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
2014-09-28
63
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 Weindmch, 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 Weindmch. "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 reduced-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
B
解析
转载请注明原文地址:https://kaotiyun.com/show/tSXd777K
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
Supermarketshoppershaveneverbeenmorespoiltforchoice.Butjustwhenwethoughttraditionalsystemsofselectivefarming
WhatarethecharacteristicsofStandardEnglish?WhichofthefollowingfactorsdidnotcontributetotheLondondialectbecom
SumuelUllmanusedtobethefollowingexcept______.What’sthemessagediscussedintheessay"Youth"?
SumuelUllmanusedtobethefollowingexcept______.What’sthesignificanceof"Youth"forJapanesebusinessmen?
Whatisnotthepossiblecauseforthesharpincreaseinbreastcancer?Formenasimilareffectofaviciouscirclemayresult
______theU.S.willproposetariff-cuttingintwophases?______theprocedureofthetariff-freeproposalarrangedthroughthe
OneofthereasonsformoreAsianstudentstostudyMBAinCaliforniais______WhichofthefollowingisNOTlistedasacharac
During1958theWestGermangovernmentcausedsomedisappointmenttotheBritishandFrenchaircraftindustriesbyfailingtoor
HowoldistheearliestsurvivingexamplesofChineseprinting?
ConfucianismhasitsgreatesteffectamongEuropeancountriesin______.WaranddevelopmentmotivatedthestudyofConfucianism
随机试题
1975年着手对各方面工作进行整顿的是()
男性,62岁。突发胸痛2小时来诊,既往糖尿病史5年,脑血栓2个月。BP100/70mmHg,心电图示如图15。患者接受急诊介入治疗后病情稳定出院,下列哪些药物需要长期服用
代谢性酸中毒常见于
已知水泥消耗量是41200吨,损耗率是3%,则水泥的净用量是()。
若曾存在工会持股、职工持股会持股、信托持股、委托持股或股东数量超过()人的情况,发行人应详细披露有关股份的形成原因及演变情况;进行过清理的,应当说明是否存在潜在问题和风险隐患,以及有关责任的承担主体等。
中国农业银行推出的用于验证网银客户身份安全的工具是()。
晕轮效应:是指个体在评价他人时的一种以偏概全的倾向,也就是说当个体对一个人的某种特征形成好或坏的印象后,还倾向于据此推论该人其他方面的特征。根据上述定义,下列属于晕轮效应的是:
一只股票指数现为350,按连续复利计的无风险利率为年8%,股指的红利收益率为年4%,一份4个月期的期货合约的期货价格为多少?()。
《后汉书.章帝纪》:“律十二月立春,不以报囚。冬至以后,在顺阳助生之文,而无鞫狱断刑之政。朕咨访儒雅,稽之典籍,以为王者生杀,宜顺时气。”《盐铁论.论蕾》:“春夏生长,利以行仁。秋冬杀藏,利以施刑。”请运用中国法制史的知识和理论,分析上
请在【答题】菜单下选择【进入考生文件夹】命令,并按照题日要求完成下面的操作。注意:以下的文件必须保存在考生文件夹下。小刘是一所初中的学生处负责人,负责本院学生的成绩管理。他通过Excel来管理学生成绩,现在第一学期期末考试刚刚结束,小刘将初一年级3个班
最新回复
(
0
)