Role of paramagnetic polyconjugated clusters in lignin antioxidant activity (in vitro)

Using physico-chemical methods (EPR, SEC, Py-GC/MS and UV/VIS spectroscopy) and wet chemical analysis, the characteristics of 6 hardwood lignins in terms of functionality, molecular weight and composition of lignin substructures were determined and considered together with the results of DPPH•, ABTS •+ and O2•- antioxidant assays with the aim to understand the relationships governing antioxidant properties of lignin. The strong positive linear correlation between lignin antioxidant capacity in the three assays used and the extent of conjugation of paramagnetic polyconjugated clusters in lignin macromolecules was found. The biological activity of the most active alkaline lignins was assessed by in vitro experiment with human blood.publishersversionPeer reviewe

Спектры возбуждения и фотолюминисценции твердых растворов на основе индата лантана со структурой перовскита, легированного ионами Pr3+, Nd3+, Cr3+

Excitation and photoluminescence spectra of La0,997Pr0,003InO3, La0,98Nd0,02InO3, La0,977Pr0,003Nd0,02InO3, La0,977Pr0,003Nd0,02In0,99Cr0,01O3, LaIn,099Cr0,01O3 solid solutions have been studied. It has been found that Cr+ ions incorporated into the In3++ sublattice of La0,977Pr0,003Nd0,02In0,99Cr0,01O3 solid solution can act as Nd3+ photoluminescence sensitizers under the excitation by visible light (λ = 445 nm).Исследованы спектры возбуждения и фотолюминесценции твердых растворов La0,997Pr0,003InO3, La0,98Nd0,02InO3, La0,977Pr0,003Nd0,02InO3, La0,977Pr0,003Nd0,02In0,99Cr0,01O3, LaIn0,99Cr0,01O3. Установлено, что ионы Cr3+, введенные в под-решетку ионов In3+ твердого раствора La0,977Pr0,003Nd0,02In0,99Cr0,01O3, являются сенсибилизаторами фотолюминесценции ионов Nd3+ при их возбуждении светом видимой области спектра (λ = 445 нм)

Behavior of one-magnon frequency in antiferromagnetic NicMg1-cO solid solutions

The one-magnon scattering was studied in antiferromagnetic NicMg1-cO solid solutions. We observed unpredicted behavior of both temperature and composition dependences of one-magnon excitation energies. First, the abrupt change of the one-magnon frequency by 7-8 cm(-1) occurs between c=0.98 and c=0.9 in the limit of T -> 0 K. Second, upon increasing temperature, the one-magnon energy for highly diluted nickel oxide vanishes significantly below the Neel temperature