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The curse of jet lag has struck most international travelers at one time or another -- and anyone lucky enough to have avoided it will surely have suffered the equally unpleasant sleep-deprivation involved in an early-morning start. Nor, as shift workers know too, is it possible to escape by going to bed earlier the previous evening, and thus putting sleep in the bank. Sleepiness is controlled by the body’s internal biological clock, so an earlier bedtime just means several wakeful hours staring in frustration at a darkened ceiling. For years, some travelers and shift workers have sworn by melatonin (褪黑素). This is a hormone that regulates the biological clock. It is made in the brain by a structure called the pineal gland (松果体), as darkness sets in after sunset. Light is the one that keeps the biological clock in the same pace with solar time. The clock then tells the brain when to go to sleep. The theory of those who use melatonin is that an external dose of it can reset the clock, and thus cause the "go to sleep" signal to be sent at a more convenient moment~ Melatonin can also increase sleepiness during the day, when the pineal gland is not producing it. This has resulted in a growing, and often unregulated, market in melatonin-supplement tablets. The pharmaceutical industry’s response to this seems to be: "If you can’t beat them, join them." A paper in this week’s Lancet, by Shantha Rajaratnam of the Harvard Medical School and his colleagues, reports two trials, funded by drug companies, of tasimelteon, a substance that binds to the same receptors in the brain as melatonin does, and which it is expected will have a similar effect. In the course of these trials, more than 400 people had their bedtimes brought forward by five hours in controlled conditions. Half an hour before lights out, a quarter of them were given common drug, while the remaining three-quarters were given varying doses of tasimelteon. Dr. Rajaratnam and his colleagues report that the new drug let people fall asleep faster at the unnaturally early time, and also allowed them to sleep longer than those given the common one. When will melatonin be made in the brain according to the passage
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An epidemic of swine flu (猪流感) has recently developed in Mexico and the United States, says the CDC. Swine flu has killed many people, and the outbreak has features that suggest it could become a global pandemic (瘟疫). A pandemic is an epidemic that spreads around the whole world. Pandemics also often cause more severe disease than epidemics. Flu is a disease caused by the influenza virus. Humans, pigs, birds and other animals all can be infected by influenza viruses. Typically, influenza viruses can infect only one species, so the influenza viruses of humans are different from those of pigs and birds. However, sometimes a virus can infect more than one species. For examples, pigs sometimes can be infected not only with pig influenza viruses, but also with human and bird influenza viruses. Then these viruses can come up to one another secretly and swap (交换) genes, creating new viruses that have a mix of genes -- from human, pig, and bird viruses. That is what has happened with this new swine flu virus. Sometimes this swapping of genes allows a virus that was originally able to infect only pigs or only birds to also infect humans. When that happens, we refer to the illness as "swine flu" or "bird flu". This current virus could actually be called "swine/bird flu", since it has some genes from pig flu viruses and other genes from bird flu viruses. Most viruses that cause swine flu or bird flu are very hard to pass from one human to another: they don’t cause epidemics. Sometimes, however, further changes in genes create a virus that can spread rapidly among humans, and can produce a more severe illness. One reason this illness is more severe is that the virus is so new. The regular flu that comes each year is caused by a regular human influenza virus that often has similarities to the viruses that have caused the flu in years past, so people have some degree of immunity to the latest virus. The unusual swine flu or bird flu viruses that develop the ability for person-to-person spread are so different that people have little or no immunity to them. The worst global pandemic in modem times was the influenza pandemic of 1918 to 1919. It affected about a third of the human race, and killed at least 40 million people in less than a year -- more than those who have been killed by AIDS in three decades. The world economy went into a deep recession. The average length of life dropped for 10 years. Unfortunately, the new swine flu virus can be transmitted between humans. It is not clear yet how easily it is transmitted, nor how it is transmitted. Almost surely it is transmitted by sneezing and coughing, and by skin-to-skin contact with an infected person. According to the passage, a pandemic ______.
患者，男性，30岁。到非洲出差回国10天后，出现寒战、面色苍白、肢体厥冷等症状，持续半小时左右继以高热、面色潮红伴头痛等症状。诊断为疟疾间日疟。 [假设信息]该患者治愈后，为控制复发，应选用的药物是
The curse of jet lag has struck most international travelers at one time or another -- and anyone lucky enough to have avoided it will surely have suffered the equally unpleasant sleep-deprivation involved in an early-morning start. Nor, as shift workers know too, is it possible to escape by going to bed earlier the previous evening, and thus putting sleep in the bank. Sleepiness is controlled by the body’s internal biological clock, so an earlier bedtime just means several wakeful hours staring in frustration at a darkened ceiling. For years, some travelers and shift workers have sworn by melatonin (褪黑素). This is a hormone that regulates the biological clock. It is made in the brain by a structure called the pineal gland (松果体), as darkness sets in after sunset. Light is the one that keeps the biological clock in the same pace with solar time. The clock then tells the brain when to go to sleep. The theory of those who use melatonin is that an external dose of it can reset the clock, and thus cause the "go to sleep" signal to be sent at a more convenient moment~ Melatonin can also increase sleepiness during the day, when the pineal gland is not producing it. This has resulted in a growing, and often unregulated, market in melatonin-supplement tablets. The pharmaceutical industry’s response to this seems to be: "If you can’t beat them, join them." A paper in this week’s Lancet, by Shantha Rajaratnam of the Harvard Medical School and his colleagues, reports two trials, funded by drug companies, of tasimelteon, a substance that binds to the same receptors in the brain as melatonin does, and which it is expected will have a similar effect. In the course of these trials, more than 400 people had their bedtimes brought forward by five hours in controlled conditions. Half an hour before lights out, a quarter of them were given common drug, while the remaining three-quarters were given varying doses of tasimelteon. Dr. Rajaratnam and his colleagues report that the new drug let people fall asleep faster at the unnaturally early time, and also allowed them to sleep longer than those given the common one. Going to bed earlier, you may be frustrated by body’s internal biological clock in keeping you ______.
Passage Three Questions 33 to 35 are based on the passage you have just heard.
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