Related topics: cells · mitochondria · antioxidants

Sunscreen ingredient may pose skin cancer risk, researchers find

(Phys.org) -- As vacationers prepare to spend time outdoors this summer, many of them will pack plenty of sunscreen in hopes it will protect their bodies from overexposure, and possibly from skin cancer. But researchers at ...

Innovative light therapy reaches deep tumors

Light long has been used to treat cancer. But phototherapy is only effective where light easily can reach, limiting its use to cancers of the skin and in areas accessible with an endoscope, such as the gastrointestinal tract.

The Long and the Short of Acrylate Polymerization

(PhysOrg.com) -- Used in such diverse applications as adhesives, detergents, and super-absorbent disposable diapers, polyacrylates are key polymers, but the mechanisms of their formation are complex and have long been incompletely ...

Ants self-medicate to fight disease

We humans have been using self-medication to cure the illnesses since the dawn of our species. There is some evidence that also other animals can exhibit this type of behavior, but the evidence has been hard to come by.

Nano-antioxidants prove their potential

Injectable nanoparticles that could protect an injured person from further damage due to oxidative stress have proven to be astoundingly effective in tests to study their mechanism.

Scientists reveal how females store sperm for decades

(PhysOrg.com) -- Scientists have discovered that all sorts of females – from birds to reptiles to insects – have a nifty trick to prolong the lifespan of sperm, letting them store it for weeks, months or even years ...

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Radical (chemistry)

In chemistry, radicals (often referred to as free radicals) are atoms, molecules, or ions with unpaired electrons on an otherwise open shell configuration. These unpaired electrons are usually highly reactive, so radicals are likely to take part in chemical reactions. Radicals play an important role in combustion, atmospheric chemistry, polymerization, plasma chemistry, biochemistry, and many other chemical processes, including human physiology. For example, superoxide and nitric oxide regulate many biological processes, such as controlling vascular tone. "Radical" and "free radical" are frequently used interchangeably, although a radical may be trapped within a solvent cage or be otherwise bound. The first organic free radical identified was triphenylmethyl radical, by Moses Gomberg in 1900 at the University of Michigan.

Historically, the term radical has also been used for bound parts of the molecule, especially when they remain unchanged in reactions. These are now called functional groups. For example, methyl alcohol was described as consisting of a methyl "radical" and a hydroxyl "radical". Neither are radicals in the modern chemical sense, as they are permanently bound to each other, and have no unpaired, reactive electrons. They can, however, be observed as radicals in mass spectrometry after breaking down the substance with a hail of energetic electrons.

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