RESUMO
CNDOL is an a priori, approximate Fockian for molecular wave functions. In this study, we employ several modes of singly excited configuration interaction (CIS) to model molecular excitation properties by using four combinations of the one electron operator terms. Those options are compared to the experimental and theoretical data for a carefully selected set of molecules. The resulting excitons are represented by CIS wave functions that encompass all valence electrons in the system for each excited state energy. The Coulomb-exchange term associated to the calculated excitation energies is rationalized to evaluate theoretical exciton binding energies. This property is shown to be useful for discriminating the charge donation ability of molecular and supermolecular systems. Multielectronic 3D maps of exciton formal charges are showcased, demonstrating the applicability of these approximate wave functions for modeling properties of large molecules and clusters at nanoscales. This modeling proves useful in designing molecular photovoltaic devices. Our methodology holds potential applications in systematic evaluations of such systems and the development of fundamental artificial intelligence databases for predicting related properties.
RESUMO
Serum from asymptomatic or symptomatic (with cardiovascular manifestations) chagasic patients depleted of the complement system displayed an antiproliferative effect on Trypanosoma cruzi epimastigotes, RA strain, when added to the growth medium. This effect was also observed when patient's serum was depleted of specific antibodies. The antiproliferative effect was both time and concentration dependent. It was confined to the non-dialyzable, high molecular weight, fraction of the serum. This effect was abrogated by allopurinol and catalase, and enhanced by N-ethylmaleimide. Xanthine oxidoreductase and xanthine oxidase activities were increased in the chagasic sera, while catalase activity remained unchanged. Parasites exposed to chagasic sera showed a decrease in Fe/superoxide dismutase activity as well as an increase in membrane lipoperoxidation. Our data provides evidence to support the idea that the antiproliferative activity observed in sera from chagasic patients may be due, at least partially, to a direct effect of hydrogen peroxide on the epimastigotes of T. cruzi. The increase of hydrogen peroxide to antiproliferative levels might result from an increase in xanthine oxidase activity in the serum of patients infected with the parasite.