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The oxygen enhancement ratio (OER) or oxygen enhancement effect in radiobiology refers to the enhancement of therapeutic or detrimental effect of ionizing radiation due to the presence of oxygen. This so-called oxygen effect [ 1 ] is most notable when cells are exposed to an ionizing radiation dose .
The best known explanation of the oxygen effect is the oxygen fixation hypothesis developed by Alexander in 1962, [9] which posited that radiation-induced non-restorable or "fixed" nuclear DNA lesions are lethal to cells in the presence of diatomic oxygen. [10] [11] Recent hypotheses include one based on oxygen-enhanced damage from first ...
Oxygen enhancement ratio, effect magnitude of ionizing radiation due to the presence of oxygen Oxygen Evolution Reaction , the formation of oxygen by electrochemical reduction of water Owner’s Equivalent Rent, an economic metric for housing prices often used in the calculation of market baskets
Tumor stroma and extracellular matrix in hypoxia. Tumor hypoxia is the situation where tumor cells have been deprived of oxygen.As a tumor grows, it rapidly outgrows its blood supply, leaving portions of the tumor with regions where the oxygen concentration is significantly lower than in healthy tissues.
Multiple studies have investigated this possibility, one being Jin. et al., 2020, where it was observed that circulating blood cells experienced a significantly lower impact during FLASH-RT, resulting in the killing of only 5-10% of cells, in contrast, CONV-RT exhibited a much more substantial effect, leading to the death of 90-100% of cells. [14]
Oxygen equivalent compares the relative amount of oxygen available for respiration at a variable pressure to that available at SATP.As external respiration depends on the exchange of gases due to partial pressures across a semipermeable membrane and normally occurs at SATP, an oxygen equivalent may aid in recognizing and managing variable oxygen availability during procedures such as ...
Commercially available medical linacs produce X-rays and electrons with an energy range from 4 MeV up to around 25 MeV. The X-rays themselves are produced by the rapid deceleration of electrons in a target material, typically a tungsten alloy, which produces an X-ray spectrum via bremsstrahlung radiation.
Yttrium-90 is produced by the nuclear decay of strontium-90 which has a half-life of nearly 29 years and is a fission product of uranium used in nuclear reactors. As the strontium-90 decays, chemical high-purity separation is used to isolate the yttrium-90 before precipitation.