Mechanistic studies on boron-doped diamond: Oxidation of small organic molecules

The electro-oxidation of ethanol, acetone, i-propanol, its fluorinated analogue hexafluoroisopropanol (HFiP) and cyclohexane in 1 M HClO4 was studied on a boron doped diamond (BDD) electrode by on-line differential electrochemical mass spectrometry (DEMS), using a dual thin layer cell. One can distinguish two oxidation pathways: at potentials below 2.5 V a direct electron transfer to the BOO takes place, while at potentials above 2.5 V OH radicals are produced and scavenged by the reactants. As a consequence, the oxygen evolution reaction is at least partially suppressed. The direct electron transfer to. the electrode is observed for i-propanol, ethanol and cyclohexane. For acetone and HFiP, only the second, indirect, pathway with the participation of OH radicals is effective. For all the reactants except HFiP CO2 formation was observed generally at 2.5 V or higher, the potential for the oxygen evolution reaction (OER) in the pure supporting electrolyte. Hence OH radicals are instrumental in the cleavage of C-C bonds. For HFiP, the cyclic voltammograms of the supporting electrolyte with and without the reactant are identical. This indicates that the oxidation of HFiP is initiated by OH radicals followed by a further electron transfer to the electrode, similarly to the oxidation of CO (I. Kisacik, A. Stefanova, S. Ernst and H. Baltruschat, PCCP, 15 (2013) 4616). For both pathways, the reactivity follows the same trend as the homogeneous hydrogen abstraction reaction rates with OH radicals. The intermediate radicals formed in the reaction with the electro-generated OH radicals can react with oxygen present in the solution. (C) 2013 Elsevier Ltd. All rights reserved

PSMA-PET/MRI-based focal dose escalation in patients with primary prostate cancer treated with stereotactic body radiation therapy (HypoFocal-SBRT) : study protocol of a randomized, multicentric phase III trial

Simple Summary Prostate cancer (PCa) is the most diagnosed malignancy of men worldwide, and radiotherapy (RT) is a main treatment option for patients in all disease stages. Modern diagnostic imaging and RT techniques enable an effective and safe delivery of high RT doses and a reduction of treatment time. We present a study protocol of a phase III trial implementing most modern imaging techniques and RT approaches. We compare the standard RT treatment with an RT concept of reduced treatment time and focal dose escalation based on the patient’s individual tumor morphology. This HypoFocal-SBRT trial aims to individualize treatment of PCa patients. Abstract Technical advances in radiotherapy (RT) treatment planning and delivery have substantially changed RT concepts for primary prostate cancer (PCa) by (i) enabling a reduction of treatment time, and by (ii) enabling safe delivery of high RT doses. Several studies proposed a dose–response relationship for patients with primary PCa and especially in patients with high-risk features, as dose escalation leads to improved tumor control. In parallel to the improvements in RT techniques, diagnostic imaging techniques like multiparametric magnetic resonance imaging (mpMRI) and positron-emission tomography targeting prostate-specific-membrane antigen (PSMA-PET) evolved and enable an accurate depiction of the intraprostatic tumor mass for the first time. The HypoFocal-SBRT study combines ultra-hypofractionated RT/stereotactic body RT, with focal RT dose escalation on intraprostatic tumor sides by applying state of the art diagnostic imaging and most modern RT concepts. This novel strategy will be compared with moderate hypofractionated RT (MHRT), one option for the curative primary treatment of PCa, which has been proven by several prospective trials and is recommended and carried out worldwide. We suspect an increase in relapse-free survival (RFS), and we will assess quality of life in order to detect potential changes