干细胞具有非凡的拉胀性
文章来源:未知 文章作者:enread 发布时间:2014-04-23 06:54 字体: [ ]  进入论坛
(单词翻译:双击或拖选)
Stem cells -- the body's master cells -- demonstrate a bizarre property never before seen at a cellular1 level, according to a study published today from scientists at the University of Cambridge. The property -- known as auxeticity(拉胀性) -- is one which may have application as wide-ranging as soundproofing, super-absorbent sponges and bulletproof vests. Most materials when stretched will contract. For example, if one pulls on an elastic2 band, the elastic itself will get thinner. The opposite is also true: squeeze a material and it will expand -- for example, if one squeezes a tennis ball between both hands, the circumference3 around the ball gets larger. However, material scientists have begun to explore auxeticity, an unusual property which has the opposite effect -- squeeze it and it will contract, stretch it and it will expand. This means that auxetic materials act as excellent shock absorbers or sponges, a fact that is being explored for various uses.
 
Until now, auxeticity has only been demonstrated in humanmade materials and very rarely in nature, such as some species of sponge. But today, in a paper published in the journal Nature Materials, a team of University of Cambridge researchers including biologists, engineers and physicists4, report having observed auxeticity in the nuclei5 of embryonic6 stem cells, master cells within the body which can turn into any other type of cell.
 
Dr Kevin Chalut from the Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, who led the study, says: "This is a pretty bizarre finding and very unexpected. When the stem cell is in the process of transforming into a particular type of cell, its nucleus7 takes on an auxetic property, allowing it to 'sponge up' essential materials from its surrounding. This property has not, to my knowledge, been seen before at a cellular level and is highly unusual in the natural world."


点击收听单词发音收听单词发音  

1 cellular aU1yo     
adj.移动的;细胞的,由细胞组成的
参考例句:
  • She has a cellular telephone in her car.她的汽车里有一部无线通讯电话机。
  • Many people use cellular materials as sensitive elements in hygrometers.很多人用蜂窝状的材料作为测量温度的传感元件。
2 elastic Tjbzq     
n.橡皮圈,松紧带;adj.有弹性的;灵活的
参考例句:
  • Rubber is an elastic material.橡胶是一种弹性材料。
  • These regulations are elastic.这些规定是有弹性的。
3 circumference HOszh     
n.圆周,周长,圆周线
参考例句:
  • It's a mile round the circumference of the field.运动场周长一英里。
  • The diameter and the circumference of a circle correlate.圆的直径与圆周有相互关系。
4 physicists 18316b43c980524885c1a898ed1528b1     
物理学家( physicist的名词复数 )
参考例句:
  • For many particle physicists, however, it was a year of frustration. 对于许多粒子物理学家来说,这是受挫折的一年。 来自英汉非文学 - 科技
  • Physicists seek rules or patterns to provide a framework. 物理学家寻求用法则或图式来构成一个框架。
5 nuclei tHCxF     
n.核
参考例句:
  • To free electrons, something has to make them whirl fast enough to break away from their nuclei. 为了释放电子,必须使电子高速旋转而足以摆脱原子核的束缚。
  • Energy is released by the fission of atomic nuclei. 能量是由原子核分裂释放出来的。
6 embryonic 58EyK     
adj.胚胎的
参考例句:
  • It is still in an embryonic stage.它还处于萌芽阶段。
  • The plan,as yet,only exists in embryonic form.这个计划迄今为止还只是在酝酿之中。
7 nucleus avSyg     
n.核,核心,原子核
参考例句:
  • These young people formed the nucleus of the club.这些年轻人成了俱乐部的核心。
  • These councils would form the nucleus of a future regime.这些委员会将成为一个未来政权的核心。
TAG标签: cells materials auxeticity
发表评论
请自觉遵守互联网相关的政策法规,严禁发布色情、暴力、反动的言论。
评价:
表情:
验证码:点击我更换图片