1. Department of Surgery, University Bonn Medical School, Bonn, Germany
2. Department of Obstetrics and Prenatal Medicine, University Bonn Medical School, Bonn, Germany
3. Department of Anesthesiology and Intensive Care Medicine, University Bonn Medical School, Bonn, Germany
4. Institute of Experimental Hematology and Transfusion Medicine, University Bonn Medical School, Bonn, Germany