Carbon DioxideNitrogen DioxideNitrogen FixationSulfur DioxideNitrogen CompoundsNitrogen IsotopesNitrogen CycleBlood Urea NitrogenReactive Nitrogen SpeciesNitrogen OxidesThorium DioxideCarbonPII Nitrogen Regulatory ProteinsNitratesAmmoniaAir PollutantsTitaniumFertilizersPartial PressureAtmosphereCapnographyOxygenAir PollutionQuaternary Ammonium CompoundsOxidesInsufflationSilicon DioxideSoilOzoneGlutamate-Ammonia LigaseBiomassUreaRespirationGasesNitrogen Mustard CompoundsNitrogenaseAmino AcidsHypercapniaSymbiosisPulmonary Gas ExchangeOxidants, PhotochemicalHydrogen-Ion ConcentrationPhotosynthesisBlood Gas Monitoring, TranscutaneousPlant LeavesGas ScavengersBlood Gas AnalysisAcetyleneEnvironmental MonitoringPlant RootsChromatography, Supercritical FluidCulture MediaOxidation-ReductionGlutamineLasers, GasTidal VolumeAirParticulate MatterVehicle EmissionsEcosystemNitritesBacterial ProteinsCarbon IsotopesDry IceNitrous OxideMolecular Sequence DataTime FactorsGene Expression Regulation, BacterialOxygen ConsumptionTemperatureCarbon MonoxideDigestionBacteriaCarbon CyclePoaceaeBicarbonatesMethanePhosphorusTreesAmmonium CompoundsAir Pollution, IndoorGlutamate SynthaseAllantoinFermentationNitrate ReductaseWaterHeliumParticle SizeChlorineKetoglutaric AcidsAcidosis, RespiratoryRoot Nodules, PlantCyanobacteriaSoil MicrobiologyAnaerobiosisAnimal FeedSulfurEnvironmental ExposureSeawaterDenitrification