SEARCH Articles Figures Tables Electron spin label nitroxide free radical Electron spin resonance studies nitroxide free radical Free radical nitroxides Free radical nitroxides Free radical reactions nitroxide concentrations Nitroxide Nitroxide free radicals orientation dependence Nitroxide free radicals proteins Nitroxide mediated living free radical Nitroxide mediated living free radical polymerization Nitroxide radicals Nitroxide structures Free radical Nitroxides Nitroxides, living free-radical Nitroxides, living free-radical polymerization