All articles starting with M

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, 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.

Oct 21, 2026

Metarhizium

Metarhizium is a genus of Clavicipitaceae fungi that kill insects via cuticle penetration and also act as plant root symbionts. Key species include M. anisopliae and M. acridum, used widely in mycoinsecticides for pest and tick control.

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.

Metasearch engine

A metasearch engine, also called meta-search, forwards a query to multiple search engines at once and fuses the results into one list; early examples include MetaCrawler (1995) and Dogpile (1996).

Metasequoia

Metasequoia (dawn redwood, 水杉) is a genus of deciduous conifers in Cupressaceae with one living species, M. glyptostroboides, described from fossils by Miki in 1941 and rediscovered alive in Hubei, China in the 1940s; IUCN Endangered.

Metasequoia glyptostroboides (水杉)

Metasequoia glyptostroboides (水杉, shui shan), dawn redwood, is a deciduous conifer and living fossil from Lichuan, Hubei, China; described from fossils by Miki in 1941, rediscovered alive in the 1940s, named by Hu and Cheng in 1948, and endangered in the wild.

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.

METASPACE

METASPACE is a cloud-based engine for metabolite annotation of imaging mass spectrometry data and a community knowledge base for spatial metabolomics, introduced in Nature Methods in 2017.

Metasploit

Metasploit is an open-source penetration testing framework written in Ruby, maintained by Rapid7 since its 2009 acquisition, whose exploits, payloads, and post-exploitation modules are used by security testers and red teams.

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.

Metastability engineering

Metastability engineering is an alloy-design strategy giving alloys metastable phases whose deformation-induced martensitic transformation raises strength and ductility, formulated for high-entropy alloys in 2016.

Metastability engineering in high-entropy alloys

Metastability engineering in high-entropy alloys is a design strategy that lowers phase stability so deformation triggers TRIP and TWIP hardening, raising strength and ductility together.

Metastable beta titanium alloys

Metastable beta titanium alloys are titanium alloys that retain the high-temperature β phase at room temperature after quenching, combining high strength, biocompatibility, and heat treatability.

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.

Sep 29, 2026

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.

Sep 29, 2026

Metastasectomy

Metastasectomy is a surgical oncology procedure that removes metastatic tumors, most often in the lung, liver, brain, bone, or adrenal gland, to treat cancer that has spread.

Metastasis

Metastasis is the spread of cancer cells from a primary tumor through blood or lymph to form new tumors elsewhere, also called stage 4 cancer; common sites are bone, liver, and lung, explained by Paget's 1889 seed and soil hypothesis.

Metástasis

Metástasis is the authorized 2014 Colombian adaptation of Breaking Bad, produced by Sony Pictures Television and Teleset, starring Diego Trujillo as Walter Blanco, 62 episodes in five seasons, filmed in Bogotá.

Sep 29, 2026

Metastasis-directed therapy

Metastasis-directed therapy (MDT) is a cancer treatment strategy for patients with limited metastatic burden, typically 1 to 5 lesions, using ablative treatments such as SABR or metastasectomy.

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 antenna

A metasurface antenna is an antenna whose radiating aperture is a metasurface, a flat sheet of subwavelength engineered elements that steers and focuses beams without phase-shifter feed networks.

Metasurface augmented-reality glasses

Metasurface augmented-reality glasses are see-through near-eye displays in which ultrathin metasurfaces replace conventional lenses and gratings, pursued as a route to lightweight, full-color AR glasses with a wide field of view.

Metasurface beam steerers

Metasurface beam steerers are flat arrays of subwavelength electromagnetic structures, or meta-atoms, that redirect beams without moving parts, serving as ultrathin alternatives to scanned mirrors and phased arrays in LiDAR, radar, and wireless links.