Life and health

Phascogale

Phascogale: Australian dasyurid marsupial genus with three species (brush-tailed P. tapoatafa, red-tailed P. calura, northern P. pirata), arboreal carnivores with bottlebrush tails and semelparous males that die after one breeding season.

Phase I/II trial

A Phase I/II trial is a clinical trial design that combines dose escalation and safety evaluation with early evidence of treatment efficacy, aiming to find the optimal biological dose.

Phase II/III trial

A Phase II/III trial, often called a seamless or adaptive seamless design, combines Phase II and Phase III objectives in one protocol, selecting doses at an interim analysis while controlling type I error.

Phase IV trial

A Phase IV trial, also called Phase 4, is a study of a drug after marketing approval, measuring safety, effectiveness, and optimal use in broader patient populations.

Phase Separation

Phase separation, especially liquid–liquid phase separation (LLPS), is the demixing of a homogeneous mixture into dense and dilute phases; in cells it forms biomolecular condensates, membraneless organelles linked to disease and materials design.

Phase Variation

Phase variation: random, frequent, reversible ON/OFF switching of bacterial contingency genes via simple sequence repeats, DNA inversion, or DNA methylation, enabling immune evasion, niche adaptation, and phasevarion-regulated virulence in pathogens.

Oct 22, 2026

Phase-change perfluorocarbon nanodroplets

Phase-change perfluorocarbon nanodroplets (PFCnDs) are submicrometer liquid perfluorocarbon particles that ultrasound or laser light converts into gas microbubbles, enabling on-demand contrast imaging and drug delivery.

Phase-contrast magnetic resonance imaging

Phase-contrast magnetic resonance imaging, also known as phase-contrast MRI, is an MRI technique that measures blood flow noninvasively by encoding fluid velocity into the signal phase.

Phase–amplitude coupling

Phase–amplitude coupling (PAC) is a signal-analysis method quantifying how the amplitude of fast neural oscillations is modulated by the phase of slower ones, used to study cognition and diseases like Parkinson's.

Phaseolus

Phaseolus is a New World legume genus (Fabaceae, tribe Phaseoleae) of about 81 species, including five domesticated beans such as common bean P. vulgaris and lima bean, with at least seven independent domestication events.

Phaseolus coccineus

Phaseolus coccineus, the runner or scarlet runner bean, is a Mesoamerican domesticated climbing legume, third-most important Phaseolus crop, grown for dry seeds and green pods, tolerating cool climates.

Phaseolus vulgaris

Phaseolus vulgaris, the common bean (fríjol, haricot), is an annual American legume domesticated independently in Mesoamerica and the Andes; grown as kidney, pinto, navy, black, and green beans, it is the world's most important direct-consumption grain legume.

Phases of clinical research

Phases of clinical research: the staged testing of new drugs and health products in humans, from Phase 0 microdosing (10–15 people, <100 micrograms) through Phase I safety (20–100), Phase II dosing, Phase III pivotal trials, to Phase IV post-marketing surveillance.

Phasianidae

Phasianidae, the pheasant family (Pheasants & Allies), is the largest family of Galliformes, with over 50 genera and 214+ species including pheasants, partridges, grouse, turkeys, and Old World quail; chickens derive from Gallus gallus.

Phasin PhaP

PhaP (PhaP1) is the major phasin protein coating polyhydroxyalkanoate granules in bacteria such as Ralstonia eutropha; it binds PHB as homotrimers, promotes PHB synthesis, is regulated by PhaR, and is used in protein purification and drug delivery.

Phasmarhabditis hermaphrodita

Phasmarhabditis hermaphrodita is a hermaphroditic slug-killing rhabditid nematode, described 1859, mass-produced with Moraxella osloensis and sold in Europe as Nemaslug since 1994 at 3 × 10^9 dauer juveniles per hectare.

Phasmatidae

Phasmatidae (walking sticks), Gray 1835, is a family of stick insects in the order Phasmatodea, with about 160 genera and 991 species under one concept; its subfamilies and authorship remain taxonomically disputed.

Phasmatodea

Phasmatodea, the stick and leaf insects (phasmids), is an order of about 3,500 camouflaged, nocturnal, herbivorous insects masquerading as twigs or leaves, including the world's longest insect, Phobaeticus chani, over 56 cm.

Oct 20, 2026

PHB1

PHB1 (prohibitin 1, formerly PHB, alias BAP32), gene ID 5245 at 17q21.33, encodes a 32 kDa conserved scaffold protein that with PHB2 forms an ~1 MDa ring-shaped chaperone complex in the mitochondrial inner membrane, stabilizing newly synthesized mitochondrial proteins, cristae, and mtDNA, with roles in senescence, immunity, and cancer.

PHB2

PHB2 (prohibitin 2, BAP37) is a human gene on 12p13.31 encoding a 34 kDa inner mitochondrial membrane protein that forms the PHB1/PHB2 ring complex, regulates OPA1 processing and cristae, acts as the first inner-membrane mitophagy receptor, and modulates estrogen-dependent transcription.

Pheasant

Pheasant (Phasianus colchicus), the ring-necked or common pheasant, an Asian gamebird introduced worldwide; about 47 million released annually in the UK, established in the US since 1881, with documented ecological effects near release sites.

Phelan-McDermid syndrome

Phelan-McDermid syndrome, or 22q13.3 deletion syndrome, is a rare neurodevelopmental disorder caused by SHANK3 haploinsufficiency, featuring developmental delay, absent speech, hypotonia, and autism spectrum disorder.

Oct 20, 2026

Phellinus

Phellinus (sanghuang, 桑黃) is a genus of about 220 perennial, shelf-shaped wood-decay fungi in Hymenochaetaceae, used for 2,000 years in East Asian medicine; over 300 bioactive compounds, mainly polysaccharides and hispidin-derived polyphenols, have been reported.

Phelsuma

Phelsuma, day geckos, is a genus of diurnal green geckos established by Gray (1825) and named for Murk van Phelsum. About 45–53 species live on Madagascar and Indian Ocean islands; all are CITES Appendix II.

Phenacemide

Phenacemide (Phenurone), phenylacetylurea, a 1948 ureide anticonvulsant for refractory psychomotor epilepsy, FDA-approved 1951, withdrawn 2004 due to liver and bone marrow toxicity.

Phenacodus

Phenacodus, condylarth mammal genus named by Cope 1873 (type P. primaevus), Paleocene-Eocene North America and Europe, five-toed plantigrade early ungulate near perissodactyl origins.

Phenazopyridine

Phenazopyridine (Pyridium, AZO) is an azo-dye urinary analgesic for dysuria, not an antibiotic. Dosed 200 mg three times daily, limited to 2 days; risks include methemoglobinemia and renal or hepatic toxicity.

Phencyclidine

Phencyclidine (PCP, angel dust), 1-(1-phenylcyclohexyl)piperidine, is a dissociative anesthetic and NMDA receptor antagonist synthesized in 1956, abandoned for human use, now a Schedule II drug of abuse.

Phendimetrazine

Phendimetrazine (Bontril PDM, Plegine) is a DEA Schedule III sympathomimetic anorectic, FDA-approved since 1959/1960 for short-term obesity treatment with caloric restriction; 35 mg tablets, tolerance within weeks, over 3 million US prescriptions 2008-2011.