RESUMO
Solid electrolyte interphase (SEI) formation in lithium ion cells prepared with advanced electrolytes is investigated by solid state multinuclear (7Li, 19F, 31P) magnetic resonance (NMR) measurements of electrode materials harvested from cycled cells subjected to an accelerated aging protocol. The electrolyte composition is varied to include the addition of fluorinated carbonates and triphenyl phosphate (TPP, a flame retardant). In addition to species associated with LiPF6 decomposition, cathode NMR spectra are characterized by the presence of compounds originating from the TPP additive. Substantial amounts of LiF are observed in the anodes as well as compounds originating from the fluorinated carbonates.
RESUMO
Bradykinin related peptides (BRPs) present in the water-soluble secretion and freshly dissected skin fragments of Phyllomedusa hypochondrialis were investigated by mass spectrometry techniques. Eighteen BRPs, along with their post-translational modifications, were characterized in the secretion by de novo MS/MS sequencing and direct MALDI imaging experiments of the frog skin. These molecules revealed strong sequence similarities to the main plasma kinin of some mammals and reptiles. Such a diversity of molecules, within the same peptide family, belonging to a single amphibian species may be related to functional specializations of these peptides and a variety of corresponding receptors that might be present in a number of different predators. Also, a novel analog, [Val]1,[Thr]6-bradykinyl-Gln,Ser had its biological activity positively detected in cell culture expressing the human bradykinin B2 receptor and in guinea pig ileum preparations.
