By its very nature, vitamin A causes drying of the skin and exfoliation. A bevy of prescription and OTC vitamin A topical preparations make use of this side effect to treat a variety of skin concerns. The term Retinoid refers to any Vitamin A based molecule. It's a category, similar to saying antibiotic. They may be related, but some are stronger and more effective than others.
Pototype sheets for Weld Quality Workmanship Standard. Undercut. Definition: A groove cut at the toe of the weld by the welding arc and left. unfilled. Depth of undercut shall not exceed 1/32.
forestry - the science of planting and caring for forests and the management of growing timber. undercut - a notch cut in the trunk of tree in order to determine the direction of its fall. biological science, biology - the science that studies living organisms. silviculture - the branch of forestry dealing with the development and care of forests. stool - (forestry) the stump of a tree that has been felled or headed for the production of saplings.