科技英語五單元

1、五單元Efforts to combat aging and extend human life date at least as far back as 3500 B.C.,and self-proclaimed experts have touted anti-aging elixirs ever since. Indeed, the prospect of immortality has always had universal appeal, spurring Alexander the Great and Ponce de León to search for the le

2、gendary Fountain of Youth and feeding alchemists' desire to manufacture gold (once believed to be the most potent anti-aging substance in existence). But the hawking of anti-aging “therapies” has taken a particularly troubling turn of late. Disturbingly large numbers of entrepreneurs are luring

3、gullible and frequently desperate customers of all ages to “l(fā)ongevity” clinics, claiming a scientific basis for the anti-aging products they recommend and, often, sell. At the same time, the Internet has enabled those who seek lucre from supposed anti-aging products to new customers with ease. 努力與衰老

4、作斗爭并延長人類的壽命至少可以追溯到公元前3500年前，從那時起那些自詡的專家就一直兜售抗衰老長生不老藥，的確，長生不老一直對人們具有普遍的吸引力，促使亞歷山大大帝和龐塞·德·里昂尋找傳說中的“青春之泉”，并滿足煉金術士們制造黃金的欲望（人們一度認為它是目前最有效的抗衰老物質(zhì)）。但是抗衰老的兜售方式的轉變令人擔憂。令人不安的是，大量的企業(yè)家都在引誘各個年齡層的易受騙和常常是絕望的顧客去“長壽”診所，聲稱他們所推薦的抗衰老產(chǎn)品有科學的依據(jù)，并常常把產(chǎn)品賣給他們。與此同時，互聯(lián)網(wǎng)使那些從所謂的抗衰老產(chǎn)品中尋找利潤的人可以輕松地接觸到新客戶。推薦精選Alarmed by thes

5、e trends, scientists who study aging have issued a position statement containing this warning: no currently marketed intervention nonehas yet been proved to slow, stop or reverse human aging, and some can be downright dangerous. 研究老化問題的科學家對這些趨勢感到震驚，他們發(fā)表了一份立場聲明，其中包含了這樣的警告：目前還沒有市場上的干預措施能夠減緩、阻止或逆轉人類的衰老

6、，其中一些措施可能是非常危險的。Any discussion of aging should first clarify its terms. Various definitions have been proposed, but we think of aging as the accumulation of random damage to the building blocks of lifeespecially to DNA, certain proteins, carbohydrates and lipids (fats)that begins life early in life

7、and eventually exceeds the body's self-repair capabilities. This damage gradually impairs the functioning of cells, tissues, organs and organ systems, thereby vulnerability to disease and giving rise to the characteristic manifestations of aging, such as a loss of muscle and bone mass, a decline

8、 in reaction time, compromised hearing and vision, and reduced elasticity of skin. 推薦精選任何關于衰老的討論都應該首先澄清它的術語。人們提出了各種不同的定義，但我們認為衰老是對生命構成要素的隨機損傷的積累特別是對DNA、某些蛋白質(zhì)、碳水化合物和脂類（脂肪）-這種損傷開始于生命早期，最終超過了身體的自我修復能力。這種損害逐漸損害細胞、組織、器官和器官系統(tǒng)的功能，從而易患病，并導致衰老的典型表現(xiàn)，如肌肉萎縮和骨量疏松，反應時間下降，聽力和視力受損，皮膚彈性降低。Aging, in our view, makes u

9、s ever more susceptible to such ills as heart disease, Alzheimer's disease, stroke and cancer, but these age-related conditions are superimposed on aging, not equivalent to it. Therefore, even if science could eliminate today's leading killers of older individuals, aging would continue to oc

10、cur, ensuring that different maladies would take their place. In addition, it would guarantee that one crucial body component or anothersay, the cardiovascular systemwould eventually experience a catastrophic failure. It is an inescapable biological reality that once the engine of life switches on,

11、the body inevitably sows the seeds of its own destruction.推薦精選在我們看來，衰老使我們更易得心臟病、阿爾茨海默病、中風和癌癥等疾病，但這些與年齡相關的疾病是衰老帶來的附加物，并不等同于衰老。因此，即使科學能夠消滅當今導致老年人死亡的主要殺手，衰老也會繼續(xù)發(fā)生，會讓不同的疾病取代他們。此外，衰老也會讓人體的某個或幾個重要的組成部分-比如心血管系統(tǒng)，最終會經(jīng)歷一場災難性的失敗。這是一個不可避免的生物現(xiàn)實，一旦生命的引擎啟動，身體就不可避免地播下自我毀滅的種子。Men and women in the developed world typ

12、ically live longer now (75 and 80 years, respectively) than they did throughout much of history (about 25 years) because human ingenuitywhich brought us sanitation systems, vaccines, antibiotics and so onhas had phenomenal success in thwarting the infectious and parasitic diseases responsible for a

13、great deal of premature death. We live longer now not because we have altered the way we age but because we have altered the way we live. 發(fā)達國家的男性和女性通常比他們在整個歷史（大約25年）中活得更久（分別為75歲和80歲），因為人類的智慧，衛(wèi)生系統(tǒng)、疫苗、抗生素等為我們帶來了非凡的成功，阻止了傳染病和寄生蟲引起的疾病帶來的大量的早逝。我們現(xiàn)在的壽命更長，不是因為改變了衰老的方式，而是因為我們改變了我們的生活方式。 Though inevitable, a

14、ging is not, as some might think, a genetically programmed process, playing itself out on a rigidly predetermined time schedule. The way evolution works makes it impossible for us to possess genes that are specifically designed to cause physiological decline with age or to control how long we live.

15、Just as an automobile does not have a built-in plan for decline written in its blueprints, we do not possess genetic intructions that tell our bodies how to age or when to die. 推薦精選雖然衰老是不可避免的，但衰老并不是一些人所認為的那樣，一個基因編程的過程，而是按照預定的時間表執(zhí)行的。進化的方式使得我們不可能擁有特定設計的基因，這些基因會隨著年齡的增長而引起生理上的衰退，或者控制我們的壽命。就像汽車藍圖中沒有內(nèi)置的衰退

16、計劃一樣，我們也沒有基因指令告訴我們的身體如何衰老或何時死亡。Without a doubt, a host of our genes influence aging, but they do so indirectly, as an inadvertent by-product of processes involved in growth, development, and the maintenance of health and vigor. The lack of a specific genetic program for aging and death means that th

17、ere are no quick fixes that will permit us to treat aging as if it were a disease. A single genetic intervention in an organism as complex as a human being would have little chance of combating the probably vast array of genes and biological activities that play subtle, unpredictable part in the tim

18、ing of our ultimate demise. 推薦精選毫無疑問，我們的很多基因都會影響衰老，但它們是間接的，是生長、發(fā)育、保持健康和活力過程中的副產(chǎn)品。缺乏針對衰老和死亡的特定基因計劃意味著，我們沒有快速的解決辦法，可以把衰老當作一種疾病來對待。對一個像人類這樣復雜的有機體進行單一的基因干預，就幾乎沒有機會與在我們最終滅亡的時間安排中扮演微妙、不可預測角色的大量基因和生物活動作斗爭。On what grounds do we assert so vehemently that no purpoted anti-aging intervention has been proved to

19、 modify aging? To assess whether an intervention has affected a biological process, researchers need a yardstick for measuring that process.In this case, no single or aggregate age-related phenomenon has proved to be a reliable indicator of the rate of aging in humans or other species. Without a yar

20、dstick, there can be no assurance that an intervention was successful. 基于什么樣的理由，我們?nèi)绱藦娏业財嘌裕瑳]有任何有針對性的抗衰老干預已被證明是修改老化？為了評估干預是否影響了生物過程，研究人員需要一個衡量該過程的標準。在這種情況下，事實證明，沒有任何單一或總體與年齡有關的現(xiàn)象是人類或其他物種老化速度的可靠指標。沒有標準，就不能測量，沒有測量，就不能保證干預是成功的。推薦精選Some people might wonder whether following today's public health recom

21、mendations for diet and exercise can serve as a more natural Fountain of Youth. Good nutrition and regular exercise do reduce the risk of various diseases and, in that way, may extend the duration of life for many peoplethereby serving as the best current prescription for a long and healthy life. As

22、 is true of other interventions, though, no one has shown that diet or exercise, or both, directly influences aging. 一些人可能想知道，按照今天的公共衛(wèi)生建議，節(jié)食和鍛煉是否可以成為一個更自然的青春源泉。良好的營養(yǎng)和有規(guī)律的鍛煉確實可以降低患各種疾病的風險，這樣，許多人的壽命可能會延長，從而成為目前長壽和健康生活的最佳處方。然而，正如其他干預措施也是一樣，沒有人表明飲食或鍛煉，或兩者都直接影響著衰老。Another avenue of research may also lead

23、 to true aging interventions. Investigators have known for decades that caloric restriction extends life and the duration of good health in all species it has been studied, as long as the diet includes enough nutrition for routine maintenance of the body. These findings suggest that caloric restrici

24、ton might have similar effects in humans. Given that few people would ever reduce their food intake enough to lengthen their lives, biologists are now trying to discover the mechanism that underlies the benefits of caloric restriction and to find agents that might mimic those helpful effects in peop

25、le without forcing them to go hungry. 推薦精選另一個研究途徑也可能導致真正的老齡化干預。幾十年來，研究人員已經(jīng)知道，只要飲食中含有足夠的營養(yǎng)以維持身體的正常運轉，熱量限制就能延長所有被研究物種的壽命和健康時間。這些發(fā)現(xiàn)表明，熱量限制子可能對人類有類似的影響?？紤]到很少有人會減少食物攝入量，從而延長壽命，生物學家現(xiàn)在正在試圖發(fā)現(xiàn)熱量限制的好處背后的機制，并尋找可以模仿這些有益效果的物質(zhì)，而不會迫使他們挨餓。A number of scientists look at current research trends and feel helpful. They

26、 can envision a time when treatments based on an understanding of aging can help slow its progression and when not yet specialized (stem) cells can be coaxed to repair and rejuvenate damaged tissues, enabling people to remain vigorous longer than they would without medical assistance. Not all resear

27、chers share that optimism, though. Some assert that aging's complexity will forever militate against the development of anti-aging therapies. 推薦精選許多科學家看到當前的研究趨勢并感到有幫助。他們可以設想這樣一個時代：基于對衰老的理解的治療能夠幫助延緩衰老的進程，那時人們可以誘導尚未分化的干細胞修復和恢復受損的組織，使人們比沒有醫(yī)療援助時可以更長時間的保持旺盛的活力，不過，并非所有研究者都持這種樂觀態(tài)度。一些人斷言，老化的復雜性將永遠不利于抗衰老療法的發(fā)展。One thing is indisputable: the number of elderly people is growing wo