首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
SURVIVING IN SPACE Motion sickness troubles more than two-thirds of all astronauts upon reaching orbit, even veteran test pi
SURVIVING IN SPACE Motion sickness troubles more than two-thirds of all astronauts upon reaching orbit, even veteran test pi
admin
2010-09-10
47
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."
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:https://kaotiyun.com/show/v887777K
0
大学英语四级
相关试题推荐
Forthispart,youareallowed30minutestowriteacompositiononthetopic:OnlineShoppingaccordingtothefollowingoutlin
ThegirlsinthissixthgradeclassinEastPaloAlto,California,allhavethesameaccesstocomputersasboys.Butresearcher
Scientistshavelearnedmoreaboutthewaycancerspreadsfromoneplaceinthebodytoanother.Onceitspreads,itgetsmored
Treesarecityplanners’firstlineofdefenseinthe【S1】______againsttheurbanheat-islandeffect,saidDaleQuattrochi,ag
Youshouldwriteatleast120wordsfollowingtheoutlinegivenbelow:1.大学生使用手机增多及其原因2.大学生使用手机所带来的问题3.你自己的观点
A、Becausetheyhadcaughtseriousdisease.B、Becausetheyhadbeenawayfromhomeformanyyears.C、Becauseitwassaidtheyhad
WhenforeignersaresometimesaskedwhatseemsmoststrangeaboutAmericansociety,somewhereonthetopofthelistwillbethe
Forthispart,youareallowed30minutestowriteacompositiononthetopicCollegeEnglishTeachinginChinaaccordingtothe
Hereisapopularbeliefamongparentsthatschoolsarenolongerinterestedinspelling.Thisis,however,a【S1】______.Noscho
A、Theywatchedtheendoftherace.B、Onlythreeofthemdidn’tfinishtherace.C、Mostofthemdidn’tnmintherace.D、Theypa
随机试题
多发伤中可迅速致死又可迅速逆转的3种情况是__________、__________和__________。
G2/M检测点的核心是
A、抑制肠内细菌生长,促进乳酸杆菌繁殖B、与游离氨结合,从而降低血氨C、与氨合成尿素和鸟氨酸,从而降低血氨D、被细菌分解成乳酸和乙酸,降低肠道的pH值E、纠正氨基酸代谢不平衡,抑制假神经递质形成支链氨基酸治疗肝性脑病的机制是()
王某委托甲房地产经纪公司(以下简称甲公司)为其购买一套二手房,并约定佣金为房价款的4%。甲公司委派房地产经纪人张某承办该业务。张某给王某介绍了一套业主李某的房屋,王某在张某带领下查验房屋后同意购买。随后,王某、张某、李某共同商谈成交手续事宜。王某、李某
下列各项中,不应计入管理费用的是()。
根据《行政处罚法》的规定,()。
企业将自产的应税矿产品对外销售,按规定应交纳的资源税计入相关资产成本。()
2010年,张明因盖房挖地基,发现一个坛子,内有500块银元及一张棉布,上写“为防日寇搜查,特埋此,王建林1938年7月1日”。王建林为王天民的爷爷,在抗战期间被日寇杀害,新中国成立后王天民被宣布为中农。这500块银元()。
已定义ch为字符型变量,以下赋值语句中错误的是
有以下程序,程序运行后的输出结果是main(){intm=12,n=34;printf("%d%d",m++,++n);printf("%d%d\n",n++,++m);}
最新回复
(
0
)