VOA标准英语2012--Nano Tool Watches Teardrop Protein Destroy Bacteria

Nano Tool Watches Teardrop Protein Destroy Bacteria

About a hundred years ago, a Scottish biologist discovered that proteins called lysozymes in human tears can kill bacteria. Scientists have studied the enzyme¹ extensively, but molecular² biologist Gregory Weiss at the University of California, Irvine set out to learn more.
“What we didn’t know is that once the enzyme latches³ on to the side of the cell wall of the bacteria," he says, "it eats all the way across the bacteria without letting go.”
The tiny lysozyme breaks down the cell wall of the much bigger bacterium⁴. Associate physics professor and collaborator⁵ Philip Collins says the scientists designed a way to study that by "listening in on a molecule⁶."
Collins and Weiss assembled columns of carbon atoms called nanotubes into a tiny transistor⁷ - an electronic switch that regulates current, just like what you’d find in a computer or a smart phone. Then, Weiss says, they attached it to a single lysozyme molecule.
“The carbon nanotube is conducting electricity and as the enzyme starts going about its motion, as it starts chewing on the walls of bacteria, it changes the conductance and flow of electrons through the carbon nanotube.”
Collins says the nanotubes are the world’s smallest wires. “You might think of our wiring as being a tiny microphone, that’s so small that we can reach and tap into the signal from a single molecule.”
Weiss and Collins recorded the signals, and say the data confirmed what is already known about the enzyme.
In addition Weiss says, they observed it in different chemical environments. “Our technique allows us to see that. [In] previous techniques, reporter molecules⁸ would fade and prevent you from watching it for long periods of time. Whereas our technique lets us watch for a really long period of time.”
Collins says the work is “expanding the envelope to where these circuits can be thought of, not just as transistors⁹ or memory, but as real tools for doing new science.”
Weiss adds that the research, published this week in Science, could lead to improvements in medical diagnostics.
“The system we’re describing in this paper is amazingly sensitive. And so, we think that we can drive this to the point of being able to look for single individual molecules associated with cancer,” Weiss says. "That means cancer or chronic¹⁰ illnesses could be detected very early and treated with better outcomes.”

1 enzyme   

n.酵素，酶

参考例句：

• Above a certain temperature,the enzyme molecule will become unfolded.超过一定温度，酶分子将会展开。
• An enzyme that dissolves the fibrin of blood clots.能溶解血凝块中的纤维的酶。

2 molecular   

adj.分子的；克分子的

参考例句：

• The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
• For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。

3 latches   

n.（门窗的）门闩( latch的名词复数 )；碰锁v.理解( latch的第三人称单数 )；纠缠；用碰锁锁上（门等）；附着（在某物上）

参考例句：

• The virus latches onto the red blood cells. 这种病毒附着在红细胞上。 来自《简明英汉词典》
• The opposite end latches onto the pathogen. 相对的一端锁在病原体上。 来自英汉非文学 - 生命科学 - 预防生物武器

4 bacterium   

n.(pl.)bacteria 细菌

参考例句：

• The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。
• A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。

5 collaborator   

n.合作者，协作者

参考例句：

• I need a collaborator to help me. 我需要个人跟我合作，帮我的忙。
• His collaborator, Hooke, was of a different opinion. 他的合作者霍克持有不同的看法。

6 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

7 transistor   

n.晶体管，晶体管收音机

参考例句：

• This make of transistor radio is small and beautifully designed.这半导体收音机小巧玲珑。
• Every transistor has at least three electrodes.每个晶体管至少有三个电极。

8 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

9 transistors   

晶体管( transistor的名词复数 )； 晶体管收音机，半导体收音机

参考例句：

• In semiconductor receivers transistors take the place of vacuum tubes. 在半导体收音机中晶体管代替了真空管。
• We often turn to this handbook for information on transistors. 我们常从这本手册查阅有关晶体管的资料。

10 chronic   

adj.(疾病)长期未愈的，慢性的；极坏的

参考例句：

• Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
• Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。