Conventional electrochemical sensors use voltammetric and amperometric methods with external power supply and modulation systems, which hinder the flexibility and application of the sensors. To avoid the use of an external power system and to minimize the number of electrochemical cell components, a self-powered electrochemical sensor (SPES) for hydrogen peroxide was investigated here. Iron phthalocyanine, an enzyme mimetic material, and Ni were used as a cathode catalyst and an anode material, respectively. The properties of the iron phthalocyanine catalyst modified by graphene nanoplatelets (GNPs) were investigated. Open circuit potential tests demonstrated the feasibility of this system. The GNP-modulated interface helped to solve the problems of aggregation and poor conductivity of iron phthalocyanine and allowed for the achievement of the best analytical characteristics of the self-powered H2O2 sensor with a low detection limit of 0.6 µM and significantly higher sensitivity of 0.198 A/(M·cm2) due to the enhanced electrochemical properties. The SPES demonstrated the best performance at pH 3.0 compared to pH 7.4 and 12.0. The sensor characteristics under the control of external variable load resistances are discussed and the cell showed the highest power density of 65.9 μW/cm2 with a 20 kOhm resistor. The practical applicability of this method was verified by the determination of H2O2 in blood serum.

In recent years, the exceptional biocatalytic properties of glucose oxidase (GOx) have spurred the development of various GOx-functionalized nanocatalysts for cancer diagnosis and treatment. Carbon dots, renowned for their excellent biocompatibility and distinctive fluorescence properties, effectively incorporate GOx. Given the paramount importance of GOx\'s enzymatic activity in therapeutic efficacy, this study conducts a thorough exploration of the molecular-level binding dynamics between GOx and near-infrared carbon dots (NIR-CDs). Utilizing various spectrometric and molecular simulation techniques, we reveal that NIR-CDs form a ground-state complex with GOx primarily via hydrogen bonds and van der Waals forces, interacting directly with amino acid residues in GOx\'s active site. This binding leads to conformational change and reduces thermal stability of GOx, slightly inhibiting its enzymatic activity and demonstrating a competitive inhibition effect. In vitro experiments demonstrate that NIR-CDs attenuate the GOx\'s capacity to produce H2O2 in HeLa cells, mitigating enzyme-induced cytotoxicity and cellular damage. This comprehensive elucidation of the intricate binding mechanisms between NIR-CDs and GOx provides critical insights for the design of NIR-CD-based nanotherapeutic platforms to augment cancer therapy. Such advancements lay the groundwork for innovative and efficacious cancer treatment strategies.

BACKGROUND: To investigate the effect of a 50% ascorbic acid with 50% citric acid solution on the immediate shear bond strength (SBS) of metallic brackets after tooth bleaching. The enamel etching pattern and the required quantity of these combined acids as antioxidants following 35% hydrogen peroxide (HP) bleaching were also determined.
METHODS: The stability of the solution at room temperature was assessed at various time intervals. Fifty teeth were randomly divided into five groups: non-bleached (G1), bleached then acid etched (G2), bleached followed by a 10-minute treatment with 10% sodium ascorbate and acid etched (G3), 5-minute treatment with 50% ascorbic acid (G4), and 5-minute treatment with a combination of 50% ascorbic acid and 50% citric acid (G5). Groups G2, G3, G4 and G5 were bleached by 35% HP gel for a total of 32 min. Acid etching in groups G1, G2, and G3 was performed using 37% phosphoric acid (Ormco®, Orange, CA, USA) for 15 s. In all groups, metal brackets were immediately bonded using Transbond™ XT primer and Transbond™ PLUS adhesive, with light curing for 40 s. The SBS was tested with a universal testing machine, and statistical analysis was conducted using one-way ANOVA followed by Tukey\'s HSD test. The level of significance was set at p < 0.05 for all statistical tests.
RESULTS: Stability tests demonstrated that the combined acids remained effective for up to 21 days. Group G5 significantly increased the SBS of bleached teeth to the level of G1 (p < 0.05), while G3 did not achieve the same increase in SBS (p > 0.05). SEM analysis revealed enamel etching patterns similar to those of both control groups (G1 and G2). Kinetic studies at 6 min indicated that the antioxidation in G5 reacted 0.2 mmole lower than in G3 and G4.
CONCLUSIONS: 5-minute application of the combined acids enhanced the SBS of bleached teeth comparable to unbleached teeth. The combined acids remain stable over two weeks, presenting a time-efficient, single-step solution for antioxidant application and enamel etching in orthodontic bracket bonding.

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There is some evidence that the serotonin receptor subtype 7 (5-HT7) could be new therapeutic target for neuroprotection. The aim of this study was to compare the neuroprotective and neurite outgrowth potential of new 5-HT7 receptor agonists (AH-494, AGH-238, AGH-194) with 5-CT (5-carboxyamidotryptamine) in human neuroblastoma SH-SY5Y cells. The results revealed that 5-HT7 mRNA expression was significantly higher in retinoic acid (RA)-differentiated cells when compared to undifferentiated ones and it was higher in cell cultured in neuroblastoma experimental medium (DMEM) compared to those placed in neuronal (NB) medium. Furthermore, the safety profile of compounds was favorable for all tested compounds at concentration used for neuroprotection evaluation (up to 1 μM), whereas at higher concentrations (above 10 μM) the one of the tested compounds, AGH-194 appeared to be cytotoxic. While we observed relatively modest protective effects of 5-CT and AH-494 in UN-SH-SY5Y cells cultured in DMEM, in UN-SH-SY5Y cells cultured in NB medium we found a significant reduction of H2O2-evoked cell damage by all tested 5-HT7 agonists. However, 5-HT7-mediated neuroprotection was not associated with inhibition of caspase-3 activity and was not observed in RA-SH-SY5Y cells exposed to H2O2. Furthermore, none of the tested 5-HT7 agonists altered the damage induced by 6-hydroxydopamine (6-OHDA), 1-methyl-4-phenylpyridinium ion (MPP +) and doxorubicin (Dox) in UN- and RA-SH-SY5Y cells cultured in NB. Finally we showed a stimulating effect of AH-494 and AGH-194 on neurite outgrowth. The obtained results provide insight into neuroprotective and neurite outgrowth potential of new 5-HT7 agonists.

The anomalies of cadmium (Cd) in karst region pose a severe threat to plant growth and development. In this study, the responses of Rhododendron decorum to Cd stress were investigated at physiological, molecular, and endophytic microbial levels, and the potential correlation among these responses was assessed. The Cd stress impeded R. decorum growth and led to an increase in malondialdehyde (MDA) and hydrogen peroxide (H2O2) levels, as well as enhanced superoxide dismutase (SOD) and catalase (CAT) activities. Meanwhile, Cd stress increased the Cd (up to 80 times compared to the control), sodium (Na), aluminum (Al), and zinc (Zn) contents, while decreased the magnesium (Mg) and manganese (Mn) contents in R. decorum leaves. Transcriptome suggested that Cd significantly regulated the pathways including \"protein repair\", \"hormone-mediated signaling pathway\", and \"ATP-binding cassette (ABC) transporters\". Additionally, q-PCR analysis showed that Cd stress significantly up-regulated the expressions of ABCB19-like and pleiotropic drug resistance, while down-regulated the expressions of indole-3-acetic acid-amido synthetase and cytokinin dehydrogenase. The Cd stress influenced the composition of endophytic microbial communities in R. decorum leaves and enhanced the interspecific bacterial associations. Furthermore, the bacterial genera Achromobacter, Aureimonas and fungal genus Vishniacozyma exhibited a high degree of connectivity with other nodes in networks constructed by the metal element contents, differentially expressed genes (DEGs), and microbial communities, respectively. These findings provide a comprehensive insight into the response of R. decorum to Cd-induced stress, which might facilitate the breeding of the Cd-tolerant R. decorum.

UNASSIGNED: To determine whether rinsing with preprocedural mouthrinses against coronavirus disease before acid etching affects resin-based sealant microleakage.
UNASSIGNED: A presented in vitro experimental study was performed on 15 extracted permanent third molars. Samples were randomly allocated into five groups: Group 1-distilled water (control); Group 2-1% hydrogen peroxide; Group 3-1.5% hydrogen peroxide; Group 4-0.5% povidone-iodine; and Group 5-1% povidone-iodine. After the teeth were immersed in the assigned mouth rinses for 60 s, they were sealed with Concise™ white sealant. Subsequently, the teeth were thermocycled for 500 cycles, immersed in 2% methylene blue solution for 24 h, and sectioned with two parallel cuts in the buccolingual direction. Sixty surfaces (12 surfaces in each group) were examined for microleakage under a 40× light microscope and scored as described by Zyskind et al. Welch\'s one-way analysis of variance test and the Games-Howell test were used to analyze the results at a significance level of P < 0.05 for all tests.
UNASSIGNED: The intergroup comparisons indicated that the 0.5% povidone-iodine group and the 1% povidone-iodine group had significantly higher microleakage compared with the control group. The 1% and 1.5% hydrogen peroxide groups demonstrated no significant difference in mean microleakage scores compared with the control group. There was no significant difference between the povidone groups and the hydrogen peroxide groups.
UNASSIGNED: Preprocedural rinsing with 0.5% and 1% povidone-iodine before acid etching caused higher microleakage of resin-based sealant, while hydrogen peroxide rinsing gave comparable microleakage compared with the control group.

The number of published literature on the effect of ultrasonic cavitation and advanced oxidation pretreatment on the dewatering performance of anaerobically digested sludge is very limited. This study aims at determining the optimum operating conditions of large-scale filtering centrifuges in wastewater treatment plants. The optimum dose of hydrogen peroxide, ultrasonic power, ultrasonic duration, ultrasonic pulse and particle size distribution for improved dewatering performance were determined in this study. In addition, shear stress-shear rate and viscosity-shear rate rheograms were developed to show the rheological flow properties for varying ultrasonic power and treatment duration. Optimum sonication power, time, pulse and amplitude were determined to be 14 W, 1 min, 55/5 and 20%, respectively. At a pH of 6.8, the optimum concentration of hydrogen peroxide was found to be 43.5 g/L. The optimum hydrogen peroxide dose in the combined conditioning experiments was determined to be 500 mg/L at a pH of 3. Under these optimum conditions, capillary suction time was reduced significantly by 71.1%. This study helps to reduce polymer consumption and provides the optimum pretreatment and dewatering operating conditions, and better monitoring and control in the dewatering unit has significant impact in the overall economy of wastewater treatment plants.

BACKGROUND: Shoulder periprosthetic joint infection (PJI) is most commonly caused by Cutibacterium. Effective removal of these bacteria from the skin is difficult because Cutibacterium live protected in the dermal sebaceous glands beneath the skin surface to which surgical preparation solutions, such as chlorhexidine gluconate (CHG), are applied. There is conflicting evidence on the additional benefit of using hydrogen peroxide (H2O2) as an adjunct to CHG in eliminating Cutibacterium from the skin. A previous study demonstrated that after CHG skin preparation, repopulation of Cutibacterium from sebaceous glands onto the skin surface occurs in 90% of shoulders by 60 minutes after application. The objective of this randomized controlled study was to determine the effectiveness of adding H2O2 to CHG in reducing skin Cutibacterium.
METHODS: Eighteen male volunteers (36 shoulders) were recruited for this study. The two shoulders of each volunteer were randomized to receive the control preparation (\"CHG-only\" - 2% CHG in 70% isopropyl alcohol [ISA] alone) or the study preparation (\"H2O2+CHG\" - 3% H2O2 followed by 2% CHG in 70% ISA). Skin swabs were taken from each shoulder prior to skin preparation and again at 60 minutes after preparation. Swabs were cultured for Cutibacterium and observed for 14 days. Cutibacterium skin load was reported using a semi-quantitative system based on the number of quadrants growing on the culture plate.
RESULTS: Prior to skin preparation, 100% of the CHG-only shoulders and 100% of the H2O2+CHG shoulders had positive skin surface cultures for Cutibacterium. Repopulation of Cutibacterium on the skin at 60 minutes occurred in 78% of CHG-only and 78% of H2O2+CHG shoulders (p=1.00). Reduction of Cutibacterium skin levels occurred in 56% of CHG-only and 61% of H2O2+CHG shoulders (p=0.735). Cutibacterium levels were significantly decreased from before skin preparation to 60 minutes after preparation in both the CHG-only (2.1 ± 0.8 to 1.3 ± 0.9, p=0.003) and the H2O2+CHG groups (2.2 ± 0.7 to 1.4 ± 0.9, p<0.001). Substantial skin surface levels of Cutibacterium were present at 60 minutes after both preparations.
CONCLUSIONS: In this randomized controlled study, there was no additional benefit of using hydrogen peroxide as an adjunct to chlorhexidine gluconate skin preparation in the reduction of cutaneous Cutibacterium levels. Neither preparation was able to eliminate repopulation of Cutibacterium on the skin surface from the dermal sebaceous glands.

Amino acid epimerization, a process of converting L-amino acids to D-amino acids, will lead to modification in the protein structure and, subsequently, its biological function. This modification causes no change in protein m/z and may be overlooked during protein analysis. Aspartic Acid Epimerization (AAE) is faster than other amino acids and could be accelerated by free radicals and peroxides. In this work, a novel and site-specific HPLC method using a chiral stationary phase for determining the AAE in the active site model peptide (AP) of Peroxiredoxin 2 has been developed and validated. The developed method showed good linearity (1 - 200 μg/mL) and recoveries of the limit of quantification (LOQ), low, medium, and high concentrations were between 85% and 115%. The Kinetics of AAE in AP were studied using the developed method, and the results showed that when ascorbic acid and Cu2+ coexisted, the AP epimerized rapidly. The AAE extent increased with time and was positively correlated with hydrogen peroxide generation.