题型:阅读理解 题类:常考题 难易度:普通
陕西省西安中学2020届高三上学期英语期中考试试卷
(The New York Times, Oct.7) The 2019 Nobel Prize in physiology(生理学) or medicine was jointly awarded to three scientists — William G. Kaelin Jr., Peter J. Ratcliffe and Gregg L. Semenza — for their work on how cells sense and adapt to oxygen availability. The Nobel Assembly announced the prize at the Karolinska Institute in Stockholm on Monday.
Their work established the genetic mechanisms(机制) that allow cells to respond to changes in oxygen levels. The findings have implications(启示) for treating a variety of diseases.
Why did they win?
"Oxygen is the lifeblood of living organisms(生物体)," said Dr. George Daley, dean of Harvard Medical School. "Without oxygen, cells can't survive." But too much or too little oxygen can be deadly. The three researchers tried to answer this question: How do cells regulate their responses?
The investigators uncovered detailed genetic responses to changing oxygen levels that allow cells in the bodies of humans and other animals to sense and respond to fluctuations(波动), increasing and decreasing how much oxygen they receive.
Why is the work important?
The discoveries reveal the cellular mechanisms that control such things as adaptation to high altitudes and how cancer cells manage to hijack(攫取) oxygen. Randall Johnson, a member of the Nobel Assembly, described the work as a "textbook discovery" and said it would be something students would start learning at the most basic levels of biology education.
"This is a basic aspect of how a cell works, and I think from that standpoint alone it's a very exciting thing." Johnson said.
The research also has implications for treating various diseases in which oxygen is in short supply — including anemia, heart attacks and strokes — as well as for treatment of cancers that are fed by and seek out oxygen.
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