All articles starting with P
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Placenta
Placenta: temporary pregnancy organ transferring nutrients, oxygen, antibodies, and waste between mother and fetus; human type is hemochorial, discoid, about 500 g at term; classified epitheliochorial, endotheliochorial, or hemochorial across mammals.
Placenta praevia
Placenta praevia (placenta previa): placenta implanted over the cervical internal os, blocking vaginal birth. Affects about 1 in 200 births; causes painless antepartum bleeding; managed with caesarean delivery.
Placental abruption
Placental abruption: premature separation of the placenta from the uterine wall before birth, causing vaginal bleeding and pain; complicates 0.6–1.2% of pregnancies and is diagnosed definitively only by placental examination after delivery.
Placental Function Tests
Placental function tests assess placental health in pregnancy via maternal biochemistry (oestriol, hPL, PlGF), uterine and umbilical artery Doppler, and ultrasound. Cochrane evidence shows biochemical tests alone do not improve pregnancy outcomes; Doppler benefits high-risk pregnancies.
Placental transfusion syndromes
Placental transfusion syndromes (ICD-11 JA8A.0) are abnormal blood transfer through placental vessels, chiefly twin-to-twin transfusion syndrome and twin anemia polycythemia sequence in monochorionic twins sharing placental anastomoses.
Placental villous trophoblast
Placental villous trophoblast, also called villous trophoblast or Langhans' cell layer plus syncytiotrophoblast, is the trophoblast covering human chorionic villi; it performs maternal-fetal exchange, hormone secretion, and pathogen defense, and is disturbed in preeclampsia and fetal growth restriction.
Placentalia
Placentalia, the placental mammals, is the clade of about 6,000 living species, from bats and whales to rodents and primates, that give birth to more developed young than marsupials.
Placentation
Placentation is the formation of a placenta, the apposition or fusion of fetal membranes to the uterine mucosa for physiological exchange, as defined by Harland Mossman.
Placenticeras
Placenticeras, an extinct Late Cretaceous ammonite genus (family Placenticeratidae) named by Meek in 1876; streamlined, weak-shelled, worldwide in distribution, and famously preserved with mosasaur bite punctures.
Placentin
Placentin, also known as insulin-like peptide 4 (INSL4) or early placenta insulin-like peptide, is a peptide hormone of the insulin family encoded by the INSL4 gene.
Placentophagy
Placentophagy, or placentophagia, is the eating of a human placenta after childbirth, most often as capsules, a practice that grew since the 1970s despite controlled research finding no evidence of its claimed benefits.
Placer County
Placer County, California: county established April 25, 1851, seat Auburn, from Sacramento Valley to North Lake Tahoe; Gold Rush origins, 442,081 residents (2025), five supervisorial districts, charter since 1980.
Placer mining
Placer mining extracts valuable minerals, mostly gold, from loose sediment like stream gravel and beach sand using water and gravity, supplying two-thirds of the world's gold.
Placer.ai
Placer.ai (Placer Labs Inc.) is an American location-intelligence company founded in 2018 by Noam Ben-Zvi and three partners, providing foot-traffic analytics built on anonymized mobile-location data.
Placerville, California
Placerville, California, historically known as Hangtown, is a Gold Rush city and the county seat of El Dorado County on the western slope of the Sierra Nevada, incorporated in 1854.
Places in Harry Potter
Places in Harry Potter: fictional locations in J.K. Rowling's wizarding world, including Hogwarts, Diagon Alley, Hogsmeade, and Little Whinging, set within real Britain and tied to real-world inspirations and tourism sites.
Places in the Heart
Places in the Heart is Robert Benton's 1984 TriStar drama set in Depression-era Waxahachie, Texas, starring Sally Field as widow Edna Spalding. It won two of seven Oscars, including Best Actress and Best Original Screenplay.
Placide Mbala‐Kingebeni
Placide Mbala-Kingebeni, also published as Placide Mbala, is a Congolese physician and virologist who directs research at INRB in Kinshasa and identified mpox clade Ib in 2024.
Placide-Louis Chapelle
Placide-Louis Chapelle was a French-born American Catholic prelate, Archbishop of New Orleans from 1897 to 1905, who also served as Apostolic Delegate to Cuba, Puerto Rico, and the Philippines.
Plácido
Plácido (1961) is a Spanish black-and-white satirical comedy by Luis García Berlanga, his key early collaboration with Rafael Azcona, about a poor man trying to save his three-wheeled van during a hypocritical Christmas charity campaign; Cannes and Oscar-nominated.
Plácido Domingo
Plácido Domingo (born 1941, Madrid) is a Spanish tenor, conductor, and opera administrator with over 150 roles and 4,000 performances, a Three Tenors founder, Operalia founder, former LA Opera chief, and subject of credible 2020 harassment findings.
Placidus Plattner
Placidus Andreas Plattner (1904–1975) was a Swiss organic chemist who taught at ETH Zurich and later directed pharmaceutical research at Ciba Geigy and Hoffmann-La Roche.
Plackett–Burman design
A Plackett–Burman design is a two-level screening design of experiments, introduced by Plackett and Burman in 1946, that estimates the main effects of many factors in few runs.
Placoderm
Placoderms (Placodermi) are extinct armored jawed fishes of the Silurian-Devonian (about 438-359 Ma), the dominant Devonian vertebrates, jaw-bearing stem gnathostomes central to the origin of jaws and teeth, extinct by the Carboniferous.
Placopecten magellanicus
Placopecten magellanicus, the Atlantic sea scallop or giant scallop, is a large swimming bivalve from Newfoundland to Cape Hatteras whose adductor muscle supports the world's largest wild scallop fishery, worth $332 million in 2024 U.S. landings.
Plactic monoid
The plactic monoid, or tableau algebra, is the monoid of semistandard Young tableaux with multiplication by insertion; two words are equal exactly when Schensted's algorithm gives the same tableau.
Placunopsis
Placunopsis is a genus of small, thin-shelled fossil bivalves in the saddle-oyster family Anomiidae, established in 1853 and found mainly in Jurassic rocks of north-west Europe.
PLAD (exoskeleton)
The PLAD (Personal Lift Assistive Device, also called the Personal Lift Augmentation Device) is a passive back-support exoskeleton developed by Queen's University and University of Waterloo researchers that reduces back muscle demand during lifting.
Plaek Phibunsongkhram
Plaek Phibunsongkhram (แปลก พิบูลสงคราม) was a Thai field marshal and prime minister who led Thailand from 1938 to 1944 and again from 1948 to 1957, allying with Japan in 1941.
PLAG1
PLAG1 (pleomorphic adenoma gene 1), a proto-oncogene at human chromosome 8q12, encodes a zinc finger transcription factor activated by promoter-swapping fusions in salivary gland pleomorphic adenoma and lipoblastoma, and is a major stature locus in cattle.