VOA慢速英语2016 一些火山灰能杀灭细菌（在线收听）

Some Volcanic Clays Kill Bacteria 一些火山灰能杀灭细菌

Ancient people knew that some kinds of clay have healing qualities. They rubbed clay on their skin to cover wounds. They also used the natural rock or soil material to treat stomach problems.

古人知道一些泥土有治愈的功效，他们将泥土涂在皮肤上来遮盖伤口，还用天然的石头或土壤来治疗胃病。

Now, American researchers have discovered how different clays work as medicine. They are researching the effectiveness of clays against antibiotic-resistant infections. 

现在，美国的研究人员发现不同种类的泥土能发挥药效的原因，他们研究了泥土治疗耐抗生素感染的效果。

Blue and green clays are found in volcanic areas of the world. Around volcanoes, native peoples used the clays to improve their health. It seems they knew what they were doing. 

世界上火山地区发现有蓝色和绿色的泥土，在火山周围，当地人使用这些泥土来促进健康，他们似乎知道自己在做什么。

Lynda Williams is a clay and mineral scientist. She works at Arizona State University’s School of Earth and Space Exploration in Tempe. She and her research team have been studying the Aboriginal people of Australia.

琳达·威廉姆斯是一名泥土和矿物质科学家，她就职于坦佩亚利桑那州立大学地球和太空探索学院，她和她的研究团队一直在研究澳洲土著。

"There is evidence of Aboriginals using clays for treating wounds and they eat it. Many cultures eat clays to settle their stomach."

“有证据表明土著人拿泥土来治愈伤口，他们还吃泥土，很多文化都有拿泥土来治疗胃病的做法。”

Williams and her team found the clay was effective against some pathogens. Pathogens are bacteria and viruses that cause disease. They examined bacteria that have developed resistance to other antibiotics.

威廉姆斯和她的团队发现这些泥土对一些病原体有疗效，病原体就是导致疾病的细菌和病毒，他们研究了那些对其他抗生素产生抗性的细菌。

In laboratory tests, they saw how a blue-colored clay is effective against the drug-resistant Staphylococcus aureus, known as MRSA. MRSA is a dangerous and sometimes deadly skin infection.

在实验室测试中，他们发现一种蓝色泥土对抗药的金黄色酿脓葡萄球菌(MRSA)有效，MRSA是一种危险的皮肤感染，有时会致命。

The clay was also effective in treating Buruli ulcer, a skin disease found in the Ivory Coast.

这种泥土对治疗布路里溃疡也有效果，这是在科特迪瓦发现的一种皮肤病。

Here is how the blue clay works. Iron is one of the chemicals found in the clay. The bacteria need the iron to survive.

下面就是这种蓝色泥土的工作原因，这种泥土中存在铁等化学元素，这种需要铁来生存。

Some of these same clays also contain aluminum. The minerals work together. Lynda Williams says aluminum lets iron flood into harmful bacteria. The iron oxidizes and then kills the bacteria.

其中一些泥土含有铝元素，这些矿物质一起起作用，琳达·威廉姆斯说铝让铁进入有害细菌内部，然后铁被氧化并杀灭细菌。

"In the end, what we found is that aluminum is attacking the proteins in the cell wall of the bacterium and allowing pores to open so that iron, reduced iron 2, goes into the interior of the bacterium, (and) has reactions with the protein inside. It becomes oxidized and it destroys the biomolecules inside the cell, killing the bacteria."

“最后我们发现铝会破坏细菌细胞壁的蛋白质，并让小孔打开，这样铁就变成二价铁，然后进入细菌的内部，并与里面的蛋白质发生反应，这样就被氧化了，然后就杀死细胞内的分子并杀灭细菌。”

Williams says she hopes the study will interest drug companies that want to explore the healing properties of blue and green clays.  

威廉姆斯称她希望这项研究能让一些探索蓝色和绿色泥土药效的药品公司感兴趣。

The National Science Foundation provided financial support for the study. Williams and her colleagues reported their findings in the journal Nature Scientific Reports.

全国科学基金会向这项研究提供了财政支持，威廉姆斯和同事们在《自然科学》杂志上发表了研究结果。

Words in This Story

pathogen – n. something such as bacteria or a virus that causes disease

oxidize – v. to change (a compound) by increasing the proportion of the electronegative part or change (an element or ion) from a lower to a higher positive valence; remove one or more electrons from (an atom, ion, or molecule)

antibiotic – n. a drug that is used to kill harmful bacteria and to cure infections

pore – n. a small opening, especially in an animal or plant, on by which matter passes through a membrane