All articles A–Z
519,064 articles
Alloimmune thrombocytopenia
Alloimmune thrombocytopenia, chiefly fetal and neonatal alloimmune thrombocytopenia (FNAIT, NAIT), is maternal anti-HPA antibody-mediated fetal platelet destruction, causing thrombocytopenia and intracranial hemorrhage; treated with IVIG and platelet transfusion.
Allomyces
Allomyces is a genus of aquatic saprobic fungi in the phylum Blastocladiomycota, established by E.J. Butler in 1911 and defined by a true alternation of generations between haploid and diploid phases.
Allon Moshe Klein
Allon Moshe Klein, also published as Allon M. Klein, is a systems biologist and Professor at Harvard Medical School known for droplet barcoding in single-cell genomics.
AlloNK1 trial
AlloNK1 (NCT07247201) is a Singapore General Hospital phase 1/2 trial adding donor-derived allogeneic NK cells to chemoradiotherapy for high-risk stage III-IV nasopharyngeal cancer, seeking the maximum tolerated dose and reduced plasma EBV-DNA detectability.
Allonzier-la-Caille
Allonzier-la-Caille (also written Allonzier la Caille), commune in Haute-Savoie, France, INSEE code 74006, 2,253 inhabitants (2023), 13 km north of Annecy; known for the Pont suspendu de la Caille (1839) and the disused Bains de la Caille thermal site.
Allonzo Trier
Allonzo Trier, born 1996, Seattle guard; undrafted 2018 from Arizona; played two seasons for the New York Knicks on a two-way then $6.9 million deal, averaging 9.7 points per game.
Allopathic medicine
Allopathic medicine, also called allopathy, biomedicine, or conventional Western medicine, is evidence-based medical care using drugs, surgery, and radiation; the term was coined by homeopathy founder Samuel Hahnemann and shaped by the 1910 Flexner Report, and denotes MD practice as distinct from osteopathic (DO) medicine.
Allopatric speciation
Allopatric speciation: formation of new species when a geographic barrier (river, mountain, ocean) splits a population and stops gene flow, letting drift, mutation, and selection build reproductive isolation; the classic null model of speciation, now tested against genomic evidence of divergence with gene flow.
Allophaiomys
Allophaiomys (Kormos, 1933) is an extinct Early Pleistocene arvicoline vole genus, 2.2–1.2 mya, ancestral or sister to Microtus, descended from Mimomys, used as a biochronological marker across Eurasia and North America.
Allophanate hydrolase
Allophanate hydrolase (EC 3.5.1.54), an amidase signature family enzyme hydrolyzing allophanate to ammonia and CO2; terminal step of urea amidolyase and bacterial atrazine/cyanuric acid catabolism (AtzF, TrzF).
Allophone
An allophone is a predictable phonetic variant of a phoneme, such as aspirated [pʰ] in English pin versus unaspirated [p] in spin, usually in complementary distribution, contrastive in other languages.
Allophycocyanin, beta subunit
Allophycocyanin beta subunit (ApcB, apcB gene): the 161-residue, single-phycocyanobilin chain of the phycobilisome core protein allophycocyanin; pairs with ApcA in (αβ)3 trimers, absorbs at 650 nm, transfers energy β-to-α, with variant beta-18 (ApcF).
Allopregnanolone
Allopregnanolone is an endogenous neurosteroid and progesterone metabolite that modulates GABA-A receptors; its formulations brexanolone and zuranolone became the first FDA-approved medications for postpartum depression.
Allopurinol
Allopurinol is an oral xanthine oxidase inhibitor, also called Zyloprim, approved in 1966 for gout, cancer-therapy hyperuricemia, and hyperuricosuric kidney stones; dosing is titrated to urate targets with HLA-B*58:01 testing advised in some groups.
Allorecognition
Allorecognition: ability to distinguish self or kin from unrelated conspecifics. Best studied in the colonial ascidian Botryllus schlosseri, whose fuhc locus governs fusion or rejection via missing-self recognition, unlike vertebrate MHC.
Allorion Therapeutics (安锐生物)
Allorion Therapeutics (安锐生物) is a clinical-stage biotechnology company founded in 2020 by Peter Ding and Fang Li in Guangzhou, China, developing small-molecule precision medicines for cancer and autoimmune diseases.
Allosaurus
Allosaurus is a genus of large carnivorous theropod dinosaur that lived in North America and Europe during the Late Jurassic, named by Othniel Charles Marsh in 1877 and now Utah's state fossil.
Allosteric regulation
Allosteric regulation: effector binding at a site other than the active (orthosteric) site changes protein conformation and activity. Key names: Monod, Jacob, MWC/KNF models; basis of allosteric drug design.
Allotransplantation
Allotransplantation, also called homologous transplantation, is the transplant of organs, tissue, or cells between members of the same species who are not identical twins, as in most human organ transplants.
Allotriocarida
Allotriocarida, also written Allotriocarida Oakley et al. 2012, is a pancrustacean superclass grouping Branchiopoda, Cephalocarida, Remipedia, and Hexapoda; internal relationships remain contested, with Copepoda sometimes included.
Allotropes of carbon
Allotropes of carbon, or carbon allotropes, are the different physical forms of the element carbon, the most common being graphite and diamond, joined after 1985 by fullerenes, graphene, and carbon nanotubes.
Allotropes of iron
The allotropes of iron are the distinct crystal forms pure iron adopts at different temperatures and pressures, from α-ferrite to γ-austenite to high-pressure ε-iron, making steel heat treatment possible.
Allotropes of phosphorus
The allotropes of phosphorus, or phosphorus allotropes, are the distinct structural forms of the element phosphorus. White phosphorus ignites in air, while black phosphorus is a stable layered semiconductor.
Allotropes of silicon
The allotropes of silicon are the distinct crystalline and amorphous solid forms of the element, including the stable diamond-cubic phase, metallic high-pressure forms, and cage-like Si24.
Allotropy
Allotropy is the existence of an element in two or more different structural forms, called allotropes, in the same physical state, a concept proposed by Berzelius in 1841.
AlloVir
AlloVir, formerly ViraCyte, was a Houston, Texas biotechnology company founded in 2013 that developed virus-specific T-cell therapies for immunocompromised patients before abandoning development in 2023.
Allow (HTTP header)
Allow is an HTTP response header listing the request methods a resource supports, and a server must send it with every 405 Method Not Allowed response.
Allowance for doubtful accounts
The allowance for doubtful accounts is a contra-asset account reducing accounts receivable to the net amount a company expects to collect, with changes recorded as credit loss expense.
Alloxan
Alloxan, also called mesoxalylurea, is an organic compound with the formula C4H2N2O4, obtained from uric acid in 1818 and used to induce experimental diabetes by destroying pancreatic beta cells.
Alloxydim
Alloxydim (alloxydim-sodium, CAS 55634-91-8) is a cyclohexanedione oxime ACCase-inhibiting herbicide for post-emergence grass weed control, the first DIM herbicide, commercialized by Nippon Soda in 1978 and now not approved in the EU.