NSC135057 Thiourea, N,N'-bis(1-.beta.-D-arabinofuranosyl-1,2-dihydro-2-oxo-4-pyrimidinyl)- Urea, 1,3-bis(1-.beta.-D-arabinofuranosyl-1,2-dihydro-2-oxo-4-pyrimidinyl)-2-thio-