All articles starting with R
22,461 articles
Retinoblastoma protein
Retinoblastoma protein (pRb, RB1 product) is the first-discovered tumor suppressor, a 928-aa nuclear protein at 13q14.2 that represses E2F to halt the G1/S transition and is inactivated by multisite Cdk phosphorylation.
Retinoic acid
Retinoic acid (vitamin A metabolite, all-trans retinoic acid; related isomers tretinoin, isotretinoin) is a morphogen signaling through RAR/RXR nuclear receptors to regulate vertebrate development, and a potent teratogen causing retinoic acid embryopathy.
Retinoic acid receptor
Retinoic acid receptor (RAR, NR1B): nuclear receptor for vitamin A's active metabolite retinoic acid, discovered 1987; three isoforms α, β, γ; acts as RAR–RXR heterodimer at RAREs; PML–RARα drives acute promyelocytic leukemia.
Retinoid
Retinoids are vitamin A (retinol) derivatives, natural and synthetic, that signal through RAR and RXR nuclear receptors; used in acne, psoriasis, and leukemia, and teratogenic.
Retinol
Retinol (all-trans-retinol) is preformed vitamin A, found in liver, fish, eggs, and dairy; absorbed at 75–100%, RDA 700–900 mcg RAE, EFSA upper limit 3,000 μg RE/day for adults.
Retinopathy
Retinopathy is a general term for disease-related damage to the retina, the light-sensitive tissue at the back of the eye, most often from diabetes or high blood pressure.
Retinopathy of prematurity
Retinopathy of prematurity (ROP), formerly retrolental fibroplasia, is abnormal retinal blood vessel growth in babies born before 30 weeks or under about 3 pounds; staged 1 to 5, screened by dilated exam, treated with laser, anti-VEGF injections, or surgery.
Retinopexy
Retinopexy is a surgical procedure that seals a retinal tear by scarring it to the underlying tissue, using laser or freezing, to treat or prevent retinal detachment.
Retinoschisis
Retinoschisis: splitting of the neurosensory retina, either common acquired (senile, outer plexiform layer, ~7% over age 40) or X-linked juvenile (RS1 gene, males). Distinct from retinal detachment; OCT differentiates them.
Retinoscopes
Retinoscopes (skiascopy instruments): handheld streak or spot devices for objective refraction by observing the retinal light reflex; Copeland streak design (1927), FDA Class I code HKM, cycloplegic retinoscopy the pediatric refraction standard.
Retinoscopy
Retinoscopy, also known as skiascopy, is an objective refraction technique that measures refractive error and derives an eyeglass prescription by observing the retinal light reflex.
Retinyl palmitate
Retinyl palmitate, or vitamin A palmitate, is the ester of retinol and palmitic acid, the main storage form of vitamin A and a common supplement ingredient.
Retiolites
Retiolites Barrande, 1850 is a Silurian planktic graptolite genus of the family Retiolitidae, with type species R. geinitzianus; its net-like skeleton of bandaged lists and ancora sleeve, three species distinguished by dorso-ventral width, and Telychian to Sheinwoodian range distinguish it from other graptolites.
Retired emperor institution
The retired emperor institution (Thái thượng hoàng) was the Vietnamese practice of an abdicated emperor governing alongside his son; the Tran dynasty kept it from start to end.
Retirement
Retirement: exit from the workforce, institutionalized through pensions from Bismarck's 1889 German system and the 1935 U.S. Social Security Act to today's rising OECD retirement ages, health effects, and phased transitions.
Retirement age
Retirement age, also called full retirement age, is the age at which a pension system makes benefits available, averaging 64.7 years for men across the OECD in 2024.
Retirement home
Retirement home, also called senior living or old age home, is residential housing for older adults with services from independent living through assisted living to nursing care; shaped by the 1935 Social Security Act, 1965 Medicare/Medicaid, and 1987 reform law.
Retirement Plan
Retirement Plan is a 2024 Irish animated short film by John Kelly, also called a 7-minute Oscar-nominated comedy. Domhnall Gleeson voices Ray, a middle-aged Dubliner listing everything he will do in retirement; it won SXSW 2025 Grand Jury and Audience Awards.
Retjenu
Retjenu, also written Retenu, is the ancient Egyptian designation for Syria-Palestine, its broadest term for the Levant, used from the Fifteenth to the Nineteenth Dynasty.
Retlirafusp alfa (SHR-1701)
Retlirafusp alfa (SHR-1701, 瑞拉芙普-α), Hengrui's bifunctional anti-PD-L1/TGF-βRII fusion protein, approved in China January 2026 with chemotherapy for first-line PD-L1-positive advanced gastric or gastroesophageal junction adenocarcinoma.
RETN
RETN (resistin, also RSTN, FIZZ3, ADSF, XCP1) is a human protein-coding gene at 19p13.2 encoding a cysteine-rich adipokine hormone discovered in 2001, secreted in humans mainly by macrophages, signaling via TLR4 and CAP1, and linked to insulin resistance, inflammation, and cardiovascular disease.
Reto Capadrutt
Reto Capadrutt (1912–1939), Swiss bobsledder; Olympic silver in two-man 1932 with Oscar Geier and four-man 1936; 1935 two-man world champion with Emil Diener; died in a St. Moritz bobsleigh crash.
Reto Fiolka
Reto Fiolka, born 1980, is a Swiss and German researcher who develops light-sheet microscopy methods and is an associate professor at UT Southwestern Medical Center in Dallas.
Reto Knutti
Reto Knutti is a Swiss climate physicist and professor at ETH Zurich who studies greenhouse gas effects on climate, developed climate model weighting methods, and contributed to IPCC reports.
Retort carbon
Retort carbon, also called gas carbon, is a dense, hard carbon deposit that forms on retort walls during the destructive distillation of coal for town gas.
Retosiban
Retosiban (GSK221149A) is a non-peptide, orally bioavailable oxytocin receptor antagonist developed by GSK as a tocolytic for spontaneous preterm labor; Phase 3 ended with recruitment failure and the program was terminated.
Retractable bridge
A retractable bridge, also called a thrust or traversing bridge, is a movable bridge whose deck rolls back from the navigation gap rather than lifting, swinging, or curling aside.
Retraction in academic publishing
A retraction is a formal journal notice stating that a published paper's findings cannot be relied upon; over 10,000 papers were retracted in 2023, mostly for misconduct.
Retraction Watch
Retraction Watch is a watchdog blog and research-integrity database, founded by health journalists Adam Marcus and Ivan Oransky in 2010, that reports on and catalogs retracted scientific papers.
Retransmission
Retransmission is the mechanism by which a network protocol resends data lost or corrupted in transit, restoring reliable delivery; TCP and QUIC rely on it for reliability.