0.6 V vs. RHE and a H2O2 productivity of 3.7 mol gcatalyst−1 h−1 are reached in a flow cell. In situ Raman spectra indicate that In2O3−x promotes the adsorption and activation of O2 and stabilizes oxygen intermediates. This work provides an insight into improving H2O2 selectivity for 2e− ORR catalysts. [ABSTRACT FROM AUTHOR]

H2O2 photosynthesis represents an appealing approach for sustainable and decentralized H2O2 production. Unfortunately, current reactions are mostly carried out in laboratory-scale single-phase batch reactors, which have a limited H2O2 production rate (<100 μmol h−1) and cannot operate in an uninterrupted manner. Herein, we propose continuous H2O2 photosynthesis and extraction in a biphasic fluid system. A superhydrophobic covalent organic framework photocatalyst with perfluoroalkyl functionalization is rationally designed and prepared via the Schiff-base reaction. When applied in a home-built biphasic fluid photo-reactor, the superhydrophobicity of our photocatalyst allows its selective dispersion in the oil phase, while formed H2O2 is spontaneously extracted to the water phase. Through optimizing reaction parameters, we achieve continuous H2O2 photosynthesis and extraction with an unprecedented production rate of up to 968 μmol h−1 and tunable H2O2 concentrations from 2.2 to 38.1 mM. As-obtained H2O2 solution could satisfactorily meet the general demands of household disinfection and wastewater treatments. Photocatalytic H2O2 synthesis is often performed in lab-scale batch reactors with low efficiency. Here, the authors report a biphasic fluid system that enables continuous H2O2 synthesis and automatic product extraction, addressing the limitations of traditional methods. [ABSTRACT FROM AUTHOR]

Determining whether plants are under stress before obvious disease symptoms is crucial for precision agriculture. Intercellular hydrogen peroxide (H2O2) in plants can be used to indicate stress. However, most current H2O2 detection methods are destructive or limited by chlorophyllous autofluorescence. Herein, we constructed an in vivo surface-enhanced Raman scattering (SERS) sensor for nondestructive, in situ, and highly sensitive detection of H2O2 in plant leaves. The sensor with the designed size can enable nondestructive and in situ H2O2 detection without fluorescence interference. In addition, Ag decahedral nanoparticles with sharp edges and tips enhance the SERS effect, and the lowest detection concentration of H2O2 can reach 10 nM in vitro. The utility of the SERS sensor is demonstrated by Oxalis corniculata under wound, heat, and cold stresses. This SERS sensor can provide warnings before plants show visible signs of damage, thereby improving crop yields and potentially becoming an essential tool for precision agriculture. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bamboo is a perennial rapid-growing plant that is given preference for renewable biosources for biofuels and bio-based chemical conversion. Bamboos are rich in cellulose and have highly recalcitrant biomass due to high lignin. Bamboo is abundantly available in Northeastern India and can be utilized as a feedstock biofuels. Here, we evaluated the pretreatment of bamboo residues Dendrocalamus strictus with different concentrations of alkali, hydrogen peroxide, and alkaline hydrogen peroxide and its influence on biomass digestibility for enhancement of sugar recovery with Celic C cellulase enzyme blend. Enzymatic hydrolysis data indicated untreated raw biomass showed a digestibility of 40% after 48 h of incubation. The biomass pretreated with alkali showed a maximum digestibility of 61% obtained from 10% loaded with 0.5% w/v NaOH. Pretreatment of the bamboo with H2O2 shows a maximum digestibility of 75% from biomass loaded with 1% w/v of H2O2. Combinational pretreatment of alkaline hydrogen peroxide showed a maximum efficiency of biomass digestibility of 83% attained from biomass loaded with 1% w/v NaOH-H2O2. Crystallinity index (CrI) analysis showed that CrI increased from 64% to 70.75% in pretreated biomass. FTIR and SEM analysis show changes in functional groups, morphology, and surface of biomass in pretreated biomass. Compositional analysis shows that 68% of lignin removal is obtained from alkaline hydrogen peroxide pretreatment. Cellulose content increased from 52% to 65%, and hemicellulose decreased from 18.6% to 8.6%. Results indicated that the potential possibility of bamboo waste biomass as feedstock for biorefinery products and alkaline hydrogen peroxide pretreatment methods is an efficient strategy for sugar recovery for bioethanol production. [ABSTRACT FROM AUTHOR]

Adzuki bean, an important legume crop, exhibits poor tolerance to low temperatures. To investigate the effect of exogenous abscisic acid (ABA) on the physiological metabolism and yield resistance of adzuki bean under low-temperature stress, we conducted a potted experiment using Longxiaodou 4 (LXD 4) and Tianjinhong (TJH) as test materials and pre-sprayed with exogenous ABA at flowering stage continuously for 5 days with an average of 12°C and an average of 15°C, respectively. We found that, compared with spraying water, foliar spraying exogenous ABA increased the activities of antioxidants and the content of non-enzymatic antioxidants, effectively inhibited the increase of malondialdehyde (MDA), hydrogen peroxide (H2O2) content, O2-· production rate. Exogenous ABA induced the activation of endogenous protective mechanisms by increasing antioxidant enzymes activities such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), as well as elevated levels of non-enzymatic antioxidants including ascorbic acid (ASA) and glutathione (GSH). Moreover, the yield loss of 5.81%-39.84% caused by chilling stress was alleviated by spraying ABA. In conclusion, foliar spraying exogenous ABA can reduce the negative effects of low-temperature stress on the yield of Adzuki beans, which is essential to ensure stable production of Adzuki beans under low-temperature conditions. [ABSTRACT FROM AUTHOR]

Background: This case report presents an exceptionally rare and atypical presentation of diphtheria in a 17-year-old female of Hausa ethnicity residing in an area with an elevated incidence within Kano State, Nigeria. By the end of 39th epidemiological week of 2023, only two cases of cutaneous diphtheria have been reported among 5,811 cases managed at MMSH diphtheria treatment center (DTC), representing approximately 0.035% of all diphtheria cases during that time period. Case presentation: A 17-year-old Hausa female presented with a 3-day history of throat discomfort, malaise, and muffled speech. Physical examination revealed a pseudomembrane covering the tonsillar pillars, grade 3 tonsillar enlargement, and an unusual genital manifestation characterized by extensive vulval edema, severe pain, and a large, greyish patch extending into the vaginal introitus. Her medical history was significant for recent exposure to diphtheria and the emotional impact of her sibling's death from the same disease. Diagnostic tests, including throat swab culture and histocytology, confirmed diphtheria in the throat and vulvovaginal regions. The patient was promptly initiated on diphtheria antitoxin, Azithromycin, and innovative sitz baths with hydrogen peroxide. After 4 days of Sitz bath therapy, complete pseudomembrane clearance was observed, and the patient's symptoms resolved. Conclusion: This case underscores the complexity of diphtheria presentations, particularly with rare pseudomembranes in both throat and vaginal regions. The successful management, combining traditional and innovative therapies, highlights the importance of recognizing and addressing unusual manifestations promptly. The potential role of auto-inoculation and the efficacy of interventions like hydrogen peroxide sitz baths warrant further investigation. Overall, this case contributes to the understanding of diverse diphtheria presentations, guiding future clinical strategies for management of diphtheria cases and emphasizing the imperative of comprehensive vaccination efforts. [ABSTRACT FROM AUTHOR]

ABSTRACT Leaf flattening plays a pivotal role in optimizing light capture and enhancing photosynthesis efficiency. While extensive research has clarified the molecular mechanisms governing the initial stages of leaf flattening, understanding the maintenance of this process in mature leaves remains limited. Our investigation focused on sly‐miR398b in tomatoes and revealed its crucial role in maintaining leaf flattening. In situ hybridization experiments indicated predominant expression of sly‐miR398b in the abaxial side. Disrupting sly‐miR398b using CRISPR/Cas9 relieved its suppression on target gene (Cu/Zn‐SOD, SlCSD1), elevating SlCSD1 levels specifically on the abaxial side. Consequently, this asymmetrical expression of SlCSD1 increased hydrogen peroxide (H2O2) levels in the abaxial side, hindering auxin influx genes while promoting auxin efflux gene expression. This shift reduced auxin response gene expression in the abaxial side of mature leaves compared to the adaxial side, leading to leaf epinasty in sly‐miR398b mutants. Exogenous H2O2 spraying induced leaf epinasty, downregulating SlGH3.5 and upregulating SlPIN3 and SlPIN4. Remarkably, spraying with 1‐naphthalacetic acid (NAA) restored leaf flattening in sly‐miR398b mutants. Our findings offer novel insights into mature leaf flattening maintenance via sly‐miR398b's regulation of auxin and H2O2 signalling pathways. [ABSTRACT FROM AUTHOR]

Summary In this research, the effects of washing treatments (potassium carbonate (PC), potassium hydroxide (PH), peracetic acid (PA), alkaline hydrogen peroxide (AHP)), ultrasound (US) and high‐intensity pulsed light (HIPL) technologies on the removal of ochratoxin A (OTA) residues in raisins were investigated. PC at 5 min (66.60%), PH at 10 min (65.25%), alkaline hydrogen peroxide at 5 min (63.30%) and HIPL at 12 J cm−2 (62.50%) were found to be the most successful applications in OTA degradation, respectively. Although the OTA degradation rate was high after chemical washing for 10 min, the raisins had a chemical odour. The results show that HIPL effectively reduces OTA levels in raisins without causing any quality loss. [ABSTRACT FROM AUTHOR]

The electrochemical production of hydrogen peroxide (H2O2) using metal‐free catalysts has emerged as a viable and sustainable alternative to the conventional anthraquinone process. However, the precise architectural design of these electrocatalysts poses a significant challenge, requiring intricate structural engineering to optimize electron transfer during the oxygen reduction reaction (ORR). Herein, we introduce a novel design of covalent organic frameworks (COFs) that effectively shift the ORR from a four‐electron to a more advantageous two‐electron pathway. Notably, the JUC‐660 COF, with strategically charge‐modified benzyl moieties, achieved a continuous high H2O2 yield of over 1200 mmol g−1 h−1 for an impressive duration of over 85 hours in a flow cell setting, marking it as one of the most efficient metal‐free and non‐pyrolyzed H2O2 electrocatalysts reported to date. Theoretical computations alongside in situ infrared spectroscopy indicate that JUC‐660 markedly diminishes the adsorption of the OOH* intermediate, thereby steering the ORR towards the desired pathway. Furthermore, the versatility of JUC‐660 was demonstrated through its application in the electro‐Fenton reaction, where it efficiently and rapidly removed aqueous contaminants. This work delineates a pioneering approach to altering the ORR pathway, ultimately paving the way for the development of highly effective metal‐free H2O2 electrocatalysts. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) is a versatile oxidant, and its eco-friendly synthesis via visible light and air oxygen is crucial. Anthraquinone compounds were employed as homogeneous photocatalysts for alcohol oxidation, yielding H2O2 under visible light. Instead of using traditional catalyst library screening, a model based on density functional theory was proposed to structurally optimize anthraquinone photocatalysts, resulting in the discovery of a novel catalyst significantly boosting H2O2 generation (up to 621.2 mM h-1 intermittently). Continuous flow reactor design improvements can enhance chemical transformation efficiency, as demonstrated by continuous H2O2 production using 2,6-di-tert-butyl anthraquinone. When isopropanol was used as the hydrogen atom donor, H2O2 production rates reached 3950.6 mM h-1 in a 7-minute reaction, with a space--time yield of 7.90 mol (L h) -1, showcasing promising advancements in green H2O2 synthesis. [ABSTRACT FROM AUTHOR]

Spontaneous ionization/breakup of water at the surface of aqueous droplets has been reported with evidence ranging from formation of hydrogen peroxide and hydroxyl radicals, indicated by ions at m/z 36 attributed to OH⋅‐H3O+ or (H2O‐OH2)+⋅ as well as oxidation products of radical scavengers in mass spectra of water droplets formed by pneumatic nebulization. Here, aqueous droplets are formed both by nanoelectrospray, which produces highly charged nanodrops with initial diameters ~100 nm, and a vibrating mesh nebulizer, which produces 2–20 μm droplets that are initially less highly charged. The lifetimes of these droplets range from 10s of μs to 560 ms and the surface‐to‐volume ratios span ~100‐fold range. No ions at m/z 36 are detected with pure water, nor are significant oxidation products for the two radical scavengers that were previously reported to be formed in high abundance. These and other results indicate that prior conclusions about spontaneous hydroxyl radical formation in unactivated water droplets are not supported by the evidence and that water appears to be stable at droplet surfaces over a wide range of droplet size, charge and lifetime. [ABSTRACT FROM AUTHOR]

Salinity is the major abiotic stress among others that determines crop productivity. The primary goal is to examine the impact of Zinc Oxide Nanoparticles (ZnO NPs) on the growth, metabolism, and defense systems of pea plants in simulated stress conditions. The ZnO NPs were synthesized via a chemical process and characterized by UV, XRD, and SEM. The ZnO NPs application (50 and 100) ppm and salt (50 mM and 100 mM) concentrations were carried out individually and in combination. At 50 ppm ZnO NPs the results revealed both positive and negative effects, demonstrating an increase in the root length and other growth parameters, along with a decrease in Malondialdehyde (MDA) and hydrogen peroxide concentrations. However, different concentrations of salt (50 mM and 100 mM) had an overall negative impact on all assessed parameters. In exploring the combined effects of ZnO NPs and salt, various concentrations yielded different outcomes. Significantly, only 50 mM NaCl combined with 50 ppm ZnO NPs demonstrated positive effects on pea physiology, leading to a substantial increase in root length and improvement in other physiological parameters. Moreover, this treatment resulted in decreased levels of MAD, Glycine betaine, and hydrogen peroxide. Conversely, all other treatments exhibited negative effects on the assessed parameters, possibly due to the high concentrations of both stressors. The findings offered valuble reference data for research on the impact of salinity on growth parameters of future agriculture crop. [ABSTRACT FROM AUTHOR]

Although conventional therapeutic approaches demonstrate significant success in treating primary tumors, their efficacy diminishes when addressing distant and metastatic tumors, calling for new technologies to transport and activate the therapeutic agents. Here, a core‐shell UCNP@MOF (upconversion nanoparticle — metal organic framework) nanoagents is constructed for Type I and Type II photodynamic therapy under biocompatible near‐infrared light irradiance (at 808 nm) and utilize their pore loading capacity to further realize synergistic immunotherapy in solid tumors. The Cu2+ to Cu+ reduction at the nodes in the MOFs shell is demonstrated to promote the generation of reactive oxygen species via depletion of overexpressed glutathione (GSH) compounds, while tumor microenvironment‐enriched hydrogen peroxide is found to substantially augment the PDT effects. Importantly, the MOFs pore‐loaded indoleamine 2,3‐dioxygenase (IDO) inhibitor, along with s‐nitroso‐n‐acetylpenicillamine (SNAP), upregulated tumor‐infiltrating lymphocytes and induced prominent immunotherapeutic effects in vivo. This core‐shell UCNP@MOF nanoagents have demonstrated effectiveness against both primary and distant tumors in xenografted tumor models, holding promise for treating solid tumors in metastasis. [ABSTRACT FROM AUTHOR]

A process for photocatalytically synthesizing hydrogen peroxide while simultaneously degrading organic pollutants is of interest. In this study, a dendritic nanopolymer was synthesized and utilized as a photocatalyst for the production of hydrogen peroxide, which was then used in tandem with the degradation of Tetracycline (TC) and Rhodamine B (Rh B) organic pollutants under a 36 W incandescent bulb. The yield of H2O2 was measured at 8.4 mg g−1 h−1, with photocatalytic degradation rates of 93.90 % for Rh B and 72.92 % for TC. The degradation kinetics of TC and Rh B by the dendritic polymer were found to follow pseudo‐first‐order kinetics, and a higher affinity for degradation was observed for Rh B. The photocatalytic degradation mechanism of TC in a Fenton‐like system was attributed to an oxidation system involving hydrogen peroxide and ferrous ions. [ABSTRACT FROM AUTHOR]

The development of novel metal–organic frameworks (MOFs) as efficient photocatalysts for hydrogen peroxide production from water and oxygen is particularly interesting, yet remains a challenge. Herein, we have prepared four cyclic trinuclear units (CTUs) based MOFs, exhibiting good light absorption ability and suitable band gaps for photosynthesis of H2O2. However, Cu‐CTU‐based MOFs are not able to photocatalyzed the formation of H2O2, while the alteration of metal nodes from Cu‐CTU to Ag‐CTU dramatically enhances the photocatalytic performance for H2O2 production and the production rates can reach as high as 17476 μmol g−1 h−1 with an apparent quantum yield of 4.72 %, at 420 nm, which is much higher than most reported MOFs. The photocatalytic mechanism is comprehensively studied by combining the isotope labeling experiments and DFT calculation. This study provides new insights into the preparation of MOF photocatalysts with high activity for H2O2 production through molecular engineering. [ABSTRACT FROM AUTHOR]

One nanoparticle possessing both peroxidase (POD) and catalase (CAT) activities is a prevalent co‐substrate nanozyme system, distinct from the extensively researched cascade nanozyme system. During the sensing of hydrogen peroxide by POD, the impact of CAT is actually ignored in most studies. In this study, the CAT effect on hydrogen peroxide detection is thoroughly investigated based on POD catalysis by finely tuning the relative activity of POD and CAT. It is discovered that the CAT effect can be changed by delaying the injection of chromogenic substrate after adding hydrogen peroxide and that the linear range grows with the delayed time. Then, a theoretical mechanism showed that the time‐delay mediated CAT effect magnification does not change the Vmax, but it causes Km to linearly increase with delayed time, consistent with the experiment results. Furthermore, the detection of high concentrations of hydrogen peroxide is successfully realized in contact lens care solutions by utilizing time‐delay‐mediated POD/CAT nanozyme. On the other hand, its linear range‐tunable characteristic is used to produce multiple standard curves, then enabled self‐verifying hydrogen peroxide detection. Overall, this work investigates the role of CAT in CAT‐inherent POD nanozymes both theoretically and experimentally, and confirms POD/CAT nanozyme's priority in developing high‐performance sensors. [ABSTRACT FROM AUTHOR]

Objective  To assess the efficacy of three disinfectants in disinfecting the ultrasonic scaling unit waterline.   Methods  Twelve periodontal ultrasonic scalers were randomly divided into four groups based on the disinfection protocol: distilled water (A group), 3% hydrogen peroxide (B group), 500 mg/L chlorine disinfectant (C group) and 5% povidone-iodine (D group). Each scaler was used for daily periodontal treatment and worked effectively for 6 hours per day. Water samples were collected at baseline, after disinfection, and 1-7 days post-disinfection. Scanning electron microscopy (SEM) was used to observe biofilm formation. Culturable bacteria were counted, isolated and purified, then identified through 16S rRNA gene sequencing. Sequences of 16S rRNA gene amplicons were clustered by operational taxonomic units (OTUs).  Results  Baseline colony counts exceeded 100 CFU/mL in all groups. However, after disinfection, the colony counts decreased significantly in all groups (P < 0.05). The colony counts remained below 100 CFU/mL within 3 d after disinfection with 3% H2O2, within 6 days after disinfection with 500 mg/L chlorine-containing disinfectant, and within 4 d after disinfection with 5% povidone-iodine (P < 0.05).Pathogens such as Stenotrophomonas maltophilia were detected in the ultrasonic scaler unit water circuit. SEM showed thinner biofilm thickness in the 3% H2O2 and 5% povidone-iodine groups compared to the control group (P < 0.05).  Conclusions  Bacterial contamination is present in the ultrasonic scaling unit waterline, posing a potential infection risk to periodontal staff and patients. In the context of increasingly severe nosocomial infections, appropriate disinfection protocols should be developed based on clinical realities. [ABSTRACT FROM AUTHOR]

Several studies have confirmed the antimicrobial effect of a mixture solution composed of hydrogen peroxide 3% and vinegar 4% (HPV) as a disinfectant solution used for Polymethylmethacrylate (PMMA) denture base. Immersing dentures in this solution may result in alterations to the physical characteristics of PMMA. This in vitro study was conducted to examine the effect of different immersion times of HPV on surface roughness of heat cure and computer-aided design/computer- aided manufacturing (CAD/CAM) PMMA. Material and methods: 60 PMMA samples were prepared and divided equally according to two different types of PMMA materials: a) heat cure (H) and b) computer-aided design/computer-aided manufacturing (CAD/CAM) (A) PMMA. Each type was subdivided into three groups (10 samples for each) according to immersion time in the HPV mixture prepared with a ratio of (1:1); the control group was not immersed (H0 and A0), the second group was immersed for 90 days (H1 and A1) and the last group for 180 days (H2 and A2). Each group was examined before and after two immersion times with surface roughness measured by a portable roughness tester. The collected data were analyzed using Shapiro-Wilk for normality test and statistically analyzed with Two-way ANOVA. The data were considered statistically significant when P≤ 0.05. Results: statical analysis shows the highest surface roughness mean value was observed for the heat cure PMMA group (0.141). Statistical analysis showed no significant changes in the two immersion times (90, and 180 days) for both materials. Conclusions: The study concluded that HPV could be used as an alternative disinfectant solution for heat and CAD/CAM PMMA without promoting deleterious effects on surface roughness. [ABSTRACT FROM AUTHOR]