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CSIs Could Estimate Victim's Age with Just Blood

CSI：僅用血跡估測受害者年齡

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這樣的畫面：在兇案現(xiàn)場總會出現(xiàn)犯罪現(xiàn)場調(diào)查員的身影?，F(xiàn)場四處血污，但是并無尸體。那么到底誰是受害者呢？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，年齡是通過人的身體外表特征，如牙齒或骨骼，來測定的。這當(dāng)然再好不過了——只要你尸骨仍存。研究人員一直嘗試?yán)醚簻y定年齡，但未曾成功。不過在這項(xiàng)研究中，科學(xué)家們利用了一種被稱為T細(xì)胞的免疫細(xì)胞。T細(xì)胞通過受體來識別外來入侵物，這些受體會抵御細(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.

隨著時間的推移，這些受體副產(chǎn)品的數(shù)量會逐漸下降。據(jù)此，科學(xué)家們設(shè)計(jì)了一種測試方法來檢測分子，并利用它以某人的血液來推斷其年齡，測定結(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年以內(nèi)。這個范圍很大——但在受害者失蹤的情況下會有利于破案。

—Cynthia Graber

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