The symbol for the element yttrium, an ultrarare metal named after Ytterby in southern Sweden. Yttrium has been used in certain nuclear medicine scans.
An environmental agent or event that provides the cue for setting or resetting a biological clock. To be synchronized with our environment, we need the input of Zeitgebers. The most important Zeitgeber in nature is light. Social factors, chemical factors and activity can also serve as Zeitgebers. Light is a so-called photic type Zeitgeber, whereas […]
- Zellweger syndrome
One of a group of related diseases called peroxisome biogenesis disorders (PBD), inherited conditions that damage myelin in the brain and also affect the metabolism of particular substances. Features include enlargement of the liver, high levels of iron and copper in the blood, and vision disturbances. It can be caused by mutations in a number […]
- Zenker diverticulum
The most common type of outpouching in the esophagus, due to increased pressure causing the mucous membrane of the esophagus to herniate through a defect in the wall of esophagus. Zenker diverticuli are usually located in the posterior hypopharyngeal wall. Small Zenker diverticuli may not cause symptoms but larger ones may collect food and obstruct […]
One of the three major preparations of red yeast rice, a tradition Chinese medicine now used to lower cholesterol.
Stands for zygote intrafallopian transfer, a method used to treat infertility in which an egg fertilized in vitro (outside the body) is placed into a woman’s fallopian tube. This technique is one used to overcome infertility, the inability of couples to produce offspring on their own. The egg and the male sperm needed to fertilize […]