All articles starting with X
1,563 articles
Xenotransfusion
Xenotransfusion is the transfusion of blood or blood products from another species into a human patient, investigated to relieve blood shortages, particularly in emergency settings.
Xenotransplantation
Xenotransplantation, also called heterologous transplantation, is the transfer of living cells, tissues, or organs from nonhuman animals, chiefly pigs, into human patients to ease the organ shortage.
XenServer
XenServer is a commercial server virtualization platform built on the open-source Xen Project hypervisor, consolidating virtual machines onto physical servers and positioned especially for Citrix Virtual Apps and Desktops workloads.
Xenu
Xenu, sometimes spelled Xemu, is the galactic ruler in Scientology's confidential OT III materials, said to have killed billions on Earth 75 million years ago.
Xeon
Xeon is Intel's brand of x86 processors for servers, workstations, and data centers, introduced in 1998 and spanning Xeon 6, Xeon Scalable, Xeon W, Xeon D, and Xeon E lines.
Xeon Phi
Xeon Phi, also called the Many Integrated Core Architecture, is a discontinued series of Intel x86 manycore processors for high-performance computing, launched in 2012 and discontinued in 2018.
Xeranthemum annuum
Xeranthemum annuum (annual everlasting, immortelle) is an Asteraceae annual native from Central and SE Europe to Central Asia and Iran, with papery pink or white flower heads used in dried arrangements and studied for antioxidant polyphenols.
Xeri
Xeri (Ξερή, Kseri) is a Greek two-player fishing card game with a 52-card deck: capture the central pile by matching its top card or with a Jack, scoring 10-20 point bonuses for a lone-card "xeri".
Xeriscaping
Xeriscaping (xeriscape): water-conserving landscaping coined by Denver Water in 1981 from Greek xeros (dry); seven principles including limited turf, efficient irrigation, mulch; cuts outdoor water use 30-50%.
Xerjoff
Xerjoff is an Italian luxury perfume house founded in Turin in 2007 by Sergio Momo and Dominique Salvo, selling more than 180 fragrances in over 125 countries.
Xero
Xero is a New Zealand-founded technology company providing a cloud-based small business platform combining accounting, payroll, and payments, serving 5 million customers in over 180 countries.
Xerocomellus chrysenteron
Xerocomellus chrysenteron, the red-cracking bolete (Boletus chrysenteron), a European Boletaceae fungus with a brown cap cracking to reveal red flesh, yellow coral-fibrillose stem, smooth spores, and frequent confusion with X. cisalpinus.
Xerocomus
Xerocomus, synonym Versipellis, is a genus of ectomycorrhizal bolete fungi (Boletaceae) established by Quélet in 1887 with type species Xerocomus subtomentosus; about 115 species, defined by bacillate spore ornamentation, but non-monophyletic and split into Xerocomellus, Hortiboletus, and Hemileccinum.
Xerocomus subtomentosus
Xerocomus subtomentosus, the suede bolete (Boletus subtomentosus L., 1753), an edible Boletaceae fungus of European broadleaf woods; type species of Xerocomus, ochre velvety cap, yellow pores, weak blueing flesh.
Xeroderma pigmentosum
Xeroderma pigmentosum (XP): rare autosomal recessive DNA repair disorder causing extreme UV sensitivity, early skin cancers, and neurodegeneration in some; no cure, managed by strict sun avoidance.
Xeroderma pigmentosum variant
Xeroderma pigmentosum variant (XP-V, XPV) is a milder autosomal recessive subtype of xeroderma pigmentosum in which DNA polymerase eta is defective, causing skin cancers from about age 20–30.
Xeroderma pigmentosum-Cockayne syndrome complex
Xeroderma pigmentosum-Cockayne syndrome complex (XP-CS, XP/CS complex) is a rare autosomal recessive nucleotide excision repair disorder combining XP skin cancer risk with Cockayne syndrome growth failure and neurodegeneration, caused by ERCC3, ERCC2, or ERCC5 mutations.
Xerography
Xerography is a dry electrostatic copying process, named from Greek for "dry writing," in which charged toner forms images on paper; Chester Carlson first demonstrated it in 1938.
Xeromammography
Xeromammography is xeroradiography of the breast, a filmless electrostatic X-ray method using selenium plates and dry toner, commercialized by Xerox around 1970-1971, widely used in the 1970s, and replaced by screen-film and digital mammography.
Xerophthalmia
Xerophthalmia, from Greek for dry eye, is the range of eye disorders caused by vitamin A deficiency, from night blindness and Bitot spots to blinding keratomalacia.
Xerophyte
Xerophyte: a plant adapted to survive in very dry habitats such as deserts. Also called dry plants; includes succulents, ephemerals, and resurrection plants with CAM or C4 photosynthesis, thick cuticles, sunken stomata, and deep roots.
Xeroradiography
Xeroradiography is a dry electrostatic method for recording X-ray images using a selenium-coated plate and charged powder toner. It was widely used in mammography in the 1970s.
Xerostomia
Xerostomia (dry mouth) is the subjective sensation of oral dryness, distinct from hyposalivation. Main causes are medications, Sjögren's disease, diabetes, and head and neck radiotherapy; pilocarpine has the best-supported benefit.
Xerox
Xerox is an American corporation in Rochester, New York, built on xerography, which it commercialized as the Xerox 914 copier in 1959; its PARC lab invented the laser printer, Ethernet, and the graphical user interface.
Xerox Alto
The Xerox Alto was an experimental personal computer designed at Xerox PARC in 1973, the first to combine a bit-mapped display, mouse, and Ethernet networking.
Xerus
Xerus, African ground squirrels, genus of diurnal burrowing rodents (Sciuridae, Xerini) described 1833; traditionally four species including Cape ground squirrel X. inauris; 2016 revision splits Euxerus and Geosciurus out.
Xerxes I
Xerxes I (Old Persian Xšaya-ṛšā), Achaemenid king 486–465 BCE, son of Darius I and Atossa; suppressed revolts in Egypt and Babylon, dropped 'King of Babylon', invaded Greece in 480 BCE, built at Persepolis, and was murdered in 465.
Xerxes II
Xerxes II (Old Persian Xshayarsha) was a king of Achaemenid Persia, son of Artaxerxes I, who reigned about 45 days in 424 BC before being murdered by his half-brother Sogdianus.
Xerxes' invasion of Greece
Xerxes' invasion of Greece was the Achaemenid Persian campaign of 480 to 479 BC, led by King Xerxes I in person and ended in Greek victory at Plataea.
XEST 17-036
XEST 17-036, also called 2MASS J04332621+2245293, is a young M4 red dwarf in the Taurus Molecular Cloud, host of the directly imaged 10.6-Jupiter-mass companion KOINTREAU-1 b at 690 au, discovered in 2026.