Optical computed tomography in a turbid medium using early arriving photons.

We employ photon migration to image absorbing objects embedded in a turbid medium. For improved resolution, we use early arriving photons (a few hundred picoseconds in excess of the time of flight), a regime in which the diffusion approximation breaks down. Our image reconstruction method is based on extension of x-ray computed tomography (CT) to the optical regime.

Membrane cholesterol alters gallbladder muscle contractility in prairie dogs.

The cause and effect relationship between membrane cholesterol and gallbladder muscle contractility was examined by altering membrane cholesterol to phospholipid mole ratio using cholesterol-rich or cholesterol-free liposomes. Gallbladder single muscle cells, from prairie dogs that were fed either a regular or high-cholesterol (1.2%) diet, were isolated enzymatically with collagenase.