Dopamine (contracted from 3,4-dihydroxyphenethylamine) is an organic chemical of the catecholamine and phenethylamine families that plays several important roles in the brain and body.
In competitive sports, doping refers to the use of banned athletic performance-enhancing drugs by athletic competitors, where the term doping is widely used by organizations that regulate sporting competitions.
The Doppler effect (or the Doppler shift) is the change in frequency or wavelength of a wave (or other periodic event) for an observer moving relative to its source.
In fiction and folklore, a doppelganger or doppelga(e)nger (/ˈdɒpəlˌɡɛŋə/ or /-ˌɡæŋə/; German: [ˈdɔpəlˌɡɛŋɐ], literally "double-goer") is a look-alike or double of a living person, sometimes portrayed as a paranormal phenomenon, and is usually seen as a harbinger of bad luck.
In semiconductor production, doping is the intentional introduction of impurities into an intrinsic semiconductor for the purpose of modulating its electrical properties.
There have been allegations of doping in the Tour de France since the race began in 1903. Early Tour riders consumed alcohol and used ether, among other substances, as a means of dulling the pain of competing in endurance cycling.
Dopamine receptors are a class of G protein-coupled receptors that are prominent in the vertebrate central nervous system (CNS).
Doping in Russian sports is a significant issue. Russia has had the most (35) Olympic medals stripped for doping violations – nearly triple the number of the second country.
Doppelgänger is a 1969 British science fiction film directed by Robert Parrish and starring Roy Thinnes, Ian Hendry, Lynn Loring and Patrick Wymark.