All articles starting with X
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Xania Monet
Xania Monet is a fully AI-generated R&B artist persona, also called a virtual singer, created by Mississippi poet Telisha "Nikki" Jones using Suno; signed a $3 million Hallwood Media deal in September 2025 and was the first AI artist to debut on a Billboard radio chart.
Xanten
Xanten is a town in Kreis Wesel, North Rhine-Westphalia, on the Lower Rhine, site of the Roman Colonia Ulpia Traiana and the LVR-Archaeological Park, part of the UNESCO Lower German Limes since 2021; about 21,000 residents on 72.43 km².
Xanth
Xanth is a long-running series of comic fantasy novels by Piers Anthony, set in a magical Florida-shaped land where every human has a unique talent; it began in 1977.
Xanthan gum
Xanthan gum (E 415, INS 415) is a microbial polysaccharide made by fermenting sugars with Xanthomonas campestris; a shear-thinning thickener and stabilizer used in food, cosmetics, pharmaceuticals, and oil drilling, FDA-approved in 1969.
Xanthate
A xanthate is a salt or O,S-ester of dithiocarbonic acid of formula ROCSSM, named from the Greek for yellow, long used as a collector reagent in sulfide froth flotation.
Xanthe Montes
Xanthe Montes is an IAU-approved mountain chain on Mars, about 499 km across near 18°N 305°E, outlining Chryse Planitia; possibly a buried impact basin rim or early Tharsis tectonic ridge.
Xanthe Terra
Xanthe Terra, a high-standing cratered plain south of Chryse Planitia on Mars, named by the IAU in 1979 ('golden-yellow land'), home to outflow channels Shalbatana and Ravi Vallis, Nanedi Valles, and the Hypanis delta.
Xantheia
Xantheia (Ξάνθεια), ancient Thracian Ciconian city named by Strabo east of Lake Vistonis, and a fortified Byzantine town on the hill above modern Xanthi, Greece; location of the ancient city unproven, Ottoman conquest 1371/1373.
Xanthelasma
Xanthelasma palpebrarum (XP) is the most common cutaneous xanthoma, a benign yellow lipid plaque on the eyelids, twice as common in women, linked variably to dyslipidemia, and treated by excision, CO2/Er:YAG laser, TCA peel, cryotherapy, or radiofrequency.
Xanthene
Xanthene, also called 9H-xanthene or 10H-9-oxaanthracene, is a tricyclic heterocyclic organic compound, formula C13H10O, that is the parent scaffold of the xanthene dyes such as fluorescein and the rhodamines.
Xanthian Obelisk
The Xanthian Obelisk, or Inscribed Pillar of Xanthos, is a Lycian pillar tomb at Xanthos, Türkiye, bearing the longest known Lycian text, dated around 400 BC.
Xanthine
Xanthine (3,7-dihydro-1H-purine-2,6-dione, CAS 69-89-6) is a purine base intermediate in purine catabolism, converted to uric acid by xanthine oxidase; its methylated forms include caffeine, theobromine, and theophylline.
Xanthine dehydrogenase D subunit
Xanthine dehydrogenase D subunit (pucD, TIGR03196) is the molybdopterin- and xanthine-binding subunit of bacterial xanthine dehydrogenase, working with FAD-binding PucC and FeS-binding PucE; counterpart of R. capsulatus XdhB.
Xanthine dehydrogenase, accessory protein PucB
PucB (WP_003228645.1) is a Bacillus accessory protein, encoded in the pucABCDE operon, required for xanthine dehydrogenase activity and proposed to function in molybdenum cofactor formation, homologous to MobA and MocA.
Xanthine oxidase
Xanthine oxidase (xanthine oxidoreductase, XOR) is a molybdenum, FAD, and iron-sulfur enzyme catalyzing hypoxanthine to xanthine to uric acid, generating ROS; inhibited by allopurinol, febuxostat, and topiroxostat for gout.
Xanthine-guanine phosphoribosyltransferase
Xanthine-guanine phosphoribosyltransferase (XGPRT, EC 2.4.2.22), the E. coli gpt gene product, is a purine salvage enzyme converting xanthine and guanine plus PRPP to XMP and GMP; also a dominant selectable marker in mammalian cells.
Xanthinol
Xanthinol (xanthinol nicotinate, xanthinol niacinate; CAS 2530-97-4 free base, 437-74-1 salt) is a water-soluble niacin-derivative vasodilator used for peripheral vascular insufficiency, causing flushing, gastric discomfort, and hypotension.
Xanthippe (Ξανθίππη)
Xanthippe (Ξανθίππη), wife of Socrates, Athenian woman born about 445 B.C.E., mother of three sons; known from Plato's Phaedo, Xenophon's 'harshest woman ever' label, Diogenes Laertius anecdotes, and the disputed Myrto two-wives tradition.
Xanthippus of Sparta
Xanthippus of Sparta was a Spartan mercenary commander who served Carthage in 255 BC during the First Punic War, defeating and capturing the Roman consul Regulus at the Bagradas river.
Xanthium
Xanthium (cocklebur) is a genus of annual Asteraceae herbs with spiny two-seeded burs dispersed by animal fur and water; taxonomically contested, toxic to livestock via carboxyatractyloside, and used in Chinese medicine as Cang-Er-Zi.
Xanthium strumarium
Xanthium strumarium (cocklebur, Cang-Er-Zi), Asteraceae annual herb; fruits are a Chinese Pharmacopoeia medicine for rhinitis, while seeds and seedlings contain toxic carboxyatractyloside.
Xanthoma
Xanthoma (xanthelasma when on the eyelids) is a benign yellowish skin deposit of cholesterol-filled macrophage foam cells, usually signaling dyslipidemia; subtypes include plane, eruptive, tendinous, tuberous, and verruciform forms.
Xanthoma disseminatum
Xanthoma disseminatum (Montgomery syndrome, xanthoma multiplex) is a rare normolipidemic non-Langerhans cell histiocytosis with yellow-brown coalescing skin and mucosal papules, diabetes insipidus, CD68+/S100- histiocytes, and about 140 reported cases.
Xanthomonas
Xanthomonas (Dowson 1939) is a genus of Gram-negative, yellow-pigmented, polar-flagellated plant-pathogenic bacteria in Lysobacteraceae; type species X. campestris; virulence via type III effectors and TALEs.
Xanthomonas axonopodis
Xanthomonas axonopodis (Starr and Garces 1950) is a gram-negative plant-pathogenic bacterium causing citrus cankers and black rot; expanded in 1995 to include 34 former X. campestris pathovars, later divided into X. citri, X. euvesicatoria, and X. phaseoli.
Xanthomonas campestris
Xanthomonas campestris, type species of the genus Xanthomonas, is a Gram-negative plant pathogen; pv. campestris causes black rot of brassicas, and the species industrially produces xanthan gum via its 12-gene gum cluster.
Xanthomonas citri
Xanthomonas citri (synonym X. axonopodis pv. citri) is a plant-pathogenic bacterium; subspecies citri causes Asiatic citrus canker (canker A), a quarantine disease, while pv. fuscans causes common bacterial blight of bean and pv. aurantifolii causes canker B and C.
Xanthomonas oryzae
Xanthomonas oryzae is a Gram-negative bacterial species with two pathovars, oryzae (Xoo, bacterial leaf blight) and oryzicola (Xoc, bacterial leaf streak), the major bacterial diseases of rice, causing 10–50% yield losses and regulated as EPPO A1 quarantine pests.
Xanthophore cell
A xanthophore is a neural crest-derived pigment cell of fish, amphibians, and reptiles, one of the chromatophores, holding pteridine and carotenoid pigments in pterinosomes and appearing yellow to orange.
Xanthoria
Xanthoria (sunburst lichens, orange wall lichens) is a genus of orange foliose lichenized fungi in Teloschistaceae, type species Xanthoria parietina, colored by the anthraquinone parietin, worldwide on bark and rock.