Anti-Tumor Efficacy of Photodynamic Therapy of Solid Tumors in Laboratory Animals with Guanidine and Biguanidine Derivatives of Chlorine e6

We evaluated antitumor efficacy of photodynamic therapy of murine Ehrlich carcinoma and rat sarcoma M-1 with new photosensitizers 131-N-(4-aminobutyl)amydo chlorine e6 (1), 132-(5-guanidylbutanamido)-chlorine e6 (2), and 132-(5-biguanidylbutanamido)-chlorine e6 (3). The inhibiting effect of the photodynamic therapy was evaluated by the following parameters: tumor growth inhibition, complete regression of the tumors, and absolute growth rate of the tumor nodes in animals with the continued neoplasia growth. The criterion of cure was the absence of tumors up to 90 days after the therapy. It is shown that the studied photosensitizers have high antitumor activity in the photodynamic therapy of the Ehrlich carcinoma and sarcoma M-1

Electronic correlations and crystal-field effects in RCu3Ru4 O12 (R=La, Pr, Nd) ELECTRONIC CORRELATIONS and CRYSTAL-FIELD ... A. GÜNTHER et al.

© 2020 American Physical Society. Among the large class of A-site ordered perovskites of stoichiometry AC3B4O12, the rare-earth (R) ruthenates RCu3Ru4O12 (R=La, Pr, Nd) are interesting compounds due both to Ru-4d-derived electronic correlations and to unconventional crystal-electric-field effects of the R ions. Here we report on detailed investigations of these compounds utilizing x-ray diffraction, neutron scattering, magnetic susceptibility, and electrical resistivity measurements as well as heat capacity and nuclear resonance experiments. A broad range of external parameters is scanned and depending on the specific technique, temperatures range from 100 mK to 730 K in external magnetic fields up to 14 T. In this work LaCu3Ru4O12 serves as reference compound with a nonmagnetic A site, characterized in detail recently [S. Riegg, Phys. Rev. B 93, 115149 (2016)2469-995010.1103/PhysRevB.93.115149]. All compounds investigated reveal heavy-fermion behavior with a T2 dependence of the low-temperature electrical resistivity and significantly enhanced Sommerfeld coefficients. Toward low temperatures, the compounds with R=Pr and Nd are dominated by the magnetic moments of the R ions, which occupy crystallographic positions with point-group symmetry Th. The crystal-electric-field effects are clearly visible especially in heat capacity and inelastic neutron scattering data from which the crystal-electric-field parameters are derived. The ground state of the Pr3+ ion is identified as a triplet (G4(1)), whereas for Nd3+ it is a quartet (G67). Evidence for lowering of the Th symmetry is observed at the Pr site at temperatures below 10 K, suggesting the formation of orbital order. Moreover, the spin-lattice relaxation derived from Cu63 nuclear quadrupole resonance indicates characteristic temperatures close to 7 K and 350 mK, probably related to orbital and magnetic order, respectively