72,234 articles
Drosophila embryogenesis
Drosophila embryogenesis, fruit fly embryo development: 13 syncytial nuclear cycles, ~6000 nuclei, cellularization, maternal/gap/pair-rule/segment polarity gene hierarchy, Heidelberg screen, 1995 Nobel Prize.
Drosophila melanogaster
Drosophila melanogaster, the fruit fly, the leading genetic model organism: 143.7 Mb genome, 13,986 coding genes, 9–10-day life cycle, four Nobel Prizes, and the 2024 complete 139,255-neuron brain connectome.
Drosophila suzukii
Drosophila suzukii, the spotted-wing drosophila or cherry drosophila (Matsumura, 1931), is an Asian vinegar fly whose females oviposit in ripening soft fruit; invasive in Hawaii (1980), mainland North America and Europe (2008), causing about $500 million yearly US crop damage.
Drosophilidae
Drosophilidae (Rondani, 1856), the vinegar, pomace, or fruit fly family of Diptera; over 4,400 species in subfamilies Steganinae and Drosophilinae; includes the model organism Drosophila melanogaster and the pest D. suzukii.
Drospirenone
Drospirenone (DRSP), a spironolactone-analogue progestin with anti-mineralocorticoid and antiandrogenic activity, used in Yasmin, Yaz, Slynd, and estetrol combination pills; VTE risk versus levonorgestrel estimated at 1.0–3.3.
Drotaverine
Drotaverine (No-Spa, Drotin) is a Hungarian benzylisoquinoline antispasmodic, a PDE4 inhibitor related to papaverine, used for gastrointestinal, biliary, and urinary smooth muscle spasms; half-life about 9 hours, not FDA or EMA approved.
Drotrecogin alfa (activated)
Drotrecogin alfa (activated), brand name Xigris, recombinant human activated protein C (rhAPC, LY-203638), an Eli Lilly antithrombotic for severe sepsis; FDA-approved 2001, EU 2002, withdrawn worldwide in 2011 after PROWESS-SHOCK showed no mortality benefit.
Drought Resistance
Drought resistance is the integrated capability of plants to escape, avoid, or tolerate water deficit, via four mechanisms (escape, avoidance, tolerance, recovery); key crops include sorghum, millet, pigeon pea, and cowpea.
Drowning
Drowning: respiratory impairment from submersion/immersion in liquid (WHO 2002 definition). About 300,000 deaths yearly, 92% in low- and middle-income countries; hypoxia is the key mechanism; CPR requires rescue breaths.
DRTST trial
DRTST (Duodenal Resection Tri-Staple Technology), NCT03277144, is an Italian multicenter randomized trial led by Maurizio Degiuli, University of Turin, comparing three-line Tri-Staple stapler closure of the duodenal stump against conventional techniques during open gastrectomy for gastric cancer, targeting 700 patients.
Drucilla J. Roberts
Drucilla J. Roberts is an American perinatal pathologist at Massachusetts General Hospital and Harvard Medical School, known for her research on placental pathology and stillbirth.
Drug
A drug is a substance that, when absorbed into a living organism, may modify one or more of its functions; the word covers medicines, abused substances, and legal categories.
Drug Administration Schedule
Drug Administration Schedule: MeSH descriptor D004334 for the timing plan of drug dosing, covering frequency, intervals, and circadian timing, and its links to adherence and adverse reactions.
Drug Carriers
Drug carriers are macromolecules, polymers, or nanoparticles that transport and release pharmacologically active compounds, prolonging drug action, reducing metabolism and toxicity. Key platforms include liposomes, SLNs, NLCs, polymeric nanoparticles, and LNPs, from Doxil (1995) to mRNA-LNP COVID-19 vaccines.
Drug Chronotherapy
Drug chronotherapy: timing drug administration to circadian rhythms for maximal efficacy and minimal toxicity; also called chronotherapeutics; key evidence in hypertension bedtime dosing and cancer chrono-chemotherapy.
Drug class
Drug class: a set of medications grouped by chemical structure, mechanism of action, physiologic effect, or therapeutic use. Formalized in the WHO ATC system (five levels, 14 main groups) and FDA Established Pharmacologic Classes.
Drug Contraindications
A drug contraindication is a situation in which a medicine or procedure must be avoided because of the risk of harm, either absolutely or relative to its benefits.
Drug Costs
Drug costs: amounts paid for medicines, formally the amount a health care institution or organization pays for its drugs (MeSH D016527). Covers list price (WAC), net price after rebates, US spending near $1 trillion, and international price gaps.
Drug delivery
Drug delivery: the field of controlling where, when, and how fast a drug reaches the body. Began with the 1952 Spansule 12-hour capsule; later milestones include Lupron Depot (1989) and 2020 lipid nanoparticle COVID-19 vaccines.
Drug design
Drug design, also called rational drug design, is the invention of new medications by designing molecules to bind biological targets. It includes structure-based and ligand-based approaches, docking, QSAR, ADMET modelling, and AI methods; HIV protease inhibitors are a landmark success.
Drug development
Drug development: the process of discovering, testing, and gaining regulatory approval for new medicines, from preclinical research through clinical trials, FDA review, and post-market safety monitoring.
Drug discovery
Drug discovery: identifying new medicines from target identification through lead optimization to clinical candidate selection. Covers timelines (12–15 years), costs ($161M–$4.54B estimates), screening methods, phenotypic vs target-based paradigms, and AI since 2023.
Drug Dosage Calculations
Drug dosage calculations convert a prescriber's order, drug concentration, and patient weight into an exact dose using dimensional analysis, ratio-proportion, or the desired-over-have formula; unit errors and decimal misplacement drive most dosing errors.
Drug injection
Drug injection is the administration of psychoactive drugs with a syringe and needle, chiefly intravenously. Also called injection drug use, it affects 10.2–23.7 million people worldwide and carries risks of HIV, hepatitis C, overdose, and tissue damage.
Drug Instillation
Drug instillation places liquid medication drop by drop or in measured volume into a body cavity: eye drops, nasal drops, ear drops, and catheter-based intravesical bladder therapy, with pharmacokinetics and evidence.
Drug interaction
Drug interaction: a drug, food, herb, or disease altering another drug's pharmacokinetics or pharmacodynamics. Covers CYP-mediated mechanisms, 1960s cheese-tyramine history, divergent interaction knowledge bases, and unproven alert benefit.
Drug Legislation
Drug legislation is the body of statutes governments use to control the testing, approval, labeling, and surveillance of medicines, centered in the US on the 1938 Federal Food, Drug, and Cosmetic Act and the FDA.
Drug liberalization
Drug liberalization: relaxing or removing prohibition-based drug policies, from decriminalization of personal use to regulated legalization. Key examples: Portugal's Law 30/2000 dissuasion commissions, Oregon Measure 110, Thailand's 2022 cannabis decriminalization and 2025 rollback.
Drug metabolism
Drug metabolism (biotransformation) is the enzymatic two-phase conversion of drugs into metabolites, mainly by hepatic cytochrome P450 enzymes, covering first-pass metabolism, induction, inhibition, pharmacogenetics, and toxicity.
Drug nomenclature
Drug nomenclature: the WHO International Nonproprietary Name (INN) system, begun in 1953, assigns unique generic names with class stems to pharmaceutical substances, alongside national names like USAN and BAN and distinct brand names.