All articles starting with S
44,216 articles
Spontaneous bacterial peritonitis
Spontaneous bacterial peritonitis (SBP), infection of ascitic fluid without an intra-abdominal source (PMN ≥250 cells/mm³), a complication of cirrhosis named by Harold Conn in 1964; treated with third-generation cephalosporins plus IV albumin, increasingly complicated by multidrug-resistant organisms.
Spontaneous breathing trial
A spontaneous breathing trial (SBT) is a bedside critical care test, usually lasting 30 to 120 minutes, that assesses whether a mechanically ventilated patient is ready for extubation.
Spontaneous combustion
Spontaneous combustion, also called spontaneous ignition, is fire that starts without an external heat source after a material self-heats, as in oily rags, moist hay, and coal piles.
Spontaneous emission
Spontaneous emission is the decay of an excited atom or molecule to a lower energy state with emission of a photon, a process Einstein described in 1917.
Spontaneous fission
Spontaneous fission, also called spontaneous nuclear fission, is radioactive decay in which a heavy nucleus splits without an incoming particle, discovered in uranium in 1941.
Spontaneous four-wave mixing
Spontaneous four-wave mixing (SFWM) is a third-order nonlinear optical process that creates signal and idler photon pairs from vacuum fluctuations, the standard route to photon pairs on silicon chips.
Spontaneous generation
Spontaneous generation, or abiogenesis in older usage, is the discredited theory that fully formed organisms arise from nonliving matter, refuted by Redi's 1668 maggot experiment and Pasteur's 1860s swan-neck flasks.
Spontaneous heparin-induced thrombocytopenia
Spontaneous heparin-induced thrombocytopenia (SpHIT, spontaneous HIT syndrome) is a rare anti-PF4 disorder causing thrombocytopenia and thrombosis without heparin exposure, triggered by knee replacement surgery or infection, treated with non-heparin anticoagulation and IVIG.
Spontaneous human combustion
Spontaneous human combustion (SHC) is the alleged burning of a living human body without external ignition. Reported since the 17th century, it is explained forensically by the fat wick effect and was popularized by Dickens's Bleak House.
Spontaneous intestinal perforation
Spontaneous intestinal perforation (SIP), also called focal intestinal perforation, is an isolated bowel perforation in extremely low-birth-weight preterm newborns, usually within 10 days of birth, distinct from NEC and treated by peritoneal drain or laparotomy.
Spontaneous order
Spontaneous order is a pattern of social coordination that emerges from many individuals following general rules, without any coordinator; classic examples include markets, money, and language.
Spontaneous parametric down-conversion
Spontaneous parametric down-conversion, also known as parametric fluorescence or parametric scattering, is a nonlinear optical process where a pump photon splits into two lower-energy photons, first observed in 1970.
Spontaneous periodic hypothermia
Spontaneous periodic hypothermia, also called Shapiro syndrome or episodic spontaneous hypothermia, is a rare neurologic disorder of recurrent core-temperature drops below 35 °C with hyperhidrosis, without hypothalamic lesions; fewer than 1 per million prevalence, onset 6 months to 62 years.
Spontaneous process
A spontaneous process, also called a spontaneous reaction or spontaneous change, is a physical or chemical change occurring naturally without continual external energy input, with spontaneity indicating direction, not speed.
Spontaneous remission
Spontaneous remission, or spontaneous regression of cancer, is the unexplained partial or complete disappearance of a malignant tumor without treatment. Documented since 1900 in about 1,000 cases; most frequent in melanoma, renal cell carcinoma, and neuroblastoma, often preceded by febrile infection.
Spontaneous rupture of oesophagus
Spontaneous rupture of oesophagus, or Boerhaave's syndrome, is a full-thickness oesophageal tear from vomiting or straining, first described by Boerhaave in 1724; treated by primary repair, endoscopy, or conservative care, with 16-18% mortality.
Spontaneous rupture of tendon
Spontaneous rupture of tendon, first named by Boyes in 1960, is the tearing of a weakened tendon under normal load without trauma, most often affecting the Achilles tendon.
Spontaneous symmetry breaking
Spontaneous symmetry breaking is a physics phenomenon where a system's equations have a symmetry its actual ground state does not share, underlying ferromagnetism, superconductivity, and particle mass.
Spontaneous tension pneumothorax
Spontaneous tension pneumothorax (ICD-11 CB21.0): air in the pleural space without trauma, with intrapleural pressure above atmospheric throughout respiration; rare in spontaneously breathing patients, treated by immediate decompression.
Spontaneous urticaria
Spontaneous urticaria (ordinary urticaria, ICD-11 EB00), including chronic spontaneous urticaria (CSU), is hives and angioedema arising without external triggers, unlike inducible urticaria; treated with second-generation H1-antihistamines, omalizumab, ciclosporin.
Spoofing attack
A spoofing attack, also called a masquerade attack, is an attack in which an adversary falsifies an identity, such as an IP address, email sender, or caller ID, to pose as a legitimate party.
Spooks (TV series)
Spooks (MI-5 in the US) is a BBC One spy drama about MI5's Counter-Terrorism section, created by David Wolstencroft, produced by Kudos, 2002–2011, 10 series, 86 episodes, Bafta-winning, famous for killing lead characters.
Spooks: The Greater Good
Spooks: The Greater Good (MI-5 in the US) is a 2015 British spy film directed by Bharat Nalluri, a spin-off of the BBC series Spooks, starring Peter Firth as Harry Pearce and Kit Harington as Will Holloway.
Spooky
Spooky is a London-based electronic music duo of Duncan Forbes and Charlie May, formed in 1992 and best known for 'Little Bullet' and the 1993 album Gargantuan.
Spooky Encounters
Spooky Encounters (鬼打鬼, Gui da gui), aka Encounter of the Spooky Kind, is Sammo Hung's 1980 Hong Kong kung fu horror-comedy about a cuckolded cart driver fighting black magic, and the film that launched the jiangshi hopping-vampire genre.
Spooky in Love
Spooky in Love (오싹한 연애, Ossakhan Yeonae, also Chilling Romance) is a 2026 tvN Korean horror-romantic-comedy series, a remake of the 2011 film Spellbound, starring Park Eun-bin and Yang Se-jong, 12 episodes, streamed on Netflix and TVING.
Spooky Pictures
Spooky Pictures is the American horror production company founded March 2, 2020 by Roy Lee and Steven Schneider under Vertigo Entertainment, backed by Image Nation Abu Dhabi, known for Watcher, Late Night with the Devil, Strange Darling, and Hokum. Distinct from Jason Stutter's New Zealand company of the same name.
Spooky Tooth
Spooky Tooth: English rock band formed October 1967 from Art plus American Gary Wright; blended prog, hard rock, and blues on Island albums Spooky Two (1969) and Ceremony (with Pierre Henry); disbanded 1974, reunited 1997–2009.
Spooky's Jump Scare Mansion
Spooky's Jump Scare Mansion, originally Spooky's House of Jump Scares by Lag Studios (2014), is a free first-person horror game of 1,000 rooms that turns from cute parody into chase horror; HD Renovation (2017) added Unity, VR, and DLC.
Spool valve
A spool valve is a directional control valve in which a cylindrical spool with lands and grooves slides axially in a bore to open, close, and redirect flow.