VOA常速英语2014--Promising Mosquito Repellent Announced 美科学家研发新一代驱蚊剂（在线收听）

Promising Mosquito Repellent Announced 美科学家研发新一代驱蚊剂

In many regions of the world, mosquitoes are a seasonal pest. In other regions, they carry serious diseases like malaria. The World Health Organization estimates that almost 630,000 people died of malaria-related causes in 2012, mostly in Sub-Saharan Africa. Now, a group of U.S.-based scientists is working to develop a more effective and less expensive mosquito repellent than currently in use.

在世界上很多地区，蚊子是季节性害虫，在一些地区，蚊子甚至是疟疾等严重疾病的传播者。据世界卫生组织估计，2012年将近63万人死于疟疾，其中大多数在撒哈拉以南的非洲地区。现在美国的科学家小组正在研发一种更有效、价格低于目前同类产品的驱蚊剂。

The research, at the University of California Riverside, is based on the fact that mosquitoes use the same receptor for detecting carbon dioxide in our breath as they do for the odor from our skin when they come closer.

蚊子在靠近我们的时候，利用同一个受体来探测我们呼吸中的二氧化碳和我们皮肤上的气味。加州大学河滨分校的科学家根据这个发现展开研究。

The lead investigator, Anandasankar Ray, says scientists tested more than a million chemical compounds until they found a substance called Ethyl pyruvate that shuts down the mosquitoes’ receptor.

首席研究员安南达桑卡尔·雷说，科学家测试了100多万种化合物，发现一种叫做丙酮酸乙酯的化合物可以抑制蚊子的受体。

“When we apply Ethyl pyruvate to a human arm and offer it to hungry mosquitoes in a cage, then very few of the mosquitoes are attracted to the human arm because only a few of them are able to smell it out," said Ray.

雷说：“我们把丙酮酸乙酯涂在人的手臂上，把手臂伸进关着饥饿蚊子的笼子里，几乎没有蚊子对手臂感兴趣，因为只有极少数能闻出气味。”

Genevieve Tauxe, also on the team, says finding the mosquito neurons that detect both our breath and skin odor was not easy.

吉娜维夫·托克斯也是研究小组成员。她说，发现蚊子探测我们呼吸和皮肤气味的神经元不是一件容易的事。

“With this apparatus, we are able to insert a very small electrode into the part of the mosquito's nose, effectively, where its olfactory neurons are and where the smell is happening," said Tauxe.

托克斯说：“利用这种仪器，我们可以把一个非常小的电极准确地放进蚊子的鼻腔里，那里有蚊子嗅觉神经元。”

With these instruments, scientists were able to detect the signals that a mosquito’s neurons send to its brain when it senses attractive odors. Spikes on the computer screen show when the attraction is strong or weak.

有了这些仪器，科学家们可以探测到蚊子闻到喜欢的气体时，神经元向大脑输送的信息，电脑上的峰波显示气体吸引力的强弱。

Ray says a repellent based on Ethyl pyruvate may be cheaper to manufacture than DEET, the most effective chemical now in use. He says it's too expensive for most people in malaria-affected areas.

雷说，以丙酮酸乙酯为主的驱蚊剂生产成本低于目前最有效的化学剂DEET。他说，对生活在有疟疾疫情地区的大多数人来说，DEET太贵了。

"Perhaps by finding designer odors, better odors that can attack other target receptors, we will be able to improve upon DEET and finally have the next generation of insect behavior control product," he said.

他说：“找到可以攻击其他受体的气味，我们也许可以改善DEET。”

The University of California scientists say they believe they will soon be able to find a way to manufacture cheaper and more effective repellents for the fight against mosquitoes.

加州大学的科学家说，他们相信，他们很快就会找到方法来生产价格低、效力高的驱蚊剂。