Abstract: Expandable cell culture substrates are provided that allow continual expansion of adherent stem cells without the need to passage cells, thereby preserving health and stem cell characteristics. The expandable cell culture substrates can include various three-dimensional structures having various coupling mechanisms that allow the structures to be joined, including where the structures are configured as interlocking blocks made from a variety of materials. The three-dimensional structures can include various coupling points, such as protrusions and opposing indentions, to allow for interlocking of the structures in the x-, y-, and z-axial directions. As a cell culture reaches a particular density, additional units can be added to increase the surface area of the expandable cell culture substrate.

Abstract: The present invention provides an improved method of and apparatus for, pneumatic drilling. The present invention includes a down hole air diverter of improved design, a corresponding computer modeling program, and method of application to optimally achieve the benefits of controlled gradient pneumatic drilling.