<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31343281</termId><termName>aldehyde</termName><termType>PT</termType><termNote><![CDATA[ Any member of a class of organic compounds that contain the carbonyl group (in which a carbon atom is doubly bonded to an oxygen atom), and in which the group is bonded to at least one hydrogen. With the exception of formaldehyde, a gas, aldehydes are acrid, volatile liquids. Their chief use is as chemical intermediates in polymer production for manufacture of solvents, dyes, resins, plasticizers, and pharmaceuticals.  ]]></termNote><termCreatedDate>2026-03-30 20:32:35</termCreatedDate><relation><relationType>UF</relationType><termId>31343282</termId><termName>aldehydes</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31319736</termId><termName>compounds</termName><termType>PT</termType></relation></term>  </Zthes>