1. Institute of Transfusion Medicine and Berlin-Brandenburg Center for Regenerative Therapies, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
2. Institute of Vegetative Physiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
3. Department of Medical Physics, Biophysics and Radiology, Medical Faculty, Trakia University, ul. “Armeiska” 11, 6000 Stara Zagora, Bulgaria