MeSH

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.

Year introduced: 1963

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.

Year introduced: 1993

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)

Year introduced: 1966

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.

Year introduced: 2002

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.

Extent to which HEMOGLOBIN is saturated with OXYGEN typically as measured in arterial blood. It can be measured by various methods (e.g., PULSE OXYMETER, blood gas analysis). A low blood oxygen saturation level indicates a condition called HYPOXEMIA.

Year introduced: 2022

Inorganic compounds that contain oxygen as an integral part of the molecule.

Year introduced: 1998

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.

Year introduced: 1975

A measure of the ability of a substance, such as a food, to quench oxygen free radicals in vitro.

Year introduced: 2017

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.

Year introduced: 2011

Enzymes that catalyze the cleavage of a phosphorus-oxygen bond by means other than hydrolysis or oxidation. EC 4.6.

Year introduced: 1998

Enzymes that catalyze the cleavage of a carbon-oxygen bond by means other than hydrolysis or oxidation. EC 4.2.

Year introduced: 1998

Enzymes that catalyze the joining of two molecules by the formation of a carbon-oxygen bond. EC 6.1.

Year introduced: 1998

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 and Stedman, 25th ed)

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.

Year introduced: 1965(1964)

Sub-optimal OXYGEN levels in the ambient air of living organisms.

Year introduced: 2017 (1966)

MW of 5 major ORPs are 260, 150, 100, 80 & 30kD; extreme hypoxia induces enhanced synthesis of ORPS; RefSeq NM_138867 (Orp150, rat); NM_006389 (HYOU1, human); NM_021395 (Hyou1, mouse)

Date introduced: October 29, 1986

An enzyme of the oxidoreductase class primarily found in PLANTS. It catalyzes reactions between linoleate and other fatty acids and oxygen to form hydroperoxy-fatty acid derivatives.

Year introduced: 1992

A measurement of OXYGEN uptake in a sitting, resting person (resting oxygen consumption), varying with age, sex, race, and other factors. In normal adult men, one MET is approximately 3.5 ml O2/kg/min of body weight. Oxygen uptake during activities or work can be measured in METs which can be use to determine health status and exercise prescription.

Year introduced: 2009

A large multisubunit protein complex found in the THYLAKOID MEMBRANE. It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to catalyze the splitting of WATER into DIOXYGEN and of reducing equivalents of HYDROGEN.

Year introduced: 2004