问答题Brady explains that the fat cells responded significantly to the loss of sleep.

共用题干
Ear Breakthrough
New research published in the journal Current Biology has added significantly to understand-ing of how the ear works,giving hope to millions of deaf and hard of hearing people.
The latest research,conducted by Dr. T. Albet,a Deafness Research UK research fel-low at the UCL Ear Institute,together with scientists at the University of Cologne,shows that fruit flies have ears which mechanically amplify sound signals in a remarkably similar way to the senso- ry（感觉的）cells found in the inner ear of vertebrates（脊椎动物）including humans. The finding means that the wealth of genetic techniques already available to study the fruit fly can now be used to target how the ear works.
Dr. Albert says.“The biophysical parallels between the ways both fruit flies and humans convert sound into nerve signals are truly amazing.We may be allowed to hope that these mecha- nistic（机械学的）similarities extend further down to the genes and molecules that bring about hearing.But even if it finally should turn out that hearing in fruit flies relies on different mole-cules than does hearing in humans,the little fruit fly can help us find answers to some key ques-tions of hearing research and -what is sometimes even more important -will surely help us ask the right questions.”
The work is welcomed by Deafness Research UK,the country's only medical research charity for deaf people.Vivienne Michael,chief executive of Deafness Research UK.says,“This is an important advance that paves the way toward a clear understanding of the genetics of deafness.The charity will continue to support culling-edge（尖端的）research through its Fellowship programme at the UCI.Ear institute and at other top research centres in the UK to achieve our goal of secu-ring audial improvements in the prevention,diagnosis and treatment of all forms of hearing impair-ment.”
There are nine million deaf and hard of hearing people in the UK and in most cases deafness results from loss of sensory cells in the inner ear known as“hair” cells.The cells can be damaged and lost through ageing,noise,genetic defects and certain drugs and,because the cells don't re- generate,the result is progressive— and irreversible—hearing loss .Damage to these cells can al-so lead to tinnitus（耳鸣）,which affects around five million people in the UK.

Hearing loss caused by damage to the sensory cells_______.
A:.can affect five million people in the UK
B:.can be progressively repaired
C:cannot be cured
D: cannot lead to tinnitus

共用题干
第三篇

Eat More, Weigh Less, Live Longer

Clever genetic detective work may have found out the reason why a near-starvation diet
prolonas the life of many animals.
Ronald Kahn at Harvard Medical School in Boston,U.S.,and his colleagues nave
been able to extend the lifespan（寿命）of mice by 18 per cent by blocking the rodent's(啮
齿动物）increase of fat in specific cells.This suggests that thinness一and not necessarily
diet一Iromotes lonq life in"calorie（热量卡）restricted" animals.
"It's very cool work",says aging researche:Cynthia Kenyon of the University ot
California, San Francisc."These mice eat all they want, lose weight and live longer.It's
like heaven."
Calorie restriction dramatically extends the lifespan of organisms as different as worms
and rodents.Whether this works in humans is still unknown,partly because few people are
willina to submit to such a strict diet.
But many researchers hope they will be able to trigger the same effect with a drug once
they understand how less food leads to a longer life.One theory is that eating less reduces
the increase of harmful things that can damage cells.But Kahn's team wondered whether
the animals simply benefit by becoming thin.
To find out, they used biology tricks to disrupt the insulin（胰岛素）receptor (受体)
gene in lab mice一but only in their fat cells."Since insulin is needed to help fat cells store
fat ,these animals were protected against becoming fat,"explains Kahn.
This slight genetic change in a single tissue had dramatic effects.By three months of
age.Kahn's modified mice had up to 70 per cent less body fat than normal control mice,
despite the fact that they ate 55 per cent more food per gram of body weight.
In addition ,their lifespan increased.The average control mouse lived 753 days,while
the thin rodents averaged a lifespan of 887 days.After three years,all the control mice had
died.but one-quarter of the modified rodents were still alive.
"That they ciet these effects by just manipulating the fat cells is controversial,"says
Leonard Guarente of the Massachusetts Institute of Technology,who studies calorie
restriction and aging.
But Guarente says Kahn has yet to prove that the same effect is responsible for
increased lifespan in calorie-restricted animals."It might be the same effect or there might
be two routes to long life,"he points out,"and that would be very interesting."

Ronald Kahn and his colleagues can make mice live longer by
A:offering them less food.
B:giving them a balanced diet.
C:disrupting the specific genes in their fat cells.
D:Dreventina them qrowinq larger.

共用题干
第三篇

Americans still have been gaining weight,although they have cut their average fat intake from 36 to 34 percent of their total diets in the past 15 years.Indeed,cutting fat to control or lose weight makes sense. Fat has nine calories per gram. Protein and carbohydrates（碳水化合物）which break down into amino acids and simple sugars respectively,have just four. Moreover,the body uses fewer calories to metabolize（新陈代谢）fat than it does to metabolize other foods.
But cutting fat from your diet doesn't necessarily mean your body won't store fat. For example, between nonfat and regular cookies,there's trivial difference in calories because manufacturers make up for the loss of fat by adding sugar. Low-fat crackers,soups and dressings can also be just as high in calories as richer versions.No matter where the calories come from,overeating will still cause weight gain.The calories from fat just do it a little quicker. A Wisconsin computer programmer who decided with a diet coach to eat only 40 grams of fat a day learned the lesson firsthand.He wasn't losing weight.Then he showed his food diary to his coach and revealed he'd been eating half a pound of jelly beans a day."They don't have any fat,"he explains.But they had enough sugar to keep him from losing an ounce.
Nonfat foods become add-on foods.When we add them to our diet,we actually increase the number of calories we eat per day and gain weight. That was born out in a Pennsylvania State University study.For breakfast,Prof. Barbara Rolls gave two groups of women yogurt that contained exactly the same amount of calories.One group's yogurt label said"high fat”一the other,"low fat". The"low fat"yogurt group ate significantly more calories later in the day than the other group. "People think they've saved fat and can indulge themselves later in the day with no adverse consequences,"says Richard Mattes,a nutrition researcher at Purdue University."But when they do that,they don't compensate very precisely,and they often end up overdoing it."

From Professor Barbara's experiment,we can learn that_________.
A:people increase the number of calories they eat per day and gain weight
B:the"low fat"yogurt group ate less calories later than the other group
C:two groups ate the same amount of yogurt
D:people who eat low fat yogurt will not gain weight

共用题干
第三篇

Americans still have been gaining weight,although they have cut their average fat intake from 36 to 34 percent of their total diets in the past 15 years.Indeed,cutting fat to control or lose weight makes sense. Fat has nine calories per gram. Protein and carbohydrates（碳水化合物）which break down into amino acids and simple sugars respectively,have just four. Moreover,the body uses fewer calories to metabolize（新陈代谢）fat than it does to metabolize other foods.
But cutting fat from your diet doesn't necessarily mean your body won't store fat. For example, between nonfat and regular cookies,there's trivial difference in calories because manufacturers make up for the loss of fat by adding sugar. Low-fat crackers,soups and dressings can also be just as high in calories as richer versions.No matter where the calories come from,overeating will still cause weight gain.The calories from fat just do it a little quicker. A Wisconsin computer programmer who decided with a diet coach to eat only 40 grams of fat a day learned the lesson firsthand.He wasn't losing weight.Then he showed his food diary to his coach and revealed he'd been eating half a pound of jelly beans a day."They don't have any fat,"he explains.But they had enough sugar to keep him from losing an ounce.
Nonfat foods become add-on foods.When we add them to our diet,we actually increase the number of calories we eat per day and gain weight. That was born out in a Pennsylvania State University study.For breakfast,Prof. Barbara Rolls gave two groups of women yogurt that contained exactly the same amount of calories.One group's yogurt label said"high fat”一the other,"low fat". The"low fat"yogurt group ate significantly more calories later in the day than the other group. "People think they've saved fat and can indulge themselves later in the day with no adverse consequences,"says Richard Mattes,a nutrition researcher at Purdue University."But when they do that,they don't compensate very precisely,and they often end up overdoing it."

What lesson did the computer programmer learn?
A:He shouldn't eat any sugar.
B:He should only eat nonfat food.
C:He shouldn't eat any food.
D:He shouldn't eat too much.

共用题干
Ear Breakthrough
New research published in the journal Current Biology has added significantly to understand-ing of how the ear works,giving hope to millions of deaf and hard of hearing people.
The latest research,conducted by Dr. T. Albet,a Deafness Research UK research fel-low at the UCL Ear Institute,together with scientists at the University of Cologne,shows that fruit flies have ears which mechanically amplify sound signals in a remarkably similar way to the senso- ry（感觉的）cells found in the inner ear of vertebrates（脊椎动物）including humans. The finding means that the wealth of genetic techniques already available to study the fruit fly can now be used to target how the ear works.
Dr. Albert says.“The biophysical parallels between the ways both fruit flies and humans convert sound into nerve signals are truly amazing.We may be allowed to hope that these mecha- nistic（机械学的）similarities extend further down to the genes and molecules that bring about hearing.But even if it finally should turn out that hearing in fruit flies relies on different mole-cules than does hearing in humans,the little fruit fly can help us find answers to some key ques-tions of hearing research and -what is sometimes even more important -will surely help us ask the right questions.”
The work is welcomed by Deafness Research UK,the country's only medical research charity for deaf people.Vivienne Michael,chief executive of Deafness Research UK.says,“This is an important advance that paves the way toward a clear understanding of the genetics of deafness.The charity will continue to support culling-edge（尖端的）research through its Fellowship programme at the UCI.Ear institute and at other top research centres in the UK to achieve our goal of secu-ring audial improvements in the prevention,diagnosis and treatment of all forms of hearing impair-ment.”
There are nine million deaf and hard of hearing people in the UK and in most cases deafness results from loss of sensory cells in the inner ear known as“hair” cells.The cells can be damaged and lost through ageing,noise,genetic defects and certain drugs and,because the cells don't re- generate,the result is progressive— and irreversible—hearing loss .Damage to these cells can al-so lead to tinnitus（耳鸣）,which affects around five million people in the UK.

A person who is hard of hearing is______.
A: not able to hear properly
B:.totally deaf form birth
C:.unwilling to listen to others
D:.ignorant of how the ear works

共用题干
第三篇

Eat More, Weigh Less, Live Longer

Clever genetic detective work may have found out the reason why a near-starvation diet
prolonas the life of many animals.
Ronald Kahn at Harvard Medical School in Boston,U.S.,and his colleagues nave
been able to extend the lifespan（寿命）of mice by 18 per cent by blocking the rodent's(啮
齿动物）increase of fat in specific cells.This suggests that thinness一and not necessarily
diet一Iromotes lonq life in"calorie（热量卡）restricted" animals.
"It's very cool work",says aging researche:Cynthia Kenyon of the University ot
California, San Francisc."These mice eat all they want, lose weight and live longer.It's
like heaven."
Calorie restriction dramatically extends the lifespan of organisms as different as worms
and rodents.Whether this works in humans is still unknown,partly because few people are
willina to submit to such a strict diet.
But many researchers hope they will be able to trigger the same effect with a drug once
they understand how less food leads to a longer life.One theory is that eating less reduces
the increase of harmful things that can damage cells.But Kahn's team wondered whether
the animals simply benefit by becoming thin.
To find out, they used biology tricks to disrupt the insulin（胰岛素）receptor (受体)
gene in lab mice一but only in their fat cells."Since insulin is needed to help fat cells store
fat ,these animals were protected against becoming fat,"explains Kahn.
This slight genetic change in a single tissue had dramatic effects.By three months of
age.Kahn's modified mice had up to 70 per cent less body fat than normal control mice,
despite the fact that they ate 55 per cent more food per gram of body weight.
In addition ,their lifespan increased.The average control mouse lived 753 days,while
the thin rodents averaged a lifespan of 887 days.After three years,all the control mice had
died.but one-quarter of the modified rodents were still alive.
"That they ciet these effects by just manipulating the fat cells is controversial,"says
Leonard Guarente of the Massachusetts Institute of Technology,who studies calorie
restriction and aging.
But Guarente says Kahn has yet to prove that the same effect is responsible for
increased lifespan in calorie-restricted animals."It might be the same effect or there might
be two routes to long life,"he points out,"and that would be very interesting."

The average modified mouse lived
A:3 years.
B:753 days.
C:More than 3 years.
D:887 days.

共用题干
第二篇

Bone Marrow Transplantation

Bone marrow is the spongy tissue inside some of your bones,such as your hip and thigh bones. It contains immature cells,called stem cells.The stem cells can develop into the red blood cells that carry oxygen through your body,the white blood cells that fight infections,and the platelets that help with blood clotting.
If there is a problem with your bone marrow,a transplant can give you healthy new marrow. You could need a transplant because of a disease,such as bone marrow diseases or cancers like leukemia kemia or lymphoma.Or you might need one if a strong cancer treatment kills your healthy blood cells.
People with cancer sometimes donate bone marrow before treatment to be transplanted later. But often the new marrow comes from a donor,either a close family member or someone unrelated.
The healthy cells for a transplant can come from three sources:bone marrow;peripheral (circulating) blood that has an increased number of healthy blood-forming cells(also called peripheral blood stem cells or PBSC);umbilical cord blood that is collected after a baby is born.
If you need an allogeneic transplant,your doctor will look for a marrow donor or cord blood unit that matches your HLA tissue type.HLA stands for human leukocyte antigen,a markei your immune system uses to recognize which cells belong in your body and which do not.
Before your body can receive the healthy cells,the diseased cells must be destroyed.This is done using chemotherapy and sometimes radiation. The destruction of diseased cells is called a preparative regimen or a conditioning regimen.
On the day of transplant,the cells from the marrow donor or cord blood unit are infused intravenously(go into your body through a large vein).These healthy cells move into the spaces inside your bones where they create new marrow. They grow and make healthy new red blood cells,white blood cells,and platelets.

Before receiving healthy cells,diseased cells must_________.
A:undergo chemotherapy
B:go through radiation
C:be prepared
D:be wrecked

共用题干
第三篇

Americans still have been gaining weight,although they have cut their average fat intake from 36 to 34 percent of their total diets in the past 15 years.Indeed,cutting fat to control or lose weight makes sense. Fat has nine calories per gram. Protein and carbohydrates（碳水化合物）which break down into amino acids and simple sugars respectively,have just four. Moreover,the body uses fewer calories to metabolize（新陈代谢）fat than it does to metabolize other foods.
But cutting fat from your diet doesn't necessarily mean your body won't store fat. For example, between nonfat and regular cookies,there's trivial difference in calories because manufacturers make up for the loss of fat by adding sugar. Low-fat crackers,soups and dressings can also be just as high in calories as richer versions.No matter where the calories come from,overeating will still cause weight gain.The calories from fat just do it a little quicker. A Wisconsin computer programmer who decided with a diet coach to eat only 40 grams of fat a day learned the lesson firsthand.He wasn't losing weight.Then he showed his food diary to his coach and revealed he'd been eating half a pound of jelly beans a day."They don't have any fat,"he explains.But they had enough sugar to keep him from losing an ounce.
Nonfat foods become add-on foods.When we add them to our diet,we actually increase the number of calories we eat per day and gain weight. That was born out in a Pennsylvania State University study.For breakfast,Prof. Barbara Rolls gave two groups of women yogurt that contained exactly the same amount of calories.One group's yogurt label said"high fat”一the other,"low fat". The"low fat"yogurt group ate significantly more calories later in the day than the other group. "People think they've saved fat and can indulge themselves later in the day with no adverse consequences,"says Richard Mattes,a nutrition researcher at Purdue University."But when they do that,they don't compensate very precisely,and they often end up overdoing it."

Americans are still gaining weight though reducing the fat intake because_________.
A:they eat regular cookies instead of nonfat ones
B:they eat too much
C:they eat too much sugar
D:they eat low-fat crackers,soups

共用题干
第三篇

Americans still have been gaining weight,although they have cut their average fat intake from 36 to 34 percent of their total diets in the past 15 years.Indeed,cutting fat to control or lose weight makes sense. Fat has nine calories per gram. Protein and carbohydrates（碳水化合物）which break down into amino acids and simple sugars respectively,have just four. Moreover,the body uses fewer calories to metabolize（新陈代谢）fat than it does to metabolize other foods.
But cutting fat from your diet doesn't necessarily mean your body won't store fat. For example, between nonfat and regular cookies,there's trivial difference in calories because manufacturers make up for the loss of fat by adding sugar. Low-fat crackers,soups and dressings can also be just as high in calories as richer versions.No matter where the calories come from,overeating will still cause weight gain.The calories from fat just do it a little quicker. A Wisconsin computer programmer who decided with a diet coach to eat only 40 grams of fat a day learned the lesson firsthand.He wasn't losing weight.Then he showed his food diary to his coach and revealed he'd been eating half a pound of jelly beans a day."They don't have any fat,"he explains.But they had enough sugar to keep him from losing an ounce.
Nonfat foods become add-on foods.When we add them to our diet,we actually increase the number of calories we eat per day and gain weight. That was born out in a Pennsylvania State University study.For breakfast,Prof. Barbara Rolls gave two groups of women yogurt that contained exactly the same amount of calories.One group's yogurt label said"high fat”一the other,"low fat". The"low fat"yogurt group ate significantly more calories later in the day than the other group. "People think they've saved fat and can indulge themselves later in the day with no adverse consequences,"says Richard Mattes,a nutrition researcher at Purdue University."But when they do that,they don't compensate very precisely,and they often end up overdoing it."

Which of the following contains fewer calories?
A:Fat.
B:Sugar.
C:Protein and carbohydrates.
D:Amino acids.