All articles starting with P

Propanil

Propanil (N-(3,4-dichlorophenyl)propanamide, CAS 709-98-8) is a post-emergence anilide herbicide used mainly on rice; it inhibits photosystem II, degrades to 3,4-dichloroaniline, causes methemoglobinemia, and is not approved in the EU.

Propantheline

Propantheline (Pro-Banthine) is a synthetic quaternary ammonium antimuscarinic approved by the FDA in 1953, used as adjunctive peptic ulcer therapy and for hyperhidrosis; US brand discontinued.

Propaphos

Propaphos is an organophosphorus insecticide, chemically 4-methylthiophenyl dipropyl phosphate, that kills insects by inhibiting acetylcholinesterase; it is acutely toxic and no longer approved in the European Union.

Propaquizafop

Propaquizafop (CGA 233380) is a selective aryloxyphenoxypropionate, post-emergence herbicide and quizalofop-P ester variant that inhibits ACCase to kill annual and perennial grass weeds in broad-leaved crops; EU-approved, soil half-life 1.41–7.75 days.

Propargite

Propargite (CAS 2312-35-8, Omite, Comite) is an organosulfur acaricide controlling mites on crops via ATP synthase inhibition; first US registration 1969, restricted use pesticide, not EU-approved since 2011.

Propargyl alcohol

Propargyl alcohol, also called prop-2-yn-1-ol, is the simplest acetylenic alcohol, a water-miscible liquid made as a coproduct of butynediol synthesis and used mainly to inhibit steel corrosion in hydrochloric acid.

Propargylic and homopropargylic alcohols

Propargylic and homopropargylic alcohols combine an alcohol with a carbon–carbon triple bond, one carbon apart, serving as bifunctional building blocks for pharmaceuticals and natural products.

Oct 22, 2026

Propargylic substitution

Propargylic substitution is a nucleophilic substitution reaction in organic synthesis in which a nucleophile replaces a leaving group at an alkyne's propargylic carbon, forming new carbon–carbon or carbon–heteroatom bonds.

Propatyl nitrate

Propatyl nitrate (propatylnitrate, ETTN, Etrynit, WIN 9317) is a trinitrate ester organic nitrate vasodilator (C6H11N3O9, ATC C01DA07) used for angina pectoris, releasing nitric oxide via ALDH2 bioactivation; distinct from nitroglycerin and isosorbide nitrates.

PropBank

PropBank (the Proposition Bank) is an English corpus annotated with predicate-argument structure, adding semantic role labels to the Penn Treebank's trees; it was created by Martha Palmer, Daniel Gildea, and Paul Kingsbury.

PROPEL trial (NCT02561221)

PROPEL (NCT02561221), the PROmoting Successful Weight Loss in Primary CarE in Louisiana trial, was a PCORI-funded cluster-randomized trial of 18 Louisiana clinics and 803 patients with obesity; health-coach lifestyle intervention produced 4.99% versus 0.48% weight loss at 24 months.

Propellant

A propellant is a substance or combination of substances that a rocket expends to produce thrust, including solid, liquid, and hybrid types, monopropellants, and expelled gases.

Propeller

A propeller is a rotating set of airfoil-shaped blades that converts engine rotational power into thrust by accelerating air or water backward, driving most small aircraft and ships.

Propeller One-Way Night Coach

Propeller One-Way Night Coach (Vol de nuit pour Los Angeles) is John Travolta's 2026 directorial debut, a 61-minute Apple TV family film adapted from his 1997 children's book about a boy's 1962 multi-stop TWA flight to Hollywood; it premiered at Cannes, where Travolta received an honorary Palme d'Or.

Propeller Platform (software)

The Propeller Platform is a cloud-based drone survey processing and worksite measurement platform developed by Propeller Aero, founded in Sydney in 2014, for civil construction, mining, and aggregates.

Propeller slipstream

The propeller slipstream is the accelerated, swirling column of fluid behind a ship's propeller or aircraft propeller, carrying energy that propulsive-efficiency devices try to recover.

Propellerheads

Propellerheads: British big beat duo from Bath (Alex Gifford, Will White), not the Swedish software firm. Known for "History Repeating" with Shirley Bassey, "Spybreak!" in The Matrix, and the 1998 album Decksandrumsandrockandroll.

Sep 29, 2026

Propensity score

A propensity score is the probability of receiving a treatment given observed covariates, used to reduce confounding in observational studies where treatment is not randomly assigned.

Propensity score matching

Propensity score matching, also known as propensity scoring, is a statistical technique that matches treated and untreated subjects with similar scores to mimic a randomized trial.

Sep 29, 2026

Propensity score weighting

Propensity score weighting is a statistical method for causal inference in observational studies that weights each subject by the inverse of the probability of the treatment received.

Proper acceleration

Proper acceleration is the acceleration experienced by an object in its own instantaneous rest frame, the quantity an accelerometer it carries measures, such as gravity at rest or zero in free fall.

Proper elements

Proper elements are quasi-constant orbital parameters of an asteroid, computed from its osculating elements by removing periodic planetary perturbations; stable over millions of years, they reveal clustered asteroid families.

Proper forcing

Proper forcing is a property of forcing notions in set theory, introduced by Saharon Shelah in 1980, that preserves ω₁ and is preserved under countable-support iterations.

Proper forcing axiom

The Proper Forcing Axiom (PFA) is a strengthening of Martin's Axiom in set theory, formulated by James Baumgartner in the early 1980s using Shelah's notion of properness.

Proper length

Proper length is the length of an object measured in its rest frame; observers who see it moving measure a contracted length along the direction of motion.

Proper morphism

In algebraic geometry, a proper morphism is a morphism of schemes that is separated, of finite type, and universally closed; projective space is proper, while affine space is not.

Proper noun

A proper noun is a noun naming a specific person, place, organization, or thing, capitalized in English and contrasted with common nouns; distinct from the noun-phrase category proper name and studied by onomastics.

Sep 19, 2026

Proper NYE/NYD 2026

Proper NYE/NYD 2026 is a two-night, 21-and-over electronic music festival held each New Year's Eve and Day at Petco Park in San Diego, presented by promoter FNGRS CRSSD.