听力文本

This is Scientific American's 60-second Science, I'm Christopher Intagliata.
Of all the stuff you can buy on eBay — here's a new one: human teeth. "I think I probably averaged maybe $5 a tooth." Kelly Keenan, a biochemist at Stockton University in New Jersey. Keenan chased down the chompers to investigate what whitening strips do to a tooth's chemical composition. So she stuck the teeth in styrofoam, applied the whitening strips per manufacturer instructions, and added some artificial saliva: a liquid mixture at the pH and with salts you'd find in regular spit.
Treatments complete, she extracted proteins from the teeth. And found that the more rounds of whitening the teeth experienced, the fewer proteins she could recover — because hydrogen peroxide in the whitening strips was snipping chemical bonds. "The bigger picture is that hydrogen peroxide can penetrate the enamel and dentin and it can cause your proteins to break down. And smaller pieces are removed from those proteins."

She and her undergraduate students presented on that research at the 2019 Experimental Biology meeting in Orlando. Now this is just a preliminary study. And the pulp of your teeth can replenish proteins in the dentin, though not the enamel — so it's unclear whether these effects would cause permanent damage in real, living teeth. One thing's for sure: supplies of teeth for experiments seem to be plentiful.
I think I bought a set of 15. And the person's like, let me know if you need more. This person also claimed the teeth were from his mouth, which, you don't have that many more to go!
Thanks for listening for Scientific American — 60-Second Science. I'm Christopher Intagliata.

参考译文

这里是科学美国人——60秒科学系列，我是克里斯托弗·因塔格里塔,q);U-vQhsU[[at,。
在eBay上能买到的所有东西中，有一件是新的：人类牙齿zwiypSRIjq1nS。“我平均一颗牙大概花了5美元m,CkTxPpP,1G(a)*。”新泽西州斯托克顿大学的生物化学家凯利·基南说到pjUXItu7NV8[tUd。基南追踪这些牙齿，以研究美白牙贴会对牙齿的化学成分产生何种影响dx3K3sg2sW)DL。她将牙齿粘在泡沫塑料上，按照制造商的说明在牙齿上贴美白贴片，再加上一些人工唾液——含pH值的液体混合物再加上你在普通唾液中可以找到的盐分=]|QOE..LMUTD5tQx。
处理完成后，她从牙齿中提取了蛋白质5z87!n9a1;NLUJD。她发现，牙齿美白的次数越多，能恢复的蛋白质就越少——因为美白牙贴中的过氧化氢会切断化学键f8bf8X!!wl&Z]jm=T。“更重要的是，过氧化氢能穿透牙釉质和牙本质，导致蛋白质分解3BSaLS9fj@YWz-。而较小的片段会从这些蛋白质中移除K0_n]TTcGz5ZV.y63[。”
她和她的本科生在2019年奥兰多实验生物学会议上展示了这项研究dBwlRP5wsErd5A6ssZ。目前这只是初步研究ElBJ2dIAiL。牙齿的牙髓可以补充牙本质中的蛋白质，但不能补充牙釉质，因此目前尚不清楚这些影响是否会对活牙造成永久损伤|Y!s1z,6^rJcF。不过有一件事是确定的：实验用的牙齿似乎很充足NL||q,AMA.NNI4&a。
“我买了一套15颗牙#(bb)La-wCEJ,。而且卖家还表示，如果你需要更多，再联系我dJ60[4KCEK7。卖家还称他卖的这些牙都是他自已的，那他可没多少牙了啊！”
谢谢大家收听科学美国人——60秒科学00+jDW9P(,。我是克里斯托弗·因塔利亚塔.+MCxcAGq.Lz。

译文为可可英语翻译，未经授权请勿转载！

重点讲解

重点讲解：
1. chase down (搜寻后)找到，找出；
That's when I chased her down to be the singer in my band.
就是那时候，我找到了她，让她在我的乐队里担任歌手P1s0LygUIa-2&3QV2&U。
2. break down （使）（物质）分解；
Over time, the protein in the eggshell breaks down into its constituent amino acids.
时间久了，蛋壳中的蛋白质就会分解为其构成成分氨基酸zcrMM*_MzsC5t%d-iuO!。
3. for sure 无疑；肯定；
We cannot say for sure what will happen.
我们无法确定会发生什么事J@rMz3NmXHW[)oD。
4. a set of 一套；一组；一系列；
He gave me a set of beautiful china.
他送给我一套漂亮的瓷器h6cJIh+sv*LZCsk2b。