• Oxygen is required to support life, but its metabolites such as Reactive Oxygen Species (ROS) can modify cell functions, endanger cell survival, or both. (scialert.net)
  • This oxidative stress can also be defined as an increase in reactive oxygen species (ROS) and a physiological decrease in endogenous antioxidants [ 8 ] Oxidative stress is closely related to cataracts. (hindawi.com)
  • Free radicals are highly reactive, unstable oxygen molecules that have been linked to the development of cancer and other serious diseases. (naturalnews.com)
  • Their average size is 25 nm and they contain reactive oxygen species (ROS) such as hydroxyl and superoxide radicals. (cdc.gov)
  • To test this hypothesis, Hb was modified by reactive oxygen species (ROS). (scialert.net)
  • There has been accumulating evidence that an additional mechanism to generate reactive oxygen species occurs in vivo (Moore et al . (scialert.net)
  • To test this hypothesis, Hb was modified by reactive oxygen species, generated by in vitro reaction of hemoglobin with hydrogen peroxide. (scialert.net)
  • Provided in the diet, antioxidants neutralize reactive oxygen species (ROS, which are produced in the system during physiological processes). (aprifel.com)
  • He explains that one way that radiation frequently damages cells and tissues is by producing "reactive oxygen species" - oxygen radicals, peroxides and hydroxyls. (news-medical.net)
  • The research team showed that zebrafish embryos exposed to ionizing radiation had more than 50 percent fewer reactive oxygen species compared to untreated embryos. (news-medical.net)
  • On the one hand, reactive oxygen species (ROS) are mandatory mediators for essential cellular functions including the function of germ cells (oocytes and spermatozoa) and thereby the fertilization process. (hindawi.com)
  • The iron gall ink-triggered chemical corrosion of hand-written documents is a big threat to Western cultural heritages, which was demonstrated to result from the iron gall (GA-Fe) chelate-promoted reactive oxygen species generation. (nature.com)
  • Therefore, the ion centers act as active sites of the metallo-gallate complex that can donate electrons from the gallate ligands to ambient free oxygen molecules for the oxygen reduction and reactive oxygen species (ROS) generation 3 , after which the ligand field around iron center attenuates due to the electron loss from gallate 12 . (nature.com)
  • Reactive oxygen species are a product of normal cellular metabolism [ 7 ]. (ijpsonline.com)
  • It is a widely accepted fact that Nox enzyme-generated reactive oxygen species (ROS) plays a noticeable role in fibrotic and inflammatory diseases. (bruker.com)
  • Furthermore, molecular nanoprobes monitoring changes in pH and reactive oxygen species activity are developed and used to further understand SOM modifications by ECM fungi. (lu.se)
  • respiratory burst (the rapid release of Reactions of oxygen radicals with Mitochondrial oxidative phosphor- reactive oxygen species from cells) cel ular components can deplete an- ylation is a major source of oxy- that involves nicotinamide adenine tioxidants, can cause direct oxidative gen radicals of endogenous origin. (who.int)
  • Exogenous agents are also impli- aldehyde) to form various pro-mu- tion, resisting cell death, enabling cated in the generation of reactive tagenic exocyclic adduct s (Bartsch replicative immortality, inducing oxygen. (who.int)
  • Metabolism of glutathione peroxidase, can further inflammation, and - along with oth- many exogenous agents through cy- convert these reactive species to er radical species - play key roles tochrome P450-mediated reactions wate r (Benzie, 2000) . (who.int)
  • A two process model is envisaged: (a) initiation of reactive oxygen species by moderate noise exposure and (b) promotion of oxidative stress through disrupting intrinsic antioxidant defenses. (cdc.gov)
  • This mechanism is based on Fenton-type reactions whereby hydroxyl radicals are produced. (lu.se)
  • These hydroxyl radicals are subsequently able to attack and degrade the complex organic soil molecules making desired nutrients more readily available for uptake. (lu.se)
  • Therefore, this review will attempt to discuss the relevance of free radicals and antioxidants in spermatozoa production and function. (scialert.net)
  • Oxidative stress is a condition where the amount of free radicals exceeds the amount of antioxidants found in the body. (hindawi.com)
  • Fresh produce is a crucial source of essential minerals, vitamins, fiber and a variety of bioactive molecules, or antioxidants , which protect our body against bacteria, viruses and free radical damage. (naturalnews.com)
  • Experiments with endothelial cells fortified with the isolated fraction from native honey enriched in antioxidants, exposed to peroxyl radicals from 1,1-diphenyl-2-picrylhydrazyl (AAPH, 10 mM) and to hydrogen peroxide (H2O2, 50-100 microM), indicated that phenolic acids and flavonoids were the main causes of the protective effect. (researchgate.net)
  • These results provide unequivocal evidence that, through the synergistic action of its antioxidants, honey by reducing and removing ROS, may lower the risks and effects of acute and chronic free radical induced pathologies in vivo. (researchgate.net)
  • They found that tetrasulfides are better radical-trapping antioxidants for petroleum products than the most common industrial antioxidant additives. (chemistryworld.com)
  • To counteract them, antioxidants have the ability to donate electrons to free radicals [ 9 ]. (ijpsonline.com)
  • The damaging effects of free radicals can be countered by antioxidants. (positivehealth.com)
  • However, the over production of oxygen free radicals in sperm membrane decreases the antioxidant defense activity thereby leading to low sperm motility and viability, DNA fragmentation and protein denaturation. (scialert.net)
  • Because of its outstanding ability to store oxygen and release it, ceria is primarily used in oxidation reactions. (nanowerk.com)
  • Cerium, a rare-earth metal, can easily switch between two different oxidation states (+IV and +III), so it undergoes a smooth transition between CeO2 and materials with a lower oxygen content. (nanowerk.com)
  • Native honey (1% w/v pH 7.4, 10(6) cells) showed strong quenching activity against lipophilic cumoxyl and cumoperoxyl radicals, with significant suppression/prevention of cell damage, complete inhibition of cell membrane oxidation, of intracellular ROS production and recovery of intracellular GSH. (researchgate.net)
  • Moreover, the resultant two-electron oxidation form of GA-Fe is an excellent Fenton-like agent that can catalyze hydrogen peroxide decomposition into hydroxyl radical, finally triggering severe oxidative damage to tumors. (nature.com)
  • These work by either stopping free radical damage by donating an electron without becoming a damaging free radical themselves, or by preventing oxidation commencing. (positivehealth.com)
  • This perspective focuses on two areas that have yielded new useful information during the last 20 years: (i) structure-activity relationship (SAR) studies of contact allergy based on the concept of hapten-protein binding and (ii) mechanistic investigations regarding activation of nonsensitizing compounds to contact allergens by air oxidation or skin metabolism. (cdc.gov)
  • Fig. 3: Proposed „dual pathway photocatalysis" relying on light-induced TiO2-based hydroxyl/superoxide radicals in addition to porphyrazine-generated singlet oxygen. (uni-kassel.de)
  • Oxygen radical absorbance capacity (ORAC) was a method of measuring antioxidant capacities in biological samples in vitro. (wikipedia.org)
  • The last one with direct transferrable results for human health is the oxygen radical absorbance capacity (ORAC) technique, which is also an effective method for measuring TAC of human blood plasma 2 . (aprifel.com)
  • We aimed to determine whether higher mortality rates with high milk consumption are modified by fruit and vegetable intake or total antioxidant intake (oxygen radical absorbance capacity). (medscape.com)
  • When tested against hindered phenols (the most common industrial antioxidant) at high temperatures, the tetrasulfide had a rate constant roughly an order of magnitude greater for their reactions with peroxyl radicals. (chemistryworld.com)
  • Each iron center coordinates with the phenate and carboxylate oxygens of four gallate molecules through six Fe-O bonds 10 . (nature.com)
  • Free radicals can form naturally since some of the body's molecules have weak bonds that spontaneously break and cause the molecule to become a free radical. (positivehealth.com)
  • Free radicals, or oxygen based molecules from toxins are the biggest culprit to advancing the aging process of your skin. (trustedhealthproducts.com)
  • To counteract the negative effects of excess ROS, spermatozoa and seminal plasma have several mechanisms to neutralize free radicals. (scialert.net)
  • To counteract oxidative damage, spermatozoa and seminal plasma have several mechanisms to neutralize free radicals. (scialert.net)
  • The most popular description in scientifi c literature related to antioxidant activity is total antioxidant activity (TAC) which determines the ability of substance, materials, food to neutralize oxygen-free radical specific form, irrespectively to specific antioxidant activity of present antioxidants1. (aprifel.com)
  • The AOX implant has been designed to neutralize these free radicals, and some early studies have shown decreased wear and failure with these types of implants. (medgadget.com)
  • In hybrid materials of Pz and TiO 2 the photocatalytic activity (i.e. the photoinduced generation of active oxygen species) of the inorganic component in the UV can be complemented by the visible-light induced singlet oxygen ( 1 O 2 ) generation of the organic dye. (uni-kassel.de)
  • 18/25842-8 - Sources, Targets and Biological Responses of Triplet Species and Singlet Oxygen: Pathogenicity and Quenching. (fapesp.br)
  • The photophysical properties of both PSs were improved when loaded in the nanocarrier, with a decrease in aggregation as well as an increase in the yield of singlet oxygen generation. (bvsalud.org)
  • In the process, which is based on propagating free-radical reactions, oxygen is absorbed very rapidly. (chemicalprocessing.com)
  • Although the evidence presented here is based on in vitro using isolated DNA, the results clearly demonstrate that the hot-water extract of Ganoderma lucidum shows good radioprotective ability, as well as protection against DNA damage induced by metal-catalyzed Fenton reactions and UV irradiation. (nih.gov)
  • The nanocomplex with a highly reductive ligand field can promote oxygen reduction reactions generating hydrogen peroxide. (nature.com)
  • 19. Alayash A.I. Redox and Radical Reactions of Hemoglobin Solutions: Toxicities and Protective Strategies // In: Blood Substitutes. (medline.ru)
  • Also, for unknown reasons a small proportion of normal oxidative reactions result in the formation of free radicals. (positivehealth.com)
  • To get a more detailed view on the SOM degradation mechanisms employed by ECM fungi, we now study radical reactions and the associated chemical modifications of carbon compounds in situ using Fourier-Transform Infrared and Raman spectromicroscopy. (lu.se)
  • to superoxide or that "autoxidize", and when coupled with catalase Oxygen radicals clearly contribute to probably through reactions catalysed within peroxisomes or with cytosolic genomic instability, are produced by by transition metals. (who.int)
  • Oxygen free radicals are naturally produced by mitochondrial and sperm plasma membrane and have beneficial and detrimental effects that cannot be overlooked. (scialert.net)
  • Agents from sunlight to chemicals, ionizing radiation, and oxygen radicals can either directly damage bases or break the phosphodiester backbone on which the bases reside. (the-scientist.com)
  • We investigated production of radical oxygen species (ROS) in sorus development of sporophyte discs and during zoospore germination of Saccharina japonica (Phaeophyceae) using the fluorescent dye 2′,7′-dichlorofluorescein diacetate (DCFH-DA). (degruyter.com)
  • The focus of this chapter is set on the application of EPR methods to carbon-based materials, from nanographites to graphene-based materials, for the resolution and characterization of the different signals, related to the presence of specific species, or structures. (benthamscience.com)
  • They scavenge free radicals without becoming themselves becoming damaging free radicals or causing other chemical species to become free radicals. (positivehealth.com)
  • Can a free radical be created by chemical reaction of non-radical species? (stackexchange.com)
  • This spectrometer enabled a better monitoring of reaction oxygen species (ROS) activity in the studied samples. (bruker.com)
  • The total phenolic contents, and the scavenging activities against DPPH, oxygen, hydroxyl and cation ABTS radicals were determined for their antioxidant capacities, along with the effects of food preparation on cell-based antioxidant capacity, and anti-inflammation and anti-proliferation activities. (usda.gov)
  • Because any shortage of oxygen can lead to the formation of undesirable byproducts, it is critical to have an excess of oxygen in the reaction zone. (chemicalprocessing.com)
  • They can otherwise degrade through autoxidation, a free radical chain reaction where oxygen in the air oxidises hydrocarbons. (chemistryworld.com)
  • A homolytic substitution reaction with a peroxyl radical occurs. (chemistryworld.com)
  • What is the state of the oxygen free radical in the following reaction? (stackexchange.com)
  • OPTEC Hydroxyl Air Sterilizer uses OH radicals to transform virus proteins, thereby decomposing bacteria and viruses. (viatrading.com)
  • As the researchers report in the journal Angewandte Chemie ( 'Synthesis and Oxygen Storage Capacity of Two-Dimensional Ceria Nanocrystals' ), these have proven to be better at storing oxygen than conventional three-dimensional nanoparticles. (nanowerk.com)
  • The nanoplates proved to be superior to the conventional particulate systems and displayed an oxygen capacity three to four times as high as that of conventional three-dimensional nanoparticles. (nanowerk.com)
  • Youkhana EQ, Feltis B, Blencowe A, Geso M. Titanium Dioxide Nanoparticles as Radiosensitisers: An In vitro and Phantom-Based Study. (medsci.org)
  • What is the functional difference between a radical anion and a nucleophile? (stackexchange.com)
  • To test the oxygen storage capacities of the various forms of ceria, the researchers established a very simple thermogravimetric test: They alternately exposed the samples to oxygen and hydrogen and recorded the change in mass due to oxygen absorption/emission. (nanowerk.com)
  • Metal interactions with hydrogen peroxide have been frequently implicated in catalyzing free radical-mediated damage. (scialert.net)
  • Background Hydrogen/oxygen therapy contribute to ameliorate dyspnea and disease progression in patients with respiratory diseases. (researchgate.net)
  • Therefore, we hypothesized that hydrogen/oxygen therapy for ordinary coronavirus disease 2019 (COVID-19) patients might reduce the length of hospitalization and increase hospital discharge rates. (researchgate.net)
  • After assigned in 1:2 ratios by PSM, 33 patients received hydrogen/oxygen therapy and 55 patients received oxygen therapy included in this study. (researchgate.net)
  • noun Any of a class of organic compounds in which two hydrocarbon groups are linked by an oxygen atom. (wordnik.com)
  • noun organic chemistry, countable A compound containing an oxygen atom bonded to two hydrocarbon groups . (wordnik.com)
  • His lab oratory is working to determine the sequence of events leading to neuronal oxidative damage and the source of the increased oxygen radicals. (utsa.edu)
  • Indoles also present in naturally occurring compounds like dimethyltryptamine (hallucinogen), tryptophan (amino acid) and melatonin [ 16 ] (antioxidant as free radical scavenger). (ijpsonline.com)
  • Naturally occurring, glutamine-deficient light-oxygen-voltage receptors likely serve as bona fide photoreceptors, as we showcase for a diguanylate cyclase. (nature.com)
  • The assay measures the oxidative degradation of the fluorescent molecule (either beta-phycoerythrin or fluorescein) after being mixed with free radical generators such as azo-initiator compounds. (wikipedia.org)
  • Our study implies that VK2 can enhance fat degradation and digestion to improve survival, supporting the effectiveness of VK2-based medical treatments. (frontiersin.org)
  • The AOX antioxidant polyethylene system, which we have covered in the past, is designed to resist free radical degradation and wear. (medgadget.com)
  • however, ORAC-EPR, electron paramagnetic resonance-based ORAC method directly measures the decrease of AAPH-radical level by the scavenging action of the antioxidant substance. (wikipedia.org)
  • The advantages of using multifrequency Electron Paramagnetic Resonance (EPR) in studying carbon-based materials are discussed. (benthamscience.com)
  • During the study, researchers found they were able to identify Nox enzyme inhibitors with reliability and accuracy using a medium-throughput plate reader-based oximetry and electron paramagnetic resonance (EPR) spin trapping. (bruker.com)
  • In contrast, iodine content was lower in the sorus than in the adjacent non-sorus tissues, suggesting the existence of an antioxidant defense mechanism based on iodine efflux. (degruyter.com)
  • Iron is a part of hemoglobin, a protein that transports oxygen from the lungs to the tissues. (medlineplus.gov)
  • Various 2-phenyl-1H-indoles and benzimidazole derivatives have been tested for total antioxidant capacity by phosphomolybednum reduction method and 2,2-diphenyl-1-picrylhydrazide free radical scavenging activity. (ijpsonline.com)
  • The present study was focused on evaluating substituted indole and benzimidazole derivatives ( Table 1 ) for total antioxidant capacity (TAC), free radical scavenging and antimicrobial activity. (ijpsonline.com)
  • Because no physiological proof in vivo existed in support of the free-radical theory or that ORAC provided information relevant to biological antioxidant potential, it was withdrawn in 2012. (wikipedia.org)
  • Structures of a light-oxygen-voltage paradigm at around 1 Å resolution revealed highly similar light-induced conformational changes, irrespective of whether the glutamine is present. (nature.com)
  • Likely via a radical-pair mechanism 12 , T 1 reacts within microseconds to the signaling state, characterized by a covalent thioadduct between a highly conserved cysteine residue in the LOV photosensor and the C4a atom of the flavin isoalloxazine ring system. (nature.com)
  • Approved for use with the SIGMA Rotating Platform Knee System and LCS® COMPLETE® Mobile Bearing Knee System, the new AOX Polyethylene delivers an advanced blend of polyethylene resin and a unique antioxidant, COVERNOX™, to create a new polyethylene material that is highly efficient in trapping free radicals and scavenging oxygen. (medgadget.com)
  • These findings suggest that recombinant vaccines rather than vaccines with higher egg-based antigen doses may provide improved antibody responses in highly vaccinated populations. (cdc.gov)
  • This technique is based on transforming atmospheric water vapor into Engineered Water Nano-Structures (EWNS) via electrospray. (cdc.gov)
  • They are water soluble compounds based on a unit involving carbon ring structures containing phenols (-OH) groups. (positivehealth.com)
  • are able to initiate a range of oxidative chemistry with similar reactivity to the hydroxyl radical (Sutton and Winterbourn, 1989). (scialert.net)
  • Researchers in Canada have discovered that the antioxidant properties of polysulfides are due to their radical reactivity rather than ionic mechanisms, contrary to previous wisdom. (chemistryworld.com)
  • However, new research from Derek Pratt and his team at the University of Ottawa demonstrates that the radical reactivity of these compounds is far more important. (chemistryworld.com)
  • Ascorbic acid has neutralizing properties of free radicals, being able to interact with superoxide, hydroxyl and free oxygen ions, preventing the inflammatory processes, carcinogens, and other processes that accelerate photoaging in the skin. (mdpi.com)
  • Finally, a great number of chemicals, especially human-produced synthetic compounds can cause free radical formation. (positivehealth.com)
  • Moreover, drugs that can reduce free radicals are protective against the promotion of noise -induced hearing loss by chemicals. (cdc.gov)
  • Their synthetic technique is based on the thermal decomposition of cerium acetate at 320 to 330 °C. Critical to their success is the presence of a mineralization agent, which speeds up the crystallization process and controls the morphology. (nanowerk.com)
  • To a synthetic chemist, it provides an opportunity to synthesize a library of compounds based on a core scaffold and to screen the derivatives for various biological activities. (ijpsonline.com)
  • Free radical now appears to be the fundamental mechanism underlying a number of neurologic and other disorders. (scialert.net)
  • So far, AAPH (2,2'-azobis(2-amidino-propane) dihydrochloride) is the sole free-radical generator used. (wikipedia.org)
  • Signaling without glutamine appears intrinsic to light-oxygen-voltage receptors, which pertains to biotechnological applications and suggests evolutionary descendance from redox-active flavoproteins. (nature.com)
  • Sperm cell membranes are high in polyunsaturated fatty acids and are sensitive to oxygen free radical induced damage mediated by lipid peroxidation. (scialert.net)
  • Nucleotide-excision repair, base-excision repair, O 6 -alkly-transferase, and mismatch repair serve to deal with base damage. (the-scientist.com)
  • Using agarose gel electrophoresis, we have evaluated the potential of Ganoderma lucidum extract as a radioprotector and antioxidant defense against oxygen radical-mediated damage. (nih.gov)
  • essential nutritional dietary compounds such as vitamin C, and small plant-derived substances which intercept free radicals and prevent them from causing damage. (positivehealth.com)
  • Cellular DNA can be damaged in several ways: Bases can be covalently altered, the phosphodiester backbone can break on one or both strands, or chemical interstrand cross-links can be introduced. (the-scientist.com)
  • In nature as in biotechnology, light-oxygen-voltage photoreceptors perceive blue light to elicit spatiotemporally defined cellular responses. (nature.com)
  • When a patient is given 100% oxygen under pressure, hemoglobin is saturated, but the blood can be hyperoxygenated by dissolving oxygen within the plasma. (medscape.com)
  • Food selection based on TAC of foods may be an effective strategy to modify the risk of cancer. (who.int)
  • Therefore, the patient cannot benefit from most of the positive effects of HBOT, which are systemic or occur at a level deeper than topical oxygen can penetrate (see Hyperbaric Physics and Physiology section below). (medscape.com)
  • In Y2, hemagglutination inhibition (HI) antibody titers against reference cell-grown vaccine viruses were compared in each ccIIV-RIV group with titers among HCP randomized both seasons to receive egg-based, standard-dose inactivated influenza vaccine (IIV), using geometric mean titer (GMT) ratios of Y2-post-vaccination titers. (cdc.gov)
  • However, few designed SAR studies based on mechanistic investigations of prohaptens have been published. (cdc.gov)
  • The excessive generation of oxygen free radicals in the form of ROS by abnormal spermatozoa and by contaminating leukocytes has been identified as one of the few defined etiologies for male infertility. (scialert.net)
  • BACKGROUND: Emerging data suggest that second-generation influenza vaccines with higher hemagglutinin (HA) antigen content and/or different production methods may induce stronger antibody responses to HA than standard-dose egg-based influenza vaccines in adults. (cdc.gov)