TY JOUR TI ANNIHILATION DELAYED FLUORESCENCE OF PROBES AS A TUMOR OXYGEN LEVEL INDICATOR KW delayed fluorescence KW biological tissues KW singlet-triplet annihilation KW singlet oxygen JO Russian Journal of Biological Physics and Chemisrty AU Ishemgulov, A.T. AU Letuta, S.N. AU Mukhanova, A.F. AU Pashkevich, S.N. AU Sokabaeva, S.S. PY 2016 IS 1 PB Federal State Educational Institution of Higher Education Sevastopol State University