Hydrochloric AcidSodiumPneumonia, AspirationNitric AcidGastric JuiceDecalcification TechniqueTrifluoroacetic AcidCountercurrent DistributionHydrogen-Ion ConcentrationEsophagusStomachFluoroacetatesAcidsSodium ChlorideAchlorhydriaParietal Cells, GastricGastric AcidSulfuric AcidsSodium HydroxideGastric FistulaSodium ChannelsAlkalosisGastric MucosaPentagastrinPepsin AAcidosisAppendixDuodenumBicarbonatesSpectrophotometry, AtomicSecretinStomach UlcerSodium, Dietary