Stress can cause physical impacts to the body, such as increased heart rate and blood pressure, the release of adrenaline and cortisol (肾上腺素和皮质醇). If adrenaline and cortisol levels are increased for an extended period of time, that can damage DNA and cells.
In a new paper, published in April in the journal Cell Metabolism, researchers described how they measured biological age by looking for changes in DNA’s structure connected to aging.
In the first stage of the research, the researchers surgically attached three-month-old mice to twenty-month-old mice so that blood could flow between them. Over three months, the biological age of the younger mice increased while they shared blood with the older mice. But after the younger mice were separated and allowed to recover for two months, their biological age fell once again.
Then, the researchers looked at human DNA from blood samples gathered in previous studies to measure how human bodies react to stress.
In one stage, the researchers examined blood samples from elderly patients. Patients who had received emergency surgery for a fractured hip (髋部骨折) had an increased biological age the morning after the procedure, but it returned to pre-surgery levels four to seven days later. However, the researchers did not find the same effect in patients who had undergone elective hip surgery or colorectal (结肠直肠的) surgery.
The team also looked at patients who had been hospitalized with Covid-19, but these results varied by sex. While the biological age of female patients dropped within two weeks of recovery, that of men did not.
“The study looked at biological age both before and after stressful events. There are just very, very few studies that have looked at these clocks before and after some kind of intervention (干预),” Daniel Belsky, a medical scientist at Columbia University who did not participate in the study, tells The Scientist.
The study shows that biological age is “much more dynamic than people previously thought,” Jesse Poganik, a co-author of the study, tells Live Science. “You can have these very severe stress events, which increase biological age, but it can be short-lived, if the stress is short-lived, then the age can be restored.”
1. What did the researchers find about the biological age of the younger mice?| A．It increased during blood sharing. |
| B．It could be restored by blood sharing. |
| C．It dropped when they were attached to the older mice. |
| D．It returned to pre-sharing levels as soon as they were separated. |
| A．Those who had had fractured hip surgery. |
| B．Those who had received colorectal surgery. |
| C．Those who had undergone elective hip surgery. |
| D．Those women who had been hospitalized with Covid-19. |
| A．It stands out in similar studies. | B．It is truly remarkable. |
| C．It has some limitations. | D．It is influential. |
| A．Biological age can be measured easily |
| B．Recovering from stress is a long process |
| C．Stress ages you with not permanent effect |
| D．Stress’ harming human bodies means protecting them well |
相似题推荐
【推荐1】The great outdoors: it’s the place to head for when you’re in need of peace and quiet, open spaces, beautiful scenery and exercise. Whether a huge mountain range or a local country park, these natural areas are perfect for us to refresh from our stressed-out lives, and their therapeutic (治疗的) effect is being used more and more to treat mental health.
As an example, in the foothills of the Snowdonia National Park in the UK, specialist therapy sessions are held to help people who suffer from depression, anxiety and stress. Outdoor art-related activities are held for patients, but the setting alone has been credited with improving the mood of patients. Art psychotherapist Pamela Stanley told the BBC that there was a “growing body of evidence” to support eco-therapy.
It’s true that for most of us connecting with the natural world definitely lifts our spirits. But the mental health charity Mind says eco-therapy has been recognized as a formal type of treatment that can sometimes be prescribed to someone by a doctor. It doesn’t involve taking medication, but instead it just develops a person’s relationship with nature. This natural remedy can take on many forms, including doing yoga in a forest, gardening or even hugging a tree.
Evidence has shown there are many benefits of this “green” therapy, including improving social contact, social and work skills and coping abilities. It’s what Dr. Rachel Bragg from the University of Essex calls “psychological recovery”. She told the BBC’s All in the Mind programme that nature-based therapies should be part of a “toolkit” of care for patients.
Of course, eco-therapy won’t cure everything, but it is an option for therapists to use. And as we become more aware of the causes and effects of mental health, it’s good to know that help might lie outside our towns and cities, and that nature can give us a helping hand.
1. In what way does nature work in the therapeutic effect?| A．It helps people get much relieved. | B．It helps people do bodybuilding. |
| C．It is doctor’s preference for treatments. | D．It can help us fully recover from the illness. |
| A．Option. | B．Contact. | C．Treatment. | D．Effect. |
| A．Looking after a garden. | B．Taking medicine. |
| C．Reading at home. | D．Gathering with friends. |
| A．Indifferent. | B．Negative. | C．Neutral. | D．Positive. |
【推荐2】A strong hit to the head will normally give you a concussion (脑震荡). Woodpeckers, however, strike their beaks (喙) into trees thousands of times a day and are perfectly fine.
We used to think that a woodpecker’s skull (头骨) worked as a kind of safety helmet which absorbed the shocks. A new study by Sam Van Wassenbergh, a researcher at the University of Antwerp in Belgum, proved that this “common sense” was in fact false.
Van Wassenbergh and his colleagues argued that, if a woodpecker’s head absorbed the force, it would not be able to strike the tree with enough force.
“If the beak absorbed much of its own impact, the unfortunate bird would have to pound even harder,” they said in their paper. In other words, if the theory were true, the woodpecker would have to peck even harder to compensate (弥补) for both the shock-absorbing qualities of the sponge-like bone inside its skull as well as the density (密度) of the wood.
The scientists recorded four different kinds of woodpeckers in zoos as they were pecking. The team used data from their high-speed recordings to build digital models of the woodpeckers. Van Wassenbergh described the woodpeckers’ motion as “a hammer (锤子) hitting wood” since their movement rigid and focused.
The research suggested that woodpeckers don’t have any shock-absorbing device or the ability to reduce the amount of force. Although they are without “helmets”, the team claimed that the woodpeckers’ tiny size and weight protect them.
A woodpecker’s brain is about 700 times smaller than that of a human. “Smaller animals can stand up to higher decelerations (减速). Think about a fly that hits a window and then just flies back again,” Van Wassenbergh said. “So that is why even the hardest hits we observed are not expected to cause any concussion.”
THEORIES OF PECKING
Previous theory 1: The shock is absorbed by a spongy (海绵似的) bone behind the woodpecker’s beak.
Previous theory 2: Woodpeckers have a long tongue that wraps around the skull, which protects the brain.
Previous theory 3: The liquid inside the skull ensures that the brain will not move violently.
New theory: There is no shock-absorbing device in the head. Woodpeckers’ tiny body is able to take the hit.
1. What did people use to believe about woodpeckers when they peck trees?| A．They could resist slight concussions. |
| B．Their heads were able to reduce the impact. |
| C．Their beaks could spread the shocks they produce. |
| D．Their bodies were soft enough to absorb the force. |
| A．The shock absorber theory is mostly correct. |
| B．How woodpeckers peck depends on their type. |
| C．Woodpeckers do not have special safety devices. |
| D．Density of the wood affects a woodpeckers’ pecking force. |
| A．Its size. | B．Its skull. | C．Its beak. | D．Its species. |
| A．An advertisement. | B．An information brochure. |
| C．An observation diary. | D．A science magzine. |
【推荐3】Think about the last time you did something that you found difficult. Was it working out a puzzle or working hard on your math homework? Can you remember the expression you had on your face? Most people will press their lips together and frown when they are doing something they find difficult. This is normally seen as a sign of effort. Now we’ve found that it can also say more than that.
A recent study at the University of Portsmouth in England suggests that the human expression of effort and frustration is our way of asking others for help. Scientists at the university gave children and chimps an impossible puzzle to work out. When the children couldn’t work out the puzzle, their faces expressed determination and effort. The chimps did not. Humans and chimps, however, have many facial expressions that share the same meaning. A human smile is the same as a chimp showing its teeth in happiness. Scientists believe that over time, humans have evolved (进化) to use this facial expression to ask for help. We have also learned to respond to it by offering help.
According to Dr Albert Mehrabian, a well-known professor of psychology at the University of California, Los Angeles (UCLA), only 7% of human communication happens through words and 55% is through body language. Therefore, understanding expressions is second nature to human beings.
With this in mind, next time you see a person with a frustrated expression, listen to your heart and stop to lend them a hand.
1. What does the underlined word “it” in Paragraph 1 refer to?| A．The occasion. | B．The facial expression. | C．The puzzle. | D．A sign of effort. |
| A．They need others’ help. | B．They can do things themselves. |
| C．They will give up. | D．They want to be alone. |
| A．They had no difficulty working out the puzzle. |
| B．They smiled as they worked out the puzzle. |
| C．Their faces didn’t show determination or effort. |
| D．They used other expressions to ask for help. |
| A．It happens more through body language. |
| B．It doesn’t have to use any word at all. |
| C．Facial expression hides true feelings. |
| D．Spoken language is more powerful. |
【推荐1】Researchers at Stanford University have developed a new material that can move heat out of buildings and into space. The researchers say the material can cool buildings even on hot days. The cooling material is a very thin sheet with many layers that could be placed on a roof like solar panels (板). However, instead of turning sunlight into energy as solar panels do, the material turns heat into infrared (红外线的) radiation.
Shanhui Fan is an electrical engineering professor at Stanford University. He says that the panels have a layer of material that is like sand. The panels act like a mirror. They take heat out of buildings and reflect the light from the sun. And he says both the heat and sunlight are sent 100 kilometers into outer space. “It's a structure that cools itself without electricity input, even under the sun. So, what it does is basically radiate heat to outer space and also reflect the sunlight so it doesn't get heated up by the sun.” Mr Fan says it is like having a window into space. The heat is sent directly into space without increasing the air temperature.
He says buildings in developing countries that do not have electricity or air conditioning could use the panels. “In areas where electricity is out of reach for many people, there is a potential benefit for storing medicine or even food. In many of these situations, being able to reduce the temperature is important. And this would provide a way to do it.”
The researchers say the main problem is creating actual cooling systems using the high-tech panels. They say it may be possible to develop a cooling spray (喷涂) that could be used on present solid structures. They believe the cooling spray technology could be developed in the next three to five years. They say as much as 15 percent of the energy used in the United States is spent providing power to air conditioning systems.
1. What is the main idea of Paragraph 1?| A．Living on hot days is no longer a big problem now. |
| B．Researchers are developing new solar panels on roofs. |
| C．A new material is created to cool the buildings. |
| D．The new material is a very thin sheet with many layers. |
| A．It takes in the heat and cools it down. | B．It uses a mirror to reflect the sunlight. |
| C．It has a window to let out the heat. | D．It sends heat away right into space. |
| A．Convenient but impractical. | B．Eco-friendly and energy-saving. |
| C．Effective but expensive. | D．Creative and cheap. |
【推荐2】Inside a large room at the International Center for Agricultural Research in the Dry Areas (ICARDA), tens of thousands of seeds are stored at a constant temperature of -20℃. Some of them may hold keys to helping us face the future.
“Our center holds as many as 120,000 varieties of seeds. Many of them come from crops as old as agriculture itself. Other seeds were selected by researchers who’ve hiked in the past four decades through forests and mountains in the Middle East, Asia and North Africa, searching for wild relatives of wheat, rice, legumes and other crops that are important to the human diet,” says Mariana Yazbek, who manages the research center.
The research center, formed in the 1970s, once mostly helped farmers in poorer countries in hot and dry climates. But now it also sends seeds to scientists in Europe, Canada and the United States, to improve certain crops’ resistance to the effects of climate change.
“What we are collecting is a sample of the diversity that we have in nature,” adds Yazbek. “We save seeds in case extreme droughts, floods or other catastrophic events should wipe out plant species. These wild relatives of crops have witnessed so many different climates. The qualities that help them adapt and survive in these conditions are stored in their DNA. We have this diversity and it can be a tool to help us face the future.”
Yazbek says scientists are particularly interested in crops like the legume because it absorbs a lot of greenhouse gas CO2 from the atmosphere. It also releases N into the soil, meaning the farmers have to use less chemical fertilizer. And the legume takes very little water to grow because it produces sugar alcohols that act as humectants, a substance that attracts and absorbs water and saves the plant from freezing or drying out.
In another case, a wild wheat seed collected in Iran has allowed scientists in the US to develop new wheat varieties resistant to the Hessian fly, a harmful insect that causes tens of millions of dollars in damage to American crops every year.
1. What can be learned about ICARDA?| A．It has a complete collection of seeds. |
| B．It just helps the undeveloped countries. |
| C．It used to develop seeds for rich countries. |
| D．It focuses on saving ancient and wild seeds. |
| A．Important. | B．Wasteful. | C．Terrible. | D．Unforgettable. |
| A．It will grow much better in wet areas. |
| B．It is friendly to the environment and soil. |
| C．It will become the main crop for humans. |
| D．It has difficulty in adapting to cold climate. |
| A．Seeds Stored at ICARDA May Help Us Improve Our Crops |
| B．A New Invaluable Seed Bank Is Constructed at ICARDA |
| C．Scientists Have Made Breakthroughs in Ancient Seed Study |
| D．New Seeds Are Successfully Developed for North America |
【推荐3】How did life come about on Earth? Did it appear in a flash of light? Well, not exactly. A study published in the journal Nature Communications in March shows that lightning may have played a significant role in the creation of life on Earth.
When lightning hits sand, soil or stone, it melts the materials into a glassy material called fulgurite (闪电熔岩). When a group of researchers examined a particular fulgurite, they found a thick, tree-root-like structure extending down about a foot and a half (about 0.46 meters). “(It was) just entirely made of glass and (had), like, burned soil on the outside of it,” said Benjamin Hess, study author and graduate student at Yale University, US.
But what Hess and his colleagues at the University of Leeds, UK, found inside the fulgurite was even more impressive. According to Science News, “By firing X-rays and electrons (电子) at the fulgurite, and observing how those beams (光线) interacted with the material, the researchers were able to detect its composition.”
They discovered that the fulgurite contained schreibersite (磷铁石), a phosphorus (磷) mineral that can be dissolved in water. Phosphorus is essential for the formation of DNA and cell membranes (薄膜), as well as the formation of teeth and bones in humans, according to the website Phys.org.
It has long been thought that meteorites (陨石) were responsible for delivering this element to Earth. However, life began between 3.5 to 4.5 billion years ago when fewer meteorites were impacting Earth, reported CNN.
According to MSN, Hess and his colleagues estimated that early Earth saw one to five billion lightning flashes every year. Of those, anywhere from 100 million to 1 billion would have struck the ground annually, accounting for between 110 to 11,000 kg of phosphorus per year. While this is a large range, “even the low end is enough to potentially fuel the first life forms, and a quantity that may have eventually exceeded meteor strikes”, MSN reported.
1. What does the underlined word “significant” in paragraph 1 mean?| A．important | B．impressive |
| C．attractive | D．interesting |
| A．It looks like a tree root. |
| B．Fulgurite can be dissolved in water. |
| C．It is essential for the formation of DNA. |
| D．Schreibersite and phosphorus mineral can be found in it. |
| A．To report. | B．To explain. |
| C．To discuss. | D．To compare. |
| A．Entertainment. | B．Health. |
| C．Science. | D．Education. |
