meaning for 化验 huàyàn:

  • - chemical examination
  • - to do a lab test

dànshì但是
mùqián目前
wéizhǐ为止
de
huàyàn化验
méiyǒu没有
rènhé任何
guānyú关于
zhèxiē这些
de
jìxiàng迹象

But the tests so far show no sign of anything like that.