Scientists have discovered a special biological behavior in dolphins(海豚) that could lead to a treatment for late-onset diabetes(晚发的糖尿病) in humans. Studies on dolphins found that healthy dolphins switch into a diabetic-like state overnight when they are not feeding, but return to normal when they eat the following morning.
The extraordinary finding has led scientists to suggest that dolphins have “genetic switch” that allows them to imitate diabetes while they are not feeding for a night, without suffering any ill effect.
If researchers can identify a similar genetic pathway in human, they may be able to develop drugs to effectively switch off diabetes. Some 2.2 million people in Britain have type 2 (or late-onset) diabetes, a figure that is expected to reach 4 million by 2025 as a consequence of rising levels of obesity(肥胖).
The tissues of people with type 2 diabetes have become resistant to insulin(胰岛素) so they lose the ability to control sugar levels in their blood. The condition can damage the heart, eyes, kidneys(肾脏) and nerves and contribute to 5% of all deaths, according to the World Healthy Organization.
Dolphins appear to imitate diabetes to keep high levels of blood sugar when food is rare. Like humans, dolphins need some sugar in their blood for their brains to function normally. Venn-Watson’s team analyzed 1,000 blood samples(样本) from 52 dolphins while they didn’t eat anything overnight and fed in the morning. At night time, the dolphins’ metabolism(新陈代谢)changed greatly and showed similar characteristics to that seen in people with type 2 diabetes.
“It is our hope that this discovery can lead to new ways to prevent, treat and maybe even cure diabetes in humans,” said Stephanie Venn-Watson, director of clinical research at the National Marine Foundation in San Diego.
1.What’s the main idea of the passage?
A. Humans get some idea of treating diabetes from dolphins.
B. Dolphins can switch into a diabetic-like state overnight.
C. Humans can suffer the same disease as dolphins.
D. Dolphins should be fed regularly to avoid diabetes.
2.The key to applying the finding to curing human diabetes lies in ____________.
A. producing insulin in a larger amount
B. developing drugs from healthy dolphins
C. identifying a similar genetic pathway in human
D. analyzing more blood samples from hungry dolphins
3. Which of the following statements is TRUE according to the passage?
A. Scientists have found a similar genetic switch in humans.
B. More British people will suffer type 2 diabetes due to obesity.
C. 2.2 million people with type 2 diabetes die in Britain every year.
D. Dolphins imitate diabetes to avoid a high blood sugar level.
4.What will happen to dolphins if not fed for a night according to Venn-Watson?
A. Their metabolism breaks down.
B. They become resistant to insulin.
C. Their heart and kidneys are damaged.
D. They keep high levels of blood sugar.
高三英语阅读理解中等难度题
Scientists have discovered a special biological behavior in dolphins(海豚) that could lead to a treatment for late-onset diabetes(晚发的糖尿病) in humans. Studies on dolphins found that healthy dolphins switch into a diabetic-like state overnight when they are not feeding, but return to normal when they eat the following morning.
The extraordinary finding has led scientists to suggest that dolphins have “genetic switch” that allows them to imitate diabetes while they are not feeding for a night, without suffering any ill effect.
If researchers can identify a similar genetic pathway in human, they may be able to develop drugs to effectively switch off diabetes. Some 2.2 million people in Britain have type 2 (or late-onset) diabetes, a figure that is expected to reach 4 million by 2025 as a consequence of rising levels of obesity(肥胖).
The tissues of people with type 2 diabetes have become resistant to insulin(胰岛素) so they lose the ability to control sugar levels in their blood. The condition can damage the heart, eyes, kidneys(肾脏) and nerves and contribute to 5% of all deaths, according to the World Healthy Organization.
Dolphins appear to imitate diabetes to keep high levels of blood sugar when food is rare. Like humans, dolphins need some sugar in their blood for their brains to function normally. Venn-Watson’s team analyzed 1,000 blood samples(样本) from 52 dolphins while they didn’t eat anything overnight and fed in the morning. At night time, the dolphins’ metabolism(新陈代谢)changed greatly and showed similar characteristics to that seen in people with type 2 diabetes.
“It is our hope that this discovery can lead to new ways to prevent, treat and maybe even cure diabetes in humans,” said Stephanie Venn-Watson, director of clinical research at the National Marine Foundation in San Diego.
1.What’s the main idea of the passage?
A. Humans get some idea of treating diabetes from dolphins.
B. Dolphins can switch into a diabetic-like state overnight.
C. Humans can suffer the same disease as dolphins.
D. Dolphins should be fed regularly to avoid diabetes.
2.The key to applying the finding to curing human diabetes lies in ____________.
A. producing insulin in a larger amount
B. developing drugs from healthy dolphins
C. identifying a similar genetic pathway in human
D. analyzing more blood samples from hungry dolphins
3. Which of the following statements is TRUE according to the passage?
A. Scientists have found a similar genetic switch in humans.
B. More British people will suffer type 2 diabetes due to obesity.
C. 2.2 million people with type 2 diabetes die in Britain every year.
D. Dolphins imitate diabetes to avoid a high blood sugar level.
4.What will happen to dolphins if not fed for a night according to Venn-Watson?
A. Their metabolism breaks down.
B. They become resistant to insulin.
C. Their heart and kidneys are damaged.
D. They keep high levels of blood sugar.
高三英语阅读理解中等难度题查看答案及解析
Scientists have exactly discovered the set of brain cells involved in making risky decisions, and have been able to control them in rats using targeted light. By changing the activity of the cells they were able to change the behaviour of risk-taking rats to avoid risk, hinting the approach could in future be used to treat people with impulse (冲动) control problems.
Risk-taking is a key part of survival, knowing when to take a chance could pay off—such as moving to a new area to look for food when pickings are slim.
While all animals need an element of risk, the preference towards it varies between individuals. Researchers found this variation, which determines how risk-averse an individual is, is regulated by brain cells in a region of the brain called the nucleus accumbens. This cluster of neurons releases the neurotransmitter dopamine, which regulates the brain’s reward and pleasure centres.
Previous studies have shown that in patients with Parkinson’s disease, taking medication which blocks specific dopamine receptors (DR2) (受体) leads to increased gambling (赌博) behaviour and risk taking behaviour. In studies with rats, researchers were able to use a technique called optogenetics (光遗传学)—which uses light sensitive proteins to change the activity of cells—to modify cells with DR2 in the nucleus accumbens.
Rats were trained to choose one of two levers, offering them a choice between a “safe” or “risky” choice. The safe option resulted in a small, but consistent amount of a sugar water treat. But the risky choice consistently delivered smaller amounts of sugar water, with the occasional large pay off—essentially encouraging the animals to gamble for a bigger prize. Around two-thirds of the animals weren’t keen on risk, opting for the safe option, but the remaining third were risk-seekers. Brain scans of the animals showed that those with low levels of DR2 consistently went for the gamble.
But using pulses of light to stimulate (刺激) the DR2 cells and improve their activity could cause the risk-takers to play it safe and opt for the guaranteed but less rewarding option. Once the light-pulses stopped, the risk-takers returned to their gambling strategy.
In the risk-averse animals, stimulating the same cells had little to no effect.
Professor Karl Deisseroth, of Stanford University in California, said: “Humans and rats have similar brain structures involved.”And we found a drug known to increase risk preference in people had the same effect on the rats. So every indication is that these findings are relevant to humans. “Risky behavior has its moments where it’ s valuable. As a species, we wouldn’t have come as far as we have without it.”
1.The variation in people’s preference towards risks is directly regulated by ________.
A. nucleus accumbens B. light sensitive proteins
C. neurons D. dopamine
2.From the experiment with rats, we can conclude that ________.
A. the lack of DR2 cells results in a safe option
B. the levels of DR2 have little to do with their choices
C. the high levels of DR2 can make animals avoid risks
D. the risky choice is a less rewarding option
3.The underlined words in Paragraph 7 most likely mean the animals that are ________.
A. willing to take big risks
B. reluctant to take risks
C. fond of gambling strategy
D. afraid of receiving stimulation
4.What can be inferred from what Professor Karl Deisseroth said?
A. Humans and rats differ in their preference for risk-taking.
B. Too much risk-taking can do more harm than good.
C. Risk-taking can be used to treat people with impulse control problems.
D. Risk-taking is a means of survival and brings higher returns to humans.
高三英语阅读理解中等难度题查看答案及解析
(NEW YORK)---Scientists have discovered small signs of awareness in some vegetative(植物人的) brain injury patients and have even communicated with one of them---findings that are beneficial to how to assess and care for such people.
The new research suggests that standard tests may ignore patients who have some consciousness, and that someday some kind of communication may be possible.
In the strongest example, a 29-year-old patient was able to answer yes-or-no questions by picturing specific scenes the doctors asked him to imagine.
“We were stunned when this happened,” said one study author, Martin Monti of the Brain Sciences Unit in Cambridge. “I find it really amazing. This was a patient who was believed to be vegetative for five years.”
Ever since a research paper four years ago described obvious signs of awareness in a vegetative patient, families of patients have been demanding brain scans, said Dr. James Bernat, a spokesman for the American Academy for Neurology.
But experts said more study is needed before the specialized brain scans could be used in medical treatment. “It’s still a research tool,” Bernat said.
Experts also pointed out that only a few tested patients showed evidence of awareness. And they said it is not clear what degree of consciousness and mental abilities the signs imply.
They also noted that the positive signals appeared only in people with traumatic(外伤的) brain injury---not in patients whose brains had been lacking in oxygen, as can happen when the heart stops.
The new study used brain scanning called functional MRI, for 23 patients in a vegetative state and 31 that are minimally(极微地) conscious.
Patients are said to be in a vegetative state if they are tested and found unable to do such things as move on command or follow a moving object with their eyes. Minimally conscious patients show signs of awareness, but they are minimal and discontinuous.
1. What is the practical use of the research?
A.It leads to studying how to cure vegetative patients. |
B.It attracts society to pay more attention to vegetative patients. |
C.It helps doctors know whether patients are vegetative or not. |
D.It drives the government to care about vegetative patients. |
2.What does the underlined word “stunned” in Paragraph 4 probably mean?
A.Relaxed | B.Amazed | C.Excited | D.Worried |
3.One is considered vegetative if _______________.
A.his eyes can’t follow a moving thing | B.his brain only has a little oxygen |
C.he has a traumatic brain injury | D.his heart stops beating |
4.The passage mainly deals with ________________.
A.how to recognize a vegetative patient | B.the significance of a new scientific finding |
C.how family members look after a vegetative patient | |
D.the latest findings on awareness in some vegetative patients |
高三英语阅读理解中等难度题查看答案及解析
Scientists have exactly discovered the set of brain cells involved in making risky decisions, and have been able to control them in rats using targeted light. By changing the activity of the cells they were able to change the behaviour of risk-taking rats to avoid risk, hinting the approach could in future be used to treat people with impulse (冲动) control problems.
Risk-taking is a key part of survival, knowing when to take a chance could pay off—such as moving to a new area to look for food when pickings are slim.
While all animals need an element of risk, the preference towards it varies between individuals. Researchers found this variation, which determines how risk-averse an individual is, is regulated by brain cells in a region of the brain called the nucleus accumbens. This cluster of neurons releases the neurotransmitter dopamine, which regulates the brain’s reward and pleasure centres.
Previous studies have shown that in patients with Parkinson’s disease, taking medication which blocks specific dopamine receptors (DR2) (受体) leads to increased gambling (赌博) behaviour and risk taking behaviour. In studies with rats, researchers were able to use a technique called optogenetics (光遗传学)—which uses light sensitive proteins to change the activity of cells—to modify cells with DR2 in the nucleus accumbens.
Rats were trained to choose one of two levers, offering them a choice between a “safe” or “risky” choice. The safe option resulted in a small, but consistent amount of a sugar water treat. But the risky choice consistently delivered smaller amounts of sugar water, with the occasional large pay off—essentially encouraging the animals to gamble for a bigger prize. Around two-thirds of the animals weren’t keen on risk, opting for the safe option, but the remaining third were risk-seekers. Brain scans of the animals showed that those with low levels of DR2 consistently went for the gamble.
But using pulses of light to stimulate (刺激) the DR2 cells and improve their activity could cause the risk-takers to play it safe and opt for the guaranteed but less rewarding option. Once the light-pulses stopped, the risk-takers returned to their gambling strategy.
In the risk-averse animals, stimulating the same cells had little to no effect.
Professor Karl Deisseroth, of Stanford University in California, said: “Humans and rats have similar brain structures involved.”And we found a drug known to increase risk preference in people had the same effect on the rats. So every indication is that these findings are relevant to humans. “Risky behavior has its moments where it’ s valuable. As a species, we wouldn’t have come as far as we have without it.”
1.The variation in people’s preference towards risks is directly regulated by ________.
A. nucleus accumbens B. light sensitive proteins
C. neurons D. dopamine
2.From the experiment with rats, we can conclude that ________.
A. the lack of DR2 cells results in a safe option
B. the levels of DR2 have little to do with their choices
C. the high levels of DR2 can make animals avoid risks
D. the risky choice is a less rewarding option
3.The underlined words in Paragraph 7 most likely mean the animals that are ________.
A. willing to take big risks
B. reluctant to take risks
C. fond of gambling strategy
D. afraid of receiving stimulation
4.What can be inferred from what Professor Karl Deisseroth said?
A. Humans and rats differ in their preference for risk-taking.
B. Too much risk-taking can do more harm than good.
C. Risk-taking can be used to treat people with impulse control problems.
D. Risk-taking is a means of survival and brings higher returns to humans.
高三英语阅读理解中等难度题查看答案及解析
Scientists have discovered that 1. (stay) in the cold could help us lose weight. Researchers at the University of California found that exposure to the cold increases levels of a protein that helps form brown fat -- the type of fat that produces heat and keeps us warm. Brown fat burns energy, 2. helps us lose weight. White fat stores extra energy, which results 3. weight gain. The researchers said that because air conditioning and heating give us constant, 4. (comfort) temperatures, our body’s need for brown fat has decreased. They found that outdoor workers in northern Finland who 5. (expose) to cold temperature have 6. significant amount of brown fat when 7. (compare) to same-aged indoor workers.
The research was conducted on two different control groups of mice. 8. group was injected with the protein that helps create brown fat. This group later gained 30% less weight after both groups were fed high-fat diets. The researchers say this could be good news in the fight against obesity. People who are obese have 9. (low) levels of brown fat than thinner people. If you can somehow increase levels of this protein, you could 10. (possible) lose more weight even if eating the same amount of food.
高三英语信息匹配中等难度题查看答案及解析
Scientists have discovered a "monster black hole" so massive that, in theory, it shouldn't exist
It’s a stellar black hole---the type that forms after stars die, collapse, and explode. Researchers had previously believed that the size limit was no more than 20 times the mass of our sun because 8S these stars die, they lose most of their mass through explosions that expel matter and gas swept away by stellar winds
This theory has now been toppled by LB-1, the newly discovered black hole. Located about 15.000 light years away, it has a mass 70 times greater than our sun, according to a press release from the Chinese Academy of Sciences.
The findings were published by Chinese researchers in the journal Nature on Wednesday.
"Black boles of such mass should not even exist in our galaxy, according to most of the current models of stellar evolution," said Liu Jifeng, head of the team that made the discovery. "LB-1 is twice as massive as what we thought possible. Now theorists will have to take up the challenge of explaining its formation."
Scientists are now scratching their heads at how LB-1 got so huge.
The Chinese team has proposed a number of theories. LB-1' sheer size suggests that it “was not formed from the collapse of only one star," the study said--- instead, it could potentially be two smaller black holes orbiting each other.
Another possibility is that it formed from “fallback supermova.” This is when a supernoma---the last stage of an exploding star---ejects material during the explosion, which then falls back into the supernova, creating a black hole.
This fallback formation is theoretically possible, but scientists have never been able to prove or observe it. If this is how LB-1 formed, then we may have "direct evidence for this process” for the first time, the study said.
There are several types of black holes and stellar black holes like LB-1 are on the smaller side, according to NASA. Supermassive black holes are much bigger---they can be billions of times the mass of our sun,
Scientists believe supermassive black holes may be connected to the formation of galaxies, as they often exist at the center of the mass star stems but it is still not clear exactly how, or which form first.
1.Why does the writer write the article?
A.To report the great achievement Chinese scientists have made in black hole theory,
B.To inform the readers of the basic knowledge about the black hole,
C.To share with the readers the new development of the black hole discovery,
D.To demonstrate the significance of discovering new black holes for science.
2.Which of the following about LB-1 is true to the passage?
A.It is the biggest black hole ever discovered,
B.It lost only a small part of its mass through explosion.
C.It couldn't have been formed from the collapse of one star,
D.Its discovery may lead to some breakthrough in the “fallback formation theory".
3.Which of the following is right according to the passage?
A.If the sun in our galaxy dies some of its mass will be taken away by stellar winds.
B.A massive supernova will be formed and then exploded if the sun in our galaxy dies.
C."The Milky Way" was formed after a supermassive black hole collapsed and exploded.
D.If “the Milky Way" dies, a supermassive black hole will be formed after its death.
高三英语阅读理解中等难度题查看答案及解析
Stress in middle age can make your brain shrink and make your memory worse, scientists have discovered. The brain-reducing effects of stress, identified in people in their 40s free from dementia - a serious mental disorder caused by brain disease or injury, were found to be caused by cortisol(皮质醇). The high levels of the stress hormone may be an early warning “sign that someone may end up with dementia, the research suggests.
Stress also made people's thinking skills worse, which the Harvard Medical School study, published in the journal Neurology found. For the research, scientists led by Dr. Justin B. Echouffo-Tcheugui studied 2,231 people with an average of 49 and free of dementia. He said." Our research detected memory loss and brain shrinkage in middle-aged people before symptoms started to show. So it's important for people to find ways to reduce stress, such as getting enough sleep, taking part in moderate exercise, making relaxation techniques part of their daily lives or asking their doctor about their cortisol levels and taking a cortisol-reducing medication if needed. "He also added, "It's important for physicians to give professional advice to all people with high cortisol levels."
Researchers found lower scores on tests of memory and thinking in people with higher levels of cortisol than those with average levels. In addition, people with higher cortisol levels had a smaller brain volume, with those with high cortisol levels having brains that were 88.5 per cent of the total cranial(颅骨的) volume. This was compared to 88. 7 percent of the total cranial volume for people with normal levels of the hormone. No links were found between low levels of cortisol and brain size.
Cortisol helps the body respond to stress and when we are stressed, cortisol levels increase because that is our fight - or - flight(战或逃) response. It can also help reduce inflammation(发炎) and control blood sugar and blood pressure. High cortisol levels can be caused by stress, medical conditions or medications.
“Cortisol affects many different functions so it is important to fully investigate how high levels of the hormone may affect the brain," Dr Echouffo-Tcheugui said, “While other studies have examined cortisol and memory, we believe our large, community-based study is the first to explore, in middle-aged people, cortisol levels and brain volume, as well as memory and thinking skills. ”
1.What may Dr. Echouffo-Tcheugui suggest people do about stress-reducing?
A.Early to bed and early to rise. B.Strengthen the social network.
C.Eat food with more protein. D.Ride a bicycle around a lake.
2.Which statement about cortisol may the author agree to?
A.Higher cortisol levels are associated with larger brain volume.
B.The more stressed one feels, the higher his cortisol levels are.
C.Age and gender play a big role in the participants' brain volume.
D.People with high cortisol levels will suffer from low blood pressure.
3.What's the possible direction for future research according to Dr. Echouffo-Tcheugui?
A.How high cortisol levels affect human brains.
B.The link between cortisol levels and memory
C.The link between cortisol levels and brain size.
D.How cortisol affects peoples response.
4.Why does the author write this passage?
A.To suggest the efficient ways to reduce stress.
B.To prevent the features and functions of cortisol.
C.To explain how cortisol affects people s stress level.
D.To show stress can cause memory loss and brain shrinkage.
高三英语阅读理解中等难度题查看答案及解析
Scientists in Israel have discovered a new way to test for water pollution by “listening” to what the plants growing in water have to say.
By shining a laser beam (激光束) on the tiny pieces of algae floating in the water,the researchers said they hear sound waves that tell them the type and amount of contamination (致污物) in the water.
“It is a red light,telling us that something is beginning to go wrong with the quality of water,” said Zvy Dubinsky,an aquatic biologist at Israel’s Bar Ilan University.“Algae is the first thing to be affected by a change in water quality.”“The secret,” he said,“is to measure the rate of photosynthesis (光合作用) in the algae,meaning the plant’s ability to transform light into energy.” During photosynthesis,plants also release oxygen into the air.
Dubinsky’s technique is easy to perform because of the overabundance of algae in the planet’s water.Most of the oxygen in the atmosphere comes from algae.A prototype tester that occupies about one square meter of a laboratory desktop,shoots a laser beam at water samples to stimulate photosynthesis in the algae.But not all of the laser’s heat is used.Depending on the condition of the algae and the rate of photosynthesis,some of the heat is shot back into the water,creating sound waves,Dubinsky said.With a special underwater microphone,researchers are able to analyze the strength of the sound waves and determine the health of the algae and the condition of the surrounding water.
“Algae suffering from lead poisoning,like waste discharged from battery and paint manufacturing plants,will produce a different sound than those suffering from lack of iron or exposure to other toxins,” said researcher Yulia Pinchasov.She said that testing algae photosynthesis can determine water quality more accurately and easily than laborintensive methods now used like chemical and radioactive carbon testing.
1.The underlined word “algae” in Paragraph 2 probably refers to a kind of________.
A.instrument B.plant
C.wood D.pollutant
2.Why is the algae tested?
A.Because it floats on the water.
B.Because it can have photosynthesis.
C.Because it is the first to be polluted.
D.Because it can produce different sounds.
3.We can infer from the passage that________.
A.algae can produce a loud sound when polluted
B.algae can die easily from pollution
C.photosynthesis of the algae can only be caused by sunlight
D.photosynthesis of the algae is related to water quality
4.What would be the best title for the passage?
A.Scientists Listen to Plants to Find Water Pollution
B.A Prototype Tester Is Used to Determine Water Pollution
C.The Importance of Photosynthesis of the Algae
D.The Problem of Chemical and Radioactive Carbon Testing
高三英语阅读理解中等难度题查看答案及解析
阅读下面材料,在空白处填入适当的内容(1个单词)或括号内单词的正确形式。
Scientists have discovered that__1. _(stay) in the cold could help us lose weight. Researchers at the University of California found that exposure to the cold increases levels of a protein that helps form brown fat-the type of fat that produces heat and keeps us warm. Brown fat burns energy, ___2.__ helps us lose weight. White fat stores extra energy, which results 3. weight gain. The researchers said that because air conditioning and heating give us constant, __4. _(comfort) temperatures, our body's need for brown fat has decreased. They found that:“Outdoor workers in northern Finland who___ 5. __(expose) to cold temperature have__ 6._ significant amount of brown fat when___7. __(compare) to same - aged indoor workers.”
The research was conducted on two different control groups of mice.__ 8. __group was injected with the protein that helps create brown fat. This group later gained 30% less weight after both groups were fed high - fat diets. The researchers say this could be good news in the fight against obesity. People who are obese have ___9.__(low) levels of brown fat than thinner people. Head researcher Hei Sook Sul said: "This protein could become an important target for research into the treatment and prevention of obesity and obesity - related diseases.” She added: "If you can somehow increase levels of this protein, you could__10.__(possible) lose more weight even if eating the same amount of food.”
高三英语语法填空中等难度题查看答案及解析
阅读下面材料,在空白处填入适当的内容(不多于3个单词)或括号内单词的正确形式。
Scientists have discovered that1._________(stay) in the cold could help us lose weight. Researchers at the University of California found that exposure to the cold increases levels of a protein that helps form brown fat — the type of fat that produces heat and keeps us warm. Brown fat burns energy, 2._________ helps us lose weight. White fat stores extra energy, which results 3.____ weight gain. The researchers said that because air conditioning and heating give us constant, 4.__________ (comfort) temperatures, our body's need for brown fat has decreased. They found that: "Outdoor workers in northern Finland who 5._______(expose) to cold temperature have 6._____significant amount of brown fat when 7.________(compare) to same-aged indoor workers."
The research was conducted on two different control groups of mice. 8.__________ group was injected with the protein that helps create brown fat. This group later gained 30% less weight after both groups were fed high-fat diets. The researchers say this could be good news in the fight against obesity. People who are obese have 9. (low) levels of brown fat than thinner people. Head researcher Hei Sook Sul said: "This protein could become an important target for research into the treatment and prevention of obesity and obesity-related diseases." She added: "If you can somehow increase levels of this protein, you could 10._________(possible) lose more weight even if eating the same amount of food."
高三英语完形填空中等难度题查看答案及解析