Abstract: Disclosed herein are compositions and methods for making germanium-based glass polyalkenoate cements. Also disclosed are methods for their use as bone cements for bone augmentation procedures.

Abstract: A toroidal engine that can be powered by a fuel/air mixture or by a compressed gas source. The toroidal engine uses one-way bearings to transfer torque generated in a toroidal chamber directly to a drive shaft. Pairs of pistons are mounted on two crank assemblies, which are concentric with the drive shaft. One-way bearings allow the crank assemblies to turn, one at a time, in one direction only. The crank assemblies are directly coupled to the drive shaft, which eliminates the need for complex gear and linkage arrangements. A system can be used with the toroidal engine to alternately stop the crank assemblies at a pre-determined position and to time the ignition of the engine.