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
For the first time, scientists have profiled specific genetic changes during the aging of experimental animals, a discovery that
For the first time, scientists have profiled specific genetic changes during the aging of experimental animals, a discovery that
admin
2009-06-24
39
问题
For the first time, scientists have profiled specific genetic changes during the aging of experimental animals, a discovery that could aid work to extend life span and preserve health. The study, conducted with mice at the University of Wisconsin, combines a powerful new genetic technique with dietary restriction, the only known way to delay the aging process.
66.____________________.
Moreover, it reveals how a low-calorie diet, the only known method of slowing aging in several animal species, works at the most basic level to extend life span and preserve health. Such knowledge, used in concert with new technologies capable of rapidly surveying the activity of thousands of genes at once, premises to accelerate the development of drugs that mimic the age-retarding effects of a low-calorie diet, according to the Wisconsin scientists.
The Wisconsin team, led by Tomas A Prolla, a UW-Madison professor of genetics, and Richard Weindruch, a UW-Madison professor of medicine, profiled the action of 6,347 genes. The team charted changes in genetic activity in two groups of mice, one group on a standard diet and another group whose diet had been reduced to 76 percent of the standard diet.
67.____________________.
"At the molecular level, normal aging looks like a state of chronic injury", said Prolla.
However, in a big step forward in understanding how a reduced-calorie diet works to dramatically slow the physical manifestations of aging, many of the same genes that exhibited changes in activity with aging in mice on a standard diet remained almost completely intact in mice on a reduced diet.
"This is a leap in our understanding of how caloric restriction works", said Weindruch, a leading authority in the field of diet and aging. "There hasn’t been much consensus on how caloric restriction retards aging".
68.____________________.
The new study, Weindruch said, tends to support the idea that caloric restriction works by slowing metabolism, the chemical processes by which living organisms and cells convert food to energy.
69.____________________.
"Taken as a whole, our results provide evidence that during aging there is an induction of a stress response as a result of damaged proteins and other macromolecules, "the Wisconsin scientists write in Science". This response ensues as the systems required for the turnover of such molecules decline, perhaps as a result of an energetic deficit in the cell".
70.____________________.
The new study, according to Weindruch, is important not only because it provides a genetic map of aging, but because it shows the potential of harnessing gene chip technology to screen for the effects of drugs on the process of growing old.
"It gives us a molecular test to see if an agent can affect the rate of aging", said Weindruch. "There are lots of implications. If we can understand the molecular mechanisms, we could perhaps develop drugs that mimic the effects of caloric restriction".
A. The research is published today in Science. The study is a milestone in aging research, providing scientists with an intimate look at the ebb and flow of genetic activity with age, and the roles individual genes play in the process of growing old. B. In the process of metabolism, some toxic byproducts are produced, damaging proteins and triggering a stress response that acts to repair damaged molecules and that seems to be governed by a few select genes. But with age, the body’s ability to repair damaged proteins declines, possibly as a result of shrinking cellular energy levels.
C. Over many years, studies of several animal species have consistently shown that reduced diets 25 to 30 percent less than a typical diet retard aging, extend life span and improve overall health in old age.
D. "This study has analyzed more genes with regard to aging than all previous studies combined", Prolla said of the study that surveyed 5 to 10 percent of the mouse genome using a "gene chip"—a small glass plate containing DNA that, when read with a laser, quickly reveals activity levels for thousands of individual genes. The Wisconsin group found that, with age, the activity of a very small number of genes—less than 2 percent of those surveyed—changed markedly. But those genes govern critical biological tasks such as stress responses, protein repair and energy production, and they changed in big ways.
E. The Wisconsin group plans to extend its studies to monkeys and humans. UW-Madison, at its Wisconsin Regional Primate Research Center, is the site of a decade-old study of rhesus macaques on a reduce & calorie diet.
F. Prolla and Weindmch have filed for a patent covering the use of gene chip technology in aging research through the Wisconsin Alumni Re-search Foundation.
选项
答案
D
解析
转载请注明原文地址:https://kaotiyun.com/show/soHd777K
本试题收录于:
公共英语五级笔试题库公共英语(PETS)分类
0
公共英语五级笔试
公共英语(PETS)
相关试题推荐
WhichofthefollowingstatementswouldBowlbysupport?Whichofthefollowingbestexpressesthewriter’sattitudetowardsear
WhichofthefollowingstatementswouldBowlbysupport?WhichofthefollowingstatementsisNOTanargumentagainstBowlby’st
WhichofthefollowingstatementswouldBowlbysupport?Itissuggestedthatmodemsocietiesdifferfromtraditionalsocieties
SolarequipmentSinceabout1800,nearthebeginningoftheIndustrialRevolution,coal,petroleum,andgashavebeenusedata
SolarequipmentSinceabout1800,nearthebeginningoftheIndustrialRevolution,coal,petroleum,andgashavebeenusedata
SolarequipmentSinceabout1800,nearthebeginningoftheIndustrialRevolution,coal,petroleum,andgashavebeenusedata
Theauthorisprimarilyaddressing______.Toimproveparent-childrelationships,teenagersareadvisedtobe______.
A.AtmosphericScientistsB.TheCalculationsMadeattheBerlinWorkshopC.ThePreviousCalculationsoftheEffectofAerosols
A.AtmosphericScientistsB.TheCalculationsMadeattheBerlinWorkshopC.ThePreviousCalculationsoftheEffectofAerosols
A.DifferencesbetweentheoristsandotherscientistsB.TheyneedsocietyC.Theorists’charactersD.Theimportanceofunreasonabl
随机试题
下列关于乳酸脱氢酶的叙述,错误的是
传染过程中表现显性感染的结果是()
图6-23所示半开阀门,阀门前后的测压管水头差为△h=1m水柱,管径不变,管中平均流速v=2m/s,则该阀门的局部阻力系数ξ为()。
消防设施施工结束后,由建设单位组织设计、施工,监理等单位进行包括消防设施在内的建设工程竣工验收。消防设施竣工验收前,下列资料不属于施工单位需要提交竣工验收资料的是()。
地铁消防通信系统的设置场所包括哪些?
甲卷烟生产企业当期出厂销售某牌号卷烟10标准箱,已知甲卷烟生产企业的该牌号卷烟出厂价格为每标准条60元(不含增值税,下同),税务机关采集其批发环节销售价格为每标准条100元,国家税务总局核定的该类卷烟的批发毛利率为15%。则甲卷烟生产企业当期应缴纳消费税(
2007年1月1日.张某正式人职A市的小马公司,主要从事软件开发工作。2015年1月1日,小马公司董事长突发疾病死亡,公司陷入财政危机,后一直未给张某发工资。张某多次催要未果后,以公司未按期足额支付劳动报酬为由与小马公司解除劳动合同并要求支付经济补偿。假设
为了自己想过的生活,勇于放弃一些东西。这个世界没有公正之处,你也永远得不到两全之计。若要自由,就得_________安全;要闲散,就不能_________别人评价中的成就;要愉悦,就别_________身边人给予的态度;要前行,就得_________你现在
Intheopeningparagraph,theauthorintroduceshistopicby______.Whichoneofthefollowingistheclosestinmeaningwith
Personalityistoalargeextentinherent—A-typeparentsusuallybringaboutA-type【B1】______.Buttheenvironmentmustalsoh
最新回复
(
0
)