72,234 articles
Hershel Jick
Hershel Jick was an American drug-safety researcher who founded and led the Boston Collaborative Drug Surveillance Program in Boston in 1966, known for studies linking coffee to heart attack.
Hershey–Chase experiment
Hershey–Chase experiment (1952, Cold Spring Harbor): Alfred Hershey and Martha Chase used 32P- and 35S-labeled bacteriophage T2 and a Waring blender to show phage DNA, not protein, enters bacteria, establishing DNA as genetic material.
Hertzel Gerstein
Hertzel Gerstein is a Canadian endocrinologist at McMaster University who led large diabetes trials, including REWIND, and was elected a Royal Society of Canada Fellow in 2023.
Hervé Avet‐Loiseau
Hervé Avet-Loiseau is a French hematologist-oncologist known for the genetics and genomics of multiple myeloma, who led the Myeloma Genomics unit at the Cancer Research Center of Toulouse.
Hervé Dombret
Hervé Dombret is a French hematologist at Hôpital Saint-Louis in Paris specializing in adult acute leukemia; he led the ALFA and GRAALL groups and the ALFA-0701 gemtuzumab trial.
Hervé Philippe
Hervé Philippe is a molecular phylogeneticist who held a Canada Research Chair in Bioinformatics and Evolutionary Genomics at Université de Montréal, known for Nature papers on early animal evolution.
Hervé Tilly
Hervé Tilly is a French hematologist-oncologist at the Centre Henri Becquerel in Rouen who led the PRIMA and POLARIX lymphoma trials and directed the center from 2007 to 2017.
Hervé Vaucheret
Hervé Vaucheret is a French plant molecular biologist at INRAE in Versailles who has led an epigenetics team since 1993 and defined the mechanisms of RNA silencing in plants.
Herwig Baier
Herwig Baier is a neuroscientist who directs the Department Genes – Circuits – Behavior at the Max Planck Institute for Biological Intelligence, using zebrafish to study behavior.
HES1
HES1 (HES-1, HRY, bHLHb39), Gene ID 3280 at 3q29, encodes a 282-amino-acid bHLH transcriptional repressor and Notch effector with bHLH, Orange, and WRPW domains, oscillatory auto-repression, and central roles in neurogenesis and cancer.
Hesham A. Sadek
Hesham A. Sadek is an Egyptian-born American cardiologist who showed the newborn mouse heart regenerates by cell division, a capacity lost by seven days of age.
Hesitancy of micturition
Hesitancy of micturition, also called urinary hesitancy or urinary hesitation, is a delay or difficulty in starting urination, classified as a symptom rather than a disease.
Hesperiidae
Hesperiidae, the skipper butterflies, is a worldwide butterfly family of over 4,100 species in about 570 genera, marked by hooked antennae, stout bodies, and rapid flight; formerly superfamily Hesperioidea, now within Papilionoidea with seven subfamilies.
Hesperis matronalis
Hesperis matronalis, dame's rocket or dame's violet, is a Eurasian biennial mustard with fragrant four-petaled purple or white flowers, widely naturalized and invasive in North America, attacked by the weevil Ceutorhynchus inaffectatus, and often confused with five-petaled garden phlox.
Hesperocyparis
Hesperocyparis (western cypresses) is a Cupressaceae genus published in 2009 for New World species formerly in Cupressus; 17 accepted species, native western North America to Central America, origin ~39.2 Ma.
Hesperornis
Hesperornis, type genus of the Hesperornithiformes, a large flightless toothed diving seabird from the Late Cretaceous Western Interior Seaway of North America, discovered by O.C. Marsh in Kansas in 1870; swam with powerful hind legs, ate fish and squids, nested on land.
Hetacillin
Hetacillin is a discontinued semisynthetic aminopenicillin prodrug, an acetone adduct of ampicillin (Versapen), with no antibacterial activity itself; it hydrolyzes in the body to ampicillin, its active form.
Heteractinida
Heteractinida (order Heteractinida, Hinde 1888) is an extinct Paleozoic order of calcareous sponges (Calcarea) with octactine spicules, Cambrian to Permian, regarded as the early stem group of Calcarea.
Heteraster
Heteraster, an extinct Cretaceous toxasterid spatangoid (heart urchin) genus by d'Orbigny, type species Spatangus oblongus; 87 nominal species, defined by alternating ambulacral pore pairs, extinct by early Cenomanian.
Heterobasidiomycetes
Heterobasidiomycetes: historical basidiomycete group with septate (phragmo)basidia, jelly fungi, rusts, and smuts, defined by Patouillard; now abandoned as polyphyletic after molecular phylogenetics.
Heterobranchia
Heterobranchia is a major clade of gastropod molluscs, established by Burmeister in 1837, that unites sea slugs, sea hares, bubble shells, and most land snails and slugs, with a fossil record reaching the Devonian.
Heterobranchus bidorsalis
Heterobranchus bidorsalis, African giant catfish or eel-like fattyfin catfish, a clariid catfish described 1809 from the Nile, ranging Senegal to Ethiopia, reaching 1500 mm and 30 kg, farmed and hybridized with Clarias gariepinus.
Heterobranchus longifilis
Heterobranchus longifilis (vundu, Sampa), Valenciennes 1840, a large African airbreathing clariid catfish up to 150 cm and 55 kg, widespread from the Nile to West Africa, Least Concern, farmed and used in heteroclarias hybrids.
Heterochromatin
Heterochromatin is the condensed, largely transcriptionally inert form of eukaryotic chromatin, defined by Emil Heitz in 1928; it comes in constitutive and facultative classes, carries H3K9me and HP1 marks, and silences repeats.
Heterochromia iridum
Heterochromia iridum, also called heterochromia iridis, is a difference in iris color between the two eyes or within one iris. Usually a harmless genetic trait, it can signal Horner syndrome, Waardenburg syndrome, neuroblastoma, injury, or latanoprost use.
Heterochronic parabiosis
Heterochronic parabiosis is a surgical method that joins the circulatory systems of a young and an old animal to test whether blood factors reverse tissue aging.
Heteroconchia
Heteroconchia is a clade of bivalve mollusks within Autobranchia, uniting Palaeoheterodonta, Archiheterodonta, and Euheterodonta; defined by heterodont hinge dentition and crossed-lamellar shell structure, supported by nuclear phylogenomics but disputed by mitochondrial trees favoring Amarsipobranchia.
Heterocyst
Heterocyst: specialized nitrogen-fixing cell of filamentous cyanobacteria such as Anabaena and Nostoc; thick glycolipid envelope shields oxygen-sensitive nitrogenase; spaced 10-15 cells apart; evolved 2,450-2,100 Ma.
Heterodera avenae
Heterodera avenae, the cereal cyst nematode or oat cyst nematode (Wollenweber, 1924), is a cyst-forming root parasite of wheat, barley, oats, and rye causing 20-50% grain losses in Australia, with one generation per year and pathotypes classified by the International Test Assortment.
Heterodermia
Heterodermia (Trevis.) is a pantropical genus of foliose to subfruticose lichens in family Physciaceae, split from Anaptychia by Poelt (1965); smooth brown 1-septate spores, constant atranorin, on bark, rock, or wood.