【英语时差8,16】干细胞，帮助白血病患者

Stem Cells That Help Leukemia Patients Y:Hey,Don,name three types of stem cells in your body? D:I've thought stem cells were from Embryos¹, Yael,do adult have them,too? Y:We’ve got a few kinds of stem cells, each with a different role.The term “potency” is used to describe the capacity of cells to change, or differentiate², into different cell types when they divide. There are totipotent, pluripotent, multipotent, oligopotent and unipotent cells. D:Wow!How about some examples? Y:Sure,a fertilized³ egg cell as it divides makes every kind of cell in the human body. That one cell can create an entire person. So a fertilized egg is an example of totipotency.Embryonic⁴ stem cells are almost as flexible. They can differentiate into almost any cell type, like lung, muscle, liver, skin or brain cells. But a single embryonic stem cell can never grow into an entire organism. This is an example of pluripotency. D:My friend had a Stem Cell Transplants as a treatment for leukemia.What kind of stem cells of those? Y:She probably received a donation of blood stem cells, like those found in bone marrow⁵.Blood stem cells are multipotent. They can make all the different blood cell types, like red and white blood cells or platelets. But they can’t create other kinds of cells. An example of oligopotency lurks⁶ in your lymph nodes. Lymphoid stem cells can produce a few, but not all, kinds of blood cells.Finally, cells that only produce identical copies of themselves are called unipotent. Like skin cells, when they divide, they only make more skin cells.

 

1 embryos   

n.晶胚；胚，胚胎( embryo的名词复数 )

参考例句：

• Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段，而且其行为象胚。 来自辞典例句
• Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句

2 differentiate   

vi.(between)区分；vt.区别；使不同

参考例句：

• You can differentiate between the houses by the shape of their chimneys.你可以凭借烟囱形状的不同来区分这两幢房子。
• He never learned to differentiate between good and evil.他从未学会分辨善恶。

3 Fertilized   

v.施肥( fertilize的过去式和过去分词 )

参考例句：

• The study of psychology has recently been widely cross-fertilized by new discoveries in genetics. 心理学研究最近从遗传学的新发现中受益匪浅。
• Flowers are often fertilized by bees as they gather nectar. 花常在蜜蜂采蜜时受粉。

4 embryonic   

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。

5 marrow   

n.骨髓；精华；活力

参考例句：

• It was so cold that he felt frozen to the marrow. 天气太冷了，他感到寒冷刺骨。
• He was tired to the marrow of his bones.他真是累得筋疲力尽了。

6 lurks   

n.潜在，潜伏；（lurk的复数形式）vi.潜伏，埋伏（lurk的第三人称单数形式）

参考例句：

• Behind his cool exterior lurks a reckless and frustrated person. 在冷酷的外表背后，他是一个鲁莽又不得志的人。 来自《简明英汉词典》
• Good fortune lies within Bad, Bad fortune lurks within good. 福兮祸所倚，祸兮福所伏。 来自互联网