yappa08 said: But what's going to happen to poor nano...
Same thing that happens to most people when a family member dies; she'll mourn for a while and then she'll move on. It's sad, but it happens. And none of the sad parts are happening here.
Deus-Helios said: And she finally had her screw removed.
Well, Hakase promised she'd do it, She's no fool, she'd know that the end was near.
Adding this to the heartbreaking pool, since while this doesn't seem sad at first, the realization that she was near death seems like it would be the only thing that would have the professor remove Nano's screw. Nano wouldn't realize the motive though, which would explain her happiness.