by Yuri VLADIMIROV, Academician of the Russian Academy of Medical Sciences, Head of the Department of Medical Biophysics, Faculty of Fundamental Medicine, Lomonosov Moscow State University The nonthermal phosphorescence of a substance-luminescence (fluorescence) has been known since the 18th century. However, only in the 20th century, with the development of physics of elementary particles, it received a clear scientific explanation. It is now used not only for practical purposes (lamps, cathode ray tubes, etc.), but also as an instrument for studies of the matter. Now we know that absorption of photons (electromagnetic radiation quanta) in living systems often leads to formation of chemically aggressive particles-free radicals. Reactions with their participation are often associated with energy release in the form of photons. The Russian scientists made an important contribution to studies of these intricate physicochemical processes. стр. 4 Electronic transitions in the course of absorption and luminescence (above) in oxidation-reduction reactions (in the middle), in photochemical reactions and hemiluminescence (below). Blue circles-upper filled in electronic orbitals, red circles-lower free orbitals of oxidized forms of molecules (A). AH2-reduced forms of molecules, A*-molecules in electronic excited state. Dots to the left from letters-unpaired electrons in radicals, figures-reaction numbers. BIOPHOTONICS The term "photonics" was suggested in 1961 by Academician (from 1939) Alexander Terenin, physico-chemist, founder of the Soviet school of photochemistry. He defined it as a "sphere of science, studying the totality of interrelated photophysical and photochemical processes which occur during light absorption by a substance". Hence, biophotonics (previously called quantum biophysics) is a science of radiation, absorption, diffusion, and activity of photons in biological systems. It incl ... Читать далее