OxygenOxygen ConsumptionPartial PressureSpectroscopy, Near-InfraredPolarographyOximetryHypoxia, BrainOxyhemoglobinsHemodilutionReactive Oxygen SpeciesAnoxiaHemoglobinsCerebrovascular CirculationHyperoxiaMicrocirculationCarbon DioxideMonitoring, PhysiologicBlood SubstitutesRegional Blood FlowBlood Gas AnalysisBrainCardiac OutputHemodynamicsIntracranial PressureFluid TherapyCell HypoxiaMuscle, SkeletalOxygen Inhalation TherapySubarachnoid HemorrhageSinglet OxygenHematocritRats, Sprague-DawleyMesenteryPostoperative PeriodIschemiaMicroelectrodesHypoxia-Inducible Factor 1, alpha SubunitArteriolesCatsBlood VolumeMicrodialysisBlood PressureBrain ChemistryHydrogen-Ion ConcentrationLactic AcidPerfusionBrain InjuriesHomeostasisOxygen IsotopesTime FactorsSwineHeart RateProspective StudiesRats, WistarHyperbaric OxygenationModels, BiologicalHydrogen PeroxideOxidation-ReductionMagnetic Resonance ImagingOxidative StressAntioxidantsAerobiosisSuperoxide DismutaseFree RadicalsFree Radical ScavengersMitochondriaCatalaseNADPH OxidaseAnaerobiosisSuperoxidesLuminescent MeasurementsKineticsPulmonary Gas ExchangeEnergy MetabolismRespirationBlood Gas Monitoring, TranscutaneousOxidantsCells, CulturedOxygen Radioisotopes