Background

Add some 3d into the background. Maybe match hues from the nucleus cell to the background, instead of just clouds/noise. I see the idea there though.

Nucleus

It's a bit blurry, except for the corners. It'd look better in my opinion if it wasn't blurred. Try adding some details to it so it won't seem as though you used that straight from the tutorial.

Lineart/Mini-pics

Pretty good. Good choice of text. Lineart could be better. Where it says "Nucleus Cell 12:5" (top), continue adding some more lineart so it has a place to go. Same with the bottom.