(am″fĭ-path′ik) [amphi- + -pathic] In chemistry, having polar and nonpolar (water-soluble and water-insoluble) regions within a single molecule. This two-part structure allows these chemicals to link, or to segregate, oils and water. Phospholipids, bile salts, and detergents are amphipathic molecules.
(am″fĭ-thē′ă-tĕr) [amphi- + theater] An auditorium with tiers of seats around it for students and other observers.
[Gr. amphō, both] Prefix meaning both, on both sides, of both kinds, or double. SEE: amphi-.
(am′fŏ-līt″) [ampho- + (electro)lyte] A substance that acts as a base or an acid, depending on the pH of the solution into which it is introduced. ampholytic (-lit′ik), adj.
(am″fŏ-fil′ik) [ampho- + -philic] Pert. to an amphophilic cell. SEE: amphophilic cell. SYN: amphophil.
(am″fŏ-ter′ik, am-fot′ĕr-ŭs) [Gr. amphoteros, each or both of two] Being able to react as both an acid and a base. amphoterism (am″fŏ-ter′izm), n.
(am″fŏ-ter′ĭ-sĭn) [amphoteric + -in] An antibiotic obtained from a strain of Streptomyces nodosus. The drug is usually administered intravenously to treat deep-seated fungal infections. Premedication with antipyretics, antihistamines, or corticosteroids is often necessary to decrease febrile hypersensitivity reactions. Patients must be monitored for hypokalemia or renal failure.
(am″pĭ-sĭl′ĭn) Asemisynthetic penicillin. Trade names include Amcill, Omnipen, Polycillin, and Principen.
(am′plĭ-kon″) An amplified segment of specific DNA or RNA sequences in which multiple copies of the nucleic acid sequences are found. Amplicons can be made during polymerase chain reactions or may occur spontaneously, e.g., in the nucleic acid content of certain organisms or tumors.
(am″plĭ-fĭ-kā′shŏn) [L. amplificatio, enlargement] 1. Magnification, expansion, or enlargement. 2. In pharmacology, the slope of the dose-effect curve, i.e., how much the effect of a drug increases as the dosage of the drug increases.
(am′plĭ-fī″ĕr) 1. That which enlarges, extends, increases, or makes more powerful. 2. In electronics, a device for increasing the electric current or signal.
(am′plĭ-tood″) [L. amplitudo] 1. Amount, extent, size, abundance, or fullness. 2. In physics, the extent of movement, as of a pendulum or sound wave. The maximum displacement of a particle, as that of a string vibrating, as measured from the mean to the extreme. 3. Magnitude of an action potential. 4. In radiography, the extent of tube travel during tomography.
a. of accommodation The difference in the refractive power of the eye when accommodating for ...