Diseases, Conditions, Syndromes

Researchers survey immune molecules found inside mycetoma lesions

Mycetoma is a common neglected disease caused by either fungi or bacteria which organize themselves into grains—areas of inflammation surrounded by a collagen capsule. Now, researchers reporting in PLOS Neglected Tropical ...

Medical research

Fish oil and cancer prevention

Increased dietary intake of fish oil, with its "healthy" omega-3 fatty acids, has been proposed to reduce risk of colorectal cancer. How it works is unclear, but it is thought to modify lipid signaling molecules associated ...

Oncology & Cancer

Redundancies in T cells

Researchers at ETH Zurich have discovered redundancies in the biochemical signalling pathways of immune cells. This finding has important implications for advances in cancer immunotherapy, among other areas.

Diseases, Conditions, Syndromes

Proteasome inhibitors show promise for drug-resistant malaria

Proteasome inhibitors have significant promise as components of novel combination therapies to treat multidrug-resistant malaria, according to a study published June 6 in the open-access journal PLOS Pathogens by David Fidock, ...

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Molecule

A molecule is defined as a sufficiently stable, electrically neutral group of at least two atoms in a definite arrangement held together by very strong (covalent) chemical bonds. Molecules are distinguished from polyatomic ions in this strict sense. In organic chemistry and biochemistry, the term molecule is used less strictly and also is applied to charged organic molecules and biomolecules.

In the kinetic theory of gases the term molecule is often used for any gaseous particle regardless of its composition. According to this definition noble gas atoms are considered molecules despite the fact that they are composed of a single non-bonded atom.

A molecule may consist of atoms of a single chemical element, as with oxygen (O2), or of different elements, as with water (H2O). Atoms and complexes connected by non-covalent bonds such as hydrogen bonds or ionic bonds are generally not considered single molecules.

No typical molecule can be defined for ionic crystals (salts) and covalent crystals (network solids), although these are often composed of repeating unit cells that extend either in a plane (such as in graphene) or three-dimensionally (such as in diamond or sodium chloride). The theme of repeated unit-cellular-structure also holds for most condensed phases with metallic bonding. In glasses (solids that exist in a vitreous disordered state), atoms may also be held together by chemical bonds without any definable molecule, but also without any of the regularity of repeating units that characterises crystals.

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