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蚕丝的妙用
添加时间:2016-12-31 10:03:09 浏览次数: 作者:未知
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  • KEEPING drugs, and particularly vaccines1, potent3 in tropical climes is a challenge. Heat tends to damage them. Such medicines have therefore to be moved from one refrigerator to another, along what is referred to as a cold chain, until they arrive at the clinics where they are to be administered. Fridges, however, are expensive. They also require electricity, which is not always available-or is available only unreliably-in the poorer parts of the world. As a consequence4, breaks in cold chains are estimated by the World Health Organisation5 to destroy almost half of the vaccines produced around the world.

    由于高温容易导致药效降低,因此,如何在炎热的气候中保持药品(尤其是疫苗)的药效一直是一个难题。为了保证药效,人们不得不沿着一条“低温链”把药品从一个冰箱转移到另一个冰箱,直至送抵相应的诊所。然而,使用冰箱一方面成本太高,另一方面,在一些贫困地区常常没有电力供应。(有些地区虽然有电,但是电力不稳定)。世界卫生组织预计,若低温链断裂,全世界近一半的疫苗都将彻底失效。

    Some vaccines can be freeze-dried, which helps. But even when treated in this way, their lifetime out of the fridge is limited. Ways of keeping drugs and vaccines stable at tropical temperatures would therefore be welcome. And David Kaplan of Tufts University, in Massachusetts, thinks he has found one. Put simply, he and his colleagues have worked out how to pack medicines into tiny silk pouches6, in a manner that makes them almost indifferent to heat.

    一些疫苗能通过冷冻干燥的方式进行保存,但尽管如此,如果没有冰箱,这些疫苗的存活时间也非常有限。因而,人们一直希望能够发明出能在高温天气中保存药物和疫苗的方法。马萨诸塞州塔夫茨大学的David Kaplan认为他已经找到了一个解决办法。简单地来说,David Kaplan和他的同事研究出了一种将药物包裹在蚕丝小袋中的方法,通过这种方法,能将药物与热量几乎完全隔绝开来。

    Dr Kaplan and his team describe their technique in a recent issue of Proceedings7 of the National Academy of Sciences. They start with silkworm cocoons8-the raw material for almost all silk production. They boil the cocoons in a solution of sodium9 carbonate to separate a protein called fibroin, which is the one they want, from another, called sericin, which they do not. They treat the fibroin with salt, then mix it with the substance to be preserved and spread the result out as films, before freeze-drying it. The resulting films consist of a fibroin matrix filled with tiny pockets a few hundred nanometres (billionths of a metre) across. These pockets contain the medicine.

    Kaplan博士和他的小组在最近一期美国《国家科学研究院学报》中介绍了他们的技术方法。他们使用的原料是人们制作几乎任何丝绸产品都要用到的东西——蚕茧。他们们将蚕茧放入煮沸的碳酸钠溶液中加热,从而分离出他们想要的物质——一种称作丝心蛋白的蛋白质,而剩下的丝胶则被去除。他们将丝心蛋白用盐处理后,与需要保存的药物进行混合,之后将混合物平铺成薄膜,最后将其冻干。制作完成的薄膜以丝心蛋白为基质,上面布满了直径只有几百纳米(十亿分之一米)的小袋,而药物就储存在这些小袋里。

    Packaging delicate medicines in this way does, indeed, help preserve them. It immobilises the molecules10, preventing them from unfolding and thus losing their potency11. It also minimises residual12 moisture even better than normal freeze-drying. Dr Kaplan and his team demonstrated the effectiveness of their new technique by trying it out on the MMR (measles, mumps13 and rubella) vaccine2.

    这种新的方法确实能有效的保存那些易变质的药物——由于药物中的分子被固定,无法展开,因而药效就得以保持。同时,和普通的冷冻干燥法相比,这种方法方法也能更有效的减少药物中残存水分。Kaplan博士和他的小组在MMR疫苗(麻疹、腮腺炎和风疹的联合疫苗)上实验了他们的方法,结果证明,该方法十分有效。

    Prolonged storage at just 25°C will cause even the freeze-dried version of MMR to break down. After six months it retains only 60-75% of its potency. If kept for that length of time at 45°C (extreme, but not unknown in the tropics) it is practically worthless. When stored using Dr Kaplan’s silk sheets, however, it was still about 85% potent after six months, regardless of temperature.

    在25℃的环境中,当储存时间过长时,即使已使用冷冻干燥法处理过的MMR疫苗也会分解。在此环境中保存6个月后,疫苗药效降低至原来的60%到75%。将疫苗放在45℃的环境中(该温度并不常见,但在热带地区仍然存在)保存同样的时间后,疫苗已完全失效。然而使用Kaplan的方法进行保存的疫苗在六个月后依然保持了约85%药效,且丝毫不受温度的影响。

    When the researchers tried the same trick with tetracycline, a commonly prescribed antibiotic14, they got similar results. Tetracycline stored at body temperature lost 80% of its potency after four weeks in ordinary solution, but lost none when stored in silk films. The new technique also worked with penicillin15. Moreover, fibroin is harmless to people-silk is, after all, often used in sutures-so there is little risk of adverse16 side-effects. It probably does not matter if some silk gets into a vaccine when it is dissolved in water prior17 to inoculation18.

    研究者们又在人们经常使用的四环素和盘尼西林上进行了同样的实验,结果也不出意料。将四环素保存在普通溶液中并置于体温环境,四个星期后药效已损失80%,但用蚕丝薄膜进行保存的四环素未收任何影响。不仅如此,,由于丝心蛋白对人体不会产生伤害(蚕丝常被用于伤口的缝合),因此不用担心会产生不良的副作用。在接种疫苗时,只需将蚕丝小袋放入水中溶解,即可取出疫苗,即使有少量蚕丝混入疫苗中也不必担心。

    That said, the vaccines and antibiotics19 stored in this new way have yet to be tested on people. That is the next step. But if they work, this new trick will help save lives being needlessly lost in some of the poorest parts of the world.

    虽然用新方法保存的疫苗和抗生素还未在人体中进行过试验(人体试验将是研究者们下一步的计划),但如果药物能够起效,这种新的储存方法将在许多极度贫困的地区发挥巨大作用,减少不必要的死亡。

     11级    英文科普 


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    1 vaccines [vækˈsi:nz] c9bb57973a82c1e95c7cd0f4988a1ded   第8级
    疫苗,痘苗( vaccine的名词复数 )
    参考例句:
    • His team are at the forefront of scientific research into vaccines. 他的小组处于疫苗科研的最前沿。
    • The vaccines were kept cool in refrigerators. 疫苗放在冰箱中冷藏。
    2 vaccine [ˈvæksi:n] Ki1wv   第8级
    n.牛痘苗,疫苗;adj.牛痘的,疫苗的
    参考例句:
    • The polio vaccine has saved millions of lives. 脊髓灰质炎疫苗挽救了数以百万计的生命。
    • She takes a vaccine against influenza every fall. 她每年秋季接种流感疫苗。
    3 potent [ˈpəʊtnt] C1uzk   第7级
    adj.强有力的,有权势的;有效力的
    参考例句:
    • The medicine had a potent effect on your disease. 这药物对你的病疗效很大。
    • We must account of his potent influence. 我们必须考虑他的强有力的影响。
    4 consequence [ˈkɒnsɪkwəns] Jajyr   第8级
    n.结果,后果;推理,推断;重要性
    参考例句:
    • The consequence was that he caught a bad cold. 结果是他得了重感冒。
    • In consequence he lost his place. 结果,他失去了他的位置。
    5 organisation [ˌɔ:gənaɪ'zeɪʃən] organisation   第8级
    n.组织,安排,团体,有机休
    参考例句:
    • The method of his organisation work is worth commending. 他的组织工作的方法值得称道。
    • His application for membership of the organisation was rejected. 他想要加入该组织的申请遭到了拒绝。
    6 pouches [paʊtʃiz] 952990a5cdea03f7970c486d570c7d8e   第10级
    n.(放在衣袋里或连在腰带上的)小袋( pouch的名词复数 );(袋鼠等的)育儿袋;邮袋;(某些动物贮存食物的)颊袋
    参考例句:
    • Pouches are a peculiarity of marsupials. 腹袋是有袋动物的特色。 来自《简明英汉词典》
    • Under my eyes the pouches were heavy. 我眼睛下的眼袋很深。 来自《简明英汉词典》
    7 proceedings [prə'si:diŋz] Wk2zvX   第7级
    n.进程,过程,议程;诉讼(程序);公报
    参考例句:
    • He was released on bail pending committal proceedings. 他交保获释正在候审。
    • to initiate legal proceedings against sb 对某人提起诉讼
    8 cocoons [kəˈku:nz] 5dceb05da0afff0d0dbbf29f10373b59   第11级
    n.茧,蚕茧( cocoon的名词复数 )v.茧,蚕茧( cocoon的第三人称单数 )
    参考例句:
    • The silkworms have gone into the bushes to spin their cocoons. 蚕上山了。 来自《现代汉英综合大词典》
    • In two more days the " little darlings" would spin their cocoons. 再得两天,“宝宝”可以上山。 来自汉英文学 - 春蚕
    9 sodium [ˈsəʊdiəm] Hrpyc   第8级
    n.(化)钠
    参考例句:
    • Out over the town the sodium lights were lit. 在外面,全城的钠光灯都亮了。
    • Common salt is a compound of sodium and chlorine. 食盐是钠和氯的复合物。
    10 molecules ['mɒlɪkju:lz] 187c25e49d45ad10b2f266c1fa7a8d49   第7级
    分子( molecule的名词复数 )
    参考例句:
    • The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
    • Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里,大分子裂变为小分子。
    11 potency [ˈpəʊtnsi] 9Smz8   第11级
    n. 效力,潜能
    参考例句:
    • Alcohol increases the drug's potency. 酒精能增加这种毒品的效力。
    • Sunscreen can lose its potency if left over winter in the bathroom cabinet. 如果把防晒霜在盥洗室的壁橱里放一个冬天,就有可能失效。
    12 residual [rɪˈzɪdjuəl] SWcxl   第9级
    adj.复播复映追加时间;存留下来的,剩余的
    参考例句:
    • There are still a few residual problems with the computer program. 电脑程序还有一些残留问题。
    • The resulting residual chromatism is known as secondary spectrum. 所得到的剩余色差叫做二次光谱。
    13 mumps [mʌmps] 6n4zbS   第10级
    n.腮腺炎
    参考例句:
    • Sarah got mumps from her brother. 萨拉的弟弟患腮腺炎,传染给她了。
    • I was told not go near Charles. He is sickening for mumps. 别人告诉我不要走近查尔斯,他染上了流行性腮腺炎。
    14 antibiotic [ˌæntibaɪˈɒtɪk] KNJzd   第8级
    adj.抗菌的;n.抗生素
    参考例句:
    • The doctor said that I should take some antibiotic. 医生说我应该服些用抗生素。
    • Antibiotic can be used against infection. 抗菌素可以用来防止感染。
    15 penicillin [ˌpenɪˈsɪlɪn] sMXxv   第8级
    n.青霉素,盘尼西林
    参考例句:
    • I should have asked him for a shot of penicillin. 我应当让他给我打一针青霉素的。
    • Penicillin was an extremely significant medical discovery. 青霉素是极其重要的医学发现。
    16 adverse [ˈædvɜ:s] 5xBzs   第7级
    adj.不利的;有害的;敌对的,不友好的
    参考例句:
    • He is adverse to going abroad. 他反对出国。
    • The improper use of medicine could lead to severe adverse reactions. 用药不当会产生严重的不良反应。
    17 prior [ˈpraɪə(r)] kQGxA   第7级
    adj.更重要的,较早的,在先的;adv.居先;n.小修道院院长;大修道院副院长
    参考例句:
    • The duty to protect my sister is prior to all others. 保护我的妹妹是我最重要的责任。
    • I took up one-year prior course in German in this college. 我在这所大学读了一年的德语预科。
    18 inoculation [ɪˌnɒkjʊ'leɪʃn] vxvyj   第11级
    n.接芽;预防接种
    参考例句:
    • Travellers are reminded that inoculation against yellow fever is advisable. 提醒旅游者接种预防黄热病的疫苗是明智的。 来自《简明英汉词典》
    • Travelers are reminded that inoculation against yellow fever is advisable. 旅客们被提醒,注射黄热病预防针是明智的。 来自辞典例句
    19 antibiotics [ˌæntɪbaɪ'ɒtɪks] LzgzQT   第8级
    n.(用作复数)抗生素;(用作单数)抗生物质的研究;抗生素,抗菌素( antibiotic的名词复数 )
    参考例句:
    • the discovery of antibiotics in the 20th century 20世纪抗生素的发现
    • The doctor gave me a prescription for antibiotics. 医生给我开了抗生素。

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