2017年医学博士外语真题试卷

In this section you will hear one dialogue and two passages. After each one, you will hear five questions. After each question read the four possible answers marked A, B, C and D. Choose the best answer and mark the letter of your choice on the ANSWER SHEET.

In this section you will hear one dialogue and two passages. After each one, you will hear five questions. After each question read the four possible answers marked A, B, C and D. Choose the best answer and mark the letter of your choice on the ANSWER SHEET.

In this section you will hear one dialogue and two passages. After each one, you will hear five questions. After each question read the four possible answers marked A, B, C and D. Choose the best answer and mark the letter of your choice on the ANSWER SHEET.

In this section there is a passage with ten numbered blanks. For each blank, there are four choices marked A, B, C and D on the right side. Choose the best answer and mark the letter of your choice on the ANSWER SHEET.

It was the kind of research that gave insight into how flu strains could mutate so quickly. The same branch of research concluded in 2005 that the 1918 flu started in birds before passing to humans. Parsing ( 分析 ) this animal-human51could provide clues to52the next potential superflu, which already has a name: H5N1, also known as avian flu or bird flu.

This potential killer also has a number: 59%. According to WHO, nearly three-fifths of the people who53H5N1 since 2003 died from the virus, which was first reported54humans in Hong Kong in 1997 before a more serious55occurred in Southeast Asia between 2003 and 2004. Some researchers argue that those mortality numbers are exaggerated because WHO only56cases in which victims are sick enough to go to the hospitals for treatment.57, compare that to the worldwide mortality rate of the 1918 pandemic; it may have killed roughly 50 million people, but that was only 10% of the number of people infected, according to a 2006 estimate.

H5N1’s saving grace—and the only reason we’re not running around masked up in public right now-is that the strain doesn’t jump from birds to humans, or from humans to humans, easily. There have been just over 600 cases (and 359 deaths) since 2003. But58its lethality, and the chance it could turn into something far more transmissible, one might expect H5N1 research to be exploding, with labs59the virus’s molecular components to understand how it spreads between animals and60to humans, and hoping to discover a vaccine that could head off a pandemic.

If you are reading this article, antibiotics have probably saved your life—and not once but several times. A rotten tooth, a knee operation, a brush with pneumonia; any number of minor infections that never turned nasty. You may not remember taking the pills, so unremarkable have these one-time wonder drugs become.

Modern medicine relies on antibiotics—not just to cure diseases, but to augment the success of surgery, childbirth and cancer treatments. Yet now health authorities are warning, in uncharacteristically apocalyptic terms, that the era of antibiotics is about to end. In some ways, bacteria are continually evolving to resist the drugs. But in the past we’ve always developed new ones that killed them again.

Not thistime. Infections that once succumbed to everyday antibiotics now require last-resort drugs with unpleasant side effects. Others have become so difficult to treat that they kill some 25,000 Europeans yearly. And some bacteria now resist every known antibiotic.

Regular readers will know why: New Scientist has reported warnings about this for years. We have misused antibiotics appallingly, handing them out to humans like medicinal candy and feeding them to livestock by the tonne, mostly not for health reasons but to make meat cheaper. Now antibiotic-resistant bacteria can be found all over the world—not just in medical facilities, but everywhere from muddy puddles in India to the snows of Antarctica（南极洲）.

How did we reach this point without viable successors to today’sincreasingly ineffectual drugs? The answer lies not in evolution but economics. Over the past 20 years, nearly every major pharmaceutical company has abandoned antibiotics. Companies must make money, and there isn’t much in short-term drugs that should be used sparingly. So researchers have discovered promising candidates, but can’t reach into the deep pockets needed to develop them.

This can be fixed. As we report this week, regulatory agencies, worried medical bodies and Big Pharma are finally hatching ways to remedy this market failure. Delinking profits from the volume of drug sold (by adjusting patent rights, say, or offering prizes for innovation) has worked for other drugs, and should work for antibiotics—although there may be a worryingly long wait before they reach the market.

One day, though, these will all to resistance too. Ultimately, we need, evolution-proof cures for bacterial infection: treatments that stop bacteria from causing disease, but don’t otherwise inconvenience thelittle blighters. When resisting drugs confers no selective advantage, drugs will stop breeding resistance.

Researchers have a couple of candidates for such treatment. But they fear regulators will drag their feet over such radical approaches. That, too, can be fixed. We must not neglect development of the sustainable medicine we need, the way we have neglected simple antibiotic R & D.

If we do, one day another top doctor will be telling us that the drugs no longer work—and there really will be no help on the way.

This issue of Science contains announcements for more than 100 different Gorgon Research Conferences, on topics that range from atomic physics to developmental biology. The brainchild（某人的主意）of Neil Gordon of Johns Hopkins University, these week-long meetings are designed to promote intimate, informal discussions of frontier science.Often confined to fewer than 125 attendees, they have traditionally been held in remote places with minimal distractions. Beginning in the early 1960s, I attended the summer Nucleic Acids Gordon Conference in rural New Hampshire，sharing austere（简朴的）dorm facilities in a private boy’s school with randomly assigned roommates. As a beginning scientist, I found the question period after each talk especially fascinating, providing valuable insights into the personalities and ways of thinking of many senior scientists whom I had not encountered previously. Back then, there were no cellphones and no internet, and all of the speakers seemed to stay for the entire week.During the long, session-free afternoons, graduate students mingled freely with professors. Many lifelong friendships were begun, and—as Gordon intended—new scientific collaborations began. Leap forward to today, and every scientist can gain immediate access to a vast store of scientific thought and to millions of other scientists via the Internet. Why,nevertheless,do in-person scientific meetings remain so valuable for a life in science?

Part of the answer is that science works best when there is a deep mutual trust and understanding between the collaborators, which is hard to develop from a distance. But most important is the critical role that face-to-face scientific meetings play in stimulating a random collision of ideas and approaches. The best science occurs when someone combines the knowledge gained by other scientists in non-obvious ways to create a new understanding of how the world works. A successful scientist needs to deeply believe, whatever the problem being tackled, that there is always a better way to approach that problem than the path currently being taken. The scientist is then constantly on the alert for new paths to take in his or her work, which is essential for making breakthroughs. Thus, as much as possible, scientific meetings should be designed to expose the attendees to ways of thinking and techniques that are different from the ones that they already know.

Back in 1896, the Swedish scientist Svante Arrhenius realized that by burning coal we were adding carbon dioxide to the air, and that this would warm the Earth. But he mentioned the issue only in passing（顺便地）, for his calculations suggested it would not become a problem for thousands of years. Others thought that the oceans would soak up any extra CO2, so there was nothing much to worry about.

That this latter argument has persisted to this day in some quarters highlights our species’ propensity（倾向）to underestimate the scale of our impact on the planet. Even the Earth’s vast oceans cannot suck up CO2as quickly as we can produce it, and we now know the stored CO2is acidifying the oceans, a problem in itself.

Now a handful of researchers are warning that energy sources we normally think of as innocuous could affect the planet’s climatetoo. If we start to extract immense amounts of power from the wind, for instance, it will have an impact on how warmth and water move around the planet, and thus on temperatures and rainfall.

Just to be clear, no one is suggesting we should stop building wind farms on the basis of this risk. Aside from the huge uncertainties about the climatic effects of extracting power from the wind, our present and near-term usage is far too tiny to make any difference. For the moment, any negative consequences on the climate are massively outweighed by the effects of pumping out even more CO2.That poses by far the greater environmental threat; weaning ourselves off fossil fuels should remain the priority.

Even so, now it is the time to start thinking about the long-term effects of the alternative energy sources we are turning to. Those who have already started to look at theseissues report weary, indifferent or even hostile reactions to their work.

That’s understandable, but disappointing. These effects may be inconsequential, in which case all that will have been wasted is some research time that may well yield interesting insights anyway. Orthey may turn out to be sharply negative, in which case the more notice we have, the better. It would be unfortunate to put it mildly,to spend countless trillions replacing fossil-fuel energy infrastructure（基础建设）only to discover that its successor（替代物）is also more damaging than it need be.

These climatic effects may even be beneficial. The first, tentative models suggest that extracting large amounts of energy from high-altitude jet streams would cool the planet, counteracting the effects of rising greenhouse gases. It might even be possible to build an energy infrastructure that gives us a degree of control over the weather:turning off wind turbines here,capturing more of the sun’s energy there.

We may also need to rethink our long-term research priorities.The sun is ultimately the only source of energy that doesn’t end up altering the planet’s energy balance. So the best bet might be invest heavily in improving solar technology and energy storage—rather than in efforts to harness, say,nuclear fusion.

For the moment,allof this remains supposition（推测）.But our species has a tendency to myopia.We have nothing to lose, and everything to gain by taking the long view for a change.

our senses But there’s more tothem than that, according to Dr. Beau Lotto, who is wowing the scientific world with work that crosses the boundaries of art, neurology, natural history and philosophy.

What they reveal, he says, is that the whole world is the creation of our brain. What we see, what we hear, feel and what we think we know is not a photographic reflection of the word, but an instantaneous unthinking calculation as to what is the most useful way of seeing the world. It’s a bestguess based on the past experience of the individual, a long evolutionary past that has shaped the structure of our brains. The world is literally shaped by our pasts.

Dr. Lotto, 40, an American who is a reader in neuroscience at University College London, has set out to prove it in stunning visual illusions, sculptures and installations, which have been included in art-science exhibitions. He explains his complex ideas from the starting point of visualillusions, which far from revealing how fragile our senses are show how remarkably robust they are at providing a picture of the world that serves a purpose to us. For centuries, artists and scientists have noted that a grey dot looks lighter against a dark background than being against a light background. The conventional belief was that it was because of some way the brain and eye is intrinsically wired. But Dr. Lotto believesit’s a learnt response; in other words, we see the world not as it is but as it is useful to us.

“Context is everything, because our brains have evolved to constantly re-define normality,” says Dr. Lotto. “What we see is defined by our own experiences of the past, but also by what the human race has experienced through its history. ”

This is illustrated by the fact that different cultures and communities have different viewpoints of the world, conditioned over generations. For example, Japanese people have a famous inability to distinguish between the “R” and the “L” sound. This arises because in Japanese the sounds are totally interchangeable. “Differentiating between them has never been useful, so the brain has never learnt to do it. It’s not just that Japanese people find it hard to tell the difference. They literally cannot hear the difference.”

Dr. Lotto’s experiments are grounding more and more hypotheses in hard science. “Yes, my work is idea-driven,” he says. “But lots of research, such as MRI brain scanning, is technique-driven. I don’t believe you can understand the brain by taking it out of its natural environment and looking at it in a laboratory.You have to look at what it evolved to do, and look at it in relationship to its ecology. ”

The biggest thing in operating rooms these days is a million-dollar, multi-armed robot named da Vinci, used in nearly 400,000 surgeries nationwide last year—triple the number just four years earlier.

But now the high-tech helper is under scrutiny over reports of problems, including several deaths that may be linked with it and the high cost of using the robotic system. There also have been a few disturbing, freak incidents: a robotic hand that wouldn’t let go of tissue grasped during surgery and a robotic arm hit-ting a patient in the face as she lay on the operating table. Is it time to curb the robot enthusiasm?

Some doctors say yes, concerned that the “wow” factor and heavy marketing have boosted use. They argue that there is not enough robust research showing that robotic surgery is at least as good or better than conventional surgeries. Many U. S. hospitals promote robotic surgery in patient brochures, online and even on highway billboards. Their aim is partly to attract business that helps pay for the costly robot.

The da Vinci is used for operations that include removing prostates, gallbladders and wombs, repairing heart valves, shrinking stomachs and transplanting organs.Its use has increased worldwide, but the system is most popular in the United States.

For surgeons, who control the robot while sitting at a computer screen rather than standing over the patient, these operations can be less tiring. Plus robot hands don’t shake. Advocates say patients sometimes have less bleeding and often are sent home sooner than with conventional laparoscopic surgeries and operations involving large incisions.
But the Food and Drug Administration is looking into a spike in reported problems during robotic surgeries. Earlier this year, the FDA began a survey of surgeons using the robotic system. The agency conducts such surveys of devices routinely, but FDA spokeswoman Synim Rivers said the reason for it now “is the increase in number of reports received” about da Vinci. Reports filed since early last year include at least five deaths.

Whether there truly are more problems recently is uncertain. Rivers said she couldn’t quantify the increase and that it may simply reflect more awareness among doctors and hospitals about the need to report problems. Doctors aren’t required to report such things; device makers and hospitals are.

Company spokesman Geoff Curtis said Intuitive Surgical has physician-educators and other trainers who teach surgeons how to use the robot. But they don’t train them how to do specific proceduresrobotically, he said, and that it’s up to hospitals and surgeons to decide “if and when a surgeon is ready to perform robotic cases.”

A 2010New England Journal of Medicine essay by a doctor and a health policy analyst said surgeons must do at least 150 procedures to become adept at using the robotic system. But there is no expert consensus on how much trainingis needed.
New Jersey banker Alexis Grattan did a lot of online research before her gallbladder was removed last month at Hackensack University Medical Center. She said the surgeon’s many years of experience with robotic operations was an important factor. She also had heard that the surgeon was among the first to do the robotic operation with just one smallincision in the belly button, instead of four cuts in conventional keyhole surgery.

In a poor, inland, gang-infested part of Los Angeles, there is a clinic for people with type 1 diabetes. As part of the country health care system, it serves persons who have fallen through all other safety-net options, the poorest of the poor. Although type 2 diabetes is rampant in this part of town, type 1 diabetes exists as well. Yet these latter individuals generally lack access to any specialty care—a type of treatment they desperately need due to a complexity of dealing with type 1 diabetes in the setting of poverty and psychosocial stress.

The Type I Clinic meets one morning per week and is staffed by four endocrinology fellows and a diabetologist, often me. I have the unique perspective of working part of the time in a county setting and the other part of the time in a clinic for people with health insurance, in Beverly Hills. I know what is possible in the treatment of type 1diabetes. East Los Angeles teaches me what happens when access to care is not available.Most of our patients, in their 20s and 30s and 40s, already have complications of their diabetes; many near end stage. Concepts about maintaining near-normal blood glucose levels often miss their mark—lack of education or money or motivation or factors I can’t even imagine make the necessity of a patient acting as his or her own exogenous pancreas nearly impossible, especially when there are acute consequences to hypoglycemia and few to moderate hyperglycemia.

Historically, in spite of these barriers, we persisted and thought we made a difference. Often, teaching simple carbohydrate counting or switching therapy to long-acting insulin improved patients control and their quality of life. The fellows felt they made a positive impact in the health of their patients. Driving home I would be encouraged by what we had accomplished, although saddened by the severity of the complications suffered by many of our patients.