"What you've got here is a legal issue and a political issue and both of those are very much in play at the present time,".

VOA: standard.2010.01.30

The danger is that it's being purified from patients that have a disease and so you want to make sure that there's not other diseases that are present in that sample at the same time.

危险在于,这是从带有疾病的病人,身上纯化出来,因此你想确保,在那个样本中不会同时,携带其它疾病

耶鲁公开课 - 生物医学工程探索课程节选

Others last for months or even years. There is no clear way of predicting at the present time how long this activity might go on for."

VOA: standard.2010.04.16