1. Department of Obstetrics, University Hospital Zurich, Zurich, Switzerland.
2. Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, Swiss Federal Institute of Technology, Zurich, Switzerland.
3. Center for Microscopy and Image Analysis, University Hospital Zurich, Switzerland.
4. Zurich Center for Integrative Human Physiology, Zurich, Switzerland.
5. Department of Materials Science, Swiss Federal Institute of Technology, Zurich, Switzerland.