Applying variational principles may allow streamlining of protein folding calculations from trillions of steps to hundreds. A variational principle is a principle in physics which is expressed in terms of the calculus of variations. The new application of the old physics method is faster because it allows them to spend less time calculating motions of molecules stuck in quasi-stable intermediate steps along the folding process. The intermediate steps account for vast amounts of wasted computation time in traditional, step-by-step simulations. Determining the structure and folding of proteins is important to control the functions that they exhibit. Mastery of proteins could lead to molecular nanotechnology.
A pair of physicists at MIT have found a class of molecules that attach to nanotubes without damaging them. Instead of simply grabbing onto the nanotubes, the molecules latch onto the tubes and break some bonds in the nanotube walls. As a result, the sum total of bonds is the same before and after the handle is attached, keeping the nanotube's original characteristics relatively intact.
Researchers led by Kingo Uchida and Shinichiro Nakamura have now synthesized a compound in the diarylethene family whose surface becomes super-water-repellent on command.