The methylpyropheophorbide-fullerene[60] dyad was synthesized by 1,3-dipolar cycloadditions of the corresponding azomethine ylide to C 60 (Prato reaction). Using the mass spectrometric method with soft matrix-activated ionization it was possible to achieve a significant reduction in fragmentation processes by the retro-Diels-Alder reaction, which allows to reliably detect the presence of polyadducts of azomethine ylide cycloadditions to fullerene. The use of gel permeation chromatography under conditions of weakening of the intermolecular π-π interaction between methylpyropheophorbide and fullerene moieties makes it possible to effectively separate mixed products with ~ 1.5 fold difference in molecular weight. It has been shown that the fluorescence of the dyad is quenched more than 5000 times (compared to the native dye). The singlet oxygen quantum yield of the dyad is 360 times less than that for the native methylpyropheophorbide a, however, its efficiency of superoxide generation increases by 18.5 times. The obtained result agrees well with the previously reported mechanism of relaxation of the excited state of the dyad through a charge-separated state, which can lead to the formation of superoxide. The observed effects indicate a change in the mechanism of photodynamic activity from type II (generation of singlet oxygen) for the native dye to type I (generation of superoxide) for the dyad, which shows a promising method of creation of highly efficient photosensitizers based on similar dye-fullerene[60] dyads.
The new form of breakdown parameter is proposed and the applicability of this parameter to shock wave flow and to shear flow has been established. This form of parameter may be applied to solutions of Boltzmann equation or to Navie-Stokes equations. Burnett constitutive relations for stresses and heat flux were analyzed in shear flow, shock wave flow, flows past circular cylinder and past plane plate at zero angle of attack. The generalization of Newton-Fourier (Navier-Stokes) relations for plane nonequilibrium flow (based on macroscopic equations established for Couette flow and for cylindrical expansion into vacuum) is proposed
The constitutive relations between stresses and heat fluxes in Couette flow and gradients of velocity and temperature, known for Maxwell molecules, are generalized for hard sphere molecules. These relations are the generalization of Newton-Fourier (Navier-Stokes) relations for shear flow with strong nonequilibrium. Similar relations are established for strong shock wave flow and for spherical expansion into vacuum for Maxwell and hard sphere molecules. General structure of constitutive relations for macroscopic description of gas flow with strong translational nonequilibrium outside the thin Knudsen boundary layers is established. Derivation is based on the hypothesis: on the solution of Boltzmann equation the stresses and heat flux depend only on velocity gradient and temperature gradient. Hamilton theorem on square dependence of arbitrary tensor function of second rank on symmetric tensor of second rank is generalized. Generalization of transport coefficients, -transport scalar function, -depends on molecular potential and on tensor invariants of symmetric and anti-symmetric parts of velocity gradient and of temperature gradient. The part of transport functions is determined by DSMC solutions of Boltzmann equation for one-dimensional flow problem.
The model of apperception of information in cognitive analysis is studied in the article. The content of the holistic image formation is described with highlighting the receiving process (reception) of original perception (perception) and consciousness (apperception). The difference between reception, perception and apperception is shown. The article introduces a new model for the formation of a system image in a cognitive analysis. The content of the cognitive chain of medical information analysis is revealed. Three stages of cognitive analysis are described. The article introduces a new model, i. e. the apperception information model. This model serves as the basis for the formation of an information image in cognitive analysis. This model serves as the basis for diagnostics. Apperceptive analysis and modelling are described.
A series of nanoparticles (NPs) with a hydrodynamic radius from 20 to 100 nm in PBS was developed over the solubilization of hydrophobic dye methyl pheophorbide a (chlorin e6 derivative) by amphiphilic copolymers of N-vinylpyrrolidone with (di)methacrylates. Photophysical properties and biological activity of the NPs aqueous solution were studied. It was found that the dye encapsulated in the copolymers is in an aggregated state. However, its aggregation degree decreases sharply, and singlet oxygen quantum yield and the fluorescence signal increase upon the interaction of these NPs with model biological membranes—liposomes or components of a tissue homogenate. The phototoxic effect of NPs in HeLa cells exceeds by 1.5–2 times that of the reference dye chlorin e6 trisodium salt—one of the most effective photosensitizers used in clinical practice. It could be explained by the effective release of the hydrophobic photosensitizer from the NPs into biological structures. The demonstrated approach can be used not only for the encapsulation of hydrophobic photosensitizers for PDT but also for other drugs, and N-vinylpyrrolidone amphiphilic copolymers show promising potential as a modern platform for the design of targeted delivery vehicles.
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