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Metaproterenol
Metaproterenol, also known as orciprenaline, is a beta-adrenergic agonist bronchodilator used to treat bronchospasm in asthma, chronic bronchitis, and emphysema, marketed from the 1960s as Alupent and later withdrawn from most markets.
METAR
METAR, short for Meteorological Aerodrome Report, is a coded hourly report of surface weather at an airport, covering wind, visibility, clouds, temperature, and altimeter setting.
Metaraminol
Metaraminol, sold as Aramine, is a sympathomimetic amine vasopressor used to treat acute hypotension, especially during spinal anaesthesia, acting mainly at alpha-1 receptors and also displacing norepinephrine as a false transmitter.
Metascience
Metascience is the study of science itself, applying philosophical, historical, sociological, and empirical methods to evaluate and improve research practice; it grew rapidly after the reproducibility crisis of the 2010s.
Metasomatism
Metasomatism is the transformation of a rock's chemical composition through reactions with infiltrating fluids, distinguishing it from metamorphism and forming skarns and many ore deposits.
Metastability
Metastability is the condition of a system in a local, but not global, minimum of its free energy, requiring an energy barrier higher than thermal energy to escape, as in supercooled water and metastable flip-flop outputs.
Metastable titanium alloys
Metastable titanium alloys are titanium alloys whose β phase, retained by β-stabilizing elements, can transform during processing or deformation; they serve in aerospace structures and orthopedic implants.
Metastable transfer emission spectroscopy
Metastable transfer emission spectroscopy (MTES) is an optical emission technique in which metastable active nitrogen excites analyte atoms, and the emitted light identifies and quantifies trace species.
Metasurface
A metasurface is a two-dimensional array of subwavelength scatterers, or meta-atoms, on a thin planar layer that controls light's phase, amplitude, and polarization, entering consumer devices in 2022.
Metasurface analog computing
Metasurface analog computing is the direct execution of mathematical operations, such as differentiation, convolution, and Fourier transformation, on optical wavefronts using metasurfaces, first proposed in 2014.
Metasurface holograms
A metasurface hologram is a hologram encoded in an ultrathin planar array of subwavelength nanostructures that shapes light's phase and polarization, used in optical security, anticounterfeiting, displays, and beam shaping.
Metasurface holograms for visible light
Metasurface holograms for visible light are holograms made from ultrathin planar arrays of nanostructures that reconstruct images in visible light, first demonstrated at Purdue University in 2013.
Metasurface perfect absorbers
A metasurface perfect absorber is an engineered, subwavelength-thick surface that absorbs nearly all incident electromagnetic radiation at selected frequencies, first proposed in 2008 and used for stealth, sensing, and solar energy.
Metasurface polarization converter
A metasurface polarization converter is an ultrathin array of subwavelength elements that converts light or microwave polarization, linear-to-linear, circular, or elliptical, within a subwavelength thickness.
Metasurface quantum emitter
A metasurface quantum emitter is a single-photon emitter, such as a quantum dot or color center, coupled to an ultrathin nanostructure array that reshapes its emission direction, rate, and structure.
Metasurfaces for spin-Hall effect of light
Metasurfaces for the spin-Hall effect of light are planar arrays of subwavelength optical antennas that greatly amplify the photonic spin Hall effect, first demonstrated in 2013 with V-shaped gold nanoantennas.
Metathesis polymerization
Metathesis polymerization builds unsaturated polymers from olefin monomers using metal carbene catalysts; its main forms are ring-opening ROMP of strained cyclic olefins and ADMET, which releases ethylene.
Metavalent bonding
Metavalent bonding is a mode of chemical bonding in solids lying between covalent and metallic, where adjacent atoms share about one electron, formalized in 2018.
Mete Atature
Mete Atatüre is a Turkish-born quantum physicist specializing in solid-state quantum optics, known for spin-photon quantum interfaces in quantum dots, and has led Cambridge's Cavendish Laboratory since 2023.
Météo-France
Météo-France is the French national meteorological service, a public establishment created in 1993 and headquartered in Toulouse, which issues forecasts and warnings for France and its overseas territories.
Meteor
A meteor, called a falling star or shooting star, is the streak of light produced when a meteoroid enters a planetary atmosphere at high speed and usually vaporizes.
Meteor shower
A meteor shower, also called a meteor swarm or star shower, is a recurring increase in meteors seen when Earth passes through dust streams shed mainly by comets.
Meteorite
A meteorite, also called an aerolite, is a natural solid object from space that survives its fiery passage through an atmosphere. Most come from asteroids, with a few from the Moon and Mars.
Meteoroid
A meteoroid is a small natural solid object moving through interplanetary space, typically a fragment of a comet or asteroid, defined by the IAU as 30 micrometers to 1 meter.
Meteoroid stream
A meteoroid stream is a population of dust to pebble-sized particles sharing similar orbits because they were released from the same parent body, usually a comet.
Meteorological reanalysis
Meteorological reanalysis is a method that reprocesses historical weather observations through a fixed, unchanging numerical weather prediction system, yielding consistent gridded estimates of past atmospheric states.
Meteorological Service of Canada
The Meteorological Service of Canada, founded in 1871, is Canada's federal agency for weather forecasts, warnings, and climate information, operating within Environment and Climate Change Canada.
Meteorologist
A meteorologist, also known as a weather forecaster, is a physical scientist who observes, studies, or forecasts the weather, typically holding a degree in meteorology or a related physical science.
Meteorology
Meteorology is the science of the Earth's atmosphere and its physical processes; modern weather forecasting rests on numerical weather prediction, a global observing system, and machine-learning models.
Meteosat Third Generation
Meteosat Third Generation (MTG) is a European system of geostationary weather satellites developed by ESA and operated by EUMETSAT to image weather over Europe and Africa.