Polypropylene resin compositions are provided that are useful in the production of biaxially oriented polypropylene films. A first substance is frozen in a cryopreservation fluid in a first well of a lid. The open cell foam can be produced by melt-kneading a polystyrene resin having a content of organic volatile matters of 100 ppm or higher together with water in an extruder, sucking out the organic volatile matters as an azeotrope with water through a vent, injecting a blowing agent and kneading the injected mixture, and extruding the mixture into a lower pressure area to cause the resin to foam. In the diaphragm pieces disposed on a single line along the X axis direction and the diaphragm pieces disposed on a single line along the Y axis direction, the areas of cross section orthogonal to the axis are set according to a maximum value of acceleration, respectively, in the X axis direction or Y axis direction. Additionally the present invention inlcudes a process for preparing such a compound, a pharmaceutical composition containing such a compound, and the use of such a compound in medicine. The aspherical optical elements have surfaces in which the in-plane radius of curvature spatially varies and the in-plane cross section surface profile is characterized in that the multiplication of the cosine of the incidence angle raised to a non-zero exponent by the in-plane radius of curvature varies less than twenty percent between any two points on the in-plane cross section surface profile.