<?xml version="1.0" encoding="utf-8"?><mads xmlns="http://www.loc.gov/mads/" xmlns:mods="http://www.loc.gov/mods/v3" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.loc.gov/mads/
mads.xsd"><authority><topic authority="http://AATesaurus.cultura.gencat.cat/aat/getty_en">urea</topic></authority><related type="other"><topic>urea-formaldehyde resin</topic></related><related type="other"><topic>urine</topic></related><related type="broader"><topic>organic compounds</topic></related><variant type="other"><topic>carbamide</topic></variant> <note xml:lang="en"><![CDATA[ A colorless crystalline organic compound that is a product of protein metabolism in mammals. Urea can break hydrogen bonds and destabilize collagen. In conservation practice, this interaction reduces hardness and deformation in parchment, leather, and related materials. ]]></note></mads>