“Dear Mr. Fact: Is it true that you can test a microwave to see if it is leaking radioactivity by holding a florescent light bulb in front of it and if it glows, it leaks? If not, is there any way to ...

In recent years, so-called upconversion nanoparticles doped with rare-earth elements have attracted interest as stains for biological imaging and even potentially as anticancer therapeutics. But to ...