All articles starting with K
16,083 articles
Keratinase
Keratinase: keratin-degrading proteolytic enzyme (EC 3.4.-.-) from microbes such as Bacillus, spanning 14 MEROPS protease families; used for feather waste valorization, detergent additives, and eco-friendly leather dehairing.
Keratinization
Keratinization is the process by which epithelial cells accumulate keratin filaments, die, and form the protective outer layers of skin, hair, and nails, occurring chiefly in keratinocytes of the epidermis.
Keratinocyte
Epidermal keratinocyte: the main epidermal skin cell (about 95% of epidermal cells), which synthesizes keratin and differentiates through basal, spinous, granular, and cornified layers to build the skin barrier over roughly a month.
Keratitis
Keratitis, inflammation of the cornea; microbial keratitis (bacterial, fungal, viral, Acanthamoeba) is a sight-threatening infection, with contact lens wear the main risk factor in Western settings.
Keratitis fugax hereditaria
Keratitis fugax hereditaria (keratoendotheliitis fugax hereditaria, KFH) is a rare autosomal dominant corneal autoinflammatory disease caused by the NLRP3 variant c.61G>C, causing recurrent unilateral painful attacks, blurred vision, and corneal opacities, mainly in people of Finnish descent.
Keratoacanthoma
Keratoacanthoma (KA), a rapidly growing hair-follicle-derived skin tumour that often regresses spontaneously over 4-6 months; closely mimics well-differentiated squamous cell carcinoma, driving a classification controversy and surgical excision as standard care.
Keratoconus
Keratoconus, also called conical cornea, is a bilateral noninflammatory ectatic corneal disease causing progressive thinning, cone-shaped bulging, and irregular astigmatism; managed with contact lenses, corneal cross-linking, ring segments, or keratoplasty.
Keratocystic odontogenic tumor
Keratocystic odontogenic tumor (KCOT), the WHO 2005 name for the odontogenic keratocyst, an aggressive parakeratinized jaw cyst linked to PTCH1 mutations and Gorlin syndrome; reclassified back as a cyst in WHO 2017 and 2022.
Keratocyte
Keratocyte (corneal keratocyte): neural crest-derived stromal cell of the cornea, dendritic and quiescent, marked by keratocan, CD34, crystallins; maintains transparency, converts to fibroblasts and myofibroblasts after injury, causing haze.
Keratoderma hereditarium mutilans
Keratoderma hereditarium mutilans, or Vohwinkel syndrome (OMIM 124500), is a rare autosomal dominant mutilating palmoplantar keratoderma with honeycomb keratosis, pseudoainhum, and deafness; classic form from GJB2 (connexin 26), ichthyosiform variant from LOR.
Keratoderma hereditarium mutilans with ichthyosis
Keratoderma hereditarium mutilans with ichthyosis, also called loricrin keratoderma or Camisa disease, is a rare autosomal dominant Vohwinkel syndrome variant caused by LOR mutations, featuring honeycomb palmoplantar keratoderma, pseudoainhum, and ichthyosis.
Keratolytic winter erythema
Keratolytic winter erythema (Oudtshoorn skin disease, erythrokeratolysis hiemalis, OMIM 148370) is a rare autosomal dominant disorder of recurrent winter-worsened palmoplantar peeling and erythema, caused by a duplicated enhancer upstream of CTSB on chromosome 8p22-p23, common in South African Afrikaans-speakers via founder François Renier Duminy.
Keratometry
Keratometry is an ophthalmic measurement technique that determines the curvature of the front corneal surface and converts it to dioptric power, mainly for contact lens fitting and cataract surgery.
Keratomileusis
Keratomileusis, Greek for sculptured cornea, is a family of refractive surgical procedures that reshape the cornea to correct myopia, hyperopia, and astigmatism, including LASIK, PRK, and SMILE.
Keratosa
Keratosa is a subclass of demosponge sponges with skeletons of spongin fibres and no mineral spicules, containing the orders Dictyoceratida and Dendroceratida, about 561 described species, and the commercial bath sponges Spongia and Hippospongia.
Keratosis follicularis spinulosa decalvans
Keratosis follicularis spinulosa decalvans (Siemens syndrome, KFSD) is a rare X-linked genodermatosis causing follicular hyperkeratosis, scarring alopecia of scalp, eyebrows, and eyelashes, photophobia, and corneal dystrophy, mainly from MBTPS2 mutations.
Keratosis linearis-ichthyosis congenita-sclerosing keratoderma syndrome
KLICK syndrome (keratosis linearis-ichthyosis congenita-sclerosing keratoderma syndrome, OMIM 601952) is a rare autosomal recessive genodermatosis caused by a c.-95delC deletion in the POMP 5′ UTR, causing palmoplantar keratoderma, linear flexural keratoses, ichthyosis, and finger constrictions.
Keratosis pilaris
Keratosis pilaris (KP, chicken skin) is a common benign follicular hyperkeratosis: keratin plugs hair follicles, causing rough sandpaper-like bumps on upper arms and thighs, worse in winter, treated with urea, lactic acid, salicylic acid, or Nd:YAG laser.
Keratotomy
Keratotomy is eye surgery that cuts incisions in the cornea to change its curvature and correct refractive error; radial keratotomy for myopia peaked in the 1980s before lasers replaced it.
Keratsíni
Keratsini (Κερατσίνι), also Keratsini-Drapetsona, is a working-class port suburb of Piraeus, Attica, Greece. Formerly an industrial belt (Saint George's Power Plant, 1926), now deindustrialized, with about 70,000-91,000 residents and no metro or rail service.
Kerb ramp
A kerb ramp, called a curb ramp or curb cut in American usage, is a short ramp linking a sidewalk to the roadway for wheelchair users.
Kerbal Space Program
Kerbal Space Program (KSP) is a physics-based spaceflight simulation by Squad, first released 2011, sold to Take-Two in 2017; uses patched-conic orbital physics, three game modes, over two million units sold by 2017.
Kerberos
Kerberos (S/2011 (134340) 1, P4) is a small moon of Pluto discovered by Hubble in 2011, orbiting between Nix and Hydra with a 32.17-day period, a double-lobed ~19 km body of bright water ice.
Kerberos (protocol)
Kerberos, also known as the Kerberos authentication protocol or Krb5, is a network authentication protocol developed at MIT in the 1980s and standardized in 1993.
Kerbogha
Kerbogha (كربغا) was a Seljuk Turkic commander and atabeg of Mosul from 1096 to 1102, defeated by the crusaders outside Antioch on 28 June 1098.
Kercado tumulus
Kercado tumulus (Tumulus-dolmen de Kercado, Cairn de Kercado): Neolithic passage grave under a dry-stone cairn at Carnac, Morbihan, Brittany, built around 4600 BC, excavated by Galles (1863) and Le Rouzic (1925), classified monument historique in 1923.
Kerch
Kerch (Керч) is a port city of about 151,000 in eastern Crimea on the Kerch Strait, occupying the site of ancient Panticapaeum, the Milesian-founded capital of the Bosporan Kingdom, now a strategic bridge and port hub hit by 2026 strikes.
Kerch Polytechnic College massacre
The Kerch Polytechnic College massacre, also called Russia's Columbine, was a school shooting and bombing at Kerch Polytechnic College in Crimea on 17 October 2018, killing at least 21 people.
Kerch Strait
Kerch Strait, the sole passage between the Black Sea and Sea of Azov between Crimea and the Taman Peninsula; site of the 2018 naval incident, the 19-km Kerch Bridge, and the 2026 UNCLOS arbitration between Ukraine and Russia.
Kerch Strait incident
The Kerch Strait incident was the 25 November 2018 Russian seizure of the Ukrainian naval vessels Berdyansk, Nikopol, and Yany Kapu and 24 sailors, leading to ITLOS provisional measures and Western sanctions.