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Roberto Aruga

Publications and source records attributed to Roberto Aruga.

3 recordsLinked to original sources

Complexes of copper(II) with adenosine or guanosine nucleosides, nucleotides 5'-monophosphate, 2'-deoxynucleosides or 2'-deoxynucleotides 5'-monophosphate in aqueous solution.

In this paper copper(II) complex formation in aqueous solution with a series of nucleosides (adenosine or guanosine) or nucleotides 5'-monophosphate is studied by means of potentiometry, visible spectrophotometry and ultraviolet circular dichroism. A chemical model has been formulated for each binary system (at T= 25 degrees C and I = 0.1 M), with particular attention to the interaction in the basic field. A spectrum (both visible absorption and ultraviolet circular dichroism) for each complex with a significant percentage of formation (in the adopted experimental conditions) has been calculated, allowing structural details to be hypothesised. The interaction with deprotonated alcoholic group(s) of the ribose moiety has been found to be fundamental in determining the co-ordination chemistry of each ligand considered while cases of co-operation between the purine and ribose donor(s) were also considered. Confirmations were also obtained by an investigation on the corresponding 2'-deoxy compounds as ligands.

Adenosine↗

Which kind of data (normally distributed, standardized, transformed) for a realistic factor analysis?

Taking into account that the problem of the best pretreatment of data for factor analysis has not yet arrived at generally accepted solutions, it has been tried to estimate, by an empiric procedure, the goodness of the results of repeated factor analyses with different pretreatments, conditions and statistical distribution of variables. Sets of multivariate data for river waters have been constructed firstly, after fixing the number and nature of the latent factors corresponding to the sources of pollution. A series of R-mode factor analyses has then been performed on these data, using various pretreatments (autoscaling, logarithmic transformation and their combinations), various factor rotations (rigid and oblique) and methods of computation of significant factors (40 data processing on the whole). Factor analyses have also been performed on real data of the Po river in the Piedmont region. Comparisons between the results obtained by factor analysis and the actual situation of the systems investigated have made it possible to draw some conclusions on how to proceed in order to obtain realistic results with this chemometric technique.

Factor Analysis, Statistical↗