A dc-dc converter system comprises a quasi-regulated bus converter and plural regulation stages that regulate the output of the bus converter. 5 inches, an inner cover layer encasing the core, and an outer cover layer encasing the inner cover layer. Methods of making the fusion proteins of the invention are also provide, as well as methods of using the fusion proteins, for example to inhibit protease activity in a biological sample or in the treatment of an individual suffering from, or at risk for, a disease or disorder involving unwanted protease activity. The light guiding device has a light guiding region facing the LED light source. A shaft may be fixedly attached to the stiffening brace and slideable relative to an orifice defined within one of at least one of the cross members.