All articles starting with P

Polydactyly of an index finger

Polydactyly of an index finger (PPD3, OMIM 174600) is a rare autosomal dominant preaxial polydactyly in which the thumb is replaced by one or two triphalangeal index-finger-patterned digits; prevalence under 1 in 1,000,000.

Polydactyly of the thumb

Polydactyly of the thumb (thumb duplication, radial or preaxial polydactyly): congenital duplication of the thumb, incidence 0.08–1.4 per 1000 births, classified by the Wassel-Flatt system, treated surgically with a 7–28% reoperation rate.

Polydactyly of toes

Polydactyly of toes (ICD-11 LB78.3) is a congenital anomaly with supernumerary toes, usually postaxial, often autosomal dominant, treated by excision of the extra digit.

PolyDADMAC

PolyDADMAC, or poly(diallyldimethylammonium chloride), is a water-soluble cationic polyelectrolyte whose positive charge neutralizes negatively charged particles, so they clump and settle out in water treatment.

Polydeoxyribonucleotide

Polydeoxyribonucleotide, or PDRN, is a DNA-derived drug extracted from salmonid fish sperm, first approved in 1994 for wound healing and now common in South Korean skincare.

Polydesmida

Polydesmida, the flat-backed millipedes, is the largest millipede order with over 5,000 species; adults have 18-21 segments with paranota, cyanide-secreting ozopores, and species-diagnostic gonopods.

Polydeuces (moon)

Polydeuces (Saturn XXXIV) is a small Trojan moon of Saturn, discovered by Cassini in 2004, trailing Dione by 60 degrees near its L5 Lagrange point.

Oct 22, 2026

Polydiketoenamine

Chemically recyclable polydiketoenamine (PDK) is a family of plastics that depolymerize in strong acid back to pristine monomers, first reported at Lawrence Berkeley National Laboratory in 2019.

Polydimethylsiloxane

Polydimethylsiloxane, also called dimethicone or dimethylpolysiloxane, is a silicone polymer known for its flexibility, hydrophobicity, and optical clarity, used in cosmetics, food antifoaming additives, lubricants, medical implants, and microfluidics.

Polydioxanone

Polydioxanone (PDO, also poly-p-dioxanone or PDS) is a synthetic, absorbable semi-crystalline polyester used in surgical sutures and implants, degrading in the body by hydrolysis and first marketed by Ethicon in 1983.

Polydipsia

Polydipsia is excessive thirst with fluid intake over 3 L/day, part of the polyuria-polydipsia syndrome. Primary polydipsia lowers AVP via high drinking, occurs in schizophrenia, and is distinguished from diabetes insipidus by copeptin testing.

Polydispersity index

The polydispersity index (PDI) is the ratio of a polymer's weight-average to number-average molar mass, measuring how wide its chain lengths are; IUPAC renamed it dispersity, Đ, in 2009.

Polydnavirus

Polydnavirus (Polydnaviridae; bracovirus, ichnovirus): symbiotic provirus of braconid and ichneumonid parasitoid wasps, injected into hosts during oviposition to suppress immunity; segmented circular dsDNA, replicates only in wasp calyx cells.

Oct 22, 2026

Polydopamine nanoparticles

Polydopamine nanoparticles (PDA NPs) are nanoscale particles of polydopamine, a mussel-inspired synthetic polymer formed by oxidative polymerization of dopamine. They strongly absorb near-infrared light, enabling photothermal cancer therapy.

Polydor Records

Polydor Records: record label founded 1913 in Leipzig by Polyphon-Musikwerke, export brand of Deutsche Grammophon from 1924, pop label from 1946, UK wing 1954; now a Universal Music Group UK label in the Polydor Label Group.

Polyelectrolyte

A polyelectrolyte, also called a polymer electrolyte, is a polymer with a substantial portion of its units bearing ionic or ionizable groups, like DNA and proteins.

Oct 20, 2026

Polyembryoma

Polyembryoma: rare malignant gonadal germ cell tumor dominated by embryoid bodies (embryonal carcinoma germ disc, amnion-like and yolk sac cavities); usually part of mixed germ cell tumor, teratoma most common companion; AFP and beta-hCG may be elevated.

Polyester

Polyester is a category of polymers containing ester groups in every repeat unit, best known as PET, the world's most widely used fiber, accounting for over half of the global fiber market.

Polyester (film)

Polyester (1981) is John Waters's black comedy starring Divine as Baltimore housewife Francine Fishpaw, with Tab Hunter. Waters's tenth film, first in 35mm, under a $1 million New Line budget, known for its Odorama scratch-and-sniff card gimmick.

Polyester fiber

Polyester fiber is a manufactured synthetic textile fiber, overwhelmingly polyethylene terephthalate, first marketed in 1951 and the world's most produced fiber at 59% of global output in 2025.

Oct 22, 2026

Polyester recycling

Polyester recycling is the set of processes that reprocesses waste polyesters, chiefly PET, either mechanically by remelting or chemically by cleaving ester bonds to recover monomers such as terephthalic acid and ethylene glycol.

Polyestradiol phosphate

Polyestradiol phosphate (PEP, Estradurin, LEO 114) is a long-acting injectable polymeric estradiol ester used for palliative androgen suppression in prostatic carcinoma, with dose-dependent testosterone suppression and mixed cardiovascular findings.

Polyether

A polyether is a polymer whose macromolecules contain ether linkages (−O−) in the backbone, a class spanning water-soluble PEG, polyurethane polyols, and high-temperature aromatic thermoplastics such as PEEK.

Polyether ether ketone

Polyether ether ketone (PEEK) is a semi-crystalline, high-performance thermoplastic first produced by Imperial Chemical Industries in 1978, combining a 343 °C melting point with broad chemical resistance.

Polyether ketone ketone

Polyether ketone ketone (PEKK) is a semi-crystalline thermoplastic in the polyaryletherketone family, invented in the 1960s for the Apollo program and used in aerospace and medical implants.

Polyetheramine

Polyetheramine (PEA) is an amine-terminated polyether with primary amino groups at the chain end, used as an epoxy hardener, polyurea component, and gasoline detergent additive.

Polyetherimide

Polyetherimide (PEI) is an amorphous thermoplastic, sold as ULTEM since General Electric introduced it in 1982 and now produced by SABIC, combining high heat resistance, strength, and inherent flame retardancy.

Polyethersulfone

Polyethersulfone (PESU, often abbreviated PES) is an amber-transparent engineering thermoplastic with a glass transition near 225 °C, used in dialysis membranes and sterilizable medical equipment.

Polyethoxylated tallow amine

Polyethoxylated tallow amine, also called POEA, is a mixture of non-ionic surfactants derived from tallow that has been the principal co-formulant in glyphosate herbicides such as Roundup for over 40 years.