All articles starting with P

Pyronaridine

Pyronaridine, a benzonaphthyridine antimalarial synthesized in China in 1970, is used with artesunate (Pyramax) as a WHO-recommended ACT for uncomplicated falciparum malaria; transient transaminase rises are its main safety signal.

Pyronemataceae

Pyronemataceae (Corda, 1842), synonyms Humariaceae and Otidiaceae, is the largest family of cup fungi in Pezizales, Ascomycota, with about 75–78 genera and 500–660 species, mostly temperate, saprotrophic or mycorrhizal, and not monophyletic as circumscribed.

Oct 15, 2026

Pyrope

Pyrope is the magnesium-aluminum garnet, a blood-red gem mineral from mantle rocks such as kimberlite, known in the jewelry trade as the classic Bohemian garnet.

Pyrophoricity

Pyrophoricity is the chemical property of a material that ignites spontaneously in air without an ignition source at or below 54.4 °C (130 °F), even in small quantities.

Pyrophosphate

Pyrophosphate (inorganic pyrophosphate, PPi, diphosphate) is the anion of pyrophosphoric acid, formed in cells by ATP hydrolysis and a key endogenous inhibitor of hydroxyapatite mineralization.

Pyrophosphate hydrolysis

Pyrophosphate hydrolysis (PPi + H2O → 2 Pi), catalyzed by inorganic pyrophosphatase (EC 3.6.1.1), removes PPi from biosynthetic reactions, driving synthesis forward; human enzymes PPA1, PPA2, LHPP.

Pyrophosphate-energised proton pump

Pyrophosphate-energised proton pump (H+-PPase, V-PPase, mPPase, EC 7.1.3.1): an integral membrane enzyme coupling pyrophosphate hydrolysis to H+ or Na+ pumping in plants, protists, bacteria, and archaea, unrelated to ATPases.

Oct 15, 2026

Pyrophyllite

Pyrophyllite is a soft hydrous aluminum silicate mineral with the formula Al2Si4O10(OH)2, similar to talc, named in 1829 for exfoliating into fan shapes when heated, and mined chiefly for refractories and ceramics.

Oct 15, 2026

Pyroprocessing

Pyroprocessing, or electrometallurgical processing, is a family of molten salt reprocessing technologies that treat spent nuclear fuel to recover uranium and transuranic elements for reuse.

Pyroptosis

Pyroptosis: lytic, inflammatory programmed cell death executed by gasdermin D pores after caspase-1/4/5/11 activation, releasing IL-1β and DAMPs; distinct from apoptosis and necroptosis, involved in infection defense, inflammation, and cancer.

Pyroquilon

Pyroquilon (pyroquilone, CGA 49104, Coratop) is a systemic pyrroloquinolinone fungicide, a melanin biosynthesis reductase inhibitor (MBI-R, FRAC 16.1) used against rice blast; developed 1973, marketed 1985, not EU-approved.

Sep 29, 2026

Pyrosequencing

Pyrosequencing is a real-time DNA sequencing-by-synthesis method, developed by Pål Nyrén's group, that converts pyrophosphate release into light peaks used for SNP genotyping and quantitative CpG methylation analysis.

Pyrosoma atlanticum

Pyrosoma atlanticum (Péron, 1804), the most widespread pyrosome, is a bioluminescent colonial pelagic tunicate forming gelatinous tubes of zooids across 50°N–50°S, known for blooms, size-dependent vertical migration, and carbon export.

Pyrosome

A pyrosome (Pyrosomida) is a free-floating colonial tunicate, a hollow gelatinous tube built from hundreds to thousands of cloned zooids that glows blue through symbiotic bacteria.

Pyrotechnics

Pyrotechnics is the science and craft of creating exothermic chemical effects such as light, color, sound, and smoke, covering fireworks, film special effects, signal flares, and safety devices like airbags.

Pyrotinib maleate (Irene)

Pyrotinib maleate (Irene, 马来酸吡咯替尼) is Hengrui's oral irreversible HER1/HER2/HER4 kinase inhibitor, approved in China in 2018 for HER2-positive metastatic breast cancer, with phase III PFS gains in PHOEBE and PHILA.

Pyrovalerone

Pyrovalerone is a synthetic cathinone stimulant developed in the 1960s to treat lethargy, fatigue, and obesity, and withdrawn from medical use after reports of abuse. It inhibits the dopamine and norepinephrine transporters.

Pyroxasulfone

Pyroxasulfone (developmental code KIH-485) is a pre-emergence herbicide developed by Kumiai Chemical Industry that controls annual grasses and broadleaf weeds in wheat, corn, and soybeans at low application rates.

Pyroxene

Pyroxene is the name of a group of dark rock-forming chain silicate minerals with formula XYZ₂O₆, abundant in igneous and metamorphic rocks and important in the Earth's upper mantle.

Pyroxsulam

Pyroxsulam is an ALS-inhibiting triazolopyrimidine sulfonamide herbicide discovered by Dow AgroSciences in 1998, sold as PowerFlex and Simplicity for selective post-emergence weed control in wheat.

Pyrrhae Chaos

Pyrrhae Chaos is a 162-km-wide chaotic terrain in Pyrrhae Regio, Mars, east of Valles Marineris, named by the IAU in 1982; studies propose a volcano-tectonic, caldera-collapse origin rather than a water-driven one.

Pyrrhae Fossae

Pyrrhae Fossae: a 430-km IAU-named system of east-west graben on Mars in northwestern Noachis Terra, centered at 29.2°S, 336.2°E; named for the classical albedo feature Pyrrhae, approved 2016, formed about 3.79 Ga.

Pyrrharctia isabella

Pyrrharctia isabella, the Isabella tiger moth (banded woolly bear caterpillar), a North American erebid moth found across the US, Canada, and Mexico; its black-and-rust larva is a freeze-tolerant winter forecaster of folklore, not fact.

Pyrrhic victory

A Pyrrhic victory is a win so costly that it amounts to a defeat, named for King Pyrrhus of Epirus, whose battles against Rome drained his army.

Pyrrhic War

Pyrrhic War (280–275 BC): war between the Roman Republic and Pyrrhus of Epirus, who fought for Tarentum. Tactical wins at Heraclea and Asculum cost so much they gave rise to the term Pyrrhic victory; ended at Beneventum.

Pyrrho

Pyrrho (Πύρρων, c. 365–360 to 275–270 BCE) of Elis, founder figure of Pyrrhonism, wrote nothing; his reported thesis that things are indifferent, unmeasurable, and indeterminate is known mainly through Timon and the Aristocles passage.

Pyrrhocorax

Pyrrhocorax is a genus of crows containing just two glossy black species, the red-billed chough and the alpine chough, mountain and coastal birds with brightly colored bills and legs.

Pyrrhocoridae

Pyrrhocoridae (red bugs, cotton stainers) is an Old World family of Heteroptera in Pyrrhocoroidea, about 46 genera and 450 species, including the cotton pest Dysdercus and the firebug Pyrrhocoris apterus.