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Photoaffinity Labels
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D019920 |
[Biologically active molecules which are covalently bound to the enzymes or binding proteins normally acting on them. Binding occurs due to activation of the label by ultraviolet light. These labels are used primarily to identify binding sites on proteins.
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Photobacterium
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D010776 |
[A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that are common in the marine environment and on the surfaces and in the intestinal contents of marine animals. Some species are bioluminescent and are found as symbionts in specialized luminous organs of fish.
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Photobiology
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D018462 |
[The branch of biology dealing with the effect of light on organisms.
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Photobioreactors
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D058433 |
[Devices for generating biological products that use light as the energy source. They are used for controlled BIOMASS production such as growing cyanobacteria, mosses, or algae.
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Photobleaching
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D038761 |
[Light-induced change in a chromophore, resulting in the loss of its absorption of light of a particular wave length. The photon energy causes a conformational change in the photoreceptor proteins affecting PHOTOTRANSDUCTION. This occurs naturally in the retina (ADAPTATION, OCULAR) on long exposure to bright light. Photobleaching presents problems when occurring in PHOTODYNAMIC THERAPY, and in FLUORESCENCE MICROSCOPY. On the other hand, this phenomenon is exploited in the technique, FLUORESCENCE RECOVERY AFTER PHOTOBLEACHING, allowing measurement of the movements of proteins and LIPIDS in the CELL MEMBRANE.
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Photochemical Processes
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D055668 |
[Chemical reactions effected by light.
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Photochemistry
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D010777 |
[A branch of physical chemistry which studies chemical reactions, isomerization and physical behavior that may occur under the influence of visible and/or ultraviolet light.
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Photochemotherapy
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D010778 |
[Therapy using oral or topical photosensitizing agents with subsequent exposure to light.
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Photoelectron Spectroscopy
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D056951 |
[A form of photoelectron spectroscopy in which a sample is irradiated with a beam of ULTRAVIOLET RAYS and the energies of the resulting photoelectrons are analyzed.
, The study of the energy of electrons ejected from matter by the photoelectric effect, i.e., as a direct result of absorption of energy from electromagnetic radiation. As the energies of the electrons are characteristic of a specific element, the measurement of the energy of these electrons is a technique used to determine the chemical composition of surfaces.
, A form of photoelectron spectroscopy in which a sample is irradiated with a beam of monochromatic X-RAYS and the energies of the resulting photoelectrons are analyzed.
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Photofluorography
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D010779 |
[The photography of images produced on a fluorescent screen by X-rays.
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Photogrammetry
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D010780 |
[Making measurements by the use of stereoscopic photographs.
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Photograph
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D059036 |
[Still image produced from radiation-sensitive materials (sensitive to light, electron beams, or nuclear radiation), generally by means of the chemical action of light on a sensitive film, paper, glass, or metal. Photographs may be positive or negative, opaque or transparent.
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Photography
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D010781 |
[Method of making images on a sensitized surface by exposure to light or other radiant energy.
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Photography, Dental
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D023861 |
[Photographic techniques used in ORTHODONTICS; DENTAL ESTHETICS; and patient education.
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Photoinitiators, Dental
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D058567 |
[Chemical compound used to initiate polymerization of dental resins by the use of DENTAL CURING LIGHTS. It absorbs UV light and undergoes decomposition into free radicals that initiate polymerization process of the resins in the mix. Each photoinitiator has optimum emission spectrum and intensity for proper curing of dental materials.
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Photolysis
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D010782 |
[Chemical bond cleavage reactions resulting from absorption of radiant energy.
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Photometry
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D010783 |
[Measurement of the various properties of light.
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Photomicrography
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D010784 |
[Photography of objects viewed under a microscope using ordinary photographic methods.
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Photons
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D017785 |
[Discrete concentrations of energy, apparently massless elementary particles, that move at the speed of light. They are the unit or quantum of electromagnetic radiation. Photons are emitted when electrons move from one energy state to another. (From Hawley's Condensed Chemical Dictionary, 11th ed)
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Photoperiod
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D017440 |
[The time period of daily exposure that an organism receives from daylight or artificial light. It is believed that photoperiodic responses may affect the control of energy balance and thermoregulation.
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