首页
登录
职称英语
SURVIVING IN SPACE Motion sickness troubles more than
SURVIVING IN SPACE Motion sickness troubles more than
游客
2024-02-23
26
管理
问题
SURVIVING IN SPACE
Motion sickness troubles more than two-thirds of all astronauts upon reaching orbit, even veteran test pilots who have never been airsick. Though everyone recovers after a few days in space, body systems continue to change. Deprived(丧失) of gravity information, a confused brain creates visual illusions. Body fluids surge to chest and head. The heart enlarges slightly, as do other organs. Sensing too much fluid, the body begins to discharge it, including calcium, electrolytes (解液) and blood plasma (血浆). The production of red blood ceils decreases, rendering astronauts slightly anaemic (贫血的). With the loss of fluid, legs shrink. Spinal (脊骨的) discs expand, and so does the astronaut--who may gain five centimeters and suffer backache. Though the .process may sound terrible, astronauts adjust to k, come to enjoy it and seem no worse for wear-at least for short missions such as space shuttle flights that last a week or two.
During longer flights, however, physiology enters an unknown realm. As director of Russia’s Institute for Biomedical Problems from 1968 to 1988, Oleg Gazenko watched cosmonauts return from long flights unable to stand without fainting, needing to be carried from the spacecraft. "We are creatures of the Earth,” Gazenko told me. "These changes are the price of a ticket to space".
Americans returning from months-long flights on Mir, the Russian space station, also paid the price, suffering losses in weight, muscle mass and bone density. NASA geared up to see how--even if--humans would survive the most demanding of space ventures, a mission to Mars, which could last up to three years. "We don’t even know if a broken bone will heal in space," said Daniel Goldin, NASA’s administrator. To get answers in 1997 Goldin established the National Space Biomedical Research Institute (NSBRI), a panel of experts from a dozen leading universities and research institute. NSBRI will study biomedical problems and by 2010 will present NASA with a "go" or "no go" recommendation on a Mars mission.
Jeffrey Sutton, leader of the medical systems team at the NSBRI, has treated the head trauma, wounds, kidney stones and heart rhythm irregularities that one could encounter on the way to Mars. On the spacecraft he envisions, Mars-hound in the year, say, 2018, there may lurk harmful bacteria or carbon monoxide. No problem. The deadly substances will be detected by smart sensors-microprocessors no bigger than a thumbnail--that wander at will through the spacecraft, communicating their finds to a computer that warns the crew.
To cope with infection, Sutton plans a factory to make drugs, even new ones, to cope with possible organisms on Mars. Miniature optical and ultrasound devices will image body and brain, while a small X-ray machine keeps track of any bone loss. Smart sensors embedded in clothing will monitor an astronaut’s vital functions. The crew will be able to craft body parts, Sutton says, precisely tooled to an astronaut’s personal anatomy and genome stored in computer memory. Researchers are building artificial liver, bone and cartilage (软骨) tissue right now.
Lying in wait beyond the Earth’s atmosphere, solar radiation poses additional problems. The sun flings billions of tons of electrically charged gas into space, relegating Earth’s volcanic eruptions to mere hiccups. Nevertheless, NASA officials are confident the accurate monitoring will warn astronauts of such events, allowing the crew to take refuge in an area where polyethylene (乙烯) shielding will absorb the radiation.
A second kind of radiation, cosmic rays from the Milky Way or other galaxies, is a more serious threat--possessing too much energy, too much speed for shielding to be effective. "There’s no way you can avoid them," says Francis Cxueinotta, manager of NASA’s Johnson Space Centre. "They pass through tissue, striking ceils and leaving them unstable, mutilated or dead. Understanding their biological effects is a priority."
Another major concern is the psychological health of astronauts. And there’s a new stressor on a three-year Mars Mission-people, other members of the crew. NASA found that the stresses of isolation and confinement can be brought on rapidly simply by giving people few tasks. Mir astronaut Andrew Thomas described how six astronauts were confined in a 12-foot square room for a week. "If you give them little to do, stress can be achieved in a couple of days, says Thomas.
Will NSBRI meet Daniel Goldin’s 2010 deadline for a decision on Mars? "Yes, we will perhaps even before. We’re very confident," says Laurence Young, the director of NABRI. Mean while some of NSBRI’s research may bear fruit on Earth. The institute has made one discovery that promises to save many people at risk of sudden cardiac death, usually brought on by a heart rhythm disorder called ventricular fibrillation. This kills 225,000 people in the US each year.
Richard Cohen, head of the NSBR1 cardiovascular (心血管的) team, explained that zero gravity may-emphasizing "may"--incite this condition in astronauts. So the team invented a noninvasive diagnostic device that measures extremely tiny changes in heart rhythm. The team found that the device can be used as part of a standard stress test to identify patients at risk. Then pacemaker-like devices can be implanted to regulate the rhythm disorder. "This technology has the potential to save hundreds of thousands of lives," says Cohen. "NASA can be proud."
Such discoveries are no accident, says Michael E. DeBakey, a cardiovascular surgeon who has saved many hearts himself. "The key word is research. When I was a medical student and a patient came to the hospital with a heart attack, things were mostly a matter of chance. Today there’s a better than 95 per cent chance of surviving. Now that all comes from research. The unfortunate thing is that there are people, even some scientists, who look at the money that goes to NASA and we could use the money to support our work. That’s very short sighted. The more research that’s done in any area of science, the better off everyone is going to be." [br] Astronauts are likely to increase in height while in space.
选项
A、Y
B、N
C、NG
答案
A
解析
第一段中提到so does the astronaut—who may gain five centimeters,说明宇航员有可能增加身高, may对应着题干中的likely to,gain five centimeters则是increase in height的具体表现。
转载请注明原文地址:http://tihaiku.com/zcyy/3476314.html
相关试题推荐
[originaltext]M:Right,Iguessyou’vegotsomeideasforourproductpromotion
Ifcouplescanlearnhowtoprovideemotionalsupportbeforetheymarry,______(他
Thedancersstandmotionlessattheirpositionandtheroomgrowssilent.B
Thedancersstandmotionlessattheirpositionandtheroomgrowssilent.B
SurvivingInSpaceMotionsicknessafflictsmoret
SurvivingInSpaceMotionsicknessafflictsmoret
SurvivingInSpaceMotionsicknessafflictsmoret
SurvivingInSpaceMotionsicknessafflictsmoret
SurvivingInSpaceMotionsicknessafflictsmoret
SurvivingInSpaceMotionsicknessafflictsmoret
随机试题
[originaltext]M:YouareawardedtheCNNHerooftheYear,Ms.Liz.Congratulat
[originaltext]M:Amy,areyouinterestedinjoiningusforthepartythisweeke
应急组织机构包括()。A.灭火行动组 B.火场指挥组 C.通信联络组 D
拜占庭建筑的教堂格局大致有三种,下列( )除外。A.巴西利卡式 B.集中式
在电子支付工具中,具有透支功能的支付工具是( )。A.信用卡 B.电子支票
糖皮质激素诱发和加重感染的主要原因()。A.用量不足,无法控制症状 B.抑制
当Excel中图表的数据源发生变化时,下列关于图表变化的描述,正确的是()。A.
在历史文化名城核心保护范围内除新建、扩建()以外,不得进行其他新建、扩建活动
某进出口公司为首次注册登记企业,海关对其按A类企业实施企业管理.( )(200
银行承兑汇票的承兑银行,应当按照票面金额向出票人收取()的手续费。A:千分之一
最新回复
(
0
)