First-hand or secondary source? Or both?
This is more biology related, but some doctors believe that diseases such as lupus and MS are caused by a bacteria, and treat it using a two-year long course of three types of antibiotics. I know a person who had MS and has been symptom-free for five years, but it's not a widely accepted treatment because it is only fairly recent. For lupus, it is currently believed to be an auto-immune disease, meaning that it is caused by the immune system attacking the body, so immune suppressants are currently the most widely used treatment. That's just a summary, you could do heaps on it.
Another thing I came across (closer to chem) is an article on graphene. It is one layer of graphite, and could be the strongest material for its weight ever discovered. But the current method of producing it is to peel it off using sticky tape, so it isn't commercially viable at all. But it could be used to make flexible electronic devices and a whole bunch of other ideas.
A good place to look is at the website for the Cosmos magazine
https://cosmosmagazine.com/
As for first hand investigations, I wouldn't know... I can't think of anything advanced you could do at home...
