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
考研
Dieting, according to an old joke, may not actually make you live longer, but it sure feels that way. Nevertheless, evidence has
Dieting, according to an old joke, may not actually make you live longer, but it sure feels that way. Nevertheless, evidence has
admin
2015-03-25
30
问题
Dieting, according to an old joke, may not actually make you live longer, but it sure feels that way. Nevertheless, evidence has been accumulating since the 1930s that calorie restriction—reducing an animal’s energy intake below its energy expenditure—extends lifespan and delays the start of age-related diseases in rats, dogs, fish and monkeys. Such results have inspired thousands of people to put up with constant hunger in the hope of living longer, healthier lives. They have also led to a search for drugs that mimic the effects of calorie restriction without the pain of going on an actual diet.
Amid the trend, it is easy to forget that no one has until now shown that calorie restriction works in humans. That omission, however, changed this month, with the publication of the initial results of the first systematic investigation into the matter. This study took 48 men and women and assigned them randomly to either a control group or a calorie-restriction regime. Those in the second group were required to cut their calorie intake for six months to 75% of that needed to maintain their weight.
The study is a
landmark
in the history of the field, because its subjects were either of normal weight or only slightly overweight. Previous projects have used individuals who were clinically fat, thus confusing the unquestionable benefits to health of reducing fatness with the possible advantages of calorie restriction to the otherwise healthy.
At a molecular level, it suggests these advantages are real. Those on restricted diets showed drops in body temperature and blood-insulin levels—both phenomena that have been seen in long-lived, calorie-restricted animals. They also suffered less damage to their DNA.
Eric Ravussin, of Louisiana State University, says that such results provide support for the theory that calorie restriction produces a metabolic adaptation over and above that which would be expected from weight loss alone. Nevertheless, such metabolic adaptation could be the reason why calorie restriction is associated with longer lifespan in other animals—and that is certainly the hope of those who, for the past 15 years, have been searching for ways of triggering that metabolic adaptation by means other than semi-starvation.
The search for a drug that will delay old age is itself as old as the hills—as is the wishful thinking of the suckers who finance such efforts. Those who hope to find it by mimicking the effect of calorie restriction are not, however, complete snake-oil salesmen, for there is known to be a family of enzymes, which act both as sensors of nutrient availability and as regulators of metabolic rate. These might provide the necessary biochemical link between starving and living longer.
The word "landmark"(Line 1, Para. 3)probably means
选项
A、an event of much profit.
B、an event of great excitement.
C、an event of great significance.
D、an event of unique features.
答案
C
解析
语义理解题。由题干提示定位previous research和effects of calorie restriction至第三段。第二段第二句指出“该项研究填补了一项空白”,由此可知此项研究意义重大,是此领域的一个landmark,然后解释原因:试验对象要么是体重正常者,要么是稍稍超重的人,故推测[C]为答案。这个超纲词所在的上下文语境没有涉及此项研究的商业利益,故排除[A];文中没有提到人们对此做出的反应,故排除[B];文章也没有提到该项研究具有某种特性,故排除[D]。
转载请注明原文地址:https://jikaoti.com/ti/SxFRFFFM
0
考研英语一
相关试题推荐
Accordingtothepassage,oilresultsinairpollutionbecauseWhichofthefollowingisNOTmentionedasadisadvantageofbur
Whatistheessenceofthistext?Accordingtothetext,whichofthefollowingstatementsisnottrue?
WhichofthefollowingstatementsisTRUEaboutTolerance.org?AccordingtoJenniferHolladay,whoarechildren’sprimaryrole
WhichofthefollowingstatementsisTRUEaboutTolerance.org?Accordingtothepassage,childrenareencouragedtojoininma
Untilrecently,mostAmericanentrepreneurs(企业家)weremen.Discriminationagainstwomeninbusiness,thedemandsofcaringforf
Americanstodaybelievethatacceptablesocialbehaviorfollowseffortlesslyfrompersonalvirtue.The(1)_____betweenmoralsa
Americanstodaybelievethatacceptablesocialbehaviorfollowseffortlesslyfrompersonalvirtue.The(1)_____betweenmoralsa
Americanstodaybelievethatacceptablesocialbehaviorfollowseffortlesslyfrompersonalvirtue.The(1)_____betweenmoralsa
Americanstodaybelievethatacceptablesocialbehaviorfollowseffortlesslyfrompersonalvirtue.The(1)_____betweenmoralsa
随机试题
一般情况下,耐火等级为一、二级的裙房和其他民用建筑之间的防火间距不应小于()m。
有一段由大管和小管串联的管路,管内液体作连续稳定的流动,大管内径为D,而小管内径为D/2,大管内液体的流速为u,则小管内液体的流速为()。
下列哪项不是绒毛膜癌的病理特点?
女,28岁,常因胃溃疡出血出现头晕乏力、苍白,经检查,HB90g/L,RBC3.50×1012/L,确诊为缺铁性贫血。诊断缺铁性贫血可靠的辅助检查是
Inwriting,whichactivityisusedtogetstudentstoexchangetheirpapersandcorrectintermsofspellingandgrammarpoint?
关于动机强度与工作效率的关系,以下说法正确的是()。
ArichAmericanwenttoParisandboughtapicturepaintedbyaFrenchartist.TheAmericanthoughtthepicturetobeveryfine
一旅客乘地铁从只出发若中途不停,则最多可以到达多少个不同的车站?一旅客要从G到达S,若要选择经过尽可能少地铁线,且经过车站的次数也尽可能地少,则他必须经过下面哪一个车站?
Speech,whetheroralorwritten,isausedcommodity.Ifwearetobeheard,wemust(1)_____ourwordsfromthose(2)_____tou
Whenyouhavetomeetsomeonefromadifferentculture,beprepared.Ifyouunderstandculturaldifferences,you’llbeabetter【
最新回复
(
0
)