皮肤如何维持正常功能-凯发k8官网

皮肤如何维持正常功能

文章来源：未知文章作者：enread 发布时间：2013-08-16 06:53 字体： [ ]　

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all organs in our body rely on stem cells in order to maintain their function. the skin is our largest organ and forms a shield against the environment. new research results from bric, university of copenhagen and cambridge university, challenge current stem cell models and explains how the skin is maintained throughout life. the results have just been published in the journal cell stem cell.

new knowledge challenge stem cell models

the skin consists of many different cell types, including hair cells, fat- and sweat ¹. it protects us against microbial and chemical attacks and forms a ² barrier that prevents fluid loss. associate professor kim jensen' group from bric have through mapping of stem cell's behaviour in the skin found out that the skin uses a unique method to renew itself. their results challenge the current perception of how our skin is renewed.

"until now, the belief was that the skin's stem cells were organized in a strict ³（层级） with a ⁴ stem cell type at the top of the hierarchy, and that this cell gave rise to all other cell types of the skin. however, our results show that there are ⁵ levels of stem cells and that it is their close micro-environment that determines whether they make hair follicles（毛囊）, fat- or sweat glands, says kim jensen.

the new research from kim jensen completes the stem cell puzzle.

"our data completes what is already known about the skin and its maintenance. researchers have until now tried to fit their results into the old model for skin maintenance. however, the results give much more meaning when we relate them to the new model that our research proposes, says kim jensen.

one such example is that it explains the current mystery of how skin cells can divide too much and ⁶ a skin cancer, without any traces of ⁷ change in the stem cells believed to maintain the outer layer of the skin. the research from the jensen group may suggest that the reason that no changes can be found is, that these cells do not take part in the over-proliferation at all.

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收听单词发音

1
n.腺( gland的名词复数 )
参考例句：
a snake's poison glands 蛇的毒腺 the sebaceous glands in the skin 皮脂腺

2
n.防水材料；adj.防水的；v.使...能防水
参考例句：
my mother bought me a waterproof watch.我妈妈给我买了一块防水手表。 all the electronics are housed in a waterproof box.所有电子设备都储放在一个防水盒中。

3
n.等级制度；统治集团，领导层
参考例句：
there is a rigid hierarchy of power in that country.那个国家有一套严密的权力等级制度。 she's high up in the management hierarchy.她在管理阶层中地位很高。

4
adj.原始的；简单的；n.原(始)人，原始事物
参考例句：
it is a primitive instinct to flee a place of danger.逃离危险的地方是一种原始本能。 his book describes the march of the civilization of a primitive society.他的著作描述了一个原始社会的开化过程。

5
区分，区别，辨别( differentiate的过去式和过去分词 )；区别对待；表明…间的差别，构成…间差别的特征
参考例句：
the development of mouse kidney tubules requires two kinds of differentiated cells. 小鼠肾小管的发育需要有两种分化的细胞。 in this enlargement, barley, alfalfa, and sugar beets can be differentiated. 在这张放大的照片上，大麦，苜蓿和甜菜都能被区分开。

6
vt.开始，创始，发动；启蒙，使入门；引入
参考例句：
a language teacher should initiate pupils into the elements of grammar.语言老师应该把基本语法教给学生。 they wanted to initiate a discussion on economics.他们想启动一次经济学讨论。

7
adj.遗传的，遗传学的
参考例句：
it's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。 each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。