Peroxide Solution Research Articles

Antiviral activity of contact lens care solutions and rub-and-rinse regimen against adenovirus.

Although human adenoviruses are the leading cause of acute viral conjunctivitis, there is a lack of data surrounding the efficacy of contact lens care products against these viruses. This study investigates the antiviral activity of several commercially available contact lens care solutions against human adenovirus type 5 (Ad5). Six contact lens care solutions (Biotrue, Boston Simplus, OPTI-FREE Puremoist, Clear Care, cleadew, and cleadew GP) were investigated. Quantitative suspensions tests were conducted on Ad5 solutions after interaction with the different contact lens care solutions for 4 or 6 hours. For the hydrogen peroxide solution (Clear Care), interaction times of 0, 2, 4, and 6 hours prior to neutralization were also investigated. Finally, the impact of rubbing and rinsing of Ad5 contaminated contact lenses with the solutions was studied. Solutions based on povidone-iodine demonstrated a more than 3-log reduction in virus after 4 and 6 hours of incubation. In contrast, hydrogen peroxide only demonstrated a 0.52-log reduction after 6 hours of incubation. Increasing the contact time with hydrogen peroxide increased Ad5 inactivation, with a 2.18-log reduction after 6 hours of incubation with the solution prior to neutralization. Nonoxidative systems did not demonstrate a significant log reduction after 4 hours of incubation. However, rubbing and rinsing of contact lenses using the nonoxidative systems reduced the virus counts from contaminated contact lenses to below the limit of quantification. Povidone-iodine solutions have a significant effect on reducing the viability of Ad5. Hydrogen peroxide care solutions are effective only if unneutralized contact time is increased. Nonoxidative systems can be effective in combating contaminated lenses only with the addition of a rub-and-rinse step.

Phosphate removal from hydrogen peroxide solutions using the ion exchange resin IRA-400.

Accurate determination of nutrients in food is becoming increasingly important. Minerals and other trace elements can be determined by a variety of highly sensitive methods, but complete mineralization of the sample is essential for correct quantification. Hydrogen peroxide is a key reagent for destruction of organic matter in conjunction with sulfuric acid. Unfortunately, commercial hydrogen peroxide is often stabilized with phosphate containing substances in amounts that can severely impair downstream phosphate determination. We propose a method to reduce phosphate content of commercial hydrogen peroxide by using the ion exchange resin IRA-400. Results show that hydrogen peroxide treated with the resin has minimal loss in strength but only 10 % of the original phosphate content. Furthermore, scaling up of the method can potentially allow for treatment of higher volumes of hydrogen peroxide and more stringent binding conditions for production of hydrogen peroxide with even lower phosphate content.

Clinical and planimetric picture of healing of ulcer lesions in the area of cows' hoofs

The article presents the results of studying the effectiveness of VetAsepRan ointment in treating ulcerative lesions in the hooves of cattle. The experimental studies were conducted at ENVOL LLC, Melekessky District, Ulyanovsk Region. Clinical assessment of orthopedically affected animals was assessed using the lameness scoring system developed by D. J. Sprecher, D. E. Hostetler and J. B. Kaneene (1997). The study was divided into 2 experimental groups: the control group (n=10) and the experimental group (n=10). After surgical lavage of the purulent-necrotic lesion and treatment with 3% hydrogen peroxide solution, VetAsepRan ointment was applied locally in the experimental group, while Levomekol ointment was used in the control group. All animals were bandaged and special tape was applied on top to prevent liquids from getting in. Digital planimetry was used to monitor the healing process, using the AnalyRan program. The dynamics of reduction of ulcer defect area (Yt) and healing rate index (Iv), as well as Popova index (ΔS) were determined. Planimetric studies of cows were carried out on days 1, 7 and 14 after the start of treatment. In the course of the study, clinical and planimetric data were established on healing of ulcer defects in the hoof area of cows. As a result of the study, it was revealed that the use of Ve-tAsepRan ointment contributed to the recovery of orthopedically diseased animals on average by 11.6±0.37 days, compared to control animals by 13.7±0.56 days. The results of planimetric studies showed the intensity of healing processes in the experimental group.

Synthesis of UiO-66-NH2@PSF Hollow Fiber Membrane with Enhanced Simultaneous Adsorption of Pb2+ and Phosphate for Hydrogen Peroxide Purification.

Electronic grade hydrogen peroxide plays a crucial role in the fabrication of large-scale integrated circuits. However, hydrogen peroxide prepared by the anthraquinone method contains impurities such as lead ions (Pb2+) and phosphate, which can seriously affect the yield of the circuit. Traditional adsorbent materials have difficulty in solving the problem of simultaneous adsorption of trace anions and cations in hydrogen peroxide due to the single adsorption site and poor adsorption kinetics. In this study, UiO-66-NH2 was prepared by introducing a -NH2 group on the terephthalic acid ligand, and a series of hybrid matrix hollow fiber membranes with different UiO-66-NH2 contents were prepared by loading it on polysulfone (PSF). This initiative not only improved the pore size and water flux of hollow fiber membranes but also enhanced the removal efficiency of ions from hydrogen peroxide solution, thereby facilitating practical application. Among them, UiO-66-NH2@PSF-1.5 showed the best adsorption of phosphate and lead ions with adsorption capacities of 3.099 and 2.160 mg g-1 and reached the removal efficiency of 67.1 and 60.1%, which fully confirms the practicability in the purification of electronic chemicals. This work innovatively proposes that UiO-66-NH2@PSF hybrid matrix hollow fiber membranes have great potential as simultaneous adsorbents for cations and anions in the efficient purification of electronic grade solvents.

Comparing the Extent of Methionine Oxidation in the Prion and Native Conformations of PrP.

Scrapie is a prion disease of sheep and goats. Prions (PrPSc) replicate by inducing a natively expressed protein (PrPC) to refold into the prion conformation. PrPC and PrPSc contain a disproportionately large number of methionines. Surface exposed methionines are more prone to chemical oxidation. Chemical oxidation is a means of measuring the surface exposure of the methionines in a prion, as these covalent changes are retained after an oxidized prion is denatured prior to analysis. Scrapie prions and recombinant sheep prion protein were oxidized in 0, 10, 20, or 50 mM solutions of hydrogen peroxide. The samples were digested with trypsin or trypsin followed by chymotrypsin to yield a set of peptides (TNMK, MLGSAMSR, ENMYR, IMER, VVEQMCITQYQR) containing the methionines present in sheep PrP. The mass spectrometry based multiple reaction monitoring (MRM) method was used to analyze these peptides. Analysis of the rPrP samples showed that surface exposed methionines (132, 137, and 157) were more oxidized than those less surface exposed (209 and 216). The extent of methionine oxidation in sheep scrapie PrPSc is 216 > 137 > 132 > 157 > 209 > 112. These results demonstrate that this approach can be used to map the surface exposure of the methionines in order to distinguish among PrP conformations and effect a kind of conformational sequence.

Hydroxymethyl Lignin‐Capped Silver Nanoparticles: Antimicrobial and Hydrogen Peroxide‐Sensing Ability

AbstractLignin (Lg) fractionation overcomes the limitations of its heterogeneous nature. In this study, the effect of methanol fractionation on the thermal degradation, crystallinity, morphology, and chemical structure of lignin and its application in hydrogen peroxide sensing are investigated. Pristine Lg was separated into low‐molecular‐weight (LMwLg) and high‐molecular‐weight fractions (HMwLg), followed by modification to hydroxymethyl lignin (HmLg), which reduced silver ions in solution to silver nanoparticles (AgNPs). The functional groups, crystallinity, thermal profile, and morphology were then investigated using Fourier transform infrared spectroscopy, powder diffraction, thermal gravimetry, and scanning electron microscopy. LMwLg was found to be crystalline, highly hygroscopic, and had four thermal degradation stages, while HMwLg had several degradation stages and was amorphous. The sharp peaks in the LMwLg diffractogram were characteristic of sodium ions, while those in AgNPs‐HmLg were characteristic of AgNPs, as evidenced by the SPR peak at 428 nm whose intensity decreased in the presence of hydrogen peroxide. Moreover, AgNPs‐HmLg exhibited higher inhibitory activity toward Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis with inhibition zones of 10.67 ± 0.58, 11.50 ± 0.00, 10.33 ± 0.58, and 8.33 ± 0.57 cm as compared to pristine lignin. In conclusion, AgNPs‐HmLg detected the presence of hydrogen peroxide in solution and inhibited the growth of selected Gram‐positive and Gram‐negative bacteria.

Continuous preparation of alkaline hydrogen peroxide solution by micromixing device: Experiment and theoretical analysis

AbstractIn the context of achieving continuous synthesis of acyl peroxides using microreactors, continuous preparation of alkaline hydrogen peroxide (AHP) solution is required. However, two key issues, Na2O2 precipitation and H2O2 decomposition, need to be considered or addressed. For the precipitation of Na2O2 during NaOH and H2O2 mixing, experiments revealed that precipitation could be avoided by appropriate selection of operation window. For the risk of violent H2O2 decomposition when NaOH and H2O2 solutions are one‐step mixed, theoretical approaches were adopted. Simulation‐derived mixing time is combined with decomposition kinetics to find a direct relationship between operation‐structure parameters and percentage of decomposed H2O2. This percentage is estimated to be in the order of 10−4 for micromixing devices, which indicates that micromixing devices can be used to one‐step mix NaOH and H2O2 solution without causing violent H2O2 decomposition. This work provides insights into the preparation of AHP solution and facilitates its continuous preparation.

De Novo Regeneration of Cannabis sativa cv. Cheungsam and Evaluation of Secondary Metabolites of Its Callus

Cannabis sativa L. cv. ‘Cheungsam’ is an industrial hemp plant of Republic of Korea origin, primarily cultivated for fiber and seed production. In vitro seed germination and tissue culture are valuable tools for developing various biotechnological techniques. In the present study, we aimed to develop a tissue culture process for hemp plants using Cheungsam as a model plant and examine the secondary metabolites produced from its callus. We also developed a method to prepare pathogen-free seedlings from field-derived seeds using hydrogen peroxide (H2O2) solution as a liquid germination medium. Treating seedlings with removed seed coat in 3% H2O2 significantly reduced the contamination rate. Callus formation and de novo organogenesis of shoots and roots from callus were successfully achieved using cotyledon and leaf tissues prepared from the pathogen-free seedlings. The most effective in vitro regeneration results were obtained using the Murashige and Skoog (MS) medium supplemented with certain targeted growth regulators. An optimal combination of 0.5 mg/L thidiazuron (TDZ) and 1.0 mg/L 1-naphthalene acetic acid proved highly effective for callus induction. The addition of 0.5 mg/L TDZ in the MS medium significantly stimulated shoot proliferation, while robust root development was best supported by MS medium supplemented with 2.5 mg/L indole-3-butyric acid for both cotyledon and leaf explants. Finally, gas chromatography–mass spectrometry (GC–MS) analysis of ethanol extract from Cheungsam leaf callus revealed the presence of different secondary metabolites, including 9-octadecenamide, methyl salicylate, dodecane, tetradecane, and phenol, 2,4-bis-(1,1-dimethylethyl). This study provides a comprehensive de novo regeneration protocol for Cheungsam plants and insight into the secondary metabolite profiles of its callus.

Pharmacological Activities of Warm Alkaline Hydrogen Peroxide Solution and Therapeutic Potential in Medicine: Physical-Chemical Reprofiling as a Promising Lead for Drug Discovery

Abstract: The traditional use of antiseptics, chemotherapeutic, expectorant, mucolytic drugs, and oxygen gas by artificial ventilation does not effectively eliminate hypoxemia in sputum, mucus, pus, and blood asphyxia in COVID-19. The emergency conversion of sputum, mucus, pus, and blood into oxygenated foam inside the airways utilizing the enzyme catalase and warm alkaline hydrogen solutions (WAHPSs) is proposed as a promising area for new therapeutic development.. The possibility of physical-chemical repurposing of hydrogen peroxide from an antiseptic in pyolytics, mucolytics, hemolytics, and oxygen-producing antihypoxants by con-verting a cold, acidic non-carbonated drug into an oxygen-saturated WAHPS and its intrap-ulmonary injection is pointed out as a way to solve this problem. The possibility of medically enriching blood oxygen in hypoxemia by catalase cleavage of hydrogen peroxide when WAHPSs are administered orally as energy drinks or directly into the blood as injections is pointed out. The fact is that virtually all human tissues are rich in catalase, which immediately breaks down hydrogen peroxide into water and oxygen gas. Inhalation and/or intrapulmonary injections of WAHPSs have been shown to provide intra-airway interaction with catalase in sputum, mucus, pus and/or blood and releases oxygen gas, which foams the biological masses, is absorbed into the blood and eliminates hypoxemia. Thus, the physical-chemical repurposing of known drugs can be considered a promising direction for the discovery of new drugs. Value of the data: 1) Why are these data useful? These studies indicate that the enzyme catalase, which is present in many tissues of animals and humans in both normal and disease, can be employed to enrich the tissues with oxygen and eradicate hypoxia when hydrogen peroxide solution is injected into them.. 2) Who can benefit from these data? Mountaineers, divers, submarine sailors, miners, astronauts, traumatologists, resuscitators, car-diologists, transplantologists, pulmonologists, obstetricians and gynecologists, emergency phy-sicians, EMERCOM personnel, and medical workers, providing emergency medical care in cases of smoke in rooms, lack of oxygen in the inhaled air, drowning, bronchial asthma attack, acute respiratory distress syndrome, and asphyxia can use the data presented in this article. 3) How can these data be used/reused for further insights or development of experi-ments? These data can be used to develop new antihypoxants, to improve methods of increasing the organism's endurance to hypoxia, methods of organ and tissue preservation, methods of ische-mia treatment, methods of emergency medical care in urgent conditions, methods of ARDS treatment and standards of medical care.

Hygienic investigation of the evaporative cooling system installed in air handling units

Abstract A significant portion of the total summer energy consumption of buildings is allocated to the treatment of ventilation air and cooling of spaces. One possible approach to reduce mechanical cooling energy consumption is indirect evaporative cooling. By implementing this method, the mechanical cooling energy demand of air handling units can be significantly reduced. Numerous studies and literature focus on the energy analysis of direct and indirect evaporative cooling system solutions. However, the hygiene assessment of these processes has received less attention thus far. This article presents an examination of the hygiene of evaporative cooling panels and the water used in these systems. The aim of the study is to assess the level of hygiene risk and explore potential cleaning technologies. It was shown that the applied disinfection method in this cooling system, using chemical solution flushing (in the case of 3 w/w% hydrogen peroxide solution) has proven more effective than chemical surface spraying process.

АНАЛИЗ ВЛИЯНИЯ ОБРАБОТКИ ПЕРЦА СЛАДКОГО СВЕЖЕГО РАЗЛИЧНЫМИ ПРЕПАРАТАМИ НА ПОКАЗАТЕЛИ КАЧЕСТВА И УБЫЛЬ МАССЫ

The article presents a study of the dependence of the quality indicators of sweet fresh pepper on the type of processing. A review of the literature on this topic has been conducted, on the basis of which information on new modern methods and promising methods, technologies for reducing pepper losses during storage, as well as their mechanism and advantages, including the use of the types of processing used by us, has been systematized. A connection has been established between the loss of pepper mass during storage and the use of various substances for processing. The effect of the type of processing on the organoleptic parameters of pepper, defined and described by the point system, has been established. An experiment was conducted to store fresh pepper at room temperature, treated with the following substances (solutions of lactic, formic, ascorbic acids and hydrogen peroxide). During the experiment on storage, conclusions were drawn about the need to use the substances used and the expediency of further studying new methods and methods for treatments Keywords: PEPPER STORAGE, QUALITY INDICATORS, PROCESSING METHODS, LOSS OF MASS

(Invited) Structure and Function Tuning of Nanostructured Titania for Photochemical and Electrochemical Applications

Titania nanotubes (TNTs) [1], that essentially has ultraviolet light responsibility, have been modified by various chemical protocols such as peroxo functional groups modification and transition metal doping via facile solution chemical routes. When peroxo functional groups (-O-O-) were introduced to the lattice of TNT by hydrogen peroxide solution treatment of pristine TNTs or by bottom-up chemical synthesis from peroxo titanium complex precursor [2,3], yellowish powders were obtained. Optical band gap energy of titania nanostructures was decreased to 2.6 eV that was lower than that of pure TNTs of typically around 3.4 eV. This large red-shift of optical absorption edge might be due to the addition of electron states owing to excess oxygen to titanium oxide lattice and followed variation of energy level of conduction band for the peroxo-modified TNTs (hereafter as PTNTs).Further materials tuning could also be possible by cation doping such as copper ions to the pristine TNT as well as PTNT by Cu2+ ion adsorption and followd UV-light irradiation to control oxidation state of copper ions. These Cu-modified nanotubes exhibited additional optical absorption band among visible light regions, provably due to the formation of d-d transition level in TNT and/or PTNT crystals. Such modifications of nanostructure titania allowed to show the photocatalytic performance enhanced under the visible light irradiating.Photo-irradiation induced active species during light irradiation of photocatalytic performance investigations were identified by using various radical trap agencies. It was found that the photo-exited electron played a major role for visible-light driven photocatalytic degradation of organic molecules via the formation of superoxide anion radicals. Addition of cupper species made enhancement of hydrogen formation under the visible light irradiation and followed water splitting.Such photo-induced functions might be expected to contribute not only to environmental cleaning but also to application as photochemical hydrogen generation. Detailed synthesis processes, formation mechanisms, chemical and photochemical properties will be discussed.

CT findings and anatomical aspects of a Labrador retriver humerus characterized by osteophytosis of the sulcus intertubercularis and obliteration of the supratrochlear foramen.

Degenerative changes in the skeletal system of dogs may occur as a consequence of aging, trauma, infection, or inflammation. The object of this study consisted of an 8-year-old male Labrador dog that was brought to a private veterinary clinic after a road traffic accident and died despite all interventions. For a different study planned in our department, CT images were taken of the Labrador retriever's humerus and osteophytes to encounter incidentally were investigated for found in these images. After the CT scan, the dissected humerus bones were boiled to remove soft tissues. Subsequently, the bones were underwent with a 10% hydrogen peroxide solution for bleaching. Osteophytes in the proximal part of the humerus extended from the tuberculum majus and tuberculum minus towards the cranial direction, forming a complete ring-like structure at the level of the sulcus intertubercularis in the left humerus. Although not fully ring-shaped, similar osteophytes were found in the right humerus. In addition, it was observed that the foramen supratrochleare seen in the left humerus in the CT images was covered with a thin membrane during dissection. The presence of this membrane suggested that it might be due to the joint not being able to reach sufficient extension due to osteophytes forming in the bone. Additionally, it was concluded that CT may not recognize thin, non-mineralized septations, such as the membrane obliterating the supratrochlear foramen, as observed during necropsy.

Membrane-free Electrolysis Production of Hydrogen Peroxide on Low-cost Metal-free Electrocatalysts for Dye Degradation.

The efficient production of hydrogen peroxide (H2O2) solution was achieved by combining cathodic two-electron oxygen reduction (2e- ORR) and anodic two-electron water oxidation (2e- WOR) in two half-reaction cells. h-BN loaded on carbon fibers (h-BN@C) is prepared and employed as an anode material to catalyze 2e- WOR, while sulfonated commercial BP-2000 carbons (BP-2000-SO3H) were prepared as the cathode materials for 2e- ORR. In a 2 M KHCO3 solution, an overall Faradaic efficiency of 97 % and a total H2O2 production rate of 1872 mmol g-1 h-1 over metal-free electrodes were accomplished in a membrane-free flow cell. The dilute H2O2 solution could be directly used to degrade Rhodamine B, methyl blue and methylene orange dyes in water. This work proved low-cost production of dilute H2O2 solution in simple membrane-free flow cells with single electrolyte and on-site utilization for efficient dye degradation.

Increased survival of aquarium fish under acute hypoxia induced by prior intragastric administration of hydrogen peroxide

BACKGROUND: A solution of 3% hydrogen peroxide is an over-the-counter oxygen-releasing antiseptic, which forms oxygen foam when interacting locally with the wound surface. Therefore, this drug is widely used for mechanical cleansing of the surface of chronic wounds from purulent masses. The release of oxygen during catalase cleavage of hydrogen peroxide indicates the possibility of achieving anti-ischemic and anti-hypoxic action. AIM: A study of the effect of intragastric hydrogen peroxide on the resistance of aquarium fish to acute hypoxia. MATERIALS AND METHODS: Experiments were conducted on 80 adult aquarium fish of the guppy, blue neon, tri-linear parsings, swordtail fish and zebrafish (Danio rerio) breeds. To create acute hypoxia, each fish was placed in a transparent plastic container containing 5, 10 or 20 ml of fresh water at a temperature of +25 - +26 °C together with the fish, after which the container was hermetically sealed. Then, the motor activity of the fish's body, the respiratory movements of the gill arches, the opening of the oral cavity, the fluctuations of the fins and the dynamics of their coloration were monitored until the complete final immobilization of the fish and their death. Immediately before the experiment, 0.05 or 0.1 ml of fresh water in the control series and 0.05 ml or 0.1 ml of 0.05% hydrogen peroxide solution in the experimental series were injected into the stomach of the fish. The liquid was injected into the fish's stomach using a gastric mini-probe connected to an insulin syringe. RESULTS: It is shown that aquarium fish retain their viability in a small volume of fresh water inside a hermetically sealed container for a limited period of time, since fish continuously consume oxygen dissolved in water, thereby deepening hypoxia. At the same time, after sealing the container, the fish very quickly assume a stationary state, in which they remain for a certain period of time until their death. However, just before death, the immobility of the fish is disturbed. At the same time, the fish suddenly appear convulsive body movements, active movements of pectoral fins, mouths and gill arches, pectoral fins change their color, after which the fish defecate into the water. The results showed that the preliminary injection of 0.05 or 0.1 ml of 0.05% hydrogen peroxide solution into the stomach of fish prolongs the period of immobility of fish in hypoxia by an average of 20%. In all likelihood, the immobile state of fish is part of the complex of their adaptive adjustment to the cessation of oxygen supply to the water and reflects the availability of reserves of adaptation to hypoxia. The fact is that the absence of muscle contractions stops the muscles from using oxygen, which they use to generate energy. It is assumed that inside the stomach, hydrogen peroxide is absorbed into the blood, where, under the action of the enzyme catalase, it is split into water and gaseous oxygen, which replaces oxygen in the gills in the absence of oxygen in the surrounding water. CONCLUSIONS: Under model conditions, it was shown that pre-administration of 0.05 or 0.1 ml of 0.05% hydrogen peroxide solution into the stomach of fish increases their survival in conditions of acute hypoxia. Therefore, hydrogen peroxide can be considered as a potential antihypoxant for prolonging life in various types of suffocation, including the final stage of COVID-19.

Hypoxic irreversible brain cells damage, associated risk factors and antihypoxants

It is reported that in the final stage of many diseases the immediate cause of biological death in humans and warm-blooded animals is hypoxic irreversible damage to brain cells. This explains the fact that to prevent biological death in all critical conditions without exception, inhalation with breathing gases containing oxygen has long been successfully used. This is also why oxygenation of the blood is considered one of the main conditions for preserving human life in all critical situations and forms the basis of emergency medical care in the intensive care unit. However, inhalation of oxygen gas and increasing blood oxygen saturation should be carried out as early as possible, and more precisely — before the onset of the stage of hypoxic irreversible damage in brain cells. The fact is that after the onset of irreversible da­mage brain cells die even in the presence of oxygen. In this connection, the mechanisms of adaptation of the organism to oxygen deficiency play a great role for longer preservation of brain cells viability and human life in conditions of hypoxemia. In order to increase resistance to hypoxemia, antihypoxants are traditionally used. But they can preserve the viability of brain cells not always, but only if they are introduced into the body before the onset of hypoxic irreversible damage to brain cells and in the case of unused reserves of adaptation to hypoxemia in the body. Risk factors of hypoxic irreversible damage of brain cells are indicated, among which excessively long duration of hypoxemia and hyperthermia are emphasized. It is shown that the most important circumstance for the development of hypoxic irreversible damage of brain cells is not so much the degree of hypoxemia as the degree of hypoxia of brain tissue and its duration, which exceeds the period of human resistance to hypoxia. It has been shown that human resistance to hypoxia can be assessed using the Stange test. It has been reported that fever and local cerebral hyperthermia decrease, and hibernation and local cerebral hypothermia increase, the resistance of brain cells to hypoxia. In this regard, recommendations not only to eliminate fever and local inflammatory processes in the head, but also recommendations to reduce brain temperature are highly appropriate to improve resistance to hypoxia. It is pointed out that among the methods of local therapeutic hypothermia, targeted temperature management is the most advanced. In addition, it is reported that in recent years a new group of promising antihypoxants — alkaline solutions of hydrogen peroxide — has been created. It is shown that hydrogen peroxide is able to decompose very quickly into water and oxygen gas under the action of catalase, which is found in all tissues. The peculiarities of using alkaline solutions of hydrogen peroxide as antihypoxants we all have to study in the future.

Surface Modification of Glass Fiber-Reinforced Composite Posts by Hydrogen Peroxide: A Scoping Review

AbstractOn the rehabilitation of endodontic treated teeth using intraradicular retention, adhesive failures often occur between the intraradicular post and the resin-matrix cement. The main aim of this study was to conduct a scoping review on the surface modification of glass fiber-reinforced composite posts by hydrogen peroxide solutions. An electronic search was performed in the PubMed database, using combinations of keywords pursuing articles published between 2010 and 2024 in English language. Of the 13 selected studies, 12 investigated the bond strength between the glass fiber-reinforced composite (GFRC) post and the resin-matrix cement after the surface treatment of the post, 5 articles analyzed failures using a stereomicroscope, and 7 studies analyzed the surface topography by scanning electron microscopy (SEM). Etching procedures with hydrogen peroxide (H2O2) altered the surface of the GFRC post by selectively dissolving the matrix without damaging the fibers, resulting in a larger surface area of exposed fibers available to react with the adhesive system or silane. Studies revealed high bond strength values between the etched GFRC posts to the resin-matrix materials. Surface treatment of GFRC posts with hydrogen peroxide seems promising considering the feasibility on the surface modification resulting in the improvement of bond strength of intraradicular posts to resin-matrix cements.

SUSTAINABLE CONVERSION OF BANANA WASTE INTO ELECTRICAL INSULATION MATERIALS FOR HIGH VOLTAGE APPLICATIONS

<p style="text-align:justify;"><span style="font-family:"Times New Roman","serif";font-size:12.0pt;line-height:150%;text-justify:inter-ideograph;">The study examined the electrical characteristics of epoxy composites that were reinforced with fibers derived from banana leaves and pseudostems. Specifically, the study focused on analysing the dissipation factor, loss factor, and dielectric constant of these composites. The study found that composites containing banana leaf fibers demonstrated enhanced dielectric properties in comparison to pure epoxy composites. This improvement can be attributed to the effective interlocking between the fibers and the matrix, as well as the polarization effects. Enhancing the amount of fibre in the material resulted in greater dielectric constants, reaching a maximum at a critical volume of 17.2%. However, at higher frequencies, the dielectric constants fell due to decreasing polarization. Chemical treatments, such as alkali and peroxide solutions, improved the bonding between the fibers and the matrix, leading to higher resistance to water and greater electrical insulation. The results also showed that banana leaf fibers had superior dielectric performance compared to pseudostem fibers, mostly because of enhanced nanoparticle bonding. Using banana fibers is particularly noteworthy since it contributes to environmental sustainability by recycling agricultural waste, hence mitigating the ecological consequences of synthetic products.</span></p>

Fractionation of Winemaking Grape Stalks by Subcritical Water Extraction to Obtain Added-Value Products.

Grape stalks (GSs) from winemaking were submitted to a green process to valorise its lignocellulosic biomass that applied subcritical water extraction (SWE) at 170 °C and 180 °C to obtain active extracts and cellulose-enriched fractions. The sum of the total phenolic content of the soluble extract and the solid residue fractions from the SWE exceeded that of the GS, which suggests the generation of compounds with antioxidant properties through SWE. All SWE fractions showed high antioxidant power. The increased temperature promoted the extraction of polyphenolic compounds, enhancing the antioxidant power of both extracts and solid residues. These solid residue fractions were bleached with alkaline hydrogen peroxide solutions (4 and 8% v/v) to purify cellulose. After two bleaching cycles, no notable delignification progress was observed, as the bleaching yield or whiteness index did not significantly change in the further cycles. The first bleaching cycle led to a significant reduction in the lignin content at both SWE temperatures. The cellulose purity was higher in the samples obtained at 170 °C and bleached with 4% alkaline hydrogen peroxide. SWE at 180 °C led to greater cellulose oxidation during the bleaching step regardless of the hydrogen peroxide concentration.

Choice of an environmentally friendly method of producing cellulose from flax biomass (<i>Linum usitatissimum linaceae</i>) grown in different regions of the Volga region

The experimental assessment of prospects of receiving cellulose material on the basis of use of vegetable raw materials – straw of a flax-dolgunetc is carried out. Results of researches showed a possibility of application for extraction of cellulose of the water solutions containing hydrogen peroxide, hydroxide and sodium bisulfite in the conditions of high-temperature influence within 2 hours with receiving the technical cellulose suitable for production of cardboard and packaging materials. For purification of technical cellulose, it was carried out additional processing by solution of hydrogen peroxide and acetic acid in similar parametrical conditions that allowed to receive a target product with high extent of maintenance of the main substance, at insignificant amount of the accompanying impurity. The presented results show a possibility of the solution of questions of environmental safety at the organization of process of receiving cellulose on the basis of renewable vegetable raw materials with use of the chemical reagents which are not containing compounds of sulfur.