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OxygenOxygen ConsumptionReactive Oxygen SpeciesOxygen Inhalation TherapySinglet OxygenOxygen IsotopesHyperbaric OxygenationPartial PressureAnoxiaHydrogen PeroxideOxidation-ReductionOxidative StressOximetryAntioxidantsOxyhemoglobinsCarbon DioxideAerobiosisSuperoxide DismutaseHemoglobinsFree RadicalsFree Radical ScavengersMitochondriaCatalaseHyperoxiaNADPH OxidaseCell HypoxiaAnaerobiosisSuperoxidesBlood Gas AnalysisPolarographyTime FactorsLuminescent MeasurementsKineticsPulmonary Gas ExchangeEnergy MetabolismBlood SubstitutesRespirationBlood Gas Monitoring, TranscutaneousOxidantsCells, CulturedOxygen RadioisotopesXanthine OxidaseNitric OxideReactive Nitrogen SpeciesAcetylcysteineGlutathioneHydrogen-Ion ConcentrationModels, BiologicalExercise TestHemodynamicsElectron TransportApoptosisElectron Spin Resonance SpectroscopyHypoxia-Inducible Factor 1, alpha SubunitDiphosphoglyceric AcidsHydroxyl RadicalSignal TransductionGlucoseLactic AcidHeart RateLipid PeroxidationElectron Transport Complex IVIon-Selective ElectrodesRats, Sprague-DawleyCerebrovascular CirculationPhysical ExertionOxidoreductasesCarbon MonoxideCell SurvivalMembrane Potential, MitochondrialCyclic N-OxidesAirSpectroscopy, Near-InfraredMyoglobinCardiac OutputHeliumExerciseDose-Response Relationship, DrugSpectrophotometryMyocardiumAltitudeRegional Blood FlowOnium CompoundsHypoxia-Inducible Factor 1LactatesHemeLungMetalloporphyrinsNitrous OxideIronBlood PressureAscorbic AcidExercise ToleranceCell DeathMuscle, SkeletalWaterBrainAdaptation, PhysiologicalLightAdenosine Triphosphate2,3-DiphosphoglycerateLung Diseases, ObstructiveHemoglobins, AbnormalHydroxidesEnzyme InhibitorsPeroxidesAtmospheric PressureRats, WistarNADH, NADPH OxidoreductasesPeroxidasesDogsDisease Models, AnimalDivingTemperatureNitratesXanthineMolecular Sequence DataMitochondria, HeartSpin LabelsNeutrophilsPhotosensitizing AgentsPhotosynthesisHemodilutionGlutathione PeroxidaseBiological Oxygen Demand AnalysisNADGlycolysisCell LineMice, Inbred C57BLEnzyme ActivationHematocritRespiration, ArtificialNitrogenPhysical EnduranceCell Line, TumorRespiratory InsufficiencyRetinopathy of PrematurityProcollagen-Proline DioxygenaseGasesGlucose OxidaseRespiratory BurstMicrocirculationHypoxia, BrainRNA, MessengerPulmonary CirculationPerfusionHemeproteinsResuscitation
Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Oxygen Consumption: The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)Reactive Oxygen Species: Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of signal transduction and gene expression, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.Oxygen Inhalation Therapy: Inhalation of oxygen aimed at restoring toward normal any pathophysiologic alterations of gas exchange in the cardiopulmonary system, as by the use of a respirator, nasal catheter, tent, chamber, or mask. (From Dorland, 27th ed & Stedman, 25th ed)Singlet Oxygen: An excited state of molecular oxygen generated photochemically or chemically. Singlet oxygen reacts with a variety of biological molecules such as NUCLEIC ACIDS; PROTEINS; and LIPIDS; causing oxidative damages.Oxygen Isotopes: Stable oxygen atoms that have the same atomic number as the element oxygen, but differ in atomic weight. O-17 and 18 are stable oxygen isotopes.Hyperbaric Oxygenation: The therapeutic intermittent administration of oxygen in a chamber at greater than sea-level atmospheric pressures (three atmospheres). It is considered effective treatment for air and gas embolisms, smoke inhalation, acute carbon monoxide poisoning, caisson disease, clostridial gangrene, etc. (From Segen, Dictionary of Modern Medicine, 1992). The list of treatment modalities includes stroke.Partial Pressure: The pressure that would be exerted by one component of a mixture of gases if it were present alone in a container. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Anoxia: Relatively complete absence of oxygen in one or more tissues.Hydrogen Peroxide: A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Oxidative Stress: A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).Oximetry: The determination of oxygen-hemoglobin saturation of blood either by withdrawing a sample and passing it through a classical photoelectric oximeter or by electrodes attached to some translucent part of the body like finger, earlobe, or skin fold. It includes non-invasive oxygen monitoring by pulse oximetry.Antioxidants: Naturally occurring or synthetic substances that inhibit or retard the oxidation of a substance to which it is added. They counteract the harmful and damaging effects of oxidation in animal tissues.Oxyhemoglobins: A compound formed by the combination of hemoglobin and oxygen. It is a complex in which the oxygen is bound directly to the iron without causing a change from the ferrous to the ferric state.Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.Aerobiosis: Life or metabolic reactions occurring in an environment containing oxygen.Superoxide Dismutase: An oxidoreductase that catalyzes the reaction between superoxide anions and hydrogen to yield molecular oxygen and hydrogen peroxide. The enzyme protects the cell against dangerous levels of superoxide. EC 1.15.1.1.Hemoglobins: The oxygen-carrying proteins of ERYTHROCYTES. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.Free Radicals: Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.Free Radical Scavengers: Substances that influence the course of a chemical reaction by ready combination with free radicals. Among other effects, this combining activity protects pancreatic islets against damage by cytokines and prevents myocardial and pulmonary perfusion injuries.Mitochondria: Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)Catalase: An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.Hyperoxia: An abnormal increase in the amount of oxygen in the tissues and organs.NADPH Oxidase: A flavoprotein enzyme that catalyzes the univalent reduction of OXYGEN using NADPH as an electron donor to create SUPEROXIDE ANION. The enzyme is dependent on a variety of CYTOCHROMES. Defects in the production of superoxide ions by enzymes such as NADPH oxidase result in GRANULOMATOUS DISEASE, CHRONIC.Cell Hypoxia: A condition of decreased oxygen content at the cellular level.Anaerobiosis: The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Superoxides: Highly reactive compounds produced when oxygen is reduced by a single electron. In biological systems, they may be generated during the normal catalytic function of a number of enzymes and during the oxidation of hemoglobin to METHEMOGLOBIN. In living organisms, SUPEROXIDE DISMUTASE protects the cell from the deleterious effects of superoxides.Blood Gas Analysis: Measurement of oxygen and carbon dioxide in the blood.Polarography: An electrochemical technique for measuring the current that flows in solution as a function of an applied voltage. The observed polarographic wave, resulting from the electrochemical response, depends on the way voltage is applied (linear sweep or differential pulse) and the type of electrode used. Usually a mercury drop electrode is used.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Luminescent Measurements: Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.Kinetics: The rate dynamics in chemical or physical systems.Pulmonary Gas Exchange: The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.Energy Metabolism: The chemical reactions involved in the production and utilization of various forms of energy in cells.Blood Substitutes: Substances that are used in place of blood, for example, as an alternative to BLOOD TRANSFUSIONS after blood loss to restore BLOOD VOLUME and oxygen-carrying capacity to the blood circulation, or to perfuse isolated organs.Respiration: The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).Blood Gas Monitoring, Transcutaneous: The noninvasive measurement or determination of the partial pressure (tension) of oxygen and/or carbon dioxide locally in the capillaries of a tissue by the application to the skin of a special set of electrodes. These electrodes contain photoelectric sensors capable of picking up the specific wavelengths of radiation emitted by oxygenated versus reduced hemoglobin.Oxidants: Electron-accepting molecules in chemical reactions in which electrons are transferred from one molecule to another (OXIDATION-REDUCTION).Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Oxygen Radioisotopes: Unstable isotopes of oxygen that decay or disintegrate emitting radiation. O atoms with atomic weights 13, 14, 15, 19, and 20 are radioactive oxygen isotopes.Xanthine Oxidase: An iron-molybdenum flavoprotein containing FLAVIN-ADENINE DINUCLEOTIDE that oxidizes hypoxanthine, some other purines and pterins, and aldehydes. Deficiency of the enzyme, an autosomal recessive trait, causes xanthinuria.Nitric Oxide: A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.Reactive Nitrogen Species: Nitrogenous products of NITRIC OXIDE synthases, ranging from NITRIC OXIDE to NITRATES. These reactive nitrogen intermediates also include the inorganic PEROXYNITROUS ACID and the organic S-NITROSOTHIOLS.Acetylcysteine: The N-acetyl derivative of CYSTEINE. It is used as a mucolytic agent to reduce the viscosity of mucous secretions. It has also been shown to have antiviral effects in patients with HIV due to inhibition of viral stimulation by reactive oxygen intermediates.Glutathione: A tripeptide with many roles in cells. It conjugates to drugs to make them more soluble for excretion, is a cofactor for some enzymes, is involved in protein disulfide bond rearrangement and reduces peroxides.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Exercise Test: Controlled physical activity which is performed in order to allow assessment of physiological functions, particularly cardiovascular and pulmonary, but also aerobic capacity. Maximal (most intense) exercise is usually required but submaximal exercise is also used.Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Electron Transport: The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)Apoptosis: One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.Electron Spin Resonance Spectroscopy: A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.Hypoxia-Inducible Factor 1, alpha Subunit: Hypoxia-inducible factor 1, alpha subunit is a basic helix-loop-helix transcription factor that is regulated by OXYGEN availability and is targeted for degradation by VHL TUMOR SUPPRESSOR PROTEIN.Diphosphoglyceric AcidsHydroxyl Radical: The univalent radical OH. Hydroxyl radical is a potent oxidizing agent.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Glucose: A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.Lactic Acid: A normal intermediate in the fermentation (oxidation, metabolism) of sugar. The concentrated form is used internally to prevent gastrointestinal fermentation. (From Stedman, 26th ed)Heart Rate: The number of times the HEART VENTRICLES contract per unit of time, usually per minute.Lipid Peroxidation: Peroxidase catalyzed oxidation of lipids using hydrogen peroxide as an electron acceptor.Electron Transport Complex IV: A multisubunit enzyme complex containing CYTOCHROME A GROUP; CYTOCHROME A3; two copper atoms; and 13 different protein subunits. It is the terminal oxidase complex of the RESPIRATORY CHAIN and collects electrons that are transferred from the reduced CYTOCHROME C GROUP and donates them to molecular OXYGEN, which is then reduced to water. The redox reaction is simultaneously coupled to the transport of PROTONS across the inner mitochondrial membrane.Ion-Selective Electrodes: Electrodes which can be used to measure the concentration of particular ions in cells, tissues, or solutions.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Cerebrovascular Circulation: The circulation of blood through the BLOOD VESSELS of the BRAIN.Physical Exertion: Expenditure of energy during PHYSICAL ACTIVITY. Intensity of exertion may be measured by rate of OXYGEN CONSUMPTION; HEAT produced, or HEART RATE. Perceived exertion, a psychological measure of exertion, is included.Oxidoreductases: The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)Carbon Monoxide: Carbon monoxide (CO). A poisonous colorless, odorless, tasteless gas. It combines with hemoglobin to form carboxyhemoglobin, which has no oxygen carrying capacity. The resultant oxygen deprivation causes headache, dizziness, decreased pulse and respiratory rates, unconsciousness, and death. (From Merck Index, 11th ed)Cell Survival: The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.Membrane Potential, Mitochondrial: The voltage difference, normally maintained at approximately -180mV, across the INNER MITOCHONDRIAL MEMBRANE, by a net movement of positive charge across the membrane. It is a major component of the PROTON MOTIVE FORCE in MITOCHONDRIA used to drive the synthesis of ATP.Cyclic N-Oxides: Heterocyclic compounds in which an oxygen is attached to a cyclic nitrogen.Air: The mixture of gases present in the earth's atmosphere consisting of oxygen, nitrogen, carbon dioxide, and small amounts of other gases.Spectroscopy, Near-Infrared: A noninvasive technique that uses the differential absorption properties of hemoglobin and myoglobin to evaluate tissue oxygenation and indirectly can measure regional hemodynamics and blood flow. Near-infrared light (NIR) can propagate through tissues and at particular wavelengths is differentially absorbed by oxygenated vs. deoxygenated forms of hemoglobin and myoglobin. Illumination of intact tissue with NIR allows qualitative assessment of changes in the tissue concentration of these molecules. The analysis is also used to determine body composition.Myoglobin: A conjugated protein which is the oxygen-transporting pigment of muscle. It is made up of one globin polypeptide chain and one heme group.Cardiac Output: The volume of BLOOD passing through the HEART per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with STROKE VOLUME (volume per beat).Helium: Helium. A noble gas with the atomic symbol He, atomic number 2, and atomic weight 4.003. It is a colorless, odorless, tasteless gas that is not combustible and does not support combustion. It was first detected in the sun and is now obtained from natural gas. Medically it is used as a diluent for other gases, being especially useful with oxygen in the treatment of certain cases of respiratory obstruction, and as a vehicle for general anesthetics. (Dorland, 27th ed)Exercise: Physical activity which is usually regular and done with the intention of improving or maintaining PHYSICAL FITNESS or HEALTH. Contrast with PHYSICAL EXERTION which is concerned largely with the physiologic and metabolic response to energy expenditure.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.Myocardium: The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.Altitude: A vertical distance measured from a known level on the surface of a planet or other celestial body.Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Onium Compounds: Ions with the suffix -onium, indicating cations with coordination number 4 of the type RxA+ which are analogous to QUATERNARY AMMONIUM COMPOUNDS (H4N+). Ions include phosphonium R4P+, oxonium R3O+, sulfonium R3S+, chloronium R2Cl+Hypoxia-Inducible Factor 1: A basic helix-loop-helix transcription factor that plays a role in APOPTOSIS. It is composed of two subunits: ARYL HYDROCARBON RECEPTOR NUCLEAR TRANSLOCATOR and HYPOXIA-INDUCIBLE FACTOR 1, ALPHA SUBUNIT.Lactates: Salts or esters of LACTIC ACID containing the general formula CH3CHOHCOOR.Heme: The color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Metalloporphyrins: Porphyrins which are combined with a metal ion. The metal is bound equally to all four nitrogen atoms of the pyrrole rings. They possess characteristic absorption spectra which can be utilized for identification or quantitative estimation of porphyrins and porphyrin-bound compounds.Nitrous Oxide: Nitrogen oxide (N2O). A colorless, odorless gas that is used as an anesthetic and analgesic. High concentrations cause a narcotic effect and may replace oxygen, causing death by asphyxia. It is also used as a food aerosol in the preparation of whipping cream.Iron: A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.Ascorbic Acid: A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.Exercise Tolerance: The exercise capacity of an individual as measured by endurance (maximal exercise duration and/or maximal attained work load) during an EXERCISE TEST.Cell Death: The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.Muscle, Skeletal: A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.Water: A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Adenosine Triphosphate: An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.2,3-Diphosphoglycerate: A highly anionic organic phosphate which is present in human red blood cells at about the same molar ratio as hemoglobin. It binds to deoxyhemoglobin but not the oxygenated form, therefore diminishing the oxygen affinity of hemoglobin. This is essential in enabling hemoglobin to unload oxygen in tissue capillaries. It is also an intermediate in the conversion of 3-phosphoglycerate to 2-phosphoglycerate by phosphoglycerate mutase (EC 5.4.2.1). (From Stryer Biochemistry, 4th ed, p160; Enzyme Nomenclature, 1992, p508)Lung Diseases, Obstructive: Any disorder marked by obstruction of conducting airways of the lung. AIRWAY OBSTRUCTION may be acute, chronic, intermittent, or persistent.Hemoglobins, Abnormal: Hemoglobins characterized by structural alterations within the molecule. The alteration can be either absence, addition or substitution of one or more amino acids in the globin part of the molecule at selected positions in the polypeptide chains.Hydroxides: Inorganic compounds that contain the OH- group.Enzyme Inhibitors: Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.Peroxides: A group of compounds that contain a bivalent O-O group, i.e., the oxygen atoms are univalent. They can either be inorganic or organic in nature. Such compounds release atomic (nascent) oxygen readily. Thus they are strong oxidizing agents and fire hazards when in contact with combustible materials, especially under high-temperature conditions. The chief industrial uses of peroxides are as oxidizing agents, bleaching agents, and initiators of polymerization. (From Hawley's Condensed Chemical Dictionary, 11th ed)Atmospheric Pressure: The pressure at any point in an atmosphere due solely to the weight of the atmospheric gases above the point concerned.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.NADH, NADPH Oxidoreductases: A group of oxidoreductases that act on NADH or NADPH. In general, enzymes using NADH or NADPH to reduce a substrate are classified according to the reverse reaction, in which NAD+ or NADP+ is formally regarded as an acceptor. This subclass includes only those enzymes in which some other redox carrier is the acceptor. (Enzyme Nomenclature, 1992, p100) EC 1.6.PeroxidasesDogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Diving: An activity in which the organism plunges into water. It includes scuba and bell diving. Diving as natural behavior of animals goes here, as well as diving in decompression experiments with humans or animals.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Nitrates: Inorganic or organic salts and esters of nitric acid. These compounds contain the NO3- radical.Xanthine: A purine base found in most body tissues and fluids, certain plants, and some urinary calculi. It is an intermediate in the degradation of adenosine monophosphate to uric acid, being formed by oxidation of hypoxanthine. The methylated xanthine compounds caffeine, theobromine, and theophylline and their derivatives are used in medicine for their bronchodilator effects. (Dorland, 28th ed)Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Mitochondria, Heart: The mitochondria of the myocardium.Spin Labels: Molecules which contain an atom or a group of atoms exhibiting an unpaired electron spin that can be detected by electron spin resonance spectroscopy and can be bonded to another molecule. (McGraw-Hill Dictionary of Chemical and Technical Terms, 4th ed)Neutrophils: Granular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.Photosensitizing Agents: Drugs that are pharmacologically inactive but when exposed to ultraviolet radiation or sunlight are converted to their active metabolite to produce a beneficial reaction affecting the diseased tissue. These compounds can be administered topically or systemically and have been used therapeutically to treat psoriasis and various types of neoplasms.Photosynthesis: The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)Hemodilution: Reduction of blood viscosity usually by the addition of cell free solutions. Used clinically (1) in states of impaired microcirculation, (2) for replacement of intraoperative blood loss without homologous blood transfusion, and (3) in cardiopulmonary bypass and hypothermia.Glutathione Peroxidase: An enzyme catalyzing the oxidation of 2 moles of glutathione in the presence of hydrogen peroxide to yield oxidized glutathione and water. EC 1.11.1.9.Biological Oxygen Demand Analysis: Testing for the amount of biodegradable organic material in a water sample by measuring the quantity of oxygen consumed by biodegradation of those materials over a specific time period.NAD: A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)Glycolysis: A metabolic process that converts GLUCOSE into two molecules of PYRUVIC ACID through a series of enzymatic reactions. Energy generated by this process is conserved in two molecules of ATP. Glycolysis is the universal catabolic pathway for glucose, free glucose, or glucose derived from complex CARBOHYDRATES, such as GLYCOGEN and STARCH.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Mice, Inbred C57BLEnzyme Activation: Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.Hematocrit: The volume of packed RED BLOOD CELLS in a blood specimen. The volume is measured by centrifugation in a tube with graduated markings, or with automated blood cell counters. It is an indicator of erythrocyte status in disease. For example, ANEMIA shows a low value; POLYCYTHEMIA, a high value.Respiration, Artificial: Any method of artificial breathing that employs mechanical or non-mechanical means to force the air into and out of the lungs. Artificial respiration or ventilation is used in individuals who have stopped breathing or have RESPIRATORY INSUFFICIENCY to increase their intake of oxygen (O2) and excretion of carbon dioxide (CO2).Nitrogen: An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.Physical Endurance: The time span between the beginning of physical activity by an individual and the termination because of exhaustion.Cell Line, Tumor: A cell line derived from cultured tumor cells.Respiratory Insufficiency: Failure to adequately provide oxygen to cells of the body and to remove excess carbon dioxide from them. (Stedman, 25th ed)Retinopathy of Prematurity: A bilateral retinopathy occurring in premature infants treated with excessively high concentrations of oxygen, characterized by vascular dilatation, proliferation, and tortuosity, edema, and retinal detachment, with ultimate conversion of the retina into a fibrous mass that can be seen as a dense retrolental membrane. Usually growth of the eye is arrested and may result in microophthalmia, and blindness may occur. (Dorland, 27th ed)Procollagen-Proline Dioxygenase: A mixed-function oxygenase that catalyzes the hydroxylation of a prolyl-glycyl containing peptide, usually in PROTOCOLLAGEN, to a hydroxyprolylglycyl-containing-peptide. The enzyme utilizes molecular OXYGEN with a concomitant oxidative decarboxylation of 2-oxoglutarate to SUCCINATE. The enzyme occurs as a tetramer of two alpha and two beta subunits. The beta subunit of procollagen-proline dioxygenase is identical to the enzyme PROTEIN DISULFIDE-ISOMERASES.Gases: The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)Glucose Oxidase: An enzyme of the oxidoreductase class that catalyzes the conversion of beta-D-glucose and oxygen to D-glucono-1,5-lactone and peroxide. It is a flavoprotein, highly specific for beta-D-glucose. The enzyme is produced by Penicillium notatum and other fungi and has antibacterial activity in the presence of glucose and oxygen. It is used to estimate glucose concentration in blood or urine samples through the formation of colored dyes by the hydrogen peroxide produced in the reaction. (From Enzyme Nomenclature, 1992) EC 1.1.3.4.Respiratory Burst: A large increase in oxygen uptake by neutrophils and most types of tissue macrophages through activation of an NADPH-cytochrome b-dependent oxidase that reduces oxygen to a superoxide. Individuals with an inherited defect in which the oxidase that reduces oxygen to superoxide is decreased or absent (GRANULOMATOUS DISEASE, CHRONIC) often die as a result of recurrent bacterial infections.Microcirculation: The circulation of the BLOOD through the MICROVASCULAR NETWORK.Hypoxia, Brain: A reduction in brain oxygen supply due to ANOXEMIA (a reduced amount of oxygen being carried in the blood by HEMOGLOBIN), or to a restriction of the blood supply to the brain, or both. Severe hypoxia is referred to as anoxia, and is a relatively common cause of injury to the central nervous system. Prolonged brain anoxia may lead to BRAIN DEATH or a PERSISTENT VEGETATIVE STATE. Histologically, this condition is characterized by neuronal loss which is most prominent in the HIPPOCAMPUS; GLOBUS PALLIDUS; CEREBELLUM; and inferior olives.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Pulmonary Circulation: The circulation of the BLOOD through the LUNGS.Perfusion: Treatment process involving the injection of fluid into an organ or tissue.Hemeproteins: Proteins that contain an iron-porphyrin, or heme, prosthetic group resembling that of hemoglobin. (From Lehninger, Principles of Biochemistry, 1982, p480)Resuscitation: The restoration to life or consciousness of one apparently dead. (Dorland, 27th ed)

Arterial blood gas tensions during upper gastrointestinal endoscopy. (1/22785)

Arterial blood gas tensions were measured before and during upper gastrointestinal endoscopy, with (group I) and without (group 2) sedation with intravenous diazepam. There was a highly significant fall in the PaO2, which occurred in both groups and was therefore not attributable to diazepam. Measurement of FEV, and FVC before endoscopy had no predictive value for those patients whose PaO2 fell the most.  (+info)

In vitro development of sheep preantral follicles. (2/22785)

Preantral ovarian follicles isolated from prepubertal sheep ovaries were individually cultured for 6 days in the presence of increasing doses of FSH (ranging from 0.01 to 1 microg/ml) and under two different oxygen concentrations, 20% and 5% O2. Follicle development was evaluated on the basis of antral cavity formation as well as the presence of healthy cumulus oocyte complexes. Follicle growth was enhanced by FSH addition to culture medium, while the use of a low oxygen concentration slightly stimulated this process. However, when follicles were cultured in the presence of high doses of FSH (1 microgram/ml) and under low oxygen concentration, a high proportion of them showed the presence of an antral cavity and of a healthy cumulus-oocyte complex. In addition, under this specific culture condition sheep preantral follicles released higher levels of estradiol as compared to those secreted at lower FSH concentrations or under 20% O2. When the meiotic competence of oocytes derived from follicles cultured at 1 microgram/ml FSH was assessed, no significant difference was recorded between the two oxygen groups. These results show that the culture conditions here identified are beneficial to in vitro growth and differentiation of sheep preantral follicles.  (+info)

Endogenous plasma endothelin concentrations and coronary circulation in patients with mild dilated cardiomyopathy. (3/22785)

OBJECTIVE: To determine whether increased plasma concentrations of endothelin-1 (ET-1) and big endothelin (BET) play a role in the regulation of coronary circulation in patients with idiopathic dilated cardiomyopathy (IDCM). SETTING: Tertiary referral centre for cardiac diseases. PATIENTS: Fourteen patients (eight male/six female; mean (SD) age 59 (9) years) with IDCM (ejection fraction 36 (9)%) and five normotensive subjects (two male/three female; age 52 (7) years) serving as controls were studied. METHODS: Functional status was classified according to New York Heart Association (NYHA) class. Endogenous ET-1 and BET plasma concentrations from the aorta and the coronary sinus were determined by radioimmunoassay. Coronary blood flow, using the inert chromatographic argon method, myocardial oxygen consumption, and coronary sinus oxygen content under basal conditions were determined. RESULTS: In the aorta, mean (SD) concentrations of ET-1 (IDCM 0.76 (0.25) v controls 0.31 (0.06) fmol/ml; p = 0.002) and BET (IDCM 3.58 (1.06) v controls 2.11 (0.58) fmol/ml; p = 0.014) were increased in patients with IDCM. Aortic ET-1 concentrations correlated positively with NYHA class (r = 0. 731; p < 0.001), myocardial oxygen consumption (r = 0.749; p < 0. 001), and coronary blood flow (r = 0.645; p = 0.003), but inversely with coronary sinus oxygen content (r = -0.633; p = 0.004), which was significantly decreased in IDCM patients (IDCM 4.68 (1.05) v controls 6.70 (1.06) vol%; p = 0.003). CONCLUSIONS: The coronary circulation in patients with IDCM is exposed to an increased endothelin load. ET-1 concentrations correlate with functional deterioration. A decrease of the coronary sinus content of oxygen suggests a mismatch between coronary blood flow and metabolic demand. Thus, ET-1 might be a marker of a disequilibrium between myocardial oxygen demand and coronary blood flow in IDCM.  (+info)

Quantification of tumour vasculature and hypoxia by immunohistochemical staining and HbO2 saturation measurements. (4/22785)

Despite the possibility that tumour hypoxia may limit radiotherapeutic response, the underlying mechanisms remain poorly understood. A new methodology has been developed in which information from several sophisticated techniques is combined and analysed at a microregional level. First, tumour oxygen availability is spatially defined by measuring intravascular blood oxygen saturations (HbO2) cryospectrophotometrically in frozen tumour blocks. Second, hypoxic development is quantified in adjacent sections using immunohistochemical detection of a fluorescently conjugated monoclonal antibody (ELK3-51) to a nitroheterocyclic hypoxia marker (EF5), thereby providing information relating to both the oxygen consumption rates and the effective oxygen diffusion distances. Third, a combination of fluorescent (Hoechst 33342 or DiOC7(3)) and immunohistological (PECAM-1/CD31) stains is used to define the anatomical vascular densities and the fraction of blood vessels containing flow. Using a computer-interfaced microscope stage, image analysis software and a 3-CCD colour video camera, multiple images are digitized, combined to form a photo-montage and revisited after each of the three staining protocols. By applying image registration techniques, the spatial distribution of HbO2 saturations is matched to corresponding hypoxic marker intensities in adjacent sections. This permits vascular configuration to be related to oxygen availability and allows the hypoxic marker intensities to be quantitated in situ.  (+info)

The respiratory responses of Carcinus maenas to declining oxygen tension. (5/22785)

The degree of respiratory independence shown by Carcinus under conditions of declining oxygen tension is dependent on the animal's level of activity. Inactive Carcinus are capable of maintaining respiratory independence down to a Po2 of 60-80 mmHg. This is achieved primarily by an increase in ventilation volume such that the amount of oxygen made available at the respiratory surfaces remains constant over a wide range of oxygen tension. The Po2 at which this can no longer be maintained corresponds closely to the Po2 at which respiratory independence is lost. Under normoxic conditions the Po2 of the post- and prebranchial blood was 97 and 18 mmHg respectively. At the high oxygen tensions prevailing in the postbranchial blood the respiratory pigment is fully saturated. Under conditions of declining oxygen tension the heart rate remains more or less constant until the Po2 reaches 60-80 mmHg, the onset of bradycardia coinciding with the loss of saturation of the haemocyanin. Although cardiac output falls during hypoxia, the capacity rate ratio remains approximately constant, which enables the effectiveness of oxygen uptake by the blood to remain at a high level.  (+info)

Active transport of calcium across the isolated midgut of Hyalophora cecropia. (6/22785)

1. The net flux of 45Ca from lumen to blood side across the isolated and short-circuited Cecropia midgut was 1-9 +/- 0-2 muequiv. cm-2h-1 in 8 mM Ca and the flux ratio was as high as 56 to 1. 2. The calcium influx was depressed by anoxia; 73% after 30 min. 3. The kinetics of Ca transport were anomalous; the apparent Km varied with Ca concentration from less than 0-2 to greater than 5-6 mM Ca and the apparent Vmax varied from less than 1-3 to greater than 3-3 muequiv. cm-2h-1. 4. The calcium influx showed a delay before the tracer steady state was attained, indicating the existence in the transport route of a calcium pool equivalent to 5-7 muequiv/g. wet weight of midgut tissue. 5 High calcium (16 mM) depressed the short-circuit current and potassium transport from blood to lumen side across the midgut. 6. Calcium depressed magnesium transport, from lumen to blood side across the midgut, and magnesium depressed the calcium transport. 7. Ca transport by the midgut does not regulate the Ca level in the haemolymph in vivo; it merely aids the diffusion of calcium down its electrochemical gradient. However, Ca transport may assist the uptake of the nutrients from the midgut contents.  (+info)

2,3 diphosphoglycerate in Parkinson's disease. (7/22785)

The red cell 2,3 DPG, the most important factor for oxygen delivery in the tissues, was found to be increased in Parkinsonism patients compared with controls. The aging process seems not to be a factor in the increased 2,3 DPG concentration. Other factors relevant to raised 2,3 DPG level such as physical activity, increased oxygen requirements, and metabolic changes are discussed.  (+info)

Nitric oxide inhibits cardiac energy production via inhibition of mitochondrial creatine kinase. (8/22785)

Nitric oxide biosynthesis in cardiac muscle leads to a decreased oxygen consumption and lower ATP synthesis. It is suggested that this effect of nitric oxide is mainly due to the inhibition of the mitochondrial respiratory chain enzyme, cytochrome c oxidase. However, this work demonstrates that nitric oxide is able to inhibit soluble mitochondrial creatine kinase (CK), mitochondrial CK bound in purified mitochondria, CK in situ in skinned fibres as well as the functional activity of mitochondrial CK in situ in skinned fibres. Since mitochondrial isoenzyme is functionally coupled to oxidative phosphorylation, its inhibition also leads to decreased sensitivity of mitochondrial respiration to ADP and thus decreases ATP synthesis and oxygen consumption under physiological ADP concentrations.  (+info)

Oxygen Saturation levels and what do they mean? | Easy OxygenOxygen Saturation levels and what do they mean? | Easy Oxygen
What should my oxygen saturation level be?. A range of 94-99% is normal for healthy adults breathing room air which contains 21% oxygen. Anyone who is not achieving the critical blood oxygen saturation level of 90% (SpO2) or of 55-60mmHg (SaO2), may require additional oxygen. A qualified medical practitioner will assess your situation and prescribe the appropriate dose of supplemental oxygen.. Oxygen saturation levels - what do they mean?. Oxygen saturation levels measure the degree to which the haemoglobin contained in the red blood cells (erythrocytes) has bonded with oxygen molecules. Oxygen is taken in by the lungs when we breathe in.. The two most common ways of assessing the saturation of oxygen in the blood are arterial blood gases (ABG) and pulsatile oxygen.. What does an ABG measure?. An ABG test measures how efficiently your lungs are bringing oxygen into the blood stream and removing carbon dioxide. Arterial blood gases are taken from an artery usually on the wrist. This procedure can ...
Abstract 11100: Effect of Different Oxygen Concentrations on Post Resuscitation Myocardial Oxidative Stress and Myocardial...Abstract 11100: Effect of Different Oxygen Concentrations on Post Resuscitation Myocardial Oxidative Stress and Myocardial...
Background: Lipid peroxidation induced by oxygen free radicals plays a prominent role in myocardial injury after global ischemia. The present study investigated whether ventilation with lower concentration of inspired oxygen would decrease the severity of myocardial lipid peroxidation and post resuscitation myocardial dysfunction.. Methods: Ventricular fibrillation was induced and untreated for 8 mins in 46 male Sprague-Dawley rats. Defibrillation was attempted after 8 mins of CPR. The animals were randomized into 3 groups: mechanical ventilation with 100% O2, 50% O2 or 21% O2 during CPR and one hr following return of spontaneous circulation. Normoxic ventilation was maintained thereafter. The level of 8-iso-Prostaglandin F2α (8-iso-PGF2α) in myocardium was evaluated using the enzyme-linked immunosorbent assay (ELISA). Blood gases, post resuscitation myocardial function and the duration of survival were monitored in all animals.. Results: Compared with the 100% and 21% groups, the 50% group ...
Influence of oxygen tension on the rheological behavior of sickle cells in microcirculation - Fingerprint - Penn StateInfluence of oxygen tension on the rheological behavior of sickle cells in microcirculation - Fingerprint - Penn State
Fingerprint Dive into the research topics of Influence of oxygen tension on the rheological behavior of sickle cells in microcirculation. Together they form a unique fingerprint. ...
Effects of oxygen tension on vascular and other smooth muscle...Effects of oxygen tension on vascular and other smooth muscle...
Effects of oxygen tension on vascular and other smooth muscle: 1. The resting tension of various isolated intestinal and vascular smooth muscle preparations var
Brain tissue oxygen regulation in awake and anesthetized neonates<...Brain tissue oxygen regulation in awake and anesthetized neonates<...
TY - JOUR. T1 - Brain tissue oxygen regulation in awake and anesthetized neonates. AU - Aksenov, Daniil P.. AU - Dmitriev, Andrey V.. AU - Miller, Michael J.. AU - Wyrwicz, Alice M.. AU - Linsenmeier, Robert A. PY - 2018/6/1. Y1 - 2018/6/1. N2 - Inhaled general anesthetics are used commonly in adults and children, and a growing body of literature from animals and humans suggests that exposure to anesthesia at an early age can impact brain development. While the origin of these effects is not well understood, it is known that anesthesia can disrupt oxygen regulation in the brain, which is critically important for maintaining healthy brain function. Here we investigated how anesthesia affected brain tissue oxygen regulation in neonatal rabbits by comparing brain tissue oxygen and single unit activity in the awake and anesthetized states. We tested two common general anesthetics, isoflurane and sevoflurane, delivered in both air and 80% oxygen. Our findings show that general anesthetics can greatly ...
The Effects of Physiologic Oxygen Tension on Clinical In Vitro Fertilization Outcomes - Full Text View - ClinicalTrials.govThe Effects of Physiologic Oxygen Tension on Clinical In Vitro Fertilization Outcomes - Full Text View - ClinicalTrials.gov
Study Design. This will be a multi-center, prospective, double-blind clinical trial of physiologic (5%) oxygen tension in culture media vs. standard of care, atmospheric (SOC, 20%) oxygen tension with 840 eligible couples recruited to participate. The randomization scheme will be coordinated through the central data coordinating center (DCC-Yale) and the randomization will be stratified by age group of the woman (18-34, 35-37, 38-40 and 40-42) and each participating site.. Treatment. Couples will be randomized to either have their gametes and embryos placed in a physiologic (5%) oxygen atmosphere or in the currently widely used atmospheric (20%) oxygen atmosphere. ...
PLOS ONE: Image-Based Modeling of Blood Flow and Oxygen Transfer in Feto-Placental CapillariesPLOS ONE: Image-Based Modeling of Blood Flow and Oxygen Transfer in Feto-Placental Capillaries
During pregnancy, oxygen diffuses from maternal to fetal blood through villous trees in the placenta. In this paper, we simulate blood flow and oxygen transfer in feto-placental capillaries by converting three-dimensional representations of villous and capillary surfaces, reconstructed from confocal laser scanning microscopy, to finite-element meshes, and calculating values of vascular flow resistance and total oxygen transfer. The relationship between the total oxygen transfer rate and the pressure drop through the capillary is shown to be captured across a wide range of pressure drops by physical scaling laws and an upper bound on the oxygen transfer rate. A regression equation is introduced that can be used to estimate the oxygen transfer in a capillary using the vascular resistance. Two techniques for quantifying the effects of statistical variability, experimental uncertainty and pathological placental structure on the calculated properties are then introduced. First, scaling arguments are used to
Myrrha | Performance of electrochemical oxygen pump in a liquid lead-bismuth eutectic loopMyrrha | Performance of electrochemical oxygen pump in a liquid lead-bismuth eutectic loop
Journal of The Electrochemical Society, Volume 166, Number 6, 02.04.2019, p E153-E158 Control of the dissolved oxygen concentration is crucial for the use of liquid lead bismuth eutectic (LBE) as a coolant of advanced nuclear reactors. An electrochemical oxygen pumping (EOP) system was applied to a non-isothermal liquid LBE loop in order to evaluate its capability to control oxygen in 700 liters of flowing LBE. Oxygen pumps were fabricated using one end closed tube of yttria partially stabilized zirconia (YPSZ) as the solid electrolyte and LSCF (lanthanum strontium cobalt ferrite) as electrode. The oxygen transfer through the oxygen pump was regulated by controlling the applied electric current using a PID controller with feedback from a potentiometric oxygen sensor. The oxygen was added to or removed from the LBE by oxygen pumps depending on target oxygen concentration and a process value given by the oxygen sensor. At low oxygen concentrations, oxygen removal rates were limited by oxygen mass ...
Oxygen Sensitivity of Anammox and Coupled N-Cycle Processes in Oxygen Minimum Zones - pdf descargarOxygen Sensitivity of Anammox and Coupled N-Cycle Processes in Oxygen Minimum Zones - pdf descargar
Oxygen Sensitivity of Anammox and Coupled N-Cycle Processes in Oxygen Minimum Zones. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Critical Assessment of Use of Central Venous Oxygen Saturation as a Mirror of Mixed Venous Oxygen in Severely Ill Cardiac...Critical Assessment of Use of Central Venous Oxygen Saturation as a Mirror of Mixed Venous Oxygen in Severely Ill Cardiac...
Bedside catheterization of the right heart with a percutaneously introduced flowdirected catheter was carried out in 24 critically ill patients; 71 determinations of mixed venous oxygen saturation (MVo2) were obtained. A second catheter was inserted either into a central intrathoracic vein or the right atrium for simultaneous sampling of central venous (CVo2) or right atrial (RAo2) oxygen saturation.. For the group as a whole, mean CVo2 (57.9% ± 15.25) was significantly greater than mean MVo2 (53.3% ± 14.84) (P,0.001), but there was no significant difference and correlation was good between changes in central venous compared to changes in mixed venous oxygen saturation. On the other hand, there was no significant mean difference as well as an excellent correlation between individual values of RAo2 and MVo2 (r=+0.95).. Patients with heart failure or shock showed poor correlation between CVo2 and simultaneously determined MVo2. Furthermore, subjects with shock showed a mean CVo2 (58.0%±13.05) ...
Refubium - Auswirkungen von Hyperoxie und Hypoxie auf juvenile organotypische hippokampale Schnittkulturen der RatteRefubium - Auswirkungen von Hyperoxie und Hypoxie auf juvenile organotypische hippokampale Schnittkulturen der Ratte
The treatment of perinatal oxygen deprivation with high oxygen tensions could cause additional damage to the still immature brain of the neonate. Using the model of juvenile hippocampale organotypical slice cultures we investigated the effects of high oxygen tensions on neuronal function and structure directly after periods of hypoxia or normoxia. Impairment of neuronal function was electrophysiologically analyzed regarding changes in spontaneously and stimulus evoked field potential characteristics. Cell injury was quantified by propidium iodide (PI) fluorescence and by lactate dehydrogenase (LDH) release into the culture medium. In a first experimental study I could demonstrate that hypoxia induced structural cell injury which was substantially larger if high oxygen tensions were used during reoxygenation. In a second experimental study I could show that hypoxia induced changes in field potential characteristics in area CA1 and that the following hyperoxic reoxygenation caused a long lasting ...
Chapter 5 Oxygen Transfer in BioreactorsChapter 5 Oxygen Transfer in Bioreactors
... Oxygen is needed by cells for respiration. Oxygen used by cells in suspension must be available as dissolved oxygen. Since oxygen solubility is quite small, about 6 to 7 mg/L under normal cultivation conditions, metabolic oxygen requirement is supplied on a as needed basis by continuous aeration of culture medium. Actively respiring yeast requires about 0.15 g O2 (g cell)-1 h. At a cell concentration of 10 g L-1, medium saturated with air can support less than 30 seconds worth of metabolic oxygen. That is, a continuous supply of oxygen must be maintained in any viable aerobic manufacturing process. In this Chapter, we will first get a quantitative appreciation for metabolic oxygen demand, followed by methods used in calculating rates at which oxygen is transfered from sparged air. We will then examine methods useful in characterizing oxygen mass transfer coefficient. Finally we will evaluate bioreactor operation and design based on oxygen transfer ...
Finger Heart Rate and Blood Oxygen Saturation Monitor - Hearttrackr.comFinger Heart Rate and Blood Oxygen Saturation Monitor - Hearttrackr.com
Finger Heart Rate and Blood Oxygen Saturation Monitors are designed to provide an accurate way for spot-checking heart rate, blood oxygen saturation levels, and pulse rate. Awesome for people with respiratory conditions, heart conditions and more. Perfect for exercise enthusiasts, athletes, and those who need to monit
Oxygen permeability and stability of Al<sub>2</sub>O<sub>3</sub>-doped SrCo<sub>0.8</sub>Fe<sub>0.2</sub...Oxygen permeability and stability of Al<sub>2</sub>O<sub>3</sub>-doped SrCo<sub>0.8</sub>Fe<sub>0.2</sub...
TY - JOUR. T1 - Oxygen permeability and stability of Al2O3-doped SrCo0.8Fe0.2O3-δ mixed conducting oxides. AU - Wu, Zhentao. AU - Jin, Wanqin. AU - Xu, Nanping. PY - 2006/8/1. Y1 - 2006/8/1. N2 - A new series of Al2O3-doped SrCo0.8Fe0.2O3-δ (SCFA) mixed conducting oxides were synthesized by the conventional solid-state reaction method. Effects of doping Al2O3 (1, 3, 5 and 10 wt.%, respectively) on the crystal structure, order-disorder phase transition, microstructure, oxygen permeability and structure stability of SrCo0.8Fe0.2O3-δ (SCF) were investigated by XRD, TG-DSC, SEM, oxygen permeation measurement and the partial oxidation of methane (POM) to syngas reaction. Although the oxygen permeability of the SCF was weakened in the oxygen permeation measurement at the air/He gradient due to the doping of Al2O3, perovskite structure of SCFA was found stable in the low oxygen partial pressure (about 1.01325 × 102 Pa (10-3 atm)). In the POM reaction, the rate of the oxygen permeation of SCFA3 (the ...
VAPOR-PHASE OXIDATION OF HYDROCARBONS. PART 2. EFFECT OF OXYGEN CONCENTRATION ON PLATINUM-CATALYZED COMBUSTION AND IONIZATION.VAPOR-PHASE OXIDATION OF HYDROCARBONS. PART 2. EFFECT OF OXYGEN CONCENTRATION ON PLATINUM-CATALYZED COMBUSTION AND IONIZATION.
The catalytic combustion of hydrocarbons has been studied further, with particular attention given to the ionization phenomena associated therewith. The greater ion yield of highly branched alkanes relative to straight-chain alkanes was confirmed. The effect of the concentration of O2 in the gas mixture on the extent of oxidation and ionization varied with the hydrocarbon used. In general, increase in O2 content caused considerable enhancement of the ion yield. However, with some hydrocarbons the fraction oxidized decreased markedly with increased O2 concentration. The data seem consistent with an explanation based on lower temperature oxidation occurring only on the Pt surface, whereas at higher temperatures the catalytic process extends itself to some degree into the vapor phase. It is also suggested that dissociative adsorption of O2 at higher temperatures is involved in the ion-producing process. (Author)(*HYDROCARBONS
What Are Safe Blood Oxygen Saturation Levels 2020What Are Safe Blood Oxygen Saturation Levels 2020
Aug 22, 2017 · When your body doesnt receive enough oxygen and you have a low blood oxygen level, hypoxemia or hypoxia, cyanosis and other conditions may occur. Because COPD and other chronic lung diseases restrict or obstruct normal breathing, low blood oxygen levels can be a serious issue.
eclipse.org-planning-council] Oxygen service release dates and Oxygen+1eclipse.org-planning-council] Oxygen service release dates and Oxygen+1
Hi, Here is my proposal for the Oxygen service release dates and the Oxygen+1 release dates. Ive basically taken last/this years dates and adapted them accordingly. Please see below for my questions. Once the planning council approves, I will communicate these dates on the cross-project-issues-dev mailing list. Oxygen Service Releases ======================= Oxygen GA Wednesday, 06/28/2017 Oxygen.1 Checkpoint Wednesday, 07/27 (no EPP packages, no release) Oxygen JDK Update Friday, 08/04 Oxygen.1 RC1 Friday, 08/25 Oxygen.1 RC2 Friday, 09/01 Oxygen.1 RC3 Friday, 09/08 Oxygen.1 RC4 Friday, 09/15 Oxygen.1 Quiet Week Friday, 09/15 - Tuesday, 09/26 Oxygen.1 GA Wednesday, 09/27/2017 Oxygen.2 Checkpoint Wednesday, 10/19 (no EPP packages, no release) Oxygen.2 RC1 Friday, 11/17 Oxygen.2 RC2 Friday, 11/24 Oxygen.2 RC3 Friday, 12/01 Oxygen.2 RC4 Friday, 12/08 Oxygen.2 Quiet Week Friday, 12/08 - Tuesday, 12/19 Oxygen.2 GA Wednesday, 12/20/2017 Oxygen.3 Checkpoint Wednesday, 01/17 (no EPP packages, no ...
Effect of Irradiation Sources and Oxygen Concentration on the Photocatalytic Oxidation of 2-Propanol and Acetone Studied by in...Effect of Irradiation Sources and Oxygen Concentration on the Photocatalytic Oxidation of 2-Propanol and Acetone Studied by in...
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Trial of a Limited Versus Traditional Oxygen Strategy During Resuscitation in Premature Newborns - Full Text View -...Trial of a Limited Versus Traditional Oxygen Strategy During Resuscitation in Premature Newborns - Full Text View -...
Preterm infants are born with immature lungs and often require help with breathing shortly after birth. This traditionally involves administering 100% oxygen. Unfortunately, delivery of high oxygen concentrations leads to the production of free radicals that can injure many organ systems. Term and near-term newborns deprived of oxygen during or prior to birth respond as well or better to resuscitation with room air (21% oxygen) compared to 100% oxygen. However, a static concentration of 21% oxygen may be inappropriate for preterm infants with lung disease.Purpose of the study is to investigate if preterm neonates where resuscitation is initiated with 21% fiO2 and adjusted to meet transitional goal saturations (Limited oxygen strategy or LOX) would have less oxidative stress as measured by the oxidative balance ratio of biological antioxidant potential/total hydroperoxide compared to infants where resuscitation is initiated with pure oxygen and titrated for targeted saturations of 85-94% ...
The effect of pure oxygen or air/oxygen mixture on arterial blood oxygenation in spontaneously ventilated isoflurane...The effect of pure oxygen or air/oxygen mixture on arterial blood oxygenation in spontaneously ventilated isoflurane...
inproceedings{2101216, author = {Schauvliege, Stijn and Savvas, I and Gasthuys, Frank}, booktitle = {AVA spring meeting Davos 2012}, language = {eng}, location = {Davos, Switzerland}, pages = {34--34}, publisher = {Association of Veterinary Anaesthetists (AVA)}, title = {The effect of pure oxygen or air/oxygen mixture on arterial blood oxygenation in spontaneously ventilated isoflurane anaesthetized horses: a retrospective study}, year = {2012 ...
ENERGY METABOLISM OF RATS BORN AND RAISED IN LOW-PRESSURE PURE OXYGEN ENVIRONMENT.ENERGY METABOLISM OF RATS BORN AND RAISED IN LOW-PRESSURE PURE OXYGEN ENVIRONMENT.
Ten rats born and maintained in a pure oxygen environment at a total pressure of 210 mm. Hg absolute were placed individually in metabolism cages at 21 days of age and remained there for 6 weeks. They were compared with a similar group of ground-level controls. In additon, 6 rats maintained at altitude and 6 controls were sacrificed at 21 days of age to provide an initial estimate of whole-body energy. Growth rates did not differ significantly; however, overall digestibility was lowered in experimentals, 74.3% versus 79.5% for controls (P < .001), with even greater differences in protein digestibility, 65.5% versus 74.6% (P < .001). Although less fat was also digested by experimentals, 75.6% versus 81.4%, this difference was not significant. Net caloric intake for both groups was the same, however, as a result of increased food intake by experimentals. Calories given off as heat did not differ, suggesting similar metabolic rates. Carcass content of fat and protein, as a percentage of dry matter,
Medical Gases Training: Oxygen - First aid for freeMedical Gases Training: Oxygen - First aid for free
In a non-emergency situation, assess the patient using a pulse oximeter before administrating oxygen. Find out whether the patient has any relevant medical history, for example, chronic obstructive pulmonary disease (COPD). In COPD even moderate levels of supplementary oxygen may increase the patients carbon dioxide levels and may lead to respiratory depression and respiratory arrest.. The target oxygen saturation level is 94-98%. Give high levels of oxygen for adults with critical illnesses until their vital signs are normal then decrease the oxygen dose to maintain saturation between 94-98% Cardiac arrest - Oxygen can be attached to a Bag-Valve Mask (BVM) or pocket mask. Carbon monoxide poisoning - give high flow oxygen until emergency medical help arrives. ...
Eppendorf® Liquid Handling - Eppendorf® | Sigma-AldrichEppendorf® Liquid Handling - Eppendorf® | Sigma-Aldrich
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Assessment of oxygen supplementation during air travel. | ThoraxAssessment of oxygen supplementation during air travel. | Thorax
BACKGROUND: The aim of this study was to simulate an in flight environment at sea level with a fractional inspired concentration of oxygen (FiO2) of 0.15 to determine how much supplemental oxygen was needed to restore a subjects oxygen saturation (SaO2) to 90% or to the level previously attained when breathing room air (FiO2 of 0.21). METHODS: Three groups were selected with normal, obstructive, and restrictive lung function. Using a sealed body plethysmograph an environment with an FiO2 of 0.15 was created and mass spectrometry was used to monitor the FiO2. Supplemental oxygen was administered to the patient by nasal cannulae. SaO2 was continuously monitored and recorded at an FiO2 of 0.21, 0.15, and 0.15 + supplemental oxygen. RESULTS: When given 2 l/m of supplemental oxygen all patients in the 15% environment returned to a similar SaO2 value as that obtained using the 21% oxygen environment. One patient with airways obstruction needed 3 l/m of supplemental oxygen to raise his SaO2 above 90%. ...
Researchers Develop Oxygen Sensor to Monitor Blood Oxygen Levels in BabiesResearchers Develop Oxygen Sensor to Monitor Blood Oxygen Levels in Babies
Typically, the system used to measure oxygen molecule levels transcutaneously requires a monitor that weighs around 5 lbs to be plugged into an electrical outlet with all sensors wired to its interface. However, the device Guler and her team have created will utilize wireless power and data transfer. It also will make innovative use of IoT technology as it can connect to the internet wirelessly; thus, if there is a sudden decline in a babys oxygen levels an alarm directly connected to a doctors office or smartphone app would notify the relevant healthcare practitioner as well as the infants family members.. Whats more, is that the device is compact and discreet, around the size of a band-aid, with the capability to measure the partial pressure of oxygen (PO2). This feature gives a more precise index of respiratory health when compared with only oxygen saturation measurements. Guler and her team at WPI claim that their system, that measures PO2 levels via non-invasive means, is as conclusive ...
18th week of 2009 patent applcation highlights part 5218th week of 2009 patent applcation highlights part 52
METHOD FOR MEASURING BLOOD OXYGEN CONTENT UNDER LOW PERFUSION - A method for measuring blood oxygen content under low perfusion, which is used in a device for measuring blood oxygen content, includes the steps of: initializing the device that is applied with power, collecting and processing data with a driving circuit of light emitting device, a bias circuit, a gain circuit and an A/D sampling circuit, which are controlled under a cone control module; calculating blood oxygen saturation based on the collected data with a data processing module which integrates the collected data in a period of time with an area integration method; and outputting from a communication functional module results of the blood oxygen saturation or pulse rate calculated with the data processing module. The method further includes a decision step of deciding the two results acquired from the data processing module with the waveform method and the integration method respectively based on the intensity of the measured ...
Global Blood Oxygen Sensor Market Competition by Company, Countries, Application, Type 2017 | HealthcareGlobal Blood Oxygen Sensor Market Competition by Company, Countries, Application, Type 2017 | Healthcare
Headline: Bitcoin & Blockchain Searches Exceed Trump! Blockchain Stocks Are Next!. Global Blood Oxygen Sensor market report addresses the detail source of information which offers a telescopic view of the current and future market status. Various key factors are discussed in the report, which will help the buyer in studying the Global Blood Oxygen Sensor market sales trends and opportunities.. The Global Blood Oxygen Sensor market report also analyses company profiles and the growth strategies of the major Global Blood Oxygen Sensor market leaders. A detailed study of product specifications, revenue, cost, price, gross capacity, production capacity, company profiles and contact information is carried out in the analysis of Global Blood Oxygen Sensor industry key manufacturers section.. View details of this meticulous Global Blood Oxygen Sensor market research Study @ http://www.360marketupdates.com/10417759. This Research study emphasis on Types:-. ...
US Patent for Oxygen blending in a piston ventilator Patent (Patent # 6,412,483 issued July 2, 2002) - Justia Patents SearchUS Patent for Oxygen blending in a piston ventilator Patent (Patent # 6,412,483 issued July 2, 2002) - Justia Patents Search
A piston ventilator is disclosed herein which uniquely includes an oxygen blending module which supplies oxygen enhancement for aiding patients requiring respiratory treatment. The oxygen blending module supplies a preselected enrichment of oxygen to a piston and cylinder assembly wherein the amount of oxygen permitted to flow therein is continuously monitored and controlled according to the volume above the piston in the cylinder as calculated by a controller. The oxygen blending module includes a flow sensor which monitors the flow of supplemental oxygen into the piston and cylinder assembly, and further includes a primary oxygen control valve which restricts the flow of oxygen through the flow sensor to the piston and cylinder assembly depending on the difference between the calculated desired amount of oxygen and the target amount of oxygen provided to the controller.
Oxygen therapy - infants - Coordinated HealthOxygen therapy - infants - Coordinated Health
Oxygen is a gas that the cells in your body need to work properly. The air we breathe normally contains 21% oxygen. We can receive up to 100% oxygen.. WHY IS OXYGEN USED?. Babies with heart or lung problems may need to breathe increased amounts of oxygen to get normal levels of oxygen in their blood.. HOW IS OXYGEN DELIVERED?. There are several different ways to deliver oxygen to a baby. Which method is used depends on how much oxygen is needed and whether the baby needs a breathing machine.. An oxygen hood is used for babies who can breathe on their own but still need extra oxygen. A hood is a plastic dome or box with warm, moist oxygen inside. The hood is placed over the babys head.. A thin, soft, plastic tube called a nasal cannula may be used instead. This tube has soft prongs that gently fit into the babys nose. Oxygen flows through the tube. The baby must be able to breathe without assistance to use this type of oxygen therapy.. Another method is a nasal CPAP system. CPAP stands for ...
The preoperative treatment of severely anemic patients with a perfluor by K. Tremper, Alan Friedman et al."The preoperative treatment of severely anemic patients with a perfluor" by K. Tremper, Alan Friedman et al.
We gave a perfluorochemical oxygen-transport fluid and plasma expander, Fluosol-DA, to seven severely anemic patients before surgery to determine its effectiveness in supplementing oxygen transport. The dose of Fluosol in the five patients completing the study was 20 ml per kilogram of body weight. When the patients breathed low levels of supplemental oxygen (mean partial pressure of arterial oxygen +/- S.D., 101 +/- 25 torr), the perfluorochemical carried a small amount of oxygen, but when they received pure oxygen (arterial oxygen pressure, 361 +/- 65 torr) it carried approximately 0.8 per cent of oxygen (by volume). This increase accounted for 7 +/- 3 per cent of the patients arterial oxygen content and 24 +/- 7 per cent of their oxygen consumption. The cardiac index and left ventricular stroke-work index decreased, whereas the oxygen delivery increased, although these changes were not statistically significant. Significant changes included a 22 per cent increase in oxygen consumption, a 59 per cent
The Dynamics and Impact of Ocean Acidification and Hypoxia: - News - Ocean OxygenThe Dynamics and Impact of Ocean Acidification and Hypoxia: - News - Ocean Oxygen
Insights from Sustained Investigations in the Northern California Current Large Marine Ecosystem Abstract. Coastal upwelling ecosystems around the world are defined by wind-generated.... Oxygen is fundamental for life in the ocean. Low oxygen environments occur naturally in some habitats, including oxygen minimum zones, deep basins of semi-enclosed seas or coastal lagoons and coastal upwelling regions. They are often associated with highly productive surface waters, where input of nutrients via upwelling, riverine or atmospheric supply fuels production of organic matter, part of which is subsequently respired and thereby consumes oxygen. The spatial extent and the severity of low oxygen conditions have increased during the past decades, and there are serious concerns that global warming, together with agricultural run-off and human waste and input of anthropogenic aerosols enhances the deoxgenation of the ocean, which will have extensive impacts on the oceans chemistry and ecosystems and eventually
High oxygen levels in blood - Answers on HealthTapHigh oxygen levels in blood - Answers on HealthTap
Doctors give trusted answers on uses, effects, side-effects, and cautions: Dr. Sneid on high oxygen levels in blood: Well you would anticipate 95 to 100% oxygen saturation for a young healthy adult. The lower the oxygen saturation the more concern.
News - Ocean OxygenNews - Ocean Oxygen
Oxygen is fundamental for life in the ocean. Low oxygen environments occur naturally in some habitats, including oxygen minimum zones, deep basins of semi-enclosed seas or coastal lagoons and coastal upwelling regions. They are often associated with highly productive surface waters, where input of nutrients via upwelling, riverine or atmospheric supply fuels production of organic matter, part of which is subsequently respired and thereby consumes oxygen. The spatial extent and the severity of low oxygen conditions have increased during the past decades, and there are serious concerns that global warming, together with agricultural run-off and human waste and input of anthropogenic aerosols enhances the deoxgenation of the ocean, which will have extensive impacts on the oceans chemistry and ecosystems and eventually also affect human wellbeing.
Retinal oxygen extraction in humans | IOVS | ARVO JournalsRetinal oxygen extraction in humans | IOVS | ARVO Journals
Purpose: Optimal function of the retina is dependent on adequate oxygen supply. In humans, the inner retina including the retinal ganglion cells is oxygenated via the retinal circulation. We present a method to calculate total retinal oxygen extraction based on non-invasive techniques in humans.. Methods: In a total of 8 healthy subjects, absolute retinal blood flow values and optical density ratio for each retinal vessel entering the optic nerve head were assessed using dual-beam bidirectional Doppler Optical Coherence Tomography (OCT) and spectrophotometric measurements, respectively. These experiments were done during breathing of ambient room air as well as during breathing of 100% oxygen. Based on these measurements, retinal oxygen extraction was calculated.. Results: Total retinal blood flow was 44.3 ± 3.0 ml/min during baseline and decreased to 18.7 ± 4.2 µl/min during 100% oxygen breathing (P , 0.001). Corrected arterio-venous oxygen difference was 0.053 ± 0.008 [ml(O2)/ml] at ...
Oxygen Toxicity - Signs and Symptoms | Dive RiteOxygen Toxicity - Signs and Symptoms | Dive Rite
The time to onset of symptoms is highly variable but most individuals can tolerate 12-16 hours of oxygen at 1.0 ATA, 8-14 hours at 1.5 ATA, and 3-6 hours at 2.0 ATA before developing mild symptoms. There are several ways to track developing pulmonary oxygen toxicity but the most sensitive and accurate is the development of symptoms. A second technique is to monitor the vital capacity. Vital capacity (the amount of air that can be moved in one large breath) decreases with increasing pulmonary toxicity. A reduction of approximately 2% in vital capacity correlates with mild symptoms while a reduction of 10% correlates symptoms so severe that most individuals will not voluntarily continue breathing oxygen. These mild effects are completely reversible and no permanent lung damage occurs. However, the damage will take 2 to 4 weeks to heal. The pathology of pulmonary oxygen toxicity is understood but beyond the scope of this discussion.. A third way to keep track, in rough terms, of pulmonary oxygen ...
Diving with Anemia | SCUBADOC - Diving Medicine OnlineDiving with Anemia | SCUBADOC - Diving Medicine Online
All physicians know that hemoglobin carries oxygen and that anemia can lead to severe hypoxemia. However, the partial pressure of oxygen and the concentration (content) of O2 requires knowledge of the oxygen content equation in order to be understood.. CaO2 = (SaO2 x Hb x 1.34) + .003(PaO2). Oxygen is a gas and its molecules do exert a pressure but, like any other substance, oxygen also has a finite content in the blood, in units of ml O2/dl blood. Tissues have to have a certain amount of oxygen per minute in order to live, a need met by oxygen content, not oxygen pressure. (Patients can and do live with very low PaO2 values, as long as their oxygen content and cardiac output are adequate.). The oxygen carrying capacity of one gram of hemoglobin is 1.34 ml.. Given normal pulmonary gas exchange (i.e., a normal respiratory system), factors that lower oxygen content - such as anemia, carbon monoxide poisoning, methemoglobinemia, shifts of the oxygen dissociation curve - do not affect PaO2. PaO2 is ...
Blood Oxygen Level-Dependent MRI of Tissue Oxygenation | Arteriosclerosis, Thrombosis, and Vascular BiologyBlood Oxygen Level-Dependent MRI of Tissue Oxygenation | Arteriosclerosis, Thrombosis, and Vascular Biology
To our knowledge, our study is the first to systematically correlate BOLD SI changes to endothelial-mediated blood flow changes in the human forearm. With increasing blood flow, we observed an increase in BOLD SI, with saturation at high blood flow levels. However, after intermittent ischemia, BOLD SI remained elevated even after normalization of blood flow. Because O2 consumption is constant for Po2 levels of ≥1 mm Hg and thus does not account for the observed dissociation, the decay time constant for the BOLD MRI signal may indicate the presence of microvascular oxygen reserve.. Our reactive hyperemia results are consistent with the magnitude and dynamics of BOLD SI-related changes reported previously.10,11 Very recent data by Towse et al also provided evidence for a dissociation of flow and BOLD SI.18 Persisting high values of BOLD SI after blood flow normalization are met by postischemic and even posthyperemic elevations of oxygen saturation of venous blood and tissue oxygen tension.19-21 ...
Plus itPlus it
To understand the role of nitric oxide (NO) in the regulation of energy metabolism of tumor cells, its effect on the respiration and calcium homeostasis was examined with ascites hepatoma (AH130) cells under different oxygen tensions. NO reversibly inhibited the respiration and depolarized the membrane potential of AH130 cells in an oxygen-dependent manner; the inhibition was more marked at physiologically low oxygen concentrations than at its high tensions. NO reversibly decreased the cellular ATP levels and elevated the cytosolic calcium, particularly under low oxygen concentrations. Since the peritoneal cavity is fairly anaerobic, the results suggested that small amounts of NO generated in this compartment might strongly affect the energy metabolism and calcium homeostasis of tumor cells in vivo.. ...
cellular respiration - If oxygen deficiency is bad even for a short while, why do people swim? - Biology Stack Exchangecellular respiration - If oxygen deficiency is bad even for a short while, why do people swim? - Biology Stack Exchange
At high initial saturation only mean 0.16% saturation drop occurs per second, thus in average a healthy individual looses 1% oxygen saturation approx every 5 seconds (Id also like to note that the urge to breathe does not come from the lack of oxygen when holding breath, but from the accumulation of CO2). According to wikipedia normal oxygen saturation is between 100-95%, and only below 90% is considered hypoxemia /hypoxia (a medical condition where blood oxygen level is low). So if we look at the data in the table, it is safe to say that it takes approx 20s until the blood saturation level drops from 97% to 93% and another 5-6 seconds until it drops to 90% (with approx 0.5% saturation loss per sec at 93% initial saturation).. People who are conditioned by exercise have larger vital-capacity (they can breathe more air in for a single breath), thus have means to acquire more oxygen can compensate for the excess use of oxygen. During heavy sport activity like swimming it is unlikely that anybody ...
Total Retinal Blood Flow and Retinal Oxygen Saturation in the Major Retinal Vessels of Healthy ParticipantsTotal Retinal Blood Flow and Retinal Oxygen Saturation in the Major Retinal Vessels of Healthy Participants
Introduction: Oxygen delivery, or utilization, is a function of retinal blood flow and blood oxygen saturation. The retinal pigment epithelium (RPE), in particular, has been shown to have the highest levels of metabolic activity within the human body. Oxygen delivery is therefore of extreme importance to the maintenance of the health and integrity of the retina. Animal models presuppose that the oxygen tension in the retina is highest in the innermost layers at the level of the choriocapillaris, less in the photoreceptors and further decreases throughout the outer retinal structures. The choroid provides by far the largest component of the oxygen for consumption by the photoreceptors. A lack of oxygen stores in the inner retina therefore makes a constant supply crucial for its normal functioning. Blood flow dysfunction and subsequent hypoxia are both a feature in the pathogenesis of several major ocular diseases such as retinopathy of prematurity (ROP), age-related macular degeneration (ARMD), ...
Detection of single oxygen molecules with fluorescence-labeled hemocyanins. - Semantic ScholarDetection of single oxygen molecules with fluorescence-labeled hemocyanins. - Semantic Scholar
This study introduces a method to detect individual oxygen molecules by fluorescence microscopy of single hemocyanins. These respiratory proteins from a tarantula bind oxygen with high affinity. A spectrometric signature of the oxygenated protein is transferred to an attached fluorescence label, which can be detected at the single-molecule level. This technique opens new perspectives for the development of small and sensitive oxygen sensors as well as for the investigation of cooperative oxygen binding in respiratory proteins.
Frontiers | ROS Production and Scavenging under Anoxia and Re-Oxygenation in Arabidopsis Cells: A Balance between Redox...Frontiers | ROS Production and Scavenging under Anoxia and Re-Oxygenation in Arabidopsis Cells: A Balance between Redox...
Plants can frequently experience low oxygen concentrations due to environmental factors such as flooding or waterlogging. It has been reported that both anoxia and the transition from anoxia to re-oxygenation determine a strong imbalance in the cellular redox state involving the production of reactive oxygen species (ROS) and nitric oxide (NO). Plant cell cultures can be a suitable system to study the response to oxygen deprivation stress since a close control of physicochemical parameters is available when using bioreactors. For this purpose, Arabidopsis cell suspension cultures grown in a stirred bioreactor were subjected to a severe anoxic stress and analyzed during anoxia and re-oxygenation for alteration in ROS and NO as well as in antioxidant enzymes and metabolites. The results obtained by confocal microscopy showed the dramatic increase of ROS, H2O2 and NO during the anoxic shock. All the ascorbate-glutathione related parameters were altered during anoxia but restored during re-oxygenation.
Search - SAE InternationalSearch - SAE International
A very competitive alcohol for use in diesel engines is butanol. Butanol is of particular interest as a renewable bio-fuel, as it is less hydrophilic and it possesses higher heating value, higher cetane number, lower vapor pressure, and higher miscibility than ethanol or methanol. These properties make butanol preferable to ethanol or methanol for blending with conventional diesel or gasoline fuel. In this paper, the spray and combustion characteristics of pure n-butanol fuel was experimentally investigated in a constant volume combustion chamber. The ambient temperatures were set to 1000 K, and three different oxygen concentrations were set to 21%, 16%, and 10.5%. The results indicate that the penetration length reduces with the increase of ambient oxygen concentration. The combustion pressure and heat release rate demonstrate the auto-ignition delay becomes longer with decreasing of oxygen concentrations ...
Oxygen, sulfide and diffusion: Why thiobiotic meiofauna must be s...: Ingenta ConnectOxygen, sulfide and diffusion: Why thiobiotic meiofauna must be s...: Ingenta Connect
Thiobios (sulfide-dependent) meiofauna have an aerobic metabolism, are sulfide-insensitive and rarely contain symbiotic sulfur-oxidizing bacteria. Adaptations so far observed in thiobios are consistent with the overriding need to maximize the diffusive flux of oxygen and sulfide to optimize energy yield. Both accrue from the requirement that oxygen and sulfide uptake and metabolism be controlled by diffusion and first-order rate reactions. These adaptations include variation in shape, mitochondrial distribution and respiratory capacity. Meiofauna can substantially supplement a more inefficient anaerobic metabolism with aerobic metabolism at oxygen concentrations as low as 0.1 M. Hence, an aerobic capacity is useful even in thiobios. Adaptation to low oxygen, by decreasing metabolic rate, is counterproductive unless oxygen consumption remains zero-order. Otherwise, aerobic metabolic capacity must be increased to maximize oxygen flux. Sulfide-insensitivity is necessary because a sulfide ...
Liquid Phase Oxygen Transfer Coefficient (KL)Liquid Phase Oxygen Transfer Coefficient (KL)
However, in the case of HRTFB, the relation was linear for surface renewal over a wide range of values. Shake flasks and un-baffled stirred vessels with surface aeration were not suitable for such a study, since the surface area in either system was difficult to define and varied as the shaker or stirrer/agitator speed was changed. In addition, the surface-to-volume ratio was unfavorable for obtaining high oxygen transfer rates.. Wetted-wall columns have been used for gas-liquid transfer studies. However, the rate of flow down or up the wetted wall is limited by gravitational force, and the requirement for recirculation of the fermentation liquid dictated an aseptic pumping operation.. Heaviside Theory (HST) based Concept: In oxic bioprocess engineering system in liquid culture transfer of oxygen from air to liquid has been measured by fast response steam sterilizable dissolved oxygen probe on line. In the measurement, the concept of flow of oxygen from higher concentration (heaviside) to lower ...
Cell behavior in low oxygen conditions mapped | EurekAlert! Science NewsCell behavior in low oxygen conditions mapped | EurekAlert! Science News
Research at the University of Liverpool has explained how cells behave when placed in a low oxygen environment, a development that could have implications for cancer patients and other serious illnesses.
The Future OceanThe Future Ocean
Steinle, L., Maltby, J., Treude, T., Kock, A., Bange, H. W., Engbersen, N., Zopfi, J., Lehmann, M. F. and Niemann, H. (2017) Effects of low oxygen concentrations on aerobic methane oxidation in seasonally hypoxic coastal waters Biogeosciences (BG), 14 (6). pp. 1631-1645. DOI 10.5194/bg-14-1631-2017.. Arevalo-Martinez, D. L., Kock, A., Steinhoff, T., Brandt, P., Dengler, M., Fischer, T., Körtzinger, A. and Bange, H. W. (2017) Nitrous oxide during the onset of the Atlantic Cold Tongue Journal of Geophysical Research - Oceans, 122 (1). pp. 171-184. DOI 10.1002/2016JC012238.. Vehmaa, A., Almen, A. K., Brutemark, A., Paul, A. J., Riebesell, U., Furuhagen, S. and Engström-Öst, J. (2016) Ocean acidification challenges copepod phenotypic plasticity Biogeosciences (BG), 13 (22). pp. 6171-6182. DOI 10.5194/bg-13-6171-2016.. Geersen, J., Scholz, F., Linke, P., Schmidt, M., Lange, D., Behrmann, J. H., Völker, D. and Hensen, C. (2016) Fault zone controlled seafloor methane seepage in the rupture area of ...
Why do insects stop breathing ?Why do insects stop breathing ?
Bradley explained that insects typically maintain 4-5 kilopascals of oxygen in their respiratory systems, 4-5 times lower than the normal oxygen concentration in the atmosphere. In a normal oxygen-concentration environment, the insect breathes for a period of time and releases a burst of carbon dioxide. It then closes its respiratory system, blocking off more intake of oxygen, to maintain the internal oxygen concentration at 4-5 kilopascals, the right oxygen concentration for its body. In a low-oxygen environment, the insect opens its respiratory system for longer periods of time; when it closes the system, it does so for only a very short time. In a stream of air with high oxygen on the other hand, the respiratory system opens briefly and then closes firmly for a long time. "In other words, insects are actively keeping oxygen out and doing it in a way that shows they know how to measure oxygen," Bradley said. "Their behavior indicates they are regulating oxygen ...
Oxygen - New World EncyclopediaOxygen - New World Encyclopedia
Oxygen is classified as a nonmetal. In the periodic table, it is located at the top of group 16 (formerly group 6A), which is a family of elements called the chalcogens or the oxygen family. In addition, it lies between nitrogen and fluorine in period 2.. At ordinary temperatures and pressures, free oxygen (unbound to any other element) is a colorless, odorless, tasteless gas that makes up about 21% (by volume) of air. Ordinarily, each molecule of oxygen gas consists of two oxygen atoms bound to each other, so the molecular formula is written as O2.. This molecular oxygen (O2) is essential for the human bodys metabolic processes, which sustain our lives. The human body cannot store oxygen for later use as it does with food. If the body is deprived of oxygen for more than a few minutes, unconsciousness results. The bodys tissues and organs (notably the heart and brain) are damaged if deprived of oxygen for much longer than four minutes.. Gaseous oxygen becomes a liquid at temperatures below ...
Dependence of Transcutaneous Oxygen Tension on Local Arteriovenous Pressure Gradient in Normal Subjects | Clinical Science |...Dependence of Transcutaneous Oxygen Tension on Local Arteriovenous Pressure Gradient in Normal Subjects | Clinical Science |...
1. We studied the relationship between trans-cutaneous oxygen tension at the foot and local arteriovenous pressure difference in 15 normal men and women; arteriovenous pressure difference was varied by changing the height of the foot with respect to the heart and by applying external pressure to the foot.. 2. Control transcutaneous oxygen tension was 67 ± 9 sd mmHg (8.9 ± 1.2 kPa) at a control arteriovenous pressure difference of 80 ± 6 sd mmHg (10.6 ± 0.8 kPa).. 3. In every subject transcutaneous oxygen tension fell non-linearly with a decrease in arteriovenous pressure difference; transcutaneous oxygen tension was relatively insensitive to changes in arteriovenous pressure difference when arteriovenous pressure difference was high, but always fell sharply to zero at some positive arteriovenous pressure difference [range 13-34 mmHg (1.7-4.5 kPa)].. 4. An analysis of the data indicated that transcutaneous oxygen tension varied with arteriovenous pressure difference approximately as the ...
Accuracy of continuous central venous oxygen saturation monitoring in patients undergoing cardiac surgery - Zurich Open...Accuracy of continuous central venous oxygen saturation monitoring in patients undergoing cardiac surgery - Zurich Open...
OBJECTIVE: Continuous assessment of central venous oxygen saturation (S(cevox)O(2)) with the CeVOX device (Pulsion Medical Systems, Munich, Germany) was evaluated against central venous oxygen saturation (S(cv)O(2)) determined by co-oximetry. METHODS: In 20 cardiac surgical patients, a CeVOX fiberoptic probe was introduced into a standard central venous catheter placed in the right internal jugular vein and advanced 2-3 cm beyond the catheter tip. After in vivo calibration of the probe, S(cevox)O(2), S(cv)O(2), mixed venous oxygen saturation (S(mv)O(2)) haemoglobin (Hb), body temperature, heart rate, central venous and mean arterial pressure, and cardiac index were assessed simultaneously at 30 min intervals during surgery and at 60 min intervals during recovery in the intensive care unit. Agreement between S(cevox)O(2), and S(cv)O(2) was determined by Bland-Altman analysis. Simple regression analysis was used to assess the correlation of S(cevox)O(2), and S(cv)O(2) to Hb, body temperature and ...
Impact of oxygen concentration on time to resolution of spontaneous pneumothorax in term infants: a population based cohort...Impact of oxygen concentration on time to resolution of spontaneous pneumothorax in term infants: a population based cohort...
Little evidence exists regarding the optimal concentration of oxygen to use in the treatment of term neonates with spontaneous pneumothorax (SP). The practice of using high oxygen concentrations to promote
Arteriovenous oxygen difference - WikipediaArteriovenous oxygen difference - Wikipedia
The arteriovenous oxygen difference, or a-vO2 diff, is the difference in the oxygen content of the blood between the arterial blood and the venous blood. It is an indication of how much oxygen is removed from the blood in capillaries as the blood circulates in the body. The a-vO2 diff and cardiac output are the main factors that allow variation in the bodys total oxygen consumption, and are important in measuring VO2. The a-vO2 diff is usually measured in millilitres of oxygen per 100 millilitres of blood (mL/100 mL). The arteriovenous oxygen difference is usually taken by comparing the difference in the oxygen concentration of oxygenated blood in the femoral, brachial, or radial artery and the oxygen concentration in the deoxygenated blood from the mixed supply found in the pulmonary artery (as an indicator of the typical mixed venous supply). Put in simple terms: a-vO2 diff = Ca - Cv where: Ca = the oxygen concentration of arterial blood (oxygenated blood) Cv = the oxygen concentration of ...
Blood oxygen level-dependent signal responses in corticolimbic emotions circuitry of lactating rats facing intruder threat to...Blood oxygen level-dependent signal responses in corticolimbic 'emotions' circuitry of lactating rats facing intruder threat to...
Lactating rats must continuously maintain a critical balance between caring for pups and aggressively responding to nest threats. We tested the neural response of lactating females to the presentation of their own pups and novel intruder males using blood oxygen level-dependent functional magnetic resonance imaging at 7 T. Dams were presented with a single sequence of a control stimulus, pups or a male intruder in one imaging session (n = 7-9). To further determine the selectivity of neural processing, dams were imaged for their response to a male intruder in both the absence and presence of their pups (n = 6). Several maternal cortical and limbic brain regions were significantly activated by intruder presentation but not by pups or a control stimulus. These included the nucleus accumbens, periaqueductal gray, anterior cingulate, anterior thalamus, basal nucleus of the amygdala, temporal cortex, prelimbic/orbital area and insula. The nucleus accumbens, periaqueductal gray, temporal cortex and
Influence of light irradiation on blood oxygen saturation level in vitro and in vivo during photodynamic therapy | (1998) |...Influence of light irradiation on blood oxygen saturation level in vitro and in vivo during photodynamic therapy | (1998) |...
Photodynamic therapy (PDT) is an effective method to treat cancer and other nononcological lesions by means of light action on photosensitizer in tissue. It is assumed that the destroying effect is mainly due to the formation of singlet oxygen resulting from the interaction of light excited photosensitizer with molecular oxygen (triplet ground state). So the destroying effect will be proportional to the rate of singlet oxygen formation which in turn depends on light intensity, photosensitizer concentration and molecular oxygen concentration. The present work deals with the investigation of blood oxygen saturation in vitro and in vivo during light irradiation in the PDT process. It has been observed that SO2 behavior strongly correlates with the light power density applied for PDT and photosensitizer concentration ...
Reversible effects of oxygen partial pressure on genes associated with placental angiogenesis and differentiation in primary...Reversible effects of oxygen partial pressure on genes associated with placental angiogenesis and differentiation in primary...
Timely regulated changes in oxygen partial pressure are important for placental formation. Disturbances could be responsible for pregnancy-related diseases like preeclampsia and intrauterine growth restriction. We aimed to (i) determine the effect of oxygen partial pressure on cytotrophoblast differentiation; (ii) measure mRNA expression and protein secretion from genes associated with placental angiogenesis; and (iii) determine the reversibility of these effects at different oxygen partial pressures. Term cytotrophoblasts were incubated at 21% and 2.5% O2 for 96 hr, or were switched between the two oxygen concentrations after 48 hr. Real-time PCR and enzyme-linked immunosorbent assays (ELISAs) were used to evaluate cell fusion and differentiation, measuring transcript levels for those genes involved in cell fusion and placental angiogenesis, including VEGF, PlGF, VEGFR1, sVEGFR1, sENG, INHA, and GCM1. Cytotrophoblasts underwent fusion and differentiation in 2.5% O2 . PlGF expression was ...
Comparison of minimally and more invasive methods of determining mixed venous oxygenationComparison of minimally and more invasive methods of determining mixed venous oxygenation
ENGLISH ABSTRACT: Circulatory efficiency is the relationship between oxygen consumption and global oxygen delivery. Manipulation of circulatory efficiency has been shown to be beneficial in critically ill surgical and medical adults, and in children. Circulatory efficiency is best assessed by measuring an index of mixed venous oxygenation (content, saturation and partial pressure) and viewing this in the context of oxygen consumption. Mixed venous oxygenation has until now required intermittent sampling via a pulmonary artery catheter, or by using a pulmonary artery catheter equipped with a fibre optic bundle for continuous mixed venous oxygen saturation monitoring. However, the use of the pulmonary artery catheter is declining as it has been (correctly or incorrectly) indicted of being an "invasive" tool. Attempts have been made to estimate mixed venous oxygenation non-invasively using the "NICO" monitor[6], near infrared spectroscopy[7], skeletal muscle oxygen saturation[8], thenar muscle ...
Oxygen therapyOxygen therapy
Not everyone with breathlessness will benefit from oxygen therapy. Oxygen therapy will only help you if you have low levels of oxygen in your blood.. If your doctor thinks that you will benefit from oxygen therapy, he or she will send you for an oxygen assessment. After your assessment, if the specialist thinks that you will benefit from oxygen therapy, you will be prescribed oxygen for use at home.. To get the benefits of oxygen therapy, you will need to use your oxygen for at least 15 hours a day. This is known as long-term oxygen therapy (LTOT). LTOT is normally provided at home using an oxygen concentrator, a machine which takes air from the room and separates the oxygen from the other gases in the air, so that you can breathe in pure oxygen. Oxygen is breathed through a nasal cannula (a small plastic tube that fits inside your nostrils) or a face mask, whichever suits you best.. If you want to use oxygen away from home, you can use portable cylinders of oxygen with a nasal cannula or mask. ...
Acute volume expansion with colloid increases oxygen delivery and consumption but does not improve the oxygen extraction in...Acute volume expansion with colloid increases oxygen delivery and consumption but does not improve the oxygen extraction in...
TY - JOUR. T1 - Acute volume expansion with colloid increases oxygen delivery and consumption but does not improve the oxygen extraction in severe preeclampsia. AU - Belfort, Michael A.. AU - Saade, George R.. AU - Wasserstrum, Nathan. AU - Johansen, Richard. AU - Anthony, John. PY - 1995/1/1. Y1 - 1995/1/1. N2 - The objective of this study was to determine the effect of volume expansion with colloid on oxygen consumption (VO2), oxygen delivery (DO2) and the oxygen extraction ratio in patients with severe preeclampsia. The study was prospective and descriptive and took place in the tertiary care labor and delivery unit in a university hospital. Fourteen women with severe preeclampsia who received a pulmonary artery catheter and radial arterial line to monitor their hemodynamic and respiratory status took part in the study. Patients who had received prior medication or volume expansion were excluded. The intervention employed was acute volume expansion, using colloidal solutions (Dextran 70 or ...
Oxygen sensitivity of mitochondrial function in rat arterial chemoreceptor cells. - CLAHRCOxygen sensitivity of mitochondrial function in rat arterial chemoreceptor cells. - CLAHRC
The mechanism of oxygen sensing in arterial chemoreceptors is unknown but has often been linked to mitochondrial function. A common criticism of this hypothesis is that mitochondrial function is insensitive to physiological levels of hypoxia. Here we investigate the effects of hypoxia (down to 0.5% O2) on mitochondrial function in neonatal rat type-1 cells. The oxygen sensitivity of mitochondrial [NADH] was assessed by monitoring autofluorescence and increased in hypoxia with a P50 of 15 mm Hg (1 mm Hg = 133.3 Pa) in normal Tyrode or 46 mm Hg in Ca(2+)-free Tyrode. Hypoxia also depolarised mitochondrial membrane potential (m, measured using rhodamine 123) with a P50 of 3.1, 3.3 and 2.8 mm Hg in normal Tyrode, Ca(2+)-free Tyrode and Tyrode containing the Ca(2+) channel antagonist Ni(2+), respectively. In the presence of oligomycin and low carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP; 75 nm) m is maintained by electron transport working against an artificial proton leak. Under these
tebu-bio Supplying Discovery Tools - January 2015tebu-bio Supplying Discovery Tools - January 2015
Oxygen concentration in tissues is a key factor for cell and organ survival. In normal conditions, partial oxygen pressure (pO2) results in the balance between oxygen delivery and its consumption. Oxygen is transported, in mammals, by circulating red blood cells. Partial oxygen pressure in tissues varies widely, depending on their respective metabolic requirements and their functional status. In normal physiological conditions, partial oxygen pressure is called physioxia. Any alteration of tissue environment leading to a decrease in partial oxygen pressure is called hypoxia ...
The precision and accuracy of Nellcor and Masimo oximeters at low oxygen saturations (70%) in newborn lambs | ADC Fetal &...The precision and accuracy of Nellcor and Masimo oximeters at low oxygen saturations (70%) in newborn lambs | ADC Fetal &...
Background Administration of oxygen in the delivery room is informed by oxygen saturation (SpO2). An oxygen saturation range of 60%-70% is the threshold for administering oxygen in the first minutes after birth. The accuracy of newer generation oximeters to measure SpO2 has not been compared against the gold standard, direct arterial blood oxygen saturation (SaO2) when SaO2 is low. The aim of this study was to determine the accuracy and precision of Nellcor and Masimo oximeters to measure SpO2 when SaO2 ,70%.. ...
Routine low-dose continuous or nocturnal oxygen for people with acute stroke: three-arm Stroke Oxygen Supplementation RCT. -...Routine low-dose continuous or nocturnal oxygen for people with acute stroke: three-arm Stroke Oxygen Supplementation RCT. -...
BACKGROUND: Stroke is a major cause of death and disability worldwide. Hypoxia is common after stroke and is associated with worse outcomes. Oxygen supplementation could prevent hypoxia and secondary brain damage. OBJECTIVES: (1) To assess whether or not routine low-dose oxygen supplementation in patients with acute stroke improves outcome compared with no oxygen; and (2) to assess whether or not oxygen given at night only, when oxygen saturation is most likely to be low, is more effective than continuous supplementation. DESIGN: Multicentre, prospective, randomised, open, blinded-end point trial. SETTING: Secondary care hospitals with acute stroke wards. PARTICIPANTS: Adult stroke patients within 24 hours of hospital admission and 48 hours of stroke onset, without definite indications for or contraindications to oxygen or a life-threatening condition other than stroke. INTERVENTIONS: Allocated by web-based minimised randomisation to: (1) continuous oxygen: oxygen via nasal cannula continuously (day and
Oxygen transfer during exercise-induced hypocapnia<...Oxygen transfer during exercise-induced hypocapnia<...
TY - JOUR. T1 - Oxygen transfer during exercise-induced hypocapnia. AU - Robertshaw, D.. AU - Rawson, R.. AU - Entin, P.. AU - Cole, F.. AU - Wilson, D.. PY - 1997/12/1. Y1 - 1997/12/1. N2 - A panting animal, the sheep, develops hyperthermia (40-41°C) , hypocapnia (10-20 Torr), and lactacidosis (3-5 mM) during exercise at 50% of maximum oxygen consumption. Experiments were performed to determine if the lactacidosis was caused by impaired oxygen transfer caused by a hypocapnic increase in oxygen affinity of hemoglobin. A flow probe (Transonic Systems, Inc., Ithaca, NY) was placed on the external iliac artery and blood samples were taken from the carotid artery and iliac vein. Net oxygen and lactate flux were calculated for one hindlimb during exercise. Oxygen delivery to the limb increased due to a rise in both hemoglobin concentration (7 to 11 g/dl) and blood flow (0.5 to 2.5 1/min). Oxygen extraction remained constant during exercise and the arteriovenous difference in lactate was zero. It was ...
A Comparison of Respiratory Patterns in Healthy Term Infants Placed in Car Safety Seats and Beds | American Academy of...A Comparison of Respiratory Patterns in Healthy Term Infants Placed in Car Safety Seats and Beds | American Academy of...
Car seats and beds are essential safety devices. However, previous studies have found that placement of infants in these devices may alter respiratory performance. As in our previous study,12 we confirmed our hypothesis that the respiration of term infants is compromised in both car beds and car seats. Our primary and secondary outcomes, including mean oxygen saturation, minimal oxygen saturation, and percentage of time with oxygen saturation level ,95%, were all significantly altered from the values obtained while infants were placed in cribs. Not all of the infants were equally affected, however. Indeed, a subgroup of infants spent ,50% of their time with oxygen saturation levels ,95%. The car bed performed better than the car seat on 1 parameter: mean oxygen saturation values recorded in the car bed were significantly higher (P , .001) than in the car seat. In the car seat, there was a trend toward more obstructive apneic events (P = .052), implicating obstructive apnea as a likely factor in ...
How Many Oxygen Molecules Can Be Transported By One Hemoglobin Molecule? | The Science LoversHow Many Oxygen Molecules Can Be Transported By One Hemoglobin Molecule? | The Science Lover's
Apr 23, 2016 · Each hemoglobin molecule can carry how many oxygen molecules? a. 4 b. 6 c. 8 d. 10 e. 12. Hemoglobin is made up of four subunits and can bind up to four oxygen molecules. that binds the globin molecules; one molecule binds one molecule of oxygen. The oxygen-carrying capacity of hemoglobin determines how much oxygen.. Fluorescence is a phenomenon in which an electron in a molecule absorbs energy from. lasting only a few billionths of a second. Many biologically important colored molecules such as hemoglobin-an.. Within the body, the transport of oxygen is performed by hemoglobin. chemically modified because free hemoglobin, without encapsulation in cells, is unstable, breaking down into smaller component.. It works a bit like sonar - scientists bombard molecules with X-rays, then measure the angles as the X-rays bounce off, or diffract. They can. in hemoglobin is crucial for oxygen transport to.. and deliver that oxygen to all cells in the body, including muscles. in the body ...
Blood oxygen level-dependent (BOLD) magnetic resonance imaging in patients with dypiridamole induced ischaemia; a PET...Blood oxygen level-dependent (BOLD) magnetic resonance imaging in patients with dypiridamole induced ischaemia; a PET...
TY - JOUR. T1 - Blood oxygen level-dependent (BOLD) magnetic resonance imaging in patients with dypiridamole induced ischaemia; a PET comparative study. AU - Egred, M.. AU - Waiter, Gordon David. AU - Semple, Scott Ian Kay. AU - Redpath, Thomas William. AU - Al-Mohammad, A.. AU - Norton, Murdoch Young. AU - Metcalfe, M. J.. AU - Walton, S.. PY - 2007/1/31. Y1 - 2007/1/31. N2 - Background: Blood oxygen level-dependent (BOLD) MRI relies on changes in deoxyhaemoglobin level in tissues under stress for signal variation and may be used for detection of ischaemic myocardium.Methods: 15 patients with stress induced myocardial ischaemia on PET scanning underwent rest and dypiridamole stress MRI using a double breath-hold T2*-weighted, ECG gated sequence to produce BOLD contrast images and cine-MRI for wall thickening assessment. Signal change on BOLD MRI and wall thickening were compared between rest and stress images in ischaemic and non-ischaemic myocardial segments.Results: Using PET, 156 segments ...
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Patent US4741343 - Method and apparatus for measuring oxygen partial pressure and temperature ... - Google PatentsPatent US4741343 - Method and apparatus for measuring oxygen partial pressure and temperature ... - Google Patents
Oxygen partial pressure and temperature are measured in living tissue by inserting a thin probe into living tissue. The probe includes a plurality of spatially separated thermal sensors secured to the probe substrate. A plurality of oxygen sensors is positioned along the length of the probe substrate and each oxygen sensor is associated with and positioned adjacent to or is an integral part of one of the thermal sensors. Electrical parameters of the sensors located on the probe are measured and used to determine oxygen partial pressure and to determine temperature at each of a plurality of sites along the probe.
METHOD FOR THE OXYGENATION OF FERMENTATIONS USING OXYGEN AND AIR OR OTHER OXYGEN REDUCING GASES - Patent applicationMETHOD FOR THE OXYGENATION OF FERMENTATIONS USING OXYGEN AND AIR OR OTHER OXYGEN REDUCING GASES - Patent application
0084] As discussed above, ammonia combustion in Oxygen is affected by the concentrations of both in a gaseous mixture. In an ideally balanced fermentation using substantially pure oxygen, the Oxygen input 30, 40 will maintain the desired dissolved Oxygen levels 90 without significant amounts of Oxygen gas being emitted into headspace 110. In operation, there are many times when Oxygen input 30, 40 will at least transiently exceed the necessary input levels. For example, at the start of fermentation, Oxygen input levels may be deliberately set higher than necessary and then calibrated back to the optimum input level. Another point in fermentation will be the shift from exponential growth to stationary growth. Oxygen input 30, 40 may transiently exceed the requirement for the target dissolved oxygen level 90 due to decreases in Oxygen consumption by the fermentation microorganisms. During such adjustments periods, Oxygen concentrations 140 in the headspace 110 may be very high such as 25 or 30% of ...
Reduced oxygen consumption induced by vasopressin in dogs depends on systemic administration | Clinical ScienceReduced oxygen consumption induced by vasopressin in dogs depends on systemic administration | Clinical Science
1. Arginine vasopressin reduces whole-body oxygen consumption in conscious dogs. To determine whether this decrease could result from limited oxygen delivery, studies were performed in two groups of chronically instrumented dogs.. 2. In the first group (n = 7), vasopressin was infused at a rate of 18.5 pmol min−1 kg−1 while the animals were breathing 10% oxygen. Hypoxaemia alone (arterial partial pressure of oxygen 4.67 kPa) decreased whole-body oxygen delivery by 30%. The fall in whole-body oxygen consumption induced by vasopressin during hypoxaemia was not different from that measured under normoxic conditions, even though whole-body oxygen delivery was more reduced.. 3. In a second group of seven dogs, hindquarter blood flow (electromagnetic flowmeter on lower abdominal aorta) and oxygen consumption (blood flow multiplied by arteriovenous oxygen difference) were measured as infusions of vasopressin were given either systemically or into the lower abdominal aorta. Systemic vasopressin ...
Patent US9126049 - Shock reduction using absolute calibrated tissue oxygen saturation and total ... - Google PatentsPatent US9126049 - Shock reduction using absolute calibrated tissue oxygen saturation and total ... - Google Patents
An implantable medical device for detecting and treating an arrhythmia includes an optical sensor adapted for positioning adjacent to a blood-perfused tissue volume. In one embodiment for controlling arrhythmia therapies delivered by the device, the optical sensor is controlled to emit light in response to detecting an arrhythmia, detect light scattered by the volume of blood perfused tissue including measuring an optical sensor output signal corresponding to the intensity of scattered light for at least four spaced-apart wavelengths, and compute a volume-independent measure of tissue oxygen saturation from the detected light. The hemodynamic status of the arrhythmia is detected in response to the measure of tissue oxygen saturation.
Hyperbaric Oxygen TherapyHyperbaric Oxygen Therapy
Cancer Center For Healing uses Hyperbaric Oxygen Therapy (HBOT) as one of the integrative treatment plans for our patients. Hyperbaric Oxygen Therapy is a well-established treatment for cancer and other diseases. Through breathing pure oxygen in a pressurized room, patients lungs can gather up to three times more oxygen than would be possible breathing pure oxygen at normal air pressure. The patients blood carries this pure oxygen throughout the body to stimulate the release of growth factors and stem cells. The release of the stem cells and growth factors promote healing.. Cancer Center For Healings Oxidative Preconditioning Therapy is to give patients hyperbaric oxygen sessions combined with Nutraceuticals and Trental (Pentoxifylline), to augment HBOTs effect. Trental is FDA-approved for the improvement the flow of blood by decreasing its viscosity (making it "thinner"), increasing blood flow through the microcirculation system and enhancing tissue oxygenation.. Our staff of physicians ...
Mr. Hiroshige Kawakami ProfileMr. Hiroshige Kawakami Profile
We studied photosensitization reaction progress in a cell culture well by oxygen partial pressure distribution measurement along the well depth direction with a high concentration of talaporfin sodium solution. The talaporfin sodium solution of 20 μg/ml in concentration with 2.8 mm thickness in the well was irradiated from the well bottom by 663 nm excitation laser with 0.29 W/cm2. A small Clark-type oxygen electrode was used to measure oxygen partial pressure during the photosensitization reaction with approximately 200 μm resolution. Corrections against solution temperature change and direct light irradiation were applied to the electrode output. The oxygen partial pressures at various depths were decreased uniformly from the atmospheric oxygen partial pressure with the photosensitization reaction progress up to the irradiation of 1.0 J/cm2 in radiant exposure. In the case of photosensitization reaction over 1.0 J/cm2 in radiant exposure, the oxygen partial pressure distribution along the ...
Patent US6247471 - Smoke hood with oxygen supply device and method of use - Google PatentsPatent US6247471 - Smoke hood with oxygen supply device and method of use - Google Patents
An emergency breathing device including a hood having use and storage configurations, which when compactly wrapped proximate to an oxygen control device for storage is recoverable for use. In use configuration, the hood is capable of being worn upon a users head, which substantially surrounds the users head. Hood surface beneath the users head includes an opening lined with elastic material, which forms a seal about the users neck at the opening when the hood is donned. An oxygen control device connected to a hood includes a valve body, an actuator, and an oxygen bottle. The valve body provides airflow communication with the interior of the hood, and the oxygen control device is connected to a plumbed breathable oxygen supply through a plumbed source disconnect means removably connected to the valve body. When connected, the oxygen control device permits airflow from the plumbed breathable oxygen supply and valve body to the interior of the hood. A cam within the valve body rotates with the
Evaluation of oesophageal pulse oximetry in patients undergoing cardiothoracic surgery - City Research OnlineEvaluation of oesophageal pulse oximetry in patients undergoing cardiothoracic surgery - City Research Online
Pulse oximetry probes placed peripherally may fail to give accurate values of blood oxygen saturation when the peripheral circulation is poor. Because central blood flow may be preferentially preserved, we investigated the oesophagus as an alternative monitoring site. A reflectance blood oxygen saturation probe was developed and evaluated in 49 patients undergoing cardiothoracic surgery. The oesophageal pulse oximeter results were in good agreement with oxygen saturation measurements obtained by a blood gas analyser, a CO-oximeter and a commercial finger pulse oximeter. The median (IQR [range]) difference between the oesophageal oxygen saturation results and those from blood gas analysis were 0.00 (-0.30 to 0.30 [-4.47 to 2.60]), and between the oesophageal oxygen saturation results and those from CO-oximetry were 0.75 (0.30 to 1.20 [-1.80 to 1.80]). Bland-Altman analysis showed that the bias and the limits of agreement between the oesophageal and finger pulse oximeters were -0.3% and -3.3 to ...
Seabed Biodiversity In Oxygen Minimum Zones - RedorbitSeabed Biodiversity In Oxygen Minimum Zones - Redorbit
Some regions of the deep ocean floor support abundant populations of organisms, despite being overlain by water that contains very little oxygen, according to an international study led by scientists at the United Kingdoms National Oceanography Center, Southampton. But global warming is likely to exacerbate oxygen depletion and thereby reduce biodiversity in these regions, they warn.. The sunlit surface waters tend to be well oxygenated as a result of their connection with the atmosphere. Here, tiny marine algae called phytoplankton thrive. When they die and sink, they are degraded by bacteria, using oxygen from the water column.. In regions of high plant growth, this can result in the natural development of mid-water oxygen minimum zones (OMZs), especially where oxygen is not replenished by mixing of the water column. Where they touch the continental slope, OMZs create strong seafloor oxygen gradients at depths between 100 and 1000 m.. In addition to low oxygen, sediments within OMZs often ...
A bilateral cortico-bulbar network associated with breath holding in humans, determined by functional magnetic resonance imagingA bilateral cortico-bulbar network associated with breath holding in humans, determined by functional magnetic resonance imaging
Few tasks are simpler to perform than a breath hold; however, the neural basis underlying this voluntary inhibitory behaviour, which must suppress spontaneous respiratory motor output, is unknown. Here, using blood oxygen level-dependent functional magnetic resonance imaging (BOLD fMRI), we investig …
Biomass size-spectra of macrobenthic communities in the oxygen minimum zone off Chile. - ePICBiomass size-spectra of macrobenthic communities in the oxygen minimum zone off Chile. - ePIC
Estimates of macrofaunal secondary production and normalized biomass size-spectra (NBSS) were constructed for macrobenthic communities associated with the oxygen minimum zone (OMZ) in four areas of the continental margin off Chile. The presence of low oxygen conditions in the Humboldt Current System (HCS) off Chile was shown to have important effects on the size structure and secondary production of the benthic communities living in this ecosystem. The distribution of normalized biomass by size was linear (log2log2 scale) at all stations. The slope of the NBSS ranged from -0.481 to-0.908. There were significant differences between the slopes of the NBS-spectra from the stations located in the OMZ (slope = - 0.837) and those located outside the OMZ(slope = - 0.463) (p , 0.05). The results of this study suggest that low oxygen conditions (, 0.5 ml L-1) appear to influence biomass size-spectra, because small organisms are better able to satisfy their metabolic demands. The annual secondary ...
High temperature conductance characteristics of LaAlO3/SrTiO3-heterostructures under equilibrium oxygen atmospheresHigh temperature conductance characteristics of LaAlO3/SrTiO3-heterostructures under equilibrium oxygen atmospheres
The interface conductance of LaAlO3/SrTiO3 heterostructures was investigated under high temperature oxygen equilibrium. The dependence of the heterostructure’s conductance on oxygen partial pressure (from 10-22 to 1 bar) and temperature (800 to 1100 K) was compared to the characteristic of SrTiO3 single crystals, which is described in terms of a defect chemistry model. Up to 950 K the equilibrated heterostructures reveal an additional influence of a metallic-like conduction path with a very slight dependence on the oxygen partial pressure. Donor-type interface states which may result from either lattice distortions or A-site cation intermixing during processing are discussed as a possible origin for the exceptional interface conduction of LaAlO3/SrTiO3 heterostructures ...
Effect of supplemental oxygen exposure on myocardial injury in ST-elevation myocardial infarction | HeartEffect of supplemental oxygen exposure on myocardial injury in ST-elevation myocardial infarction | Heart
Nehme and coworkers tested out the effect of air versus oxygen on myocardial injury in ST-elevation myocardial infarction (STEMI).1 When administered in the first 12 hours after STEMI oxygen was associated with a dose-dependent increase in troponin and creatine kinase. In 2015 the same group of investigators published a study in Circulation showing that air instead of oxygen supplementation in STEMI led to improved outcome. The conclusions of these two studies seem to be that supplemental oxygen therapy in patients with STEMI but without hypoxia may increase early myocardial injury and is associated with larger myocardial infarct size assessed at 6 months. In 1980 we were the first to suggest that due to production of oxygen free radicals air could be better than oxygen supplementation during reoxygenation.2 During the next 30 years we performed a series of studies demonstrating that air compared to 100% oxygen caused significantly less oxidative stress and less myocardial and kidney injury, and ...
Accuracy of pulse oximetry in detection of oxygen saturation in patients admitted to the intensive care unit of heart surgery:...Accuracy of pulse oximetry in detection of oxygen saturation in patients admitted to the intensive care unit of heart surgery:...
Heart surgery patients are more at risk of poor peripheral perfusion, and peripheral capillary oxygen saturation (SpO2) measurement is regular care for continuous analysis of blood oxygen saturation in these patients. With regard to controversial studies on accuracy of the current pulse oximetry probes and lack of data related to patients undergoing heart surgery, the present study was conducted to determine accuracy of pulse oximetry probes of finger, toe, forehead and earlobe in detection of oxygen saturation in patients admitted to intensive care units for coronary artery bypass surgery. In this clinical trial, 67 patients were recruited based on convenience sampling method among those admitted to intensive care units for coronary artery bypass surgery. The SpO2 value was measured using finger, toe, forehead and earlobe probes and then compared with the standard value of arterial oxygen saturation (SaO2). Data were entered into STATA-11 software and analyzed using descriptive, inferential and Bland
CICECO Oxygen permeability of LaGaO3-based ceramic membranesCICECO Oxygen permeability of LaGaO3-based ceramic membranes
Acceptor-type doping of perovskite-type La1-x,SrxGa0.80-y,MgyM0.20O3-delta (x = 0-0.20, y = 0.15-0.20, M = Fe, Co, Ni) leads to significant enhancement of the oxygen permeability due to increasing oxygen vacancy concentration and, thus, ionic conductivity. The increase in strontium and magnesium content is accompanied, however, with increasing role of the surface exchange kinetics as a permeation-limiting factor. At temperatures below 1223 K, the oxygen permeation (OP) fluxes through dense La(Sr)Ga(Mg,M)O3-delta membranes with the thickness less than 1.5 mm are mainly limited by the exchange rate at membrane/gas boundaries. For transition metal-containing La(Sr)Ga(Mg)O3-delta (LSGM) ceramics, the oxygen transport increases in the sequence Co < Fe < Ni. The highest permeation is observed for La0.90Sr0.10Ga0.65Mg0.15Ni0.20O3-delta perovskite membranes, which exhibit level of the oxygen permeability similar to that of La(Sr)Fe(Co)O3-delta and La2NiO4-based solid solutions. The average thermal expansion
Oxygen Minimum ZonesOxygen Minimum Zones
... (OMZ) are the places in the world ocean where oxygen saturation in the water column is at its lowest. This zone typically occurs at depths of about 200 to 1,000 meters. The AOG lab is interested in OMZs because of their importance in controlling carbon and nitrogen cycling in the oceans. OMZ water is exposed to the rain of sinking organic matter, which we evaluate using our drifting net traps and in situ incubators. Bacteria and archea feed on this organic matter and oxygen is used. Thus, the concentration of oxygen in deep water is dependent on the amount of oxygen it had when it was at the surface minus depletion by deep sea organisms.. In many OMZ regions oxygen actually reaches zero, in which case the OMZ can be called an ODZ (oxygen deficient zone). ODZs provide appropriate conditions to enable substantial nitrogen loss because in the absence of oxygen, nitrate represents the next best electron acceptor available for respiration. Starting with organic nitrogen ...
Hyperbaric OxygenHyperbaric Oxygen
HBOT damages bacterial cellular DNA and enhances the oxygen dependent peroxidase system leukocytes used to kill bacteria. The transport of certain antibiotics into tissues that use oxygen-dependent transport mechanisms is increased, thereby, enhancing their efficacy. This is most effective for aminoglycosides and trimethoprim sulfa. Flouroquinolones are less effective in a hypoxic environment and HBOT will restore their effectiveness.. Creating a large oxygen gradient at the periphery of ischemic or poorly healing wounds enhances fibroblast function and the oxygen dependent matrix formation needed for angiogenesis, enhances wound healing.. During reperfusion injuries, leukocytes adhere to damaged/ischemic tissues releasing oxygen free radicals and proteases, further damaging tissues and causing further vasoconstriction. HBOT will reduce leukocyte adherence and post-ischemic vasoconstriction thereby providing a beneficial effect on reperfusion injuries (crush injuries, compartment syndromes, ...
Effects of hyperventilation on conjunctival oxygen tension in humans<...Effects of hyperventilation on conjunctival oxygen tension in humans<...
TY - JOUR. T1 - Effects of hyperventilation on conjunctival oxygen tension in humans. AU - Nisam, M.. AU - Albertson, Timothy E. AU - Panacek, Edward A. AU - Rutherford, W.. AU - Fisher, C. J.. PY - 1986. Y1 - 1986. N2 - A polarographic conjunctival oxygen sensor was used to measure oxygen tension in a tissue bed supplied by the internal carotid artery. The shared vascular source of the conjunctiva and brain suggests that conjunctival PO2 monitoring may provide an index of cerebral perfusion. We studied the effects of hyperventilation, a known stimulus of cerebral vasconstriction, on conjunctival oxygen tension (P(cj)O2) in six normal, healthy adults; arterial blood gases were simultaneously measured in four of these subjects. A 5-min period of hyperventilation to a PaCO2 near 20 torr resulted in a rapid and significant (p,.01) increase in systemic oxygen tension as measured by arterial blood gases and a transcutaneous oxygen monitor. These values gradually returned to baseline upon cessation of ...
48. Disorders of oxygen transport (abnormal hemoglobin, CO-poisoning, methemoglobinemia) - greek.doctor48. Disorders of oxygen transport (abnormal hemoglobin, CO-poisoning, methemoglobinemia) - greek.doctor
As seen on the figure above does the oxygen saturation change very little when pO2 is between 80 and 100 mmHg. Its only when pO2 becomes lower than 80 that the saturation starts to decrease significantly and rapidly.. When oxygenated blood has reached an area that requires oxygen will the oxygen that is dissolved in the blood diffuse across the capillary wall to the interstitium. Oxygen in the interstitium is then taken up by the cells. Oxygen will then dissociate from haemoglobin to "refill" the dissolved oxygen in the blood that was just emptied.. In the veins is the oxygen saturation only 75%, which equals 40 mmHg of pO2, as seen on the figure above. Arterial blood contains 20 mL oxygen per 100 mL blood, while venous blood contains 15 mL O2 per 100 mL blood. The difference is only 5 mL. Oxygen content of blood can also be expressed as a volume percentage. For example, 20% of arterial blood is oxygen, while 15% of venous blood is oxygen. Because of this we can also write the difference ...
Accelerate Your Healing With Hyperbaric Oxygen Therapy (Hbot) - International Journal of Conference ProceedingsAccelerate Your Healing With Hyperbaric Oxygen Therapy (Hbot) - International Journal of Conference Proceedings
Introduction - Hyperbaric oxygen therapy (HBOT) is a non-invasive therapy that uses 100% oxygen under increased atmospheric pressure in a controlled total body chamber, to treat patients.. Mechanism of Action of HBOT? : At hyperbaric (higher than atmospheric) pressures, gases can accumulate at higher concentrations and dissolve more readily in liquids. In a hyperbaric oxygen chamber, a specially designed chamber that delivers pressurized oxygen to the body in a safe, painless, and non-invasive way, a patients exposure to 100% oxygen can infuse their tissues with oxygen. The oxygen not only saturates the red blood cells, it also dissolves in the plasma, lymph system, and cerebrospinal fluid. As a patient relaxes inside a HBOT chamber, the bodys tissues and organs receive a massive infusion of oxygen, resulting in remarkable benefits that cannot be achieved by any other therapy.. Indications: Hyperbaric oxygen therapy promotes physiological changes in the body that support healing and ...
Physiological responses of Pseudomonas aeruginosa PAO1 to oxidative stress in controlled microaerobic and aerobic cultures |...Physiological responses of Pseudomonas aeruginosa PAO1 to oxidative stress in controlled microaerobic and aerobic cultures |...
Pseudomonas aeruginosa PAO1 was found to exhibit several remarkable physiological responses to oxidative stress upon its growth in a computer-controlled suspension culture. First, it strongly reduced the transfer rate of oxygen from the gas into the liquid phase, causing oxygen-limited or microaerophilic conditions in the culture after a short period of cultivation, even at high aeration rates with pure oxygen. Second, PAO1 that was previously classified as non-mucoid formed a clear polysaccharide capsule on the cell surface (mucoid phenotype) under oxidative-stress conditions. Third, the strain showed a reduced growth rate and a longer lag phase under high oxygen tension. Finally, P. aeruginosa PAO1 released a high amount of proteins into the culture broth. The release of some virulence factors by PAO1, such as elastase, was significantly enhanced or only occurred under microaerobic conditions (i.e. dissolved oxygen tension value around 1% of air saturation). Hence, it is concluded that P. aeruginosa
30: CEREBRAL BLOOD FLOW AND CEREBRAL OXYGEN METABOLISM IN NORMAL AGING: A PRECURSOR FOR STUDY OF DEMENTIA AND ALZHEIMERS...30: CEREBRAL BLOOD FLOW AND CEREBRAL OXYGEN METABOLISM IN NORMAL AGING: A PRECURSOR FOR STUDY OF DEMENTIA AND ALZHEIMER'S...
Background and aims: Aging brain has been demonstrated to be the main risk factor for dementia and Alzheimers disease (AD). Recent findings provide clear evidence that the structural and functional integrity of the brain depends on the delicate balance between substrate delivery through blood flow and energy demands imposed by neural activity. Imaging studies of aging have in general shown reductions of cerebral blood flow (CBF) and the cerebral metabolic rates of oxygen (CMRO2) in healthy elderly adults. Based on the existing evidence, we hypothesized the CBF and CMRO2 in healthy young subjects will be higher than CBF and CMRO2 in elderly adults which itself should be higher than AD patients. Therefore, we designed the present studies specifically to reveal the role of defective cerebral oxygen metabolism and cerebral blood flow in normal aging. ...
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Pure oxygen is mixed with air to produce an enriched air containing 50 volume % of oxygen. The ratio of moles of air to oxygen...Pure oxygen is mixed with air to produce an enriched air containing 50 volume % of oxygen. The ratio of moles of air to oxygen...
✅ Answered - [1.72] [0.58] [0.5] [0.2] are the options of mcq question Pure oxygen is mixed with air to produce an enriched air containing 50 volume % of oxygen. The ratio of moles of air to oxygen used is realted topics , Chemical Engineering, Stoichiometry topics with 0 Attempts, 0 % Average Score, 2 Topic Tagged and 0 People Bookmarked this question which was asked on Nov 25, 2018 17:36
Hyperbaric Oxygen Therapy | Baylor Scott & White HealthHyperbaric Oxygen Therapy | Baylor Scott & White Health
Baylor Scott & White uses oxygen therapy to treat hard-to-heal wounds that come from diabetes and diabetic neuropathy, soft-tissue damage from skin grafts and cancer radiation therapy, as well as to help salvage limbs. Oxygen therapy is when oxygen is used to begin or speed up the healing process. Hyperbaric oxygen therapy has you breathing pure oxygen in a pressurized environment, which increases the oxygen levels in body tissue to help heal and fight infection. One benefit is blood vessel growth in areas that have been deprived of oxygen due to poor blood flow. Increased blood flow to the area of an oxygen-starved wound also results in increased healing.. Comprehensive wound programs at Baylor Scott & White have several types of hyperbaric oxygen chambers at various locations. ​Monoplace chambers can hold only one person at a time, whereas a multispace chamber is designed to hold up to eight people at once. Each session typically last approximately 90 minutes. ...
Surviving anoxia in marine sediments: The metabolic response of ubiquitous benthic foraminifera (Ammonia tepida)Surviving anoxia in marine sediments: The metabolic response of ubiquitous benthic foraminifera (Ammonia tepida)
High input of organic carbon and/or slowly renewing bottom waters frequently create periods with low dissolved oxygen concentrations on continental shelves and in coastal areas; such events can have strong impacts on benthic ecosystems. Among the meiofauna living in these environments, benthic foraminifera are often the most tolerant to low oxygen levels. Indeed, some species are able to survive complete anoxia for weeks to months. One known mechanism for this, observed in several species, is denitrification. For other species, a state of highly reduced metabolism, essentially a state of dormancy, has been proposed but never demonstrated. Here, we combined a 4 weeks feeding experiment, using C-13-enriched diatom biofilm, with correlated TEM and NanoSIMS imaging, plus bulk analysis of concentration and stable carbon isotopic composition of total organic matter and individual fatty acids, to study metabolic differences in the intertidal species Ammonia tepida exposed to oxic and anoxic conditions. ...
Plus itPlus it
Oxygen supplementation has been a cornerstone in the initial treatment of individuals with acute coronary syndrome. While consensus for oxygen supplementation exists for patients with hypoxia, oxygen supplementation has also been routinely used in those presenting with acute myocardial infarction (MI) with normal oxygen saturations based on the rationale that oxygen therapy could improve oxygen supply to the ischemic myocardium, thereby reducing the infarct size and complications. Indeed, reports of oxygen supplementation to relieve angina pectoris were described as early as 1900 (1). These reports were followed by small studies that suggested benefit with oxygen supplementation in acute MI, but these studies were limited by lack of randomization and unblinded end point ascertainment (2-4). Nonetheless, supplemental oxygen was incorporated into routine clinical practice, as evidenced in 2007 cardiology practice guidelines that recommended routine supplemental oxygen to all patients with acute ...
Notes from Dr. RW: Another study on oxygen administration in acute MINotes from Dr. RW: Another study on oxygen administration in acute MI
Methods and Results-We conducted a multicenter, prospective, randomized, controlled trial comparing oxygen (8 L/min) with no supplemental oxygen in patients with ST-elevation-myocardial infarction diagnosed on paramedic 12-lead ECG. Of 638 patients randomized, 441 patients had confirmed ST-elevation-myocardial infarction and underwent primary end-point analysis. The primary end point was myocardial infarct size as assessed by cardiac enzymes, troponin I, and creatine kinase. Secondary end points included recurrent myocardial infarction, cardiac arrhythmia, and myocardial infarct size assessed by cardiac magnetic resonance imaging at 6 months. Mean peak troponin was similar in the oxygen and no oxygen groups (57.4 versus 48.0 μg/L; ratio, 1.20; 95% confidence interval, 0.92-1.56; P=0.18). There was a significant increase in mean peak creatine kinase in the oxygen group compared with the no oxygen group (1948 versus 1543 U/L; means ratio, 1.27; 95% confidence interval, 1.04-1.52; P=0.01). There ...
Inhaled nitric oxide and arterial oxygen tension in patients with chronic obstructive pulmonary disease and severe pulmonary...Inhaled nitric oxide and arterial oxygen tension in patients with chronic obstructive pulmonary disease and severe pulmonary...
BACKGROUND: Inhaled nitric oxide (NO) is a selective pulmonary vasodilator which can improve gas exchange in acute lung injury. However, it is uncertain that this effect on arterial oxygenation can be generalised to all lung diseases. METHODS: The effects of inhaled NO on gas exchange were studied in nine patients with chronic obstructive pulmonary disease (COPD), 11 patients with severe pulmonary hypertension, and 14 healthy volunteers. A randomized sequence of 40 ppm of NO or air was inhaled for 20 minutes through an orofacial mask. RESULTS: Inhaled NO reduced mean (SE) transcutaneous arterial oxygen tension (TcPO2) from 9.6 (0.3) to 8.9 (0.4) kPa in healthy volunteers and from 7.4 (0.6) to 7.0 (0.5) kPa in patients with COPD. There was no change in TcPO2 in patients with severe pulmonary hypertension. During inhalation of NO and air no change occurred in transcutaneous arterial carbon dioxide tension (TcPCO2), arterial oxygen saturation (SaO2) measured by pulse oximeter, or cardiac output ...
Dissolved Oxygen « AQUAPLANTDissolved Oxygen « AQUAPLANT
Dissolved oxygen is probably the single most important water quality factor that pond managers need to understand. Oxygen dissolves in water at very low concentrations. Our atmosphere is 20% oxygen or 200,000 ppm but seldom will a pond have more than 10 ppm oxygen dissolved in its water. Dissolved oxygen concentrations below 3 ppm stress most warmwater species of fish and concentrations below 2 ppm will kill some species. Often fish that have been stressed by dissolved oxygen concentrations in the range of 2 or 3 ppm will become susceptible to disease.. Oxygen dissolves into water from two sources: the atmosphere and from plants in the water. The primary source of oxygen for a pond is from microscopic algae (phytoplankton) or submerged plants. In the presence of sunlight, these produce oxygen through photosynthesis and release this oxygen into the pond water. At night and on very cloudy days, algae and submerged plants remove oxygen from the water for respiration. During daylight hours plants ...
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AnatomyOrganismsDiseasesChemicals and DrugsAnalytical, Diagnostic and Therapeutic Techniques and EquipmentPhenomena and ProcessesAnthropology, Education, Sociology and Social PhenomenaTechnology, Industry, AgricultureInformation ScienceHealth Care
OxygenOxygen ConsumptionReactive Oxygen SpeciesOxygen Inhalation TherapySinglet OxygenOxygen IsotopesHyperbaric OxygenationPartial PressureAnoxiaHydrogen PeroxideOxidation-ReductionOxidative StressOximetryAntioxidantsOxyhemoglobinsCarbon DioxideAerobiosisSuperoxide DismutaseHemoglobinsFree RadicalsFree Radical ScavengersMitochondriaCatalaseHyperoxiaNADPH OxidaseCell HypoxiaAnaerobiosisSuperoxidesBlood Gas AnalysisPolarographyTime FactorsLuminescent MeasurementsKineticsPulmonary Gas ExchangeEnergy MetabolismBlood SubstitutesRespirationBlood Gas Monitoring, TranscutaneousOxidantsCells, CulturedOxygen RadioisotopesXanthine OxidaseNitric OxideReactive Nitrogen SpeciesAcetylcysteineGlutathioneHydrogen-Ion ConcentrationModels, BiologicalExercise TestHemodynamicsElectron TransportApoptosisElectron Spin Resonance SpectroscopyHypoxia-Inducible Factor 1, alpha SubunitDiphosphoglyceric AcidsHydroxyl RadicalSignal TransductionGlucoseLactic AcidHeart RateLipid PeroxidationElectron Transport Complex IVIon-Selective ElectrodesRats, Sprague-DawleyCerebrovascular CirculationPhysical ExertionOxidoreductasesCarbon MonoxideCell SurvivalMembrane Potential, MitochondrialCyclic N-OxidesAirSpectroscopy, Near-InfraredMyoglobinCardiac OutputHeliumExerciseDose-Response Relationship, DrugSpectrophotometryMyocardiumAltitudeRegional Blood FlowOnium CompoundsHypoxia-Inducible Factor 1LactatesHemeLungMetalloporphyrinsNitrous OxideIronBlood PressureAscorbic AcidExercise ToleranceCell DeathMuscle, SkeletalWaterBrainAdaptation, PhysiologicalLightAdenosine Triphosphate2,3-DiphosphoglycerateLung Diseases, ObstructiveHemoglobins, AbnormalHydroxidesEnzyme InhibitorsPeroxidesAtmospheric PressureRats, WistarNADH, NADPH OxidoreductasesPeroxidasesDogsDisease Models, AnimalDivingTemperatureNitratesXanthineMolecular Sequence DataMitochondria, HeartSpin LabelsNeutrophilsPhotosensitizing AgentsPhotosynthesisHemodilutionGlutathione PeroxidaseBiological Oxygen Demand AnalysisNADGlycolysisCell LineMice, Inbred C57BLEnzyme ActivationHematocritRespiration, ArtificialNitrogenPhysical EnduranceCell Line, TumorRespiratory InsufficiencyRetinopathy of PrematurityProcollagen-Proline DioxygenaseGasesGlucose OxidaseRespiratory BurstMicrocirculationHypoxia, BrainRNA, MessengerPulmonary CirculationPerfusionHemeproteinsResuscitation
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AnatomyOrganismsDiseasesChemicals and DrugsAnalytical, Diagnostic and Therapeutic Techniques and EquipmentPhenomena and ProcessesAnthropology, Education, Sociology and Social PhenomenaTechnology, Industry, AgricultureInformation ScienceHealth Care
OxygenOxygen ConsumptionReactive Oxygen SpeciesOxygen Inhalation TherapySinglet OxygenOxygen IsotopesHyperbaric OxygenationPartial PressureAnoxiaHydrogen PeroxideOxidation-ReductionOxidative StressOximetryAntioxidantsOxyhemoglobinsCarbon DioxideAerobiosisSuperoxide DismutaseHemoglobinsFree RadicalsFree Radical ScavengersMitochondriaCatalaseHyperoxiaNADPH OxidaseCell HypoxiaAnaerobiosisSuperoxidesBlood Gas AnalysisPolarographyTime FactorsLuminescent MeasurementsKineticsPulmonary Gas ExchangeEnergy MetabolismBlood SubstitutesRespirationBlood Gas Monitoring, TranscutaneousOxidantsCells, CulturedOxygen RadioisotopesXanthine OxidaseNitric OxideReactive Nitrogen SpeciesAcetylcysteineGlutathioneHydrogen-Ion ConcentrationModels, BiologicalExercise TestHemodynamicsElectron TransportApoptosisElectron Spin Resonance SpectroscopyHypoxia-Inducible Factor 1, alpha SubunitDiphosphoglyceric AcidsHydroxyl RadicalSignal TransductionGlucoseLactic AcidHeart RateLipid PeroxidationElectron Transport Complex IVIon-Selective ElectrodesRats, Sprague-DawleyCerebrovascular CirculationPhysical ExertionOxidoreductasesCarbon MonoxideCell SurvivalMembrane Potential, MitochondrialCyclic N-OxidesAirSpectroscopy, Near-InfraredMyoglobinCardiac OutputHeliumExerciseDose-Response Relationship, DrugSpectrophotometryMyocardiumAltitudeRegional Blood FlowOnium CompoundsHypoxia-Inducible Factor 1LactatesHemeLungMetalloporphyrinsNitrous OxideIronBlood PressureAscorbic AcidExercise ToleranceCell DeathMuscle, SkeletalWaterBrainAdaptation, PhysiologicalLightAdenosine Triphosphate2,3-DiphosphoglycerateLung Diseases, ObstructiveHemoglobins, AbnormalHydroxidesEnzyme InhibitorsPeroxidesAtmospheric PressureRats, WistarNADH, NADPH OxidoreductasesPeroxidasesDogsDisease Models, AnimalDivingTemperatureNitratesXanthineMolecular Sequence DataMitochondria, HeartSpin LabelsNeutrophilsPhotosensitizing AgentsPhotosynthesisHemodilutionGlutathione PeroxidaseBiological Oxygen Demand AnalysisNADGlycolysisCell LineMice, Inbred C57BLEnzyme ActivationHematocritRespiration, ArtificialNitrogenPhysical EnduranceCell Line, TumorRespiratory InsufficiencyRetinopathy of PrematurityProcollagen-Proline DioxygenaseGasesGlucose OxidaseRespiratory BurstMicrocirculationHypoxia, BrainRNA, MessengerPulmonary CirculationPerfusionHemeproteinsResuscitation
SupplementalRespiratoryAmount of oxygenToxicityLack of oxygenCarbonNasal2017RetinalRespirationLungsConcentratorsArterialConcentrationSaturation levelsEnough oxygenConcentrationsMass transfer coPure oxygenCompoundsConsumptionGasesEarth'sSensorPartial pressureAtmosphericAmounts of oxygenAddition to oxygenLevelsMetabolicMeasurementTissuesTherapyFree oxygenDeliver oxygenIncrease oxygenLungMolecularBlood
Supplemental7
  • Our findings show that general anesthetics can greatly increase brain tissue PO 2 in neonates, especially when combined with supplemental oxygen. (northwestern.edu)
  • Our findings point to the need to consider the potential effects of hyperoxia when supplemental oxygen is utilized, particularly in children and neonates. (northwestern.edu)
  • The oxygen blending module includes a flow sensor which monitors the flow of supplemental oxygen into the piston and cylinder assembly, and further includes a primary oxygen control valve which restricts the flow of oxygen through the flow sensor to the piston and cylinder assembly depending on the difference between the calculated desired amount of oxygen and the target amount of oxygen provided to the controller. (justia.com)
  • This invention relates to a method and apparatus for blending oxygen, in a piston-type ventilator which permits constant and accurate supply of supplemental oxygen to the user through a closed loop pressure support ventilation system. (justia.com)
  • Ventilation systems are designed to supply air at a pressure greater than atmospheric pressure to assist in breathing, and may include systems which provide supplemental oxygen which is blended with air to enrich the gas which is inhaled. (justia.com)
  • Such systems are typically employed for patients with respiratory ailments wherein the oxygen-enriched air is provided by blending bottled air or less often atmospheric air with supplemental oxygen in a controlled manner for each breath. (justia.com)
  • A qualified medical practitioner will assess your situation and prescribe the appropriate dose of supplemental oxygen. (easyoxygen.com.au)
Respiratory3
  • Oxygen is essential for the respiratory function of humans, animals, plants, and some types of bacteria. (newworldencyclopedia.org)
  • A piston ventilator is disclosed herein which uniquely includes an oxygen blending module which supplies oxygen enhancement for aiding patients requiring respiratory treatment. (justia.com)
  • Our staff attend regular training in the fields of oxygen therapy and respiratory conditions which allow them to provide the best solution for you, in consultation with your Doctor or Specialist. (easyoxygen.com.au)
Amount of oxygen3
  • Considering that air contains 21% oxygen, the amount of oxygen that would be carried into the liquid when rotating surface liquid film was submerged would be theoretically 2.04 x 10 -7 mmol/cm 2 . (biologydiscussion.com)
  • The oxygen blending module supplies a preselected enrichment of oxygen to a piston and cylinder assembly wherein the amount of oxygen permitted to flow therein is continuously monitored and controlled according to the volume above the piston in the cylinder as calculated by a controller. (justia.com)
  • More particularly, it is concerned with a piston ventilator used to ventilate patients having difficulty respirating, which adjusts the amount of oxygen supplied both to the piston cylinder and to the patient circuit for ensuring a satisfactory oxygen content throughout the air in the circuit inhaled by the patient. (justia.com)
Toxicity1
  • According to Warburg, it is the increased amounts of carcinogens, toxicity and pollution that cause cells to be unable to uptake oxygen efficiently. (cancerbuster.net)
Lack of oxygen2
Carbon4
Nasal3
20171
  • By a stroke of luck, the W.H.O., UNICEF and the Bill & Melinda Gates Foundation in 2017 began searching for ways to increase oxygen delivery in poor and middle-income countries - not in anticipation of a pandemic, but because oxygen can save the lives of premature infants and children with pneumonia. (medxr.com)
Retinal3
  • Introduction: Oxygen delivery, or utilization, is a function of retinal blood flow and blood oxygen saturation. (uwaterloo.ca)
  • Animal models presuppose that the oxygen tension in the retina is highest in the innermost layers at the level of the choriocapillaris, less in the photoreceptors and further decreases throughout the outer retinal structures. (uwaterloo.ca)
  • The development of methods to measure retinal blood flow and blood oxygen saturation is crucial to improve understanding of the patho-physiology of major ocular diseases. (uwaterloo.ca)
Respiration1
  • Contrary to accepted knowledge, blood can bring more oxygen to mice brains when they exercise because the increased respiration packs more oxygen into the hemoglobin, according to an international team of researchers who believe that this holds true for all mammals. (bionewscentral.com)
Lungs4
  • Left shift of the curve is a sign of hemoglobin's increased affinity for oxygen (e.g. at the lungs). (cancerbuster.net)
  • Oxygen is taken in by the lungs when we breathe in. (easyoxygen.com.au)
  • For patients who need large volumes and help keeping the air sacs in their lungs open, tanks can deliver oxygen at high pressure through a mask strapped tightly over the nose and mouth. (medxr.com)
  • While many poor countries have plants making industrial-grade oxygen for construction jobs like welding, it cannot be used on patients because the tanks often contain rust or oily water that could lodge in the lungs, said Paul Molinaro, chief of operations support and logistics at the W.H.O. (medxr.com)
Concentrators2
Arterial1
Concentration3
  • In the measurement, the concept of flow of oxygen from higher concentration (heaviside) to lower concentration has been conceived. (biologydiscussion.com)
  • No. 5,383,449 provides for control of oxygen concentration in a breathable gas by calculation of the mole ratios and pressure in the containment vessel, and by sequentially injecting oxygen and another gas to desired pressure values. (justia.com)
  • The presence of oxygen in such concentration inhibits methanogesis (and methane production more than 2 times) and increases hydrogen production 6 times. (mostwiedzy.pl)
Saturation levels5
Enough oxygen1
Concentrations2
Mass transfer co1
  • This divergence of opinion concerning the physical meaning of K L led to extensive studies on the oxygen mass transfer coefficient in gas-liquid absorbers. (biologydiscussion.com)
Pure oxygen1
  • Tanks contain nearly pure oxygen. (medxr.com)
Compounds1
Consumption1
Gases1
Earth's2
Sensor1
  • A demand valve is alternately provided for reducing the pressure of the oxygen supplied before mixing, and a pressure sensor is also provided downstream of the demand valve for detecting failure of the demand valve to shut off the supply of the oxygen to prevent overpressurization. (justia.com)
Partial pressure2
Atmospheric1
  • The atmospheric abundance of free oxygen in later geological epochs up to the present has been driven largely by photosynthetic organisms-roughly three quarters by phytoplankton and algae in the oceans and one quarter by terrestrial plants . (newworldencyclopedia.org)
Amounts of oxygen1
  • Babies with heart or lung problems may need to breathe increased amounts of oxygen to get normal levels of oxygen in their blood. (coordinatedhealth.com)
Addition to oxygen1
  • In addition to oxygen debt, your body also has to replenish the glycogen that it uses during a workout. (fitday.com)
Levels6
Metabolic2
  • Unbound oxygen (called molecular oxygen or molecular dioxygen, O 2 ) is thought to have first appeared in significant quantities on our planet during the Paleoproterozoic era (2500-1600 million years ago), produced by the metabolic action of early single-celled organisms classified as archaea and bacteria . (newworldencyclopedia.org)
  • Oxygen also buffers/oxidizes metabolic waste acids helping to keep you more alkaline. (cancerbuster.net)
Measurement2
  • respectively) on the crystal structure, order-disorder phase transition, microstructure, oxygen permeability and structure stability of SrCo 0.8 Fe 0.2 O 3-δ (SCF) were investigated by XRD, TG-DSC, SEM, oxygen permeation measurement and the partial oxidation of methane (POM) to syngas reaction. (aston.ac.uk)
  • membrane was about 10 times higher than that in the oxygen permeation measurement at 1223 K, and the SCFA3 membrane was successfully operated in the POM reaction for more than 500 h without fracture. (aston.ac.uk)
Tissues2
  • According to Annelie Pompe, a prominent mountaineer and world-champion free diver , alkaline tissues can hold up to 20 times more oxygen than acidic ones . (cancerbuster.net)
  • When our body cells and tissues are acidic (below pH of 6.5-7.0), they lose their ability to exchange oxygen. (cancerbuster.net)
Therapy1
Free oxygen2
  • At ordinary temperatures and pressures, free oxygen (unbound to any other element) is a colorless, odorless, tasteless gas that makes up about 21% (by volume) of air. (newworldencyclopedia.org)
  • According to expert opinion, this new presence of large amounts of free oxygen drove most of the organisms then living to extinction. (newworldencyclopedia.org)
Deliver oxygen1
Increase oxygen2
  • The quickest way to increase oxygen and pH is through the administration of sodium bicarbonate and that is why bicarbonate has always been a mainstay emergency room and intensive care medicine . (cancerbuster.net)
  • The World Health Organization is hoping to raise $ 250 million to increase oxygen delivery to those regions. (medxr.com)
Lung1
Molecular2
  • Since then, the definition of an acid has been revised so that oxygen is not necessarily part of the molecular structure of every acid. (newworldencyclopedia.org)
  • In this concept, oxygen mass transfer occurred by molecular diffusion through a thin film in stagnant fluid underlying the surface of the bulk liquid phase. (biologydiscussion.com)
Blood6
  • Your body uses red blood cells to transport oxygen to all of the different muscles that have to work together during a cardio workout. (fitday.com)
  • Under certain conditions, too much oxygen in the blood may also lead to problems in the brain and eye. (coordinatedhealth.com)
  • Standard thought was that mammalian blood is always completely saturated with oxygen," said Patrick J. Drew, Huck Distinguished Associate Professor of Neural Engineering and Neurosurgery and associate director of the Penn State Neuroscience Institute. (bionewscentral.com)
  • That would mean that the only way to get more oxygen to the brain would be to get more blood to the brain by increasing blood flow. (bionewscentral.com)
  • The critical oxygen blood level is 55-60mmHg (SaO 2 ), with readings below this level indicating the person is underoxygenated. (easyoxygen.com.au)
  • The underlying principle of the oximeter is that it measures the redness of the blood - the redder the blood the higher the oxygen saturation. (easyoxygen.com.au)