Neuroscience

Cannabinoids decrease the metabolism of glucose in the brain

The nervous system comprises neurons and glial cells (glia means 'glue'). Astrocytes are the most abundant among the glial cells. Among many other functions they undertake to capture glucose from the blood stream to provide ...

Cardiology

Newly discovered mechanism regulates myocardial distensibility

A healthy heart beats 50 to 100 times a minute and pumps 8,000 liters of blood around our body every day. A precondition for this function is the elasticity of the cardiac walls, which dilate as blood flows in (diastole) ...

Inflammatory disorders

New imaging agent spotlights inflammation

Many of the most common diseases—cancer, diabetes, cardiovascular and lung disease, and even COVID-19—have been linked to chronic or excessive inflammation. Blood tests can indicate that some part of a person's body is ...

Diseases, Conditions, Syndromes

Time to decannulation shorter if based on suctioning frequency

(HealthDay)—A protocol based on suctioning frequency plus continuous high-flow oxygen therapy results in a shorter time to decannulation among conscious, critically ill patients with a tracheostomy tube, according to a ...

Biomedical technology

Oxygen-releasing bioink for 3-D bioprinting

Engineering new tissues can be used to alleviate shortages of organs in transplantation, as well as to develop physiological models for drug discovery applications. One of the emerging approaches to building tissues is through ...

Medical research

A lack of oxygen in tumors promotes metastasis

Metastases are formed by cancer cells that break away from the primary tumor. A research group at the University of Basel has now identified lack of oxygen as the trigger for this process. The results reveal an important ...

Diseases, Conditions, Syndromes

Mask up and breathe easy: Masks have no effect on oxygen levels

Wearing a mask, while necessary and required at the University of Kentucky, can cause some people to feel anxious and panic. It's all a part of "anxiety sensitivity," a psychological trait that causes people to view certain ...

page 1 from 100

Oxygen

Oxygen (pronounced /ˈɒksɨdʒɨn/, from the Greek roots ὀξύς (oxys) (acid, literally "sharp", from the taste of acids) and -γενής (-genēs) (producer, literally begetter) is the element with atomic number 8 and represented by the symbol O. It is a member of the chalcogen group on the periodic table, and is a highly reactive nonmetallic period 2 element that readily forms compounds (notably oxides) with almost all other elements. At standard temperature and pressure two atoms of the element bind to form dioxygen, a colorless, odorless, tasteless diatomic gas with the formula O2. Oxygen is the third most abundant element in the universe by mass after hydrogen and helium and the most abundant element by mass in the Earth's crust. Diatomic oxygen gas constitutes 20.9% of the volume of air.

All major classes of structural molecules in living organisms, such as proteins, carbohydrates, and fats, contain oxygen, as do the major inorganic compounds that comprise animal shells, teeth, and bone. Oxygen in the form of O2 is produced from water by cyanobacteria, algae and plants during photosynthesis and is used in cellular respiration for all complex life. Oxygen is toxic to obligately anaerobic organisms, which were the dominant form of early life on Earth until O2 began to accumulate in the atmosphere 2.5 billion years ago. Another form (allotrope) of oxygen, ozone (O3), helps protect the biosphere from ultraviolet radiation with the high-altitude ozone layer, but is a pollutant near the surface where it is a by-product of smog. At even higher low earth orbit altitudes monatomic oxygen (O1) is a significant presence and a cause of erosion for spacecraft.

Oxygen was independently discovered by Carl Wilhelm Scheele, in Uppsala, in 1773 or earlier, and Joseph Priestley in Wiltshire, in 1774, but Priestley is often given priority because his publication came out in print first. The name oxygen was coined in 1777 by Antoine Lavoisier, whose experiments with oxygen helped to discredit the then-popular phlogiston theory of combustion and corrosion. Oxygen is produced industrially by fractional distillation of liquefied air, use of zeolites to remove carbon dioxide and nitrogen from air, electrolysis of water and other means. Uses of oxygen include the production of steel, plastics and textiles; rocket propellant; oxygen therapy; and life support in aircraft, submarines, spaceflight and diving.

This text uses material from Wikipedia, licensed under CC BY-SA