Search results for "Oxidation"

showing 10 items of 1913 documents

Redox-Responsive Host-Guest Chemistry of a Flexible Cage with Naphthalene Walls

2020

“Naphthocage”, a naphthalene-based organic cage, reveals very strong binding (up to 1010 M–1) to aromatic (di)cationic guests, i.e., the tetrathiafulvalene mono- and dication and methyl viologen. Intercalation of the guests between two naphthalene walls is mediated by C–H···O, C–H···π, and cation···π interactions. The guests can be switched into and out of the cage by redox processes with high binding selectivity. Oxidation of the flexible cage itself in the absence of a guest leads to a stable radical cation with the oxidized naphthalene intercalated between and stabilized by the other two. Encapsulated guest cations are released from the cavity upon cage oxidation, paving the way to futur…

aromatic compundsaromaattiset yhdisteethapetusredox reactionskationitpelkistysmacromolecular substanceshydrocarbonshapetus-pelkistysreaktiooxidation cationsredox-reaktiohiilivedyt
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Photochemistry of oxidized Hg(I) and Hg(II) species suggests missing mercury oxidation in the troposphere.

2020

8 pags., 5 figs., 2 tabs.

atmospheric chemistryAtmospheric chemistry010504 meteorology & atmospheric sciencesTropospheric chemistryMercury photoreductionchemistry.chemical_elementatmospheric modelingAtmospheric model010501 environmental sciencesPhotochemistry01 natural sciencesTroposphereMercury oxidationComputer SimulationGas-phase mercury reactivitygas-phase mercury reactivity0105 earth and related environmental sciencesmercury photoreductionThermal oxidationMultidisciplinaryAtmospherePhotodissociationCorrectionMercuryModels TheoreticalPhotochemical Processestropospheric chemistryMercury (element)Atmospheric modelingDeposition (aerosol physics)chemistry13. Climate actionAtmospheric chemistry[CHIM.OTHE]Chemical Sciences/OtherOxidation-ReductionProceedings of the National Academy of Sciences of the United States of America
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The catalytic mechanism of glyceraldehyde 3-phosphate dehydrogenase from Trypanosoma cruzi elucidated via the QM/MM approach

2013

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has been identified as a key enzyme involved in glycolysis processes for energy production in the Trypanosoma cruzi parasite. This enzyme catalyses the oxidative phosphorylation of glyceraldehyde 3-phosphate (G3P) in the presence of inorganic phosphate (Pi) and nicotinamide adenosine dinucleotide (NAD+). The catalytic mechanism used by GAPDH has been intensively investigated. However, the individual roles of Pi and the C3 phosphate of G3P (Ps) sites, as well as some residues such as His194 in the catalytic mechanism, remain unclear. In this study, we have employed Molecular Dynamics (MD) simulations within hybrid quantum mechanical/molecular …

biocatalysisEnzims proteolíticsParàsitsStereochemistryTrypanosoma cruziGeneral Physics and AstronomyDehydrogenaseMolecular Dynamics SimulationNicotinamide adenine dinucleotideOxidative PhosphorylationSubstrate Specificityglyceraldehyde 3 phosphate dehydrogenaseQM/MMchemistry.chemical_compoundstomatognathic systemGlyceraldehydePhysical and Theoretical Chemistrynicotinamide adenine dinucleotideGlyceraldehyde 3-phosphate dehydrogenasechemistry.chemical_classificationbiologyGlyceraldehyde-3-Phosphate DehydrogenasesActive siteNADmolecular dynamicsEnzymechemistryBiochemistryBiocatalysisbiology.proteinQuantum TheoryNAD+ kinaseOxidation-ReductionPhysical Chemistry Chemical Physics
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Biochar Particles Obtained from Agricultural Carob Waste as a Suitable Filler for Sustainable Biocomposite Formulations

2022

In the context of sustainable and circular economy, the recovery of biowaste for sustainable biocomposites formulation is a challenging issue. The aim of this work is to give a new life to agricultural carob waste after glucose extraction carried out by a local factory for carob candy production. A pyrolysis process was carried out on bio-waste to produce biofuel and, later, the solid residual fraction of pyrolysis process was used as interesting filler for biocomposites production. In this work, biochar particles (BC) as a pyrolysis product, after fuels recovery of organic biowaste, specifically, pyrolyzed carobs after glucose extraction, were added on poly(butylene-adipate-co-terephthalat…

biocompositesPolymers and Plasticscircular economybiocomposites; biochar particles; circular economy; radical scavenging activity; photo-oxidation resistanceBiochar particlesGeneral Chemistryradical scavenging activityphoto-oxidation resistancePolymers; Volume 14; Issue 15; Pages: 3075
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Exploiting the Redox Activity of MIL-100(Fe) Carrier Enables Prolonged Carvacrol Antimicrobial Activity

2022

The design of efficient food contact materials that maintain optimal levels of food safety is of paramount relevance to reduce the increasing number of foodborne illnesses. In this work, we develop a smart composite metal-organic framework (MOF)-based material that fosters a unique prolonged antibacterial activity. The composite is obtained by entrapping a natural food preserving molecule, carvacrol, into a mesoporous MIL-100(Fe) material following a direct and biocompatible impregnation method, and obtaining particularly high payloads. By exploiting the intrinsic redox nature of the MIL-100(Fe) material, it is possible to achieve a prolonged activity against Escherichia coli and Listeria i…

biocompositesantimicrobial activityUNESCO::CIENCIAS TECNOLÓGICASBacterisAliments MicrobiologiaMOFsAnti-Bacterial AgentsLysergic Acid DiethylamideCymenesGeneral Materials ScienceMaterialsOxidation-Reductioncontrolled deliveryMetal-Organic Frameworksfood packaging
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Natural compounds as light stabilizers for biodegradable polymers

2013

biodegradable polymerNatural anti-oxidantphoto-oxidation
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Photo-Oxidative and Soil Burial Degradation of Irrigation Tubes Based on Biodegradable Polymer Blends

2019

: Irrigation tubes based on biodegradable polymers were prepared via an extrusion-drawing process by Irritec and compared to conventional pipes made of high-density polyethylene (HDPE). A commercial polylactide/poly (butyleneadipate-co-butyleneterephthalate) (PLA/PBAT) blend (Bio-Flex&reg

biodegradable polymers; rheological properties; irrigation pipes; soil burial test; polyesters; Bio-Flex®; Mater-Bi®; polymer degradation; photo-oxidationIrrigationMaterials sciencePolymers and PlasticsBio-Flex<sup>®</sup>polymer degradationIrrigation pipePolyester02 engineering and technologyMater-Bi<sup>®</sup>polyesters010402 general chemistry01 natural sciencesArticlelcsh:QD241-441chemistry.chemical_compoundPolymer degradationlcsh:Organic chemistryBiodegradable polymerRheological propertieIrradiationirrigation pipeschemistry.chemical_classificationsoil burial testGeneral ChemistryPolymerPolyethylene021001 nanoscience & nanotechnologyBiodegradable polymerphoto-oxidation0104 chemical sciencesrheological propertiesChemical engineeringchemistrybiodegradable polymersDegradation (geology)Bio-Flex®High-density polyethylene0210 nano-technologyMater-Bi®Polymers
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Theoretical ab initio study of the vinylcarbene-CuO complex: application to last step of the propylene partial oxidation mechanism on Cu2O

1988

Abstract Using non-empirical pseudopotentials, we have performed a theoretical study on the last step of the propylene partial oxidation mechanism, the acrolein desorption from the catalyst surface. To represent the catalyst we have used a simplified model of a catalyst active site. We have study the C 3 H 4 CuO complex, analysing the dissociation process of the oxygenated complex from a metallic centre. The results indicate that this complex dissociates into cis - and trans -acrolein and a metal site, in a process without energetic barrier.

biologyAcroleinGeneral EngineeringAb initioActive siteDissociation (chemistry)CatalysisMetalchemistry.chemical_compoundchemistryComputational chemistryDesorptionvisual_artbiology.proteinvisual_art.visual_art_mediumPartial oxidationJournal of Molecular Catalysis
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[33] Use of repair endonucleases to assess DNA damage by peroxynitrite

1999

Publisher Summary This chapter discusses the use of repair endonucleases to assess DNA damage by peroxynitrite. Repair endonucleases allow a convenient quantification of various types of oxidative modifications induced by peroxynitrite, both in cultured cells and in cell-free DNA. The high sensitivity of the assays allows highly ectotoxic exposure conditions to be avoided—as well as the generation of secondary DNA modifications—that often become a problem at high levels of damage because primary DNA oxidation products can be orders of magnitude more reactive than the original bases, as demonstrated for the reaction of 8-hydroxyguanine with singlet oxygen. The ratio of the various types of m…

biologyDNA damageDNA repairSinglet oxygenDNA oxidationmedicine.disease_causechemistry.chemical_compoundchemistryBiochemistrybiology.proteinmedicineEndodeoxyribonucleasesPeroxynitriteOxidative stressDNA
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Changes of morphogenic competence in mature Pinus sylvestris L. buds in vitro.

2002

The effects of season and cold storage on morphogenic competence in mature Pinus sylvestris buds were investigated. Peroxidase and polyphenol oxidase activity were measured as markers of oxidative metabolism. No growth in vitro was observed on explants detached from the end of January until the beginning of March. Brachioblasts, each with a couple of needles, formed on 11 % of the buds without macrostrobili that were detached in early April and introduced immediately into culture. Of the explants detached in late July, 15 % formed shoots with brachioblasts and needles. The lowest activity of peroxidase and polyphenol oxidase in pine buds was observed from the end of April until the beginnin…

biologyShort CommunicationsCold storagefood and beveragesPinus sylvestrisPlant SciencePolyphenol oxidase activityPinusPolyphenol oxidaseIn vitroCold TemperatureOxygenPlant LeavesCulture TechniquesBotanyShootbiology.proteinCatechol oxidaseOxidation-ReductionBiomarkersCatechol OxidasePlant ShootsPeroxidaseExplant culturePeroxidaseAnnals of botany
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