A photomultiplier can amplify the signal to detectable levels 光电倍增管可将此讯号放大到可侦测的程度。
In the families of babies who had detectable levels of nnal , family members reported smoking an average of 76 cigarettes per week 研究显示,在那些尿液样本中含有nnal的婴儿的家庭中,家庭成员平均每周吸烟76支。
For babies who had no detectable levels of nnal in their urine , the average number of cigarettes reportedly smoked by family members was 27 per week 而那些尿液样本中未发现nnal的婴儿的家庭中,家庭成员平均每周吸烟27支。
Urine from nearly half of the infants contained detectable levels of nnal , a chemical byproduct produced in the human body when it processes nnk , a cancer - causing chemical , or carcinogen , found only in tobacco 在他们生活的家庭环境中,父母至少有一人是烟民。研究人员在将近一半的尿液样本中发现了相当水平的nnal 。