Publications by authors named "Dorota V Burchardt"

Three experimental techniques (1)H-(14)N NQDR, (13)C CP/MAS NMR and X-ray and Density Functional Theory (GGA/BLYP with PBC) and Hirshfeld surfaces were applied for the structure-activity oriented studies of two phyto-antioxidants and anticarcinogens: indole-3-carbinol, I3C, and 3,3'-diindolylmethane, DIM, (its bioactive metabolite). One set of (14)N NQR frequencies for DIM (2.310, 2.

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Antineoplastic chemo-therapeutic drug 5-(3,3-dimethyl-1-triazenyl)imidazole-4-carboxamide (Dacarbazine, DTIC), has been studied experimentally in solid state by ¹H-¹⁴N NQDR double resonance at 295 K and theoretically by the Density Functional Theory (DFT)/Quantum Theory of Atoms in Molecules (QTAIM) and Hirshfeld surfaces analysis. Only one set of eighteen resonance frequencies was found in the experiment. This indicates the presence of six inequivalent nitrogen sites: -N(CH₃), -NH₂, -NH- and three -N= (of which one is a ring, two are from triazene) in the DTIC molecule.

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The influence of different dental materials used for conserving reconstruction of teeth on the magnetic resonance imaging assessed on the basis of changes in NMR proton relaxation T1 of the physiological environment represented by the physiological salt solution has been studied. The dental materials studied varied in a wide range of chemical compositions: composites (Silux Plus made by 3M Dental, Tetric Cream made by Ivoclar-Vivadent), pH controlling composite (Ariston pHc made by Vivadent), hybrid glass ionomer (Vitremer made by 3M Dental), compomer (Hytac made by ESPE), amalgamate without the gamma phase (Septalloy made by Septodont), chemocured phosphate cement (Agatos made by Chema-Elektromet), phosphate cement with addition of silver (Argil made by Spora-Dental). The reference standard was a 0.

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A potential antileukemic and anticancer agent, 2-thiocytosine (2-TC), has been studied experimentally in the solid state by (1)H-(14)N NMR-NQR double resonance (NQDR) and theoretically by the quantum theory of atoms in molecules (QTAIM)/density functional theory (DFT). Eighteen resonance frequencies on (14)N were detected at 180 K and assigned to particular nitrogen sites (-NH(2), -N=, and -NH-) in 2-thiocytosine. Factors such as the nonequivalence of molecules (connected to the duplication of sites) and possible prototropic tautomerism (capable of modifying the type of site due to proton transfer) were taken into account during frequency assignment.

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