首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Jonas Frisen had his eureka moment in 1997. Back then, scientists suspected that there was a special type of cell in the brain t
Jonas Frisen had his eureka moment in 1997. Back then, scientists suspected that there was a special type of cell in the brain t
admin
2010-07-19
31
问题
Jonas Frisen had his eureka moment in 1997. Back then, scientists suspected that there was a special type of cell in the brain that had the power to give rise to new brain cells. If they could harness these so-called neural stem cells to regenerate damaged brain tissue, they might someday find a cure for such brain diseases as Alzheimer’s and Parkinson’s. But first they had to figure out where neural stem cells were and what they looked like. Frisen, then a freshly minted Ph. D. at the Karolinska Institute in Stockholm, was peering through his microscope at some tissue taken from a rat’s injured spinal cord when he saw cells that appeared to have been enervated by the injury, as though they were busy making repairs. Frisen thought these might be the neural stem cells scientists had been looking for. It took him six years of painstaking research to make sure.
Frisen is quick to emphasize that his research is basic and that treatments are years off. But the findings so far hint at extraordinary potential. Two years ago he identified neural stem cells in the adult humanbrain. And he’s now researching the mechanisms by which these ceils grow into different types of brain cells. Rather than growing brain tissue in a petri dish and implanting it in, say, the forebrain of a Parkinson’s patient, doctors might someday stimulate the spontaneous growth of new neural ceils merely by administering a drug. "It sounds like science fiction," Frisen says, "but we can already do it in mice." In 2007 he will publish the results of his recent experiments, lie’s isolated a protein in the mouse brain that inhibits the generation of nerve cells. Using other chemicals, he’s been able to block the action of this inhibitor, which in turn leads to the production of new brain cells.
Frisen honed his analytical mind at the dinner table in Goteborg, in southwest Sweden. His mother was a mathematics professor and his father was an ophthalmologist. Frisen went to medical school intending to be a brain surgeon or perhaps a psychiatrist, but ended up spending all his free time in the lab. In 1998 he got seed money from a Swedish venture capitalist to set up his own company, NeuroNova, to commercialize his work. A private foundation tried to lure him to Texas, but Swedish businessman Marcus Storch persuaded him to stay by funding a IS-year professorship at Karolinska, covering his salary and the running costs of his 15-person lab. "Jonas Frisen stood out from all candidates by far," says Storch, who*Ic Tobias Foundation sponsors stem-cell research. "He is something of a king in Sweden." Two years ago two more venture capitalists helped the company expand by hiring a CEO and setting up a separate lab.
Since most researchers are interested in stem cells taken from embryos, the practice has attracted considerable controversy in the past few years. Frisen has benefited indirectly from research restrictions in the United States, which have driven funds and brain-power to Singapore, the United Kingdom and Sweden. The Bush Administration currently forbids U. S. -funded work on all but 78 approved stem-cell cultures, many of which are located outside the country. In just one sign of the times, the U. S. -based Juvenile Diabetes Research Foundation recently announced grants totaling $ 20 million for stem cell research--the largest award yet given to the field by a medical charity--to research institutes in Sweden and elsewhere, but not in the United States.
Since Frisen doesn’t work with embryonic stem cells, he’s unwittingly become a champion of the radical right, which argues that scientists ought to concentrate solely on adult stem cells. He happens to disagree. "It would be overoptimistic or outright stupid." he says. "To really understand adult cells, we need to master how embryonic stem cells work." But what really gets Frisen going is when people ask him when they can expect a drug for Parkinson’s and other diseases. "I say, five decades, just to get the number thing out of the way," he quips. "I’m not going to oversell this." When pressed, he admits that clinical trials might begin in five years. That would be a eureka moment worth waiting for.
The word "enervated" in the first paragraph probably means ______.
选项
A、weakened.
B、demolished.
C、vitalized.
D、enlivened.
答案
A
解析
语义理解题。由题干定位至首段。倒数第三句提到、...he saw cells that appeared to have been enervated by the injury,as though they were busy making repairs.由句中的injury和making repairs可知细胞受到伤害,[C]“有生命力的”和[D]“有生气的”不符合文意,排除。[B]意为“彻底破坏的”,句中只是提到injury,并未指出情况严重,[B]程度过重。[A]“虚弱的”符合上下文语境,故为答案。
转载请注明原文地址:https://jikaoti.com/ti/aV3YFFFM
0
专业英语八级
相关试题推荐
TheFederationofAmericanScientistsbelievesthatAccordingtothepassage,playingvideogameshasallofthefollowingadva
WhichofthefollowingwriterswaseverappointedasPoetLaureate?
WhichofthefollowingphilosophersevermentionedthetermSemanticsfirst?
ItusedtobesaidthatEnglishpeopletaketheirpleasuresadly.Nodoubtthiswouldstillbetrueiftheyhadanypleasureto
Wecaninferfromthefirsttwoparagraphsthattheindustrialistsdisregardenvironmentalprotectionchieflybecause______.W
Speechacttheoryisanimportanttheoryinthe______studyoflanguage.
Thousandsofteachersattheelementary,secondary,andcollegelevelscantestifythattheirstudents’writingexhibitsatende
1 Owingtothewidespreadexpansionofcasinos,thecostofpathologicalandproblemgamblinghassoaredtonearlyhalftheann
1 Afolkcultureisasmallisolated,cohesive,conservative,nearlyself-sufficientgroupthatishomogeneousincustomandra
1 Thereisanacceleratingtrendtowardgreaterrealisminmediacommunications.Thistrendcanbeattributedtotechnological
随机试题
肺气肿病人
截瘫病人常见的并发症是
高渗性缺水与低渗性缺水临床表现的主要鉴别点是()
根据需要,异步电动机应装设低电压保护时,其电压动作值一般为电动机额定电压的()。
下列施工质量事故属于由技术原因引发的有()。
1949─2008年江苏省城镇人口变化经历了以下五个阶段。第一阶段:1949—1957年。全省城镇人口由437万人增加到782万人,年均增长7.5%,是总人口年均增长速度(2.2%)的3.43倍;城镇人口占总人口的比重也由1949年的12.4
小明骑在牛背上赶牛过河,共有甲乙丙丁四头牛,甲牛过河需要1分钟,乙牛过河需要2分钟,丙牛过河需要3分钟,丁牛过河需要5分钟。小明每次只能骑一头牛,赶一头牛过河。问小明要让四头牛全部过河,最少需要多少时间?
设事件A与B相互独立,已知它们都不发生的概率为0.16,又知A发生NB不发生的概率与B发生A不发生的概率相等,则A与B都发生的概率是______.
程序流程图中带有箭头的线段表示的是
十进制数60转换成二进制数是( )。
最新回复
(
0
)