蛋壳比金属还要坚硬小鸡如何破壳而出英语美文蛋壳比金属还要坚硬小鸡如何破壳而出英语美文It’sbeenatoughonetocrack,butscientistssaytheyhavezoomedin,toanunprecedenteddegree,onthestructureofshellssurroundingchickenembryos,revealinghowtheychangetoallowyoungbirdstohatch.科学家说他们以前所未有的程度对蛋壳的结构进行放大并进一步了解，揭示了它们如何改变以允许幼鸡孵化。Beforebeinglaid,birdeggsformahardcalcium-richshellwiththreemainlayers.Whileitwasalreadyknownthatthesethinfromtheinnermostoutasachickgrowsinpreparationforhatching–withcalciumfromtheshellbeingincorporatedintoitsskeletonintheprocess–quitewhathappensatthemolecularscalehasbeensomethingofamystery.鸡蛋离开母体时蛋壳富含钙质，蛋壳有3层构造，小鸡在蛋壳中一点点成长起来，在这个过程中，蛋壳由内到外变薄，来自蛋壳的钙质也会被小鸡的骨骼吸收。但在分子尺度上这一过程至今还是秘密，到底是怎么发生的呢?Nowscientistssaytheyhavediscoveredthateggshellshaveananostructure,andthatitappearstoplayakeyroleinthestrengthoftheshell.现在科学家们说他们已经发现蛋壳具有纳米结构，并且它似乎在贝壳强度方面起着关键作用。“Everybodythinkseggshellsarefragile–[when]we’recareful,we‘walkoneggshells’–butinfact,fortheirthinnesstheyareextremelystrong,harderthansomemetals,”saidProfMarcMcKee,acoauthorofthestudyfromMcGillUniversityinCanada.“Wearereallyunderstandingnowatthealmostmolecularscalehowaneggshellisassembledandhowitdissolves.”“每个人都认为蛋壳很脆弱，当我们小心翼翼，我们走在蛋壳上时，但事实上，由于它们的纤薄，它们比一些金属更坚硬，更硬，”该研究的合着者来自加拿大麦吉尔大学马克麦基教授说。“我们正在了解蛋壳的组装方式和分解过程。”WritinginthejournalScienceAdvances,McKeeandcolleaguesdescribehowtheyprobedtheissuebyfocusingontheroleofaproteinknownasosteopontin.Thissubstanceisfoundthroughouttheeggshellandwasalreadythoughttobeimportantinorganisingthestructureofitsminerals.McKee及其同事在“科学进展”杂志上撰文，并描述他们如何通过关注骨桥蛋白这一蛋白质的作用来探讨这个问题。这种物质在整个蛋壳中均可发现，并已被认为是组织其矿物结构的重要组成部分。“Somethingasdifferentasaneggshellandatoothandabone,theyallhavethisprotein,”saidMcKee.“Wethinkitisproteinslikethatthathelpguidethemineralisationprocesstogivethesetissuestheirproperties.”“像蛋壳，牙齿和骨头那样不同的东西，它们都含有这种蛋白质，”麦基说。“我们认为这些蛋白质能够辅助矿化过程，并赋予这些组织特性。”Usinganumberofmicroscopytechniques,aswellasacutting-edgemethodknownasfocused-ionbeamforpreparingthinsectionsoftheeggshell,theteamfoundthatallofthelayersappeartobeformedfromanarrayoftinyare