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The effects of copper nanoparticles on the structure and function of the immune system organs (thymus and spleen) and intensity of free radical processes in the spleens of rats with sarcoma 45 were studied. A relationship between morphological and biochemical changes and antitumor efficiency of copper nanoparticles was demonstrated.

A computational study of the monomers and hydrogen-bonded dimers of 2-pyrrolidone was executed at different DFT levels and basis sets. The above dimeric complexes were treated theoretically to elucidate the nature of the intermolecular hydrogen bonds, geometry, thermodynamic parameters, interaction energies, and charge transfer. The processes of dimer formation from monomers and concerted reactions of double proton transfer were considered. The evolution of geometry, vibrational frequencies, charge distribution, and AIM properties in going from monomers to dimers was systematically followed. The solvent effects upon dimer formation were investigated in terms of the self-consistent reaction field (SCRF Onsager model). For the monomers and three dimers, vibrational frequencies were calculated and the changes in frequencies of the vibrations most sensitive to complexation were discussed. The orbital interactions were shown to lengthen the X-H (X = N, O) bond and lower its vibrational frequency (a red shift). To better understand the nature of the corresponding intermolecular interactions, we performed natural bond orbital (NBO) analysis. Topological analysis of electron density at bond critical points (BCP) was executed for complex molecules using the Bader's atoms in molecules (AIM) theory. The interaction energies were calculated, and the basis set superposition errors (BSSE) were estimated systematically. Satisfactory correlations between the structural parameters, interaction energies, and electron density characteristics at BCP were found.

An unusual 3:1 stoichiometry for complex formation between an elongated bis-netropsin compound and its binding site on DNA has been observed. Circular dichroism measurements distinguish two types of complexes formed between this bis-netropsin and poly[d(A-T)].poly[d(A-T)]. The first type is characterized by a 1:1 saturating ratio of bound molecules per ten base pairs. Formation of the second type results from the cooperative binding of two additional bis-netropsin molecules to the first type of complex. In contrast to these results observed for binding to the alternating polynucleotide, only the 1:1 type of complex is formed when this ligand binds to the homopolymer poly(dA).poly(dT).