All articles starting with O
9,097 articles
ORF9b
ORF9b (Orf9b, 9b) is an ~11 kDa accessory protein of SARS-CoV and SARS-CoV-2, encoded in an alternate reading frame inside the nucleocapsid gene, that suppresses interferon signaling by binding the mitochondrial receptor Tom70 and forms a lipid-bound beta-sheet homodimer.
Orfeo ed Euridice
Orfeo ed Euridice (Orphée et Eurydice) is Gluck's 1762 reform opera to a Calzabigi libretto, premiered in Vienna with castrato Gaetano Guadagni; revised for Parma 1769 and Paris 1774, and reworked by Berlioz in 1859.
Orfeón
Orfeón, also known as Orfeón Videovox, is a Mexican record label founded in 1958 by Rogerio Azcárraga Madero, with over 500 artists including Pedro Infante and Celia Cruz.
Orfeu
Orfeu is Carlos Diegues's 1999 Brazilian film, a remake of Black Orpheus, adapting Vinicius de Moraes's play Orfeu da Conceição; Toni Garrido stars as a favela samba composer, with music by Caetano Veloso, and it was Brazil's 2000 Oscar submission.
Orfeu da Conceição
Orfeu da Conceição is a 1956 musical play by Vinicius de Moraes that transposes the Greek myth of Orpheus and Eurydice to a Rio de Janeiro favela during Carnaval.
Orff Schulwerk
Orff Schulwerk (Orff approach): music and movement education developed by Carl Orff and Gunild Keetman from 1920s Munich, rebuilt after 1948 Bavarian Radio broadcasts, with Musik für Kinder (1950–54), the Salzburg Orff Institute (1961), and 49 societies worldwide.
Orforglipron
Orforglipron (Foundayo) is Eli Lilly's once-daily oral, non-peptide GLP-1 receptor agonist, discovered by Chugai and FDA-approved April 1, 2026 for weight management; doses up to 17.2 mg, no food or water restrictions, half-life 29-49 hours.
Organ (biology)
Organ (biology): a body structure made of two or more tissue types performing specific functions; from Greek organon (tool). Humans have eleven organ systems; organs include the heart, liver, brain, and skin.
Organ (music)
Organ (music), 管风琴, pipe organ: a wind-driven keyboard instrument with manuals, pedalboard, and stops; oldest large keyboard instrument, king of instruments, central to church liturgy and concert halls.
Organ culture
Organ culture is a laboratory method that maintains whole organs or tissue slices alive in vitro, preserving their normal structure, cell relationships, and physiological function for research.
Organ donation
Organ donation: giving organs for transplantation from living donors (kidney, liver, lung, intestine portions) or deceased donors (kidney, liver, heart, lungs, pancreas, intestine), governed by OPTN allocation, preservation limits, and opt-in versus opt-out consent laws.
Organ donation for heart transplantation
Organ donation for heart transplantation covers DBD and DCD donor selection, 4-hour cold ischemia limits, machine perfusion, NRP ethics, and DCD trial outcomes showing noninferior 6-month survival versus brain-death donors.
Organ of Corti
Organ of Corti: the mammalian cochlea's hearing sensory epithelium, on the basilar membrane under the tectorial membrane; one inner and three outer hair-cell rows, tunnel of Corti, described by Corti in 1851.
Organ pipe coral
Organ pipe coral (Tubipora musica) is a reef-building octocoral of the Indo-West Pacific with a deep red skeleton of parallel tubes joined by horizontal plates; CITES Appendix II, IUCN Least Concern, with at least 15 hidden endemic lineages.
Organ Preservation
Organ preservation keeps donor organs viable between procurement and transplant, mainly by static cold storage at 0–4 °C and machine perfusion (HMP, NMP), with cryopreservation as a long-term research goal.
Organ printing
Organ printing (organ bioprinting) is computer-aided 3D printing of living tissues and organs using bioinks, proposed in 2003 by Mironov et al. Key barriers are vascularization beyond 300 μm thickness, immune response, and regulation; ARPA-H PRINT funds on-demand organs.
Organ procurement
Organ procurement: surgical removal of organs, corneas, or tissue from donors for transplant, performed in the U.S. by about 55 nonprofit OPOs under OPTN and CMS oversight, with strict preservation time limits.
Organ Size
Organ size: measurement of a bodily organ in volume, mass, or heaviness (MeSH D009929, formerly Organ Weight). Covers biological size regulation and clinical measurement by CT, MRI, and ultrasound.
Organ Sparing Treatments
Organ Sparing Treatments (MeSH D059351): therapies on diseased organs that avoid complete removal and preserve function, e.g. organ-sparing cystectomy, rectal watchful waiting, partial nephrectomy, breast-conserving surgery.
Organ Specificity
Organ specificity, also called tissue specificity, is the restriction of a biological characteristic such as gene expression, a cell type, or a metabolic response to a particular organ; measured by the tau index and exploited in targeted drug delivery.
Organ system
An organ system is a group of organs working together to carry out major body functions. The human body has eleven, including the nervous, cardiovascular, digestive, and respiratory systems.
Organ trade
Organ trade: the buying, selling, and brokering of human organs, also called organ trafficking and transplant tourism. Condemned by WHO and the Declaration of Istanbul; Iran alone permits legal paid kidney donation.
Organ Trail (film)
Organ Trail is a 2023 American western horror-thriller directed by Michael Patrick Jann, written by Meg Turner, starring Zoé De Grand Maison. Set in 1870s Montana, it follows Abigale Archer, sole survivor of a bandit attack, retrieving her family's horse; released by Paramount April 14, 2023.
Organ transplantation
Organ transplantation: surgical replacement of failing organs (kidney, liver, heart, lung) with organs from living or deceased donors. Began with the 1954 twin kidney transplant; over 100,000 Americans now wait, mostly for kidneys.
Organ-on-a-chip
An organ-on-a-chip is a microfluidic device that cultures living human cells in tiny channels to model organ function, developed since 2010 to predict drug toxicity better than animal models.
Organellar ribosomal RNA
Organellar ribosomal RNA is the rRNA inside mitochondrial and chloroplast ribosomes, ranging from bacterial-like forms in plants and chloroplasts to drastically shortened ones in animals.
Organelle
Organelle: membrane-surrounded subcellular structure with a specific function, such as the nucleus, mitochondria, lysosomes, ER, Golgi, and peroxisomes; eukaryotic cells compartmentalize nearly half their volume in organelles, unlike prokaryotes.
Organic acid
An organic acid is an organic compound with acidic properties, most commonly a carboxylic acid with the structure RC(=O)OH, and includes sulfonic acids and some phenols.
Organic acid anhydride
An organic acid anhydride is a compound with two acyl groups bonded to one oxygen atom, formed by removing water from two carboxylic acid molecules.
Organic architecture
Organic architecture is a philosophy of building, first named by Frank Lloyd Wright in 1914, that designs structures as one with their site, materials, and inhabitants, exemplified by Fallingwater.