<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31373554</termId><termName>urea</termName><termType>PT</termType><termNote><![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. ]]></termNote><termCreatedDate>2026-03-30 20:40:44</termCreatedDate><relation><relationType>UF</relationType><termId>31373555</termId><termName>carbamide</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31343241</termId><termName>organic compounds</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>31409856</termId><termName>urea-formaldehyde resin</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>31438194</termId><termName>urine</termName><termType>PT</termType></relation></term>  </Zthes>