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Oxidative stress mechanisms in tissue injury. Free radical toxicity induced by xenobiotics and the subsequent detoxification by cellular enzymes (termination).. Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage. [1]
According to the free radical theory of aging, oxidative damage initiated by reactive oxygen species is a major contributor to the functional decline that is characteristic of aging.
2,4,6-TTBP is used as stabilizers, free-radical scavengers and antioxidants in technical applications, such as in fuels, hydraulic fluids and lubricating oils, as well as in elastomeric and thermoplastic polymers.
Thioesters: Act by decomposing peroxides into non-radical products. Thioesters are also used as co-stabilisers with primary antioxidants. [citation needed] Hindered Amine Light Stabilizers (HALS): HALS act by scavenging free radicals generated during photo-oxidation, thus preventing the polymer material from UV radiation. [citation needed]
The regulation theory considers a polyphenolic ability to scavenge free radicals and up-regulate certain metal chelation reactions. [1] Various reactive oxygen species, such as singlet oxygen, peroxynitrite and hydrogen peroxide, must be continually removed from cells to maintain healthy metabolic function.
The free radical theory of aging states that organisms age because cells accumulate free radical damage over time. [1] A free radical is any atom or molecule that has a single unpaired electron in an outer shell. [2] While a few free radicals such as melanin are not chemically reactive, most biologically relevant free radicals are highly ...
In atmospheric chemistry, the most common scavenger is the hydroxyl radical, a short-lived radical produced photolytically in the atmosphere. It is the most important oxidant for carbon monoxide, methane and other hydrocarbons, sulfur dioxide, hydrogen sulfide, and most of other contaminants, removing them from the atmosphere.
Radical polymerisation of unsaturated monomers is generally propagated by C-radicals. These can be effectively terminated by combining with other radicals to form neutral species and many true inhibitors operate through this mechanism. In the simplest example oxygen can be used as it exists naturally in its triplet state (i.e. it is a diradical).