In 2004, the former Amersham plc business segments were separated into the GE Healthcare Medical Diagnostics and Life Sciences business segments and 1 May 2013, both the business were combined again under the GE Life Sciences brand with Kieran Murphy taking the leadership role. Also in 2004, GE Healthcare along with other healthcare companies built a research reactor for neutron and unit cell research at GE's European Research Center near Garching (outside of Munich), Germany. It is the only such reactor currently in operation. In 2005, Sir William Castell, CEO of GE Healthcare and former CEO of Amersham plc stepped down as CEO to become Chairman of the Wellcome Trust—a charity that fosters and promotes human and animal research—in the United Kingdom. Former GE Medical Systems CEO Joe Hogan became the overall CEO for the GE Healthcare business. In 2005, Dental Imaging operations were separated from GE Healthcare. The PaloDEx Group Oy was founded and continues the business with its subsidiaries Instrumentarium Dental and SOREDEX. Specifically, Instrumentarium Dental continues the brands Orthopantomograph and intraoral systems FOCUS and SIGMA, formerly known as Instrumentarium Imaging or GE Healthcare products.