All articles starting with P
28,818 articles
Phenmetrazine
Phenmetrazine, sold under the brand name Preludin, is a morpholine-derived stimulant marketed from 1959 as an appetite suppressant for obesity, later controlled in Schedule II and no longer marketed.
Phenobarbital
Phenobarbital (phenobarbitone, Luminal) is a long-acting barbiturate antiseizure medicine synthesized in 1911, found effective against epilepsy by Hauptmann in 1912, on the WHO essential medicines list since 1977, and a CYP450 enzyme inducer.
PhenoFluor
PhenoFluor is a deoxyfluorination reagent developed in Tobias Ritter's laboratory at Harvard University that converts phenols and alcohols directly into aryl and alkyl fluorides, first reported in 2011 with better safety than DAST.
Phenol
Phenol, also known as carbolic acid or hydroxybenzene, is an aromatic organic compound made chiefly by the cumene process for resins, bisphenol A, and nylons.
Phenol formaldehyde resin
Phenol formaldehyde resin, also known as phenolic resin, is a thermosetting polymer made from phenol and formaldehyde, the first fully synthetic plastic, marketed from 1907 as Bakelite.
Phenol hydroxylase
Phenol hydroxylase (phenol 2-monooxygenase, EC 1.14.13.7) is a flavoprotein or multicomponent enzyme that hydroxylates phenol to catechol, the first, rate-limiting step of aerobic microbial phenol degradation used in bioremediation.
Phenol red
Phenol red, also called phenolsulfonphthalein (PSP), is a synthetic sulfonephthalein pH indicator dye that changes from yellow below pH 6.8 to bright pink above pH 8.2.
Phenol-chloroform extraction
Phenol-chloroform extraction is a liquid-liquid method separating nucleic acids from proteins between an organic phenol-chloroform phase and an aqueous phase, long used for DNA and RNA purification.
Phenolic impregnated carbon ablator
The phenolic impregnated carbon ablator (PICA) is a low-density heat shield material developed at NASA Ames in the 1990s, flown on Stardust, Curiosity, OSIRIS-REx, and Mars 2020.
Phenolphthalein
Phenolphthalein (C20H14O4, CAS 77-09-8) is an acid-base indicator, colorless below pH 8.2 and pink above, synthesized by Baeyer in 1871; formerly a top-selling laxative, withdrawn in 1999 and classified IARC Group 2B.
Phenols
Phenols, also called phenolic compounds, are organic compounds with one or more hydroxy groups attached directly to an aromatic ring, distinct from alcohols in acidity and reactivity.
Phenom II
Phenom II is a family of AMD desktop processors launched in January 2009 as a 45 nm die shrink of the original Phenom, with an integrated memory controller.
Phenomena (film)
Phenomena (aka Creepers) is Dario Argento's 1985 Italian supernatural giallo starring Jennifer Connelly as a sleepwalking girl who communicates with insects, helping Donald Pleasence's entomologist hunt a killer at a Swiss boarding school; released in 116, 110, and 83-minute cuts.
Phenomenography
Phenomenography is a qualitative research approach that maps the qualitatively different ways a group experiences a phenomenon, originating in Swedish higher-education research and best known for deep and surface approaches to learning.
Phenomenological analysis
Phenomenological analysis is a qualitative research method that analyzes participants' descriptions of lived experiences to identify their essential meanings, with descriptive and interpretive traditions used in health research.
Phenomenological quantum gravity
Phenomenological quantum gravity is the branch of physics that searches for observable signatures of a quantum theory of gravity in astrophysical observations, gravitational waves, and laboratory experiments, since Planck-scale effects lie beyond any accelerator.
Phenomenology (philosophy)
Phenomenology, in philosophy, is the study of structures of consciousness from the first-person view, centered on intentionality. Founded by Husserl (Logical Investigations, 1900-01), later shaped by Heidegger, Sartre, and Merleau-Ponty; distinct from Hegel's Phenomenology of Spirit and from physics usage.
Phenomenology of spacetime discreteness
Phenomenology of spacetime discreteness is the study of what observations would reveal, and what they already rule out, if spacetime has a smallest length scale near the Planck length.
Phenomenon
Phenomenon (Greek phainomenon, "thing seen"): anything observed by the senses; in philosophy, what appears to the mind, opposed to the noumenon in Kant, and the object of study in phenomenology.
Phenomenon (film)
Phenomenon is a 1996 American romantic fantasy drama directed by Jon Turteltaub, written by Gerald Di Pego, and starring John Travolta as a mechanic who gains genius-level intelligence and telekinetic powers.
Phenothiazine
Phenothiazine, also known as dibenzothiazine, is an aromatic tricyclic organic compound synthesized in 1883, parent of the first antipsychotic drugs like chlorpromazine and itself used as a veterinary anthelmintic.
Phenothiazine photocatalysts
Phenothiazine photocatalysts are metal-free organic photoredox catalysts derived from the phenothiazine heterocycle, whose strongly reducing excited states can reduce aryl chlorides that metal complexes cannot.
Phenothrin
Phenothrin (Sumithrin, d-phenothrin) is a Type I synthetic pyrethroid insecticide discovered by Sumitomo Chemical around 1968-1969, used as a household insecticide, pediculicide, mosquito adulticide, and scabies treatment, not registered for agriculture in Japan.
Phenotype
A phenotype is the set of observable characteristics or traits of an organism, such as height, eye color, or blood type, shaped by its genotype and environment.
Phenotype mapping
Phenotype mapping is a family of genetics methods, including QTL mapping and GWAS, that associates observable traits with genomic loci, yielding statistical evidence for regions influencing a trait.
Phenotypic clustering
Phenotypic clustering is a computational method that groups cells, mutants, or perturbations by measured phenotypic features such as morphology or fitness, revealing subpopulations and shared functional profiles.
Phenotypic plasticity
Phenotypic plasticity: a genotype producing different phenotypes under different environments, described by reaction norms (Woltereck 1909), spanning polyphenism, adaptive and nonadaptive responses, genetic assimilation, and climate change roles.
Phenotypic screening
Phenotypic screening is a drug discovery method that tests compounds in cells or organisms for observable changes in a disease-relevant phenotype rather than against a pre-specified molecular target.
Phenotypic trait
Phenotypic trait: an observable characteristic of an organism, part of its overall phenotype, determined by genotype and environment. Coined with phenotype by Wilhelm Johannsen in 1909; heritability h² quantifies genetic contribution to trait variation.
Phenoxazine photocatalysts
Phenoxazine photocatalysts are organic photoredox catalysts based on the phenoxazine scaffold, whose strongly reducing excited states drive single-electron chemistry under visible light as metal-free alternatives to iridium and ruthenium catalysts.