2015考研英语阅读压力和老化
<p> <span word="Stress">Stress</span> <span word="and">and</span> <span word="ageing">ageing</span> <span word="A">A</span> <span word="question">question</span> <span word="of">of</span> <span word="attitude">attitude</span></p><p> 压力和老化 一个态度问题</p><p> <span word="The">The</span> <span word="link">link</span> <span word="between">between</span> <span word="chronic">chronic</span> <span word="stress">stress</span> <span word="and">and</span> <span word="a">a</span> <span word="marker">marker</span> <span word="of">of</span> <span word="old">old</span> <span word="age">age</span> <span word="is">is</span> <span word="being">being</span> <span word="disentangled">disentangled</span></p><p> 科学家发现了长期压力与一个衰老标志间的联系</p><p> <span word="TELOMERES">TELOMERES</span> <span word="are">are</span> <span word="to">to</span> <span word="chromosomes">chromosomes</span> <span word="what">what</span> <span word="plastic">plastic</span> <span word="caps">caps</span> <span word="are">are</span> <span word="to">to</span> <span word="shoelacesthey">shoelacesthey</span> <span word="stop">stop</span> <span word="them">them</span> <span word="frayingat">frayingat</span> <span word="the">the</span> <span word="ends">ends</span>.</p><p> 端粒之于染色体，如同塑料帽之于鞋带它们阻止了其末端的磨损。</p><p> <span word="Unlike">Unlike</span> <span word="shoelaces">shoelaces</span>, <span word="though">though</span>, <span word="chromosomes">chromosomes</span> <span word="replicate">replicate</span> <span word="themselves">themselves</span> <span word="from">from</span> <span word="time">time</span> <span word="to">to</span> <span word="time">time</span> <span word="as">as</span> <span word="the">the</span> <span word="cellsthey">cellsthey</span> <span word="are">are</span> <span word="in">in</span> <span word="divide">divide</span>.</p><p> 和鞋带不同的是，随着它们所在细胞的分裂，染色体可以不断进行复制。</p><p> <span word="This">This</span> <span word="shortens">shortens</span> <span word="the">the</span> <span word="telomere">telomere</span> <span word="and">and</span>, <span word="after">after</span> 50-70 <span word="such">such</span> <span word="divisions">divisions</span> ,</p><p> 这种复制过程使端粒不断缩短，并且，在经过50到70次的细胞分裂后，</p><p> <span word="a">a</span> <span word="chromosome">chromosome</span> <span word="can">can</span> <span word="grow">grow</span> <span word="no">no</span> <span word="shorter">shorter</span> <span word="and">and</span> <span word="the">the</span> <span word="cell">cell</span> <span word="it">it</span> <span word="is">is</span> <span word="in">in</span> <span word="can">can</span> <span word="divide">divide</span> <span word="no">no</span> <span word="more">more</span>.</p><p> 染色体的缩短达到极限，细胞分裂活动也从此终止。</p><p> <span word="That">That</span> <span word="provides">provides</span> <span word="a">a</span> <span word="backstop">backstop</span> <span word="against">against</span> <span word="cancer">cancer</span>. <span word="The">The</span> <span word="rapidly">rapidly</span> <span word="dividing">dividing</span> <span word="cells">cells</span> <span word="in">in</span> <span word="a">a</span> <span word="tumour">tumour</span> <span word="soon">soon</span> <span word="hit">hit</span> <span word="theHayflick">theHayflick</span> <span word="limit">limit</span> <span word="and">and</span> <span word="the">the</span> <span word="process">process</span> <span word="is">is</span> <span word="brought">brought</span> <span word="to">to</span> <span word="a">a</span> <span word="screeching">screeching</span> <span word="halt">halt</span>.</p><p> 这一机制有助于对抗癌症。快速分裂的细胞不久就会到达其海弗利克界限，使得该过程能够急刹车。这是个好现象。</p>
页:
[1]