<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31471162</termId><termName>hydroxyapatite</termName><termType>PT</termType><termNote><![CDATA[ A complex calcium phosphate, a naturally occuring mineral form of calcium apatite,  that serves as an important component of tooth enamel and vertebrate bone. In an archaeological context,  hydroxyapatite from human and animal remains is studied to reconstruct ancient diet. ]]></termNote><termCreatedDate>2026-03-30 21:06:48</termCreatedDate><relation><relationType>UF</relationType><termId>31471163</termId><termName>calcium hydroxyapatite</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31471164</termId><termName>calcium phosphate hydroxide</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31471165</termId><termName>hydroxylapatite</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31457262</termId><termName>calcium phosphate</termName><termType>PT</termType></relation></term>  </Zthes>