All articles starting with P

Preparation H

Preparation H, an American hemorrhoid treatment brand first sold in 1949 and now owned by Haleon, offers ointments, creams, suppositories, wipes, and sprays with phenylephrine, pramoxine, lidocaine, and witch hazel.

Preparative chromatography

Preparative chromatography is a separation technique that isolates and collects purified quantities of compounds from mixtures, when the goal is the compound itself rather than information about it.

Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization

The Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization is an international body in Vienna, Austria, that operates the International Monitoring System and detected North Korea's nuclear tests.

Sep 23, 2026

Preparatory Constitutionalism and the Outline Imperial Constitution

Preparatory Constitutionalism and the Outline Imperial Constitution (预备立宪与钦定宪法大纲) was the Qing dynasty's deferred constitutional reform program, launched in 1906 and embodied in the 1908 Outline Imperial Constitution.

PrePARe study

PrePARe (NCT04213963) is a University of Turin prospective study measuring primary aldosteronism prevalence in resistant hypertension via saline infusion testing, and comparing organ damage, metabolic, and oxidative stress outcomes against essential resistant hypertension.

Oct 20, 2026

PREPARE trial (NCT03073317)

PREPARE (NCT03073317), Prematurity Reduction by Pre-eclampsia Care: a Brazilian stepped-wedge cluster-randomized trial of fullPIERS plus sFlt-1/PlGF risk stratification in 1250 women with preterm preeclampsia; it showed no statistical reduction in preterm deliveries.

Prepared statement

A prepared statement, also known as a parameterized query or bind variable, is a database feature in which SQL is pre-parsed and parameter values are supplied separately, preventing SQL injection.

PREPARED study

PREPARED study (NCT00743613), Predicting Peripheral Arterial Disease in Men With Erectile Dysfunction: completed 2005-2008 observational trial by Bruton Avenue Family Practice using SHIM and ankle-brachial index; distinct from the UK PREPARED PAD registry.

Prepatellar bursitis

Prepatellar bursitis (housemaid's knee) is inflammation of the bursa in front of the kneecap, caused mainly by kneeling occupations; about one third of cases are septic, usually Staphylococcus aureus, treated with antibiotics or bursectomy.

Prepectoral breast reconstruction

Prepectoral breast reconstruction is an implant-based technique performed after mastectomy in which the implant is placed above the pectoralis major muscle, avoiding animation deformity, muscle pain, and pectoralis dissection.

Preperitoneal repair

Preperitoneal repair is a hernia operation placing mesh in the space between the peritoneum and transversalis fascia, covering the myopectineal orifice so intra-abdominal pressure secures it.

Prephenate dehydratase

Prephenate dehydratase (PDT, EC 4.2.1.51), also called prephenate hydro-lyase, converts prephenate to phenylpyruvate in L-phenylalanine biosynthesis; bifunctional with chorismate mutase in enteric bacteria, ACT-domain regulated.

Oct 20, 2026

Prephenate dehydrogenase

Prephenate dehydrogenase (PDH, TyrA, EC 1.3.1.12) is a TyrA-family oxidoreductase catalyzing NAD+-dependent oxidative decarboxylation of prephenate to 4-hydroxyphenylpyruvate in tyrosine biosynthesis; monofunctional or fused to chorismate mutase in enteric bacteria.

Oct 15, 2026

Preply, Inc.

Preply is an online language-learning marketplace connecting learners with independent tutors for live one-on-one video lessons, founded in 2012 and valued at $1.2 billion in 2026.

Preppy

Preppy (preppie) is an American informal term for preparatory-school students and graduates and for the classic, neat dress style associated with them, rooted in Ivy League campus wear, peaking in the 1980s, and repeatedly revived since.

Oct 15, 2026

Prepreg

Prepreg, a contraction of pre-impregnated, is fiber reinforcement pre-impregnated with catalyzed but uncured resin, typically epoxy, ready for cure into composite laminates and most common in aerospace composites.

Preprint

Preprint: a scientific manuscript publicly posted before peer review, on servers such as arXiv (1991), bioRxiv (2013), and medRxiv (2019); grew 63-fold in 30 years, reaching audiences 14 months earlier.

Preprosthetic Oral Surgical Procedures

Preprosthetic oral surgical procedures are operations on the jaws' hard and soft tissues performed before dentures or implants, removing bony undercuts, excess tissue, and hyperplasias.

Oct 20, 2026

Prepubertal anorexia nervosa

Prepubertal anorexia nervosa, also called early-onset anorexia nervosa, is a rare eating disorder of prepubescent children, defined by onset before puberty and generally before age 13.

Prepulse inhibition

Prepulse inhibition (PPI) is the weakening of the startle reflex when a weak prepulse precedes a startling stimulus by 20–500 ms, a standard measure of sensorimotor gating.

Prequel

Prequel: a film, book, or play telling events before those of an earlier work; coined from pre- + sequel (1958 Anthony Boucher usage; 1970s mainstream), exemplified by Wide Sargasso Sea and the Star Wars prequel trilogy, and rarer than sequels.

Prequelle

Prequelle is the fourth studio album by Swedish rock band Ghost, released June 1, 2018 on Loma Vista, produced by Tom Dalgety. A Black Plague concept album introducing Cardinal Copia, it hit No. 3 on Billboard, No. 10 in the UK, and scored 81 on Metacritic.