72,234 articles
Habitat suitability model
A habitat suitability model, also known as a species distribution model (SDM), is an ecological method that maps where habitat suits a species by relating occurrence records to environmental variables.
Habituation
Habituation: progressive decrease of a response to repeated stimulation, not caused by sensory adaptation or fatigue; distinguished by dishabituation, stimulus specificity, and spontaneous recovery; HPA axis habituates rapidly to repeated stress.
Habushu (ハブ酒)
Habushu (ハブ酒), or habu sake, is an Okinawan liqueur of awamori rice spirit with a habu pit viper (Protobothrops flavoviridis) inside; venom is denatured by ethanol, tradition from Chinese snake wine via Ryukyu trade.
HaCaT
HaCaT (CVCL_0038) is a spontaneously immortalized, aneuploid, nontumorigenic human keratinocyte cell line from adult back skin, established 1988 by Boukamp et al.; widely used skin biology and toxicology model with mutant TP53.
Hachikō (ハチ公)
Hachikō (ハチ公), the faithful Akita of Shibuya Station, waited for his dead owner Professor Ueno for about nine years after 1925; famous from a 1932 Asahi article, statue, and Japanese, American, and Chinese films.
Hachiman anti-defense 1
Hachiman anti-defense 1 (Had1) is a 53-amino-acid protein of Bacillus phage SBSphiJ4 that inhibits the bacterial Hachiman HamAB antiphage defense system; identified by Yirmiya et al. (Nature 2024), with 23 homologs in Bacillus phages and a known homodimer structure (PDB 8TTO).
Hacienda
Hacienda: large landed estate of Spanish America, from Old Spanish facienda; colonial landholding system based on resident labor and debt peonage, central to Mexican political economy, dismantled by 20th-century land reform.
HACP trial
HACP trial (NCT02368678), Study of Halitosis in Patients With Advanced Chronic Periodontitis: Brazilian randomized trial comparing full-mouth disinfection with quadrant scaling; both reduced halitosis at 90 days, FMD showing the larger methyl mercaptan reduction.
Haddock
Haddock (Melanogrammus aeglefinus), scrod, a North Atlantic cod-family groundfish with a black thumbprint mark; lean sweet white flesh, major fish-and-chips species, U.S. stocks not overfished per 2024 assessments.
Hadesarchaea
Hadesarchaea (Hadarchaeia, formerly SAGMEG) is an uncultivated class of subsurface Archaea named in 2016, with streamlined ~1.5 Mbp genomes encoding CO/H2 oxidation and DNRA, found in anoxic sediments, gold mines, and hot springs.
HADHA
HADHA (hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit alpha) is a gene on chromosome 2p23 encoding the alpha subunit of mitochondrial trifunctional protein; biallelic variants cause LCHAD deficiency and trifunctional protein deficiency.
Hadrianus
Hadrianus is a Latin name used for several subjects, most often the extinct Eocene tortoise genus named by Edward Drinker Cope in 1872 or the Roman emperor Hadrian, who ruled from 117 to 138.
Hadron therapy
Hadron therapy is a radiation treatment using charged particle beams, chiefly protons and carbon ions, which deposit most of their energy in the tumor while sparing healthy tissue.
Hadronyche formidabilis
Hadronyche formidabilis, the Northern Tree Funnel-web Spider, is Australia's largest funnel-web (4–5 cm body), a tree-dwelling Atracidae spider of northern NSW and southern Queensland with severe envenoming in 63% of recorded bites.
Haemagogus
Haemagogus (shoulder mosquito), a Neotropical mosquito genus of tribe Aedini with two subgenera and about 28 species, whose arboreal, day-biting species such as Hg. janthinomys and Hg. leucocelaenus are the primary sylvatic vectors of yellow fever and Mayaro viruses in the Americas.
Haemaphysalis
Haemaphysalis (Koch, 1844) is a genus of hard ticks in Ixodidae, the second largest tick genus with about 166-176 species on all continents except Antarctica; includes the invasive Asian longhorned tick H. longicornis.
Haematemesis
Haematemesis is vomiting of blood, fresh or coffee-ground, signaling upper gastrointestinal bleeding from the esophagus, stomach, or duodenum. Key facts: peptic ulcers cause 43.6% of cases; Glasgow Blatchford score 1 or less identifies outpatient-manageable patients.
Haematobia irritans
Haematobia irritans, the horn fly (mouche des cornes), is a small blood-feeding muscid fly that lives permanently on cattle, feeding 24–38 times daily; larvae develop in dung, and the species causes about US$1 billion in annual North American cattle losses.
Haematococcus pluvialis astaxanthin extract
Haematococcus pluvialis astaxanthin extract: oleoresin from the green microalga H. pluvialis, the richest natural astaxanthin source (up to 5.5% dry weight); FDA GRAS (GRN 294, 580), EU novel food limit 8 mg/day.
Haematocolpos
Haematocolpos, also spelled hematocolpos, is the accumulation of menstrual blood in the vagina caused by an obstruction, most often an imperforate hymen, and typically appears at puberty.
Haematologica
Haematologica: monthly open-access hematology journal founded 1920 in Naples by Ferrata and Moreschi, oldest hematology journal, owned by the Ferrata Storti Foundation, official EHA journal, 2025 Impact Factor 8.2.
Haematoma of broad ligament
Broad ligament haematoma: blood collecting in the broad ligament of the uterus, a rare obstetric emergency (incidence about 1:500 to 1:20,000) caused by tears extending into uterine or vaginal vessels, treated conservatively or surgically.
Haematometra
Haematometra (hemometra, haemometra) is retention of blood in the uterine cavity, usually from outflow obstruction such as imperforate hymen, transverse vaginal septum, or cervical stenosis after procedures; treated by cervical dilatation and drainage.
Haematopoiesis
Haematopoiesis, also spelled hematopoiesis and known as blood formation or haemogenesis, is the process by which blood cells form from stem cells, primarily in adult bone marrow.
Haematopus
Haematopus is the genus of oystercatchers, family Haematopodidae, 12 coastal species worldwide that open bivalves with strong bills; includes extinct H. meadewaldoi and rapidly radiating Old World lineages.
Haematosalpinx
Haematosalpinx (hematosalpinx, haemosalpinx), blood accumulation in a distended fallopian tube; ICD-11 GA17.3. Most often from ectopic pregnancy; also endometriosis, PID, torsion, neoplasm. Diagnosed by ultrasound and MRI.
Haematuria
Haematuria, also spelled hematuria, is the presence of blood in the urine, classified as visible when it discolors the urine and non-visible when found only on testing.
Haemerythrin
Haemerythrin (hemerythrin, Hr): a non-heme, diiron oxygen-binding protein of marine invertebrates (sipunculids, brachiopods, priapulids, annelids) and many bacteria; binds O2 as a peroxide at a two-iron center in a four-helix-bundle homooctamer.
Haemoglobinuria
Haemoglobinuria (hemoglobinuria, hemoglobin in urine) is free hemoglobin in urine from intravascular red cell hemolysis after haptoglobin saturation; dipstick positive without red cells; causes include PNH, malaria, burns, and march hemoglobinuria.
Haemolymph juvenile hormone binding
Haemolymph juvenile hormone binding (JHBP): carrier proteins that transport lipophilic juvenile hormone through insect hemolymph from the corpora allata to target tissues and protect it from esterases; best known from Manduca sexta, Bombyx mori, and Galleria mellonella.