All articles starting with O
9,097 articles
Ōei Invasion
The Ōei Invasion, known in Korea as the Gihwa Eastern Expedition (기해동정), was Joseon Korea's 1419 naval attack on Tsushima, aimed at the wakō pirates' base.
Ōei Rebellion
The Ōei Rebellion (応永の乱) was a 1399 revolt by Ōuchi Yoshihiro against shogun Ashikaga Yoshimitsu; defeated at Sakai, Yoshihiro died and the Ōuchi lost four provinces.
Oeko-Tex
Oeko-Tex (OEKO-TEX®) is a textile and leather certification system run by an association of 17 independent testing institutes founded in 1992. STANDARD 100, its flagship label, tests finished products for over 1,000 harmful substances; other standards include ORGANIC COTTON, STeP, ECO PASSPORT, and MADE IN GREEN.
Oena
Oena is a monotypic dove genus (Swainson, 1837) holding the Namaqua Dove, Oena capensis, a 28 cm arid-zone columbid of sub-Saharan Africa, Madagascar, and Arabia, Least Concern with an increasing, northward-expanding population.
Oenanthe (Ptolemaic courtier)
Oenanthe (Greek Οἰνάνθη) was a Greek woman of the Ptolemaic court, mother of Agathocles and Agathoclea, killed by a mob in Alexandria in 203 BC.
Oene Bottema
Oene Bottema (1901–1992) was a Dutch mathematician known as "the great geometer", professor of mathematics at Delft from 1941 to 1971 and co-author, with Bernard Roth, of Theoretical Kinematics (1979).
Oenoanda/Termessos Mikra
Oenoanda/Termessos Mikra (Oinoanda), ancient Greek city in northern Lycia, Turkey, colonized from Pisidian Termessos around 200 BCE; joined the Lycian League in 84 BCE and home to Diogenes' Epicurean inscription, the largest known of Greco-Roman antiquity.
Oenococcus
Oenococcus is a lactic acid bacteria genus, type species O. oeni (formerly Leuconostoc oenos, reclassified 1995), the wine bacterium driving malolactic fermentation, with a compact 1.8 Mb genome and species kitaharae and alcoholitolerans.
Oenocyte
Oenocyte (oenocytes): large secretory cells of ectodermal origin in arthropods, mainly insects, specialized in very-long-chain fatty acid and cuticular hydrocarbon synthesis; hepatocyte-like, linked to fat body and tracheae; Cell Ontology CL:0000487.
Oenology
Oenology (enology) is the science of winemaking, paired with viticulture. Covers grape domestication origins, alcoholic and malolactic fermentation, OIV analytical standards, UC Davis research milestones, and modern AI benchmarking.
Oenopides (lunar crater)
Oenopides is a 73.47-km-wide IAU-named lunar impact crater at 57.17°N, 64.17°W in the Moon's northwest, adopted in 1935 and named for the Greek astronomer Oenopides of Chios, with ten lettered satellite craters including Oenopides B.
Oenothera
Oenothera (evening primroses) is a New World genus of about 140-156 herbaceous species in Onagraceae, famous as de Vries's mutation-theory plant, with biparental chloroplast inheritance, Renner complexes, and seed oil rich in gamma-linolenic acid.
Oenothera biennis
Oenothera biennis, the common evening primrose, is a biennial herb native to North America with bright yellow flowers that open at night, grown as the source of evening primrose oil.
Oenotria Cavi
Oenotria Cavi is a 247-km-wide group of hollows (cavi) on Mars near 3.86°S, 78.90°E, named for the classical albedo feature Oenotria and approved by the IAU on January 30, 2018.
Oenotria Scopuli
Oenotria Scopuli, formerly Oenotria Scopulus, is an IAU-approved 1,425 km system of irregular cliffs (scarps) in Mars' southern highlands, part of the Isidis impact basin's circular structure, imaged by THEMIS, HiRISE, and Psyche.
Oerlikon 20 mm cannon
The Oerlikon 20 mm cannon is a Swiss-designed automatic antiaircraft gun that became one of the most widely used naval weapons of World War II.
Oerlikon GDF
Oerlikon GDF (GDF-001 to GDF-007, Skyguard system): Swiss towed twin 35mm anti-aircraft gun by Oerlikon Contraves, now Rheinmetall Air Defence; 550 rpm/barrel, 4,000 m range, AHEAD airburst rounds, 2,000+ guns in about 30 countries.
Oersted
The oersted (symbol Oe) is the CGS unit of magnetic field strength, named for Hans Christian Ørsted; one oersted equals about 79.577 amperes per meter in SI units.
Oersted Medal
The Oersted Medal, established in 1936 and named for physicist Hans Christian Oersted, is the American Association of Physics Teachers' award for lasting impact on physics teaching.
Oescus
Oescus (Colonia Ulpia Oescus), Roman colony at Gigen, Bulgaria, on the lower Danube; legionary base of Legio V Macedonica, raised to colony by Trajan after 106, linked by Constantine's 328 bridge to Sucidava, destroyed 585.
Oesia
Oesia (Oesia disjuncta) is a middle Cambrian Burgess Shale fossil reinterpreted in 2016 as a primitive hemichordate, a tubicolous suspension-feeding enteropneust whose perforated tube was formerly assigned to the green alga Margaretia.
Oesling
Oesling (Éislek, E'Slek) is the forested upland region covering the northern third of Luxembourg, part of the Ardennes massif bordering the German Eifel; Lower Devonian schists, 450-500 m plateau, colder and wetter than the Gutland.
Oesophageal erosion
Oesophageal erosion (esophageal erosion, ICD-11 DA25.0) is a shallow mucosal breach of the oesophagus not extending through the muscularis mucosa, usually caused by acid reflux, diagnosed by endoscopy, and treated with proton pump inhibitors.
Oesophageal fistula without atresia
Oesophageal fistula without atresia, or H-type tracheoesophageal fistula (Gross type E), is a rare congenital trachea-oesophagus connection with a patent oesophagus, occurring in 1 in 50,000–80,000 births, diagnosed by bronchoscopy and cured by surgical division.
Oesophageal haemorrhage
Oesophageal haemorrhage (食道出血), ICD-11 code ME24.A2, is bleeding from the oesophagus classified under upper gastrointestinal bleeding; causes include varices, oesophagitis, Mallory-Weiss tears, and oesophageal haematoma.
Oesophageal obstruction
Oesophageal obstruction (ICD-11 DA20.0, ICD-10 K22.2): partial or complete blockage of the esophagus from intrinsic causes (tumors, rings, webs, strictures) or extrinsic compression, presenting as dysphagia and treated by cause-directed endoscopy.
Oesophageal ulcer
An oesophageal ulcer, spelled esophageal ulcer in American English, is a mucosal break in the oesophagus extending into deeper wall layers, usually caused by reflux or drugs.
Oesophageal varices with bleeding
Oesophageal varices with bleeding (ICD-11 DA26.00) is rupture of dilated portosystemic collateral veins in the lower oesophagus due to portal hypertension, treated with vasoactive drugs, band ligation, and TIPS; six-week mortality is 10-20%.
Oesophageal varices without bleeding
Oesophageal varices without bleeding, also called unruptured esophageal varices, are dilated lower-esophageal collateral veins from portal hypertension, present in about 60% of cirrhosis patients, graded small or large, and managed with beta-blockers or band ligation.
Oesophageal web
Oesophageal web (esophageal web): thin mucosal membrane across the upper esophagus, often with iron-deficiency anemia or Plummer-Vinson syndrome; causes dysphagia, diagnosed by barium swallow, treated by dilation.