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CSIs Could Estimate Victim's Age with Just Blood

CSI：僅用血跡估測(cè)受害者年齡

You’ve seen it on TV. Crime scene investigators show up at what might be a murder scene. There are blood spatters—but no body. Who’s the victim? Now, a new technique developed in the Netherlands might help real-world investigators establish the age of the victim using only blood. The research was published in the journal Current Biology.

你一定在電視上看到過(guò)這樣的畫(huà)面：在兇案現(xiàn)場(chǎng)總會(huì)出現(xiàn)犯罪現(xiàn)場(chǎng)調(diào)查員的身影?，F(xiàn)場(chǎng)四處血污，但是并無(wú)尸體。那么到底誰(shuí)是受害者呢？如今，根據(jù)《當(dāng)代生物學(xué)》刊登的研究結(jié)果，一項(xiàng)在荷蘭研究而成的新技術(shù)或許可以幫助現(xiàn)實(shí)世界的調(diào)查人員利用血跡來(lái)確定受害者的年齡。

Usually, age is determined by physical characteristics, such as teeth or bones. Great—if you have a body. Researchers have tried unsuccessfully to use blood. But in this study, the scientists used immune cells called T-cells. T-cells recognize invaders through receptors that match molecules on bacteria, viruses, even tumors. The cellular activity that produces these receptors also produces a type of circular DNA molecule as a by-product.

通常情況下，年齡是通過(guò)人的身體外表特征，如牙齒或骨骼，來(lái)測(cè)定的。這當(dāng)然再好不過(guò)了——只要你尸骨仍存。研究人員一直嘗試?yán)醚簻y(cè)定年齡，但未曾成功。不過(guò)在這項(xiàng)研究中，科學(xué)家們利用了一種被稱(chēng)為T(mén)細(xì)胞的免疫細(xì)胞。T細(xì)胞通過(guò)受體來(lái)識(shí)別外來(lái)入侵物，這些受體會(huì)抵御細(xì)菌、病毒、甚至是腫瘤分子。而產(chǎn)生這些受體的細(xì)胞活性也會(huì)制造副產(chǎn)品——一種環(huán)狀DNA分子。

The number of these receptor by-products declines regularly over time. So scientists devised a test to measure the molecules—and use that to infer someone’s age based on his or her blood. The results appear to be accurate to within plus or minus nine years. So forensic scientists could use a bloodstain to narrow a victim’s age to within two decades. That’s a big range—but it could help solve crimes when the victims can’t be found.

隨著時(shí)間的推移，這些受體副產(chǎn)品的數(shù)量會(huì)逐漸下降。據(jù)此，科學(xué)家們?cè)O(shè)計(jì)了一種測(cè)試方法來(lái)檢測(cè)分子，并利用它以某人的血液來(lái)推斷其年齡，測(cè)定結(jié)果能精確到上下9年內(nèi)。這樣，法醫(yī)可以利用血跡是受害者的年齡范圍縮小到20年以?xún)?nèi)。這個(gè)范圍很大——但在受害者失蹤的情況下會(huì)有利于破案。

—Cynthia Graber

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