2021年医学博士外语真题试卷

Historically, humans get serious about avoiding disasters only after one has just struck them. On that logic, 2006 should have been a breakthrough year for rational behavior. With the memory of⁹⁄₁₁still【C1】_____in their minds, Americans watched hurricane Katrina, the most expensive disaster in U. S. history, on live TV. Anyone who didn’t know it before should have learned that bad things can happen. And they are made【C2】_____worse by our willful blindness to risk as much as our reluctance to work together before everything goes to hell.

Granted, some amount of delusion is probably part of the【C3】_____condition. In A. D. 63, Pompeii was seriously damaged by an earthquake, and the locals immediately went to work【C4】__, in the same spot— until they were buried altogether by a volcano eruption 16 years later. But a review of the past year in disaster history suggests that modem Americans are particularly bad at【C5】__themselves from guaranteed threats. We know more than we ever did about the dangers we face. But it turns【C6】_____that in times of cri-sis, our greatest enemy is rarely the storm, the quake or the surge itself. More often, it is ourselves.

So what has happened in the year that【C7】_____the disaster on the Gulf Coast? In New Orleans, the Army Corps of Engineers has worked day and night to rebuild the flood walls. They have got the walls to where they were before Katrina, more or less. That’s not【C8】_____, we can now say with confidence. But it may be all that can be expected from one year of hustle.

Meanwhile, New Orleans officials have crafted a plan to use buses and trains to【C9】_____the sick and the dis-abled. The city estimates that 15,000 people will need a ride out. However, state officials have not yet deter-mined where these people will be taken. The【C10】_____ with neighboring communities are ongoing and difficult.

“He sounded harsh, “my wife said after she hung up the phone with her physician.

In the office, she had found her physician compassionate and warm. But on the phone that day, she felt that the physician was distant and regimented. As a palliative medicine physician practicing at a cancer center, I knew what she meant. When the COVID-19 pandemic began spreading across the globe, waiting rooms of medical offices emptied almost overnight, including our own. Many patients with cancer who were not receiving active treatment stayed home, uncertain about their future, often scared and worried. Telemedicine seemed like a perfect solution to stay in touch, offer ongoing care and counseling, and reach out. Health care systems recognized this, and in a blitzkrieg-like move, transitioned many of their nonurgent outpatient visits to virtual. But neither the patients nor the clinicians were prepared for it.

“I have to ask you a question before we get started, “a long-time patient asked when I reached her via telephone at home: “Are you wearing your white coat?” We both burst out laughing at the absurdity of the image: a physician sitting at his desk, talking to a patient who cannot see him, and yet still wearing a white coat.

During more than 20 years of practicing medicine, I have worked on 2 different continents and in a variety of medical systems and settings. But one thing has always remained constant: thepractice of medicine as an in-person endeavor.

The potential benefits of telemedicine are many and easy to appreciate during normal times; in the times of the pandemic they are priceless. Telemedicine allows for quick contact and maintains continuity of care, especially for patients who have an established relationship with the clinician or practice. This option can be particularly helpful for patients who live in remote areas or cannot easily travel, including frail older adults. Patients can be quickly assessed and supported without the risk of being exposed to the virus. The video encounters also offer a direct glimpse into the lives of patients, an updated version of the traditional home visit.

But, compared with the face-to-face interactions, the virtual interactions seem barren, devoid of the richness the personal contact brings. In a specialty like mine, where a lot depends on emotional connection with the patient and their caregivers, the virtual visits demanded more of me and yet felt a lot less fulfil-ling. And they all seemed to be plagued by annoying technical issues: a weak Wi-Fi signal, dropped connections, wrong phone numbers in the chart, malfunctioning headphones, or a broken phone camera. And what to do about the omnipresent background noise of a lawn mower? As I spent more time doing telemedicine visits, I noticed their cumulative effect wore on me.

Times are chaotic now. For all of us. Our health care systems struggle to provide the best care possible. Telemedicine has proven to be incredibly useful, and it is here to stay. Over time, supporting technology and systems will make virtual visits more efficient, better coordinated, and hopefully, more patient-friendly.

But there is no doubt that the virtual visit is a fundamental alteration to the patient-physician encounter. Recent weeks have brought a massive and hurried adaptation that risks changing the ancient and sacrosanct practice of medicine. And as news, discoveries, ideas, and policies spin around in a flurry, now more than ever we must anchor ourselves in and cherish the wisdom of personal interactions. The place where it all starts.

Scientists have a duty to talk to the public. Why? Because social policies need to be decided on the basis of rational grounds and facts. These include important issue ranging from climate change, to the goals of the space program, to the protection of endangered species, to the use of embryonic stem cells or animals in biomedical research. Both the public and policy makers need to understand not only the scientific justification for our work but also, in some cases, why we deem our studies to be morally justifiable.

The time is ripe for a more open, public and honest debate about the role of scientific experimentation in animals. What follows are some of my thoughts on this topic. I hope this perspective encourages other scientists to join the discussion and prompts opponents of animal research to create an atmosphere where civil discourse can take place, free of the threats, harassment and intimidation (恐吓) that are increasingly directed at biomedical scientists and their families.

Criticism to the use of animals in biomedical research rests on varied scientific and ethical arguments. One extreme view holds that information gathered from animal research cannot, even in principle, be used to improve human health. It is often accompanied by catchy slogan such as “If society funds mouse models of cancer, we will find more cures for cancer in mice.” It is argued that the physiology of animals and humans are too different to allow results from animal research to be extrapolated (推断) to humans.

Such a blanket statement is falsified by numerous cases where experimentation on animals has demonstrably contributed to medical breakthroughs. The experiments on cardiovascular and pulmonary function in animals that began with Harvey and continued with the Oxford physiologists established the under-standing of what the heart and lungs do and how they do it, on which the modern practice of internal medicine rests. Modern medical practice is inconceivable in the absence of the insights gained from these experiments. Anticoagulants were first isolated in dogs：insulin was discovered in dogs and purified in rabbits; lung surfactants were first extracted and studied in dogs; rabbits were used in the development of in vitro fertilization; mice in the development of efficient breast cancer drugs and so on.

For the sake of completeness, it must be noted that the other extreme—the notion that all medical advances are a result of animal research—is false as well. Important medical advances, such as sanitation and the discovery of aspirin, were conducted without the use of animals.

For half a century, researchers have dreamed of giving cancer patients a vaccine that helps the immune system detect the tumors as foreign tissue and wipe them out. Now, a new approach that tailors a personalized vaccine to the mutated proteins in an individual’s tumor appears to have prevented early re-lapses in 12 people with skin cancer.

“We’re in this very exciting, new moment” for personalized cancer vaccines, says Catherine Wu of the Dana Farber Cancer Institute in Boston, whose team presented results last week at the annual meeting of the American Association for Cancer Research (AACR) in Washington, D. C. A second team has similarly encouraging data. The two small studies, mainly designed to test safety and immune responses, are indeed “promising, “says Drew Pardoll of Johns Hopkins University in Baltimore, Maryland. But, he cautions, it is “way too early” to draw firm conclusions about whether the vaccines will extend the lives of cancer patients.

Whereas earlier, unsuccessful cancer vaccines usually targeted a single distinctive cancer protein shared among patients, these new ones contain multiple mutated proteins, or “neoantigens, “that are specific to an individual patient’s tumor. Giving patients a dose of their tumor neoantigens, which look foreign to the immune system, should help activate immune cells called T cells to attack the cancer cells.

One new study was conducted in six patients with melanoma that had spread to their lymph nodes and sometimes other sites. The patients’ tumors had been removed surgically, but were likely to regrow. Wu’s team sequenced the DNA from each patient’s tumors and used computational methods to predict mutations that coded for neoantigens. Then they made each patient a personal vaccine containing about 20 of these neoantigens. The researchers injected the vaccine under the patients’skin periodically for 5 months. They had no serious side effects and showed “strong, potent T cell responses” specific to many of their vaccine neoantigens. All are now cancer-free up to 32 months later.

The two patients with the most advanced disease did relapse, but Wu’s team deployed an additional weapon. an immunotherapy drug called a PD-1 checkpoint inhibitor. These antibody drugs block receptors on T cells that tumors use to hide from the immune system. On their own, the drugs have vanquished tumors in people with certain cancers who otherwise had no hope.

Similar results come from an international trial using a vaccine developed by Ugur Sahin of University Medical Center of Johannes Gutenberg University in Mainz, Germany. The team injected RNA coding for up to 10 tumor neoantigens into the lymph nodes of 13 advanced melanoma patients whose tumors had been removed. Eleven remain cancer-free up to 26 months later, including two whose tumors reappeared, then shrank or were surgically removed, Sahin says. Another patient whose cancer returned received a PD-1 inhibitor and is also tumor-free.

Pardoll and others caution, however, that it’s not possible to know whether neoantigen vaccines per-form better than a PD-1 inhibitor alone without doing larger studies. Other questions remain about how best to design and deliver neoantigen vaccines. Right now the vaccines are costly and take months to make, which may be too long for some patients with metastatic disease.

Meanwhile, several biotech companies are launching trials combining neoantigen vaccines and check-point inhibitors for various cancers. The Parker Institute for Cancer Immunotherapy in San Francisco, California, launched a year ago by Napster co-founder and biotech billionaire Sean Parker, is trying to figure out how to tailor the best possible vaccines through a competition.

BY EARLY 1920, nearly two years after the end of The First World War and the first outbreak of Spanish flu, the disease had killed as many as 100m people—more than both world wars combined. Yet few would name it as the biggest disaster of the 20th century. Some call it the “forgotten flu”. Almost a century on, “Pale Rider”, a scientific and historic account of Spanish flu, addresses this collective amnesia.

Influenza, like all viruses, is a parasite. Laura Spinney traces its long shadow over human history; re-cords are patchy and uncertain, but Hippocrates’s “Cough of Perinthus”in 412 BC may be its first written description. Influenza-shaped footprints can be traced down the centuries: the epidemic that struck during Rome’s siege of Syracuse in 212 BC: the febrisitalica that plagued Charlemagne’s troops in the ninth century. The word “influenza”started being used towards the end of the Middle Ages from the Italian for “in-fluence”—the influence of the stars. That was the state of knowledge then: in some ways at the start of the 20th century it was little better.

Ms. Spinney, an occasional contributor to The Economist, recreates the world that Spanish flu came into. At the beginning of the 20th century science was on the rise. Scientists had switched miasma theory of disease for germ theory: they understood that many diseases were caused not by “bad airs”, but by microscopic organisms like bacteria. This led to improvements in hygiene and sanitation, as well as the development of vaccines. But viruses were almost unknown. The magnification of optical microscopes was too weak to show them up. People could spot bacteria, but not viruses, which are smaller than the wave-length of visible light. Until the electron microscope was invented in the 1930s, influenza was, like the Higgs boson before 2012, a theoretical entity: its existence was deduced from its effects. In the face of such uncertainty, public faith in medicine wavered. People reverted to superstition: sugar lumps soaked in kerosene, and aromatic fires to clear “miasmas”.

Even so, Spanish flu was exceptionally deadly—about 25 times more so than seasonal flu. No one fully understands why. Ms. Spinney ties the virulence of Spanish flu to its genetic irregularities and does a good job of explaining containment strategies through epidemiology. She draws on contemporary research, too, including the recent controversy about recreating the strain responsible for the pandemic. Ms. Spinney issanguineabout the risks of such experiments. influenza appears to have all the ingredients for another cat-astrophic pandemic and scientists, using caution, should probably do all they can to learn more about it.

Perhaps the most valuable aspect of this book, though, is its global perspective, tracing the course of the disease in Brazil, India, South Africa and Australia, among other places. In Europe and North America the first world war killed more than Spanish flu; everywhere else the reverse is true. Yet most narratives focus on the West, and only partly because that is where the best records are. Ms. Spinney’s book goes some way to redress the balance.

Some western countries have lower vaccination rates than poor parts of Africa. Anti-vaxxers are not the main culprits. ERADICATING a disease is the sort of aim that rich countries come up with, and poor ones struggle to reach. But for some diseases, the pattern is reversed. These are the ailments for which vaccinations exist. Many poor countries run highly effective vaccination programmes. But as memories of the toll from infectious diseases fades across the rich world, in some places they are making a comeback. The World Health Organisation (WHO) reckons that vaccines save 2.5m lives a year.

Smallpox was eradicated in 1980 with the help of a vaccine: polio should soon follow. In both cases, rich countries led the way. The new pattern looks very different. The trend is most evident for measles, which is highly contagious. At least 95% of people must be vaccinated to stop its spread (a threshold known as “herd immunity”). Although usually mild, it can lead to pneumonia and cause brain damage or blindness. The countries with the lowest vaccination rates are all very poor, but many developing countries run excellent programmes. Eritrea, Rwanda and Sri Lanka manage to vaccinate nearly everyone. By contrast several rich countries, including America, Britain, France and Italy, are below herd immunity. Last year Europe missed the deadline it had set itself in 2010 to eradicate measles, and had almost 4,000 cases. America was declared measles-free in 2000: in 2014 it had hundreds of cases across 27 states and last year saw its first death from the disease in more than a decade. The trends for other vaccine-preventable diseases, such as rubella, which can cause congenital disabilities if a pregnant woman catches it, are alarming, too. This sorry state of affairs is often blamed on hardline “anti-vaxxers, “parents who refuse all vaccines for their children. They are a motley lot. The Amish in America spurn modern medicine, along with almost everything else invented since the 17th century. Some vegans object to the use of animal-de-rived products in vaccines’ manufacture. The Protestant Dutch Reformed Church thinks vaccines thwart divine will. Anthroposophy, founded in the 19th century by Rudolf Steiner, an Austrian mystic-cum-philosopher, preaches that diseases strengthen children’s physical and mental development. In most countries such refuseniks are only 2%-3% of parents. But because they tend to live in clusters, they can be the source of outbreaks.

A bigger problem, though, is the growing number of parents who delay vaccination, or pick and choose jabs. Studies from America, Australia and Europe suggest that about a quarter of parents fall into this group, generally because they think that the standard vaccination schedule, which protects against around a dozen diseases, “overloads”children’s immune systems, or that particular vaccines are unsafe. Some believe vaccines interfere with “natural immunity”. Many were shaken by a claim, later debunked, that there was a link between autism and the MMR vaccine, which protects against measles, mumps and rubella. In America, some poor children miss out on vaccines despite a federal programme to provide the jabs free, since they have no regular relationship with a family doctor.

When a disease of epidemic proportions rips into the populace, scientists immediately get to work, trying to locate the source of the affliction and find ways to combat it.

Oftentimes, success is achieved, as medical science is able to isolate the parasite, germ or cell that causes the problem and finds ways to effectively kill or contain it. In the most serious of cases, in which the entire population of a region or country may be at grave risk, it is deemed necessary to protect the entire population through vaccination, so as to safeguard lives and ensure that the disease will not spread.