Publications by authors named "G Yu Nikolaeva"

Article Synopsis
  • * Raman spectroscopy is highlighted as an effective method for monitoring changes in the structure of these glycol solutions over time, especially how water content decreases on substrates.
  • * The study also reveals that the water content reduction affects the presence of certain molecular conformations in the glycols and demonstrates that a specific laser wavelength (1064 nm) is effective for analyzing antifreeze products containing dyes.
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The severity of ischemic injury was evaluated by densitometry of brain samples stained with 2,3,5-triphenyltetrazolium chloride (TTC) on a rat model of cerebral ischemia/reperfusion (common carotid artery occlusion) and the neuroprotective activity of an extract of Astragalus membranaceus, Scutellaria baicalensis, and Phlojodicarpus sibiricus was assessed. Occlusion of the common carotid arteries led to a weakening of TTC staining of the brain tissue: densitometric indicators of the staining intensity for the cortex and striatum were lower than the corresponding indicators of sham-operated rats by 18.3 and 10.

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In this work, we study two series of the copolymers of L-lactide (LLA) and ε-caprolactone (CL) with the CL molar content of 5, 15, and 30 %. The first series was the commercial semicrystalline granules (Corbion, Netherlands), which we analyzed without any additional modification. The second series was amorphous films, prepared from the granules by hot pressing with the subsequent fast quenching in order to avoid the crystallization.

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The electrochemical behavior of new electrode materials based on poly-N-phenylanthranilic acid (P-N-PAA) composites with reduced graphene oxide (RGO) was studied for the first time. Two methods of obtaining RGO/P-N-PAA composites were suggested. Hybrid materials were synthesized via in situ oxidative polymerization of N-phenylanthranilic acid (N-PAA) in the presence of graphene oxide (GO) (RGO/P-N-PAA-1), as well as from a P-N-PAA solution in DMF containing GO (RGO/P-N-PAA-2).

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We present an in-depth analysis of Raman spectra of novel block copolymers of methyl ethylene phosphate (MeOEP) with caprolactone (CL) and L-lactide (LA), recorded with the excitation wavelengths of 532 and 785 nm. The experimental peak positions, relative intensities and profiles of the poly(methyl ethylene phosphate) (PMeOEP), polycaprolactone (PCL) and poly(L-lactide) (PLA) bands in the spectra of the copolymers and in the spectra of the PMeOEP, PCL and PLA homopolymers turn out to be very similar. This clearly indicates the similarity between the conformational and phase compositions of PMeOEP, PCL and PLA parts in molecules of the copolymers and in the PMeOEP, PCL and PLA homopolymers.

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