A chemical or other agent used to destroy rats or other rodent pests or prevent them from damaging food, crops, etc. Rat poison is a familiar rodenticide.
1. Simple backward displacement of a structure or organ such as the uterus. 2. In genetics, the integration of a sequence derived from RNA into a DNA genome. Messenger RNA (mRNA) is reverse-transcribed and reintegrated into the genome. Retroposition is an important mechanism of gene copying. It produces a large number of functional genes in […]
“You have revealed yourself as a miserable, carping, retromingent vigilante, and I for one am sick of wasting my time communicating with you” (Benjamin C. Bradlee, Editor, The Washington Post). From the Latin retro- (back) + mingent from mingere (to urinate).
- Retrograde intrarenal surgery (RIRS)
Retrograde intrarenal surgery (RIRS) is a procedure for doing surgery within the kidney using a viewing tube called a fiberoptic endoscope. In RIRS the scope is placed through the urethra (the urinary opening) into the bladder and then through the ureter into the urine-collecting part of the kidney. The scope thus is moved retrograde (up […]
- Roentgen, Wilhelm
Wilhelm Conrad Rontgen (1845-1923), German-born, Dutch-educated physicist who first observed and documented X-rays on November 8, 1895. He made this seminal discovery by accident while experimenting with a set of cathode ray instruments. He was surprised to find a flickering image cast by his instruments separated from them by some distance. He knew that the […]
Radiology, the science of radiation and, specifically, the use of both ionizing (like X-ray) and nonionizing (like ultrasound) modalities for the diagnosis and treatment of disease. Roentgenology is named for Wilhelm Conrad Roentgen who discovered X-rays. Roentgen, a professor of physics in Germany, wanted to prove his hypothesis that cathode rays could penetrate substances besides […]