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Helge Thorsten Lumbsch
Helge Thorsten Lumbsch (born 1964, Frankfurt) is a German lichenologist, Chief Scientific Officer and Curator of Lichens at the Field Museum, Chicago; over 590 papers, 280+ new lichen species, Acharius Medal 2026.
Heliamphora
Heliamphora (sun pitchers, marsh pitchers) is a genus of about 21 to 24 carnivorous Sarraceniaceae pitcher plants endemic to the tepuis of Venezuela, Guyana, and northern Brazil, with pitfall traps, nectar spoons, and confirmed endogenous digestive enzymes.
Helianthemum
Helianthemum (rock rose, sun rose) is the largest genus of Cistaceae, about 140 Palearctic taxa centered on the Mediterranean, with three radiating sections since the Late Miocene and hard-coated seeds needing scarification.
Helianthus
Helianthus (sunflowers) is a North American Asteraceae genus of 56 accepted species, including cultivated sunflower (H. annuus) and Jerusalem artichoke (H. tuberosus); domesticated ~4,000-5,000 years ago and a model for hybrid speciation.
Helical tomotherapy
Helical tomotherapy, also known as tomotherapy, is an intensity-modulated radiation therapy technique in which a rotating fan beam traces a helix around the moving patient, with integrated CT image guidance.
Helicase
Helicase: NTP-driven motor enzymes that unwind duplex DNA or RNA into single strands for replication, repair, recombination, and RNA metabolism. Classified into six superfamilies (SF1–SF6); discovered 1976; targeted by antiviral helicase-primase inhibitors and cancer drugs such as WRN inhibitors.
Helicase structure and mechanism
Helicase structure and mechanism describes how helicase enzymes use ATP hydrolysis to separate DNA strands, organized into six superfamilies built on conserved RecA-like motor cores.
Helicase-dependent amplification
Helicase-dependent amplification (HDA) is an isothermal DNA amplification method, reported in 2004, in which a helicase enzyme separates DNA strands, replacing PCR's thermal cycling and suiting point-of-care diagnostics.
Helicases in transcription and chromatin remodeling
Helicases in transcription and chromatin remodeling are ATP-dependent motor enzymes that slide, eject, or restructure nucleosomes to support transcription, including the SWI/SNF, ISWI, CHD, and INO80 remodeler families.
Helichrysum
Helichrysum (everlasting flowers) is a genus of about 564 accepted Asteraceae species native from Europe and Africa to Australia, widely used in traditional medicine; H. italicum yields a commercially important essential oil.
Heliciculture
Heliciculture, also called snail farming, is the rearing of land snails for food or cosmetics, practiced since the 1st century BC, when Romans kept snail gardens.
Helicinidae
Helicinidae (Férussac, 1822) are operculate terrestrial snails of the neritimorph superfamily Helicinoidea, with 500-750 species in the Caribbean, Indo-Pacific islands, and Asian-Australian margins, distinguished by a calcareous operculum and one tentacle pair.
Helicobacter
Helicobacter is a genus of gram-negative, spiral-shaped bacteria that colonize the stomach lining; its best-known species, H. pylori, causes chronic gastritis, peptic ulcers, and gastric cancer.
Helicobacter pylori
Helicobacter pylori, a spiral stomach bacterium discovered by Marshall and Warren in 1982, causes gastritis, peptic ulcers, and gastric cancer; their 1984 Lancet report earned the 2005 Nobel Prize.
Helicobacter pylori associated gastric ulcer
Helicobacter pylori associated gastric ulcer (ICD-11 DA60.1): a stomach ulcer caused by H. pylori infection, accounting for 70% of gastric ulcers; eradication therapy prevents recurrence and rebleeding.
Helicobacter pylori eradication therapy
Helicobacter pylori eradication therapy is a combination antibiotic and acid-suppressing treatment, usually 14 days long, that cures H. pylori infection, healing ulcers and reducing gastric cancer risk.
Helicobacter pylori induced gastritis
Helicobacter pylori induced gastritis (ICD-11 DA42.1) is stomach lining inflammation from H. pylori infection, progressing from acute to chronic and atrophic gastritis, a gastric cancer risk factor; discovered by Marshall and Warren in 1982, treated by eradication therapy.
Helicobacter-pylori associated duodenal ulcer
Helicobacter-pylori associated duodenal ulcer (ICD-11 DA63.1) is a duodenal ulcer caused by chronic H. pylori infection, which accounts for over 90% of duodenal ulcers; eradication therapy, now optimized bismuth quadruple therapy for 14 days, cures the ulcer and prevents recurrence.
Helicobasidium
Helicobasidium (violet root rot fungi) is a genus of Pucciniomycetes basidiomycetes in Helicobasidiales; species such as H. purpureum and H. mompa cause violet root rot of crops, while their Tuberculina asexual stage parasitizes rust fungi.
Helicoid peripapillary chorioretinal degeneration
Helicoid peripapillary chorioretinal degeneration (Sveinsson chorioretinal atrophy, atrophia areata) is a rare autosomal dominant TEAD1-related retinal dystrophy with bilateral wing-shaped chorioretinal atrophy radiating from the optic disc, onset in infancy, sometimes with congenital anterior polar cataracts.
Heliconia
Heliconia (lobster-claw, false bird-of-paradise) is the sole genus of Heliconiaceae in Zingiberales, tropical herbs with colorful bracts pollinated by hummingbirds; about 187 species from Mexico to tropical America and the Pacific, nearly half threatened.
Heliconia bihai
Heliconia bihai (macawflower, lobster claw) is a large rhizomatous Heliconiaceae herb native to Mexico, the Caribbean, and northern South America, hummingbird-pollinated, polymorphic in bract color, and cultivated as an ornamental, food, and medicine.
Helicoprion
Helicoprion, an extinct Permian eugeneodont cartilaginous fish (not a true shark) known from spiral tooth whorls embedded in the lower jaw; named by Karpinsky in 1899, resolved by 2013 CT scans of Idaho specimen IMNH 37899.
Helicoverpa armigera
Helicoverpa armigera, the Old World bollworm or cotton bollworm (Noctuidae), is a major polyphagous crop pest native to the Old World that invaded South America around 2013, hybridizes with H. zea, and resists 48 insecticide active ingredients.
Helicoverpa zea
Helicoverpa zea (corn earworm, bollworm, tomato fruitworm), a noctuid moth native to the Americas and a major polyphagous crop pest, known for Bt and insecticide resistance and hybridization with invasive Helicoverpa armigera in Brazil.
Helictotrichon
Helictotrichon (oat grasses), Poaceae genus published 1827 by Besser ex Schultes & Schult.f.; about 30 accepted species of temperate perennial grasses, narrowed by molecular work, including ornamental blue oat grass H. sempervirens.
Heliolites
Heliolites is an extinct colonial tabulate coral, type genus of the family Heliolitidae, named by James Dwight Dana in 1846 and sometimes called the "sun coral" for its sunburst-like colonies.
Heliotherapy
Heliotherapy: therapeutic use of natural sunlight, also called climate therapy, for skin disease. Ancient Egyptian and Indian roots; Finsen's 1903 Nobel Prize; Dead Sea regimens for psoriasis; risks include sunburn and skin cancer.
Heliotropium
Heliotropium (heliotrope), a genus of about 250 species in Heliotropiaceae (Boraginales) established by Linnaeus in 1753; cosmopolitan herbs and shrubs with scorpioid cymes, pyrrolizidine alkaloids, and C4 species in section Orthostachys.
Heliotropium arborescens
Heliotropium arborescens, garden heliotrope or cherry pie plant (syn. H. peruvianum), is a Boraginaceae subshrub native to Bolivia, Colombia, and Peru, grown for vanilla-scented purple flowers; toxic via pyrrolizidine alkaloids.