Department of Medicine, University of Padova, 35128 Padova, Italy. Magnetic Resonance Center (CERM) at the Department of Chemistry "Ugo Schiff", University of Florence, 50019 Sesto Fiorentino, Italy. Consorzio Interuniversitario Risonanze Magnetiche MetalloProteine (CIRMMP), 50019 Sesto Fiorentino, Italy. Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35129 Padova, Italy. Department of Clinical and Experimental Medicine, University of Catania, 95125 Catania, Italy. Centro HERA-Unità di Medicina della Riproduzione, Via Barriera del Bosco, 51/53, Sant'Agata li Battiati, 95030 Catania, Italy. Department of Medicine, Unit of Andrology and Reproductive Medicine, University of Padova, Via Giustiniani, 2, 35128 Padova, Italy.