Publications by authors named "Alexandra Gracheva"

Synthetic graphite of complex fractional composition was mixed with phenolic resin as a binder and pore-forming component. The mixtures were pressed and subsequently heat-treated to obtain porous matrices. The structural transformations of phenolic resin by heating up to 900 °C in oxygen and inert gas media were studied and the patterns of amorphization of fixed carbon formed on the walls of the pore system during carbonization were investigated.

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This study investigates the tribological properties of graphite foils (GF) with densities of 1.0, 1.3, and 1.

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Flexible graphite foils with varying thicknesses (S = 282 ± 5 μm, M = 494 ± 7 μm, L = 746 ± 8 μm) and an initial density of 0.70 g/cm were obtained using the nitrate method. The specific electrical and thermal conductivity of these foils were investigated.

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The physical and mechanical properties and structural condition of flexible graphite foils produced by processing natural graphite with nitric acid, hydrolysis, thermal expansion of graphite and subsequent rolling were studied. The processes of obtaining materials and changing their characteristics has been thoroughly described and demonstrated. The structural transformations of graphite in the manufacture of foils were studied by X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM).

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The emergence of drug resistant (MTB) strains has become a global public health problem, while, at the same time, there has been development of new antimicrobial agents. The main goals of this study were to determine new variants associated with drug resistance in MTB and to observe which polymorphisms emerge in MTB genomes after anti-tuberculosis treatment. We performed whole-genome sequencing of 152 MTB isolates including 70 isolates as 32 series of pre- and post-treatment MTB.

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Article Synopsis
  • A study involving 5,340 residents of Moscow investigated the relationship between immune responses (antibodies and T cells) to SARS-CoV-2 and the likelihood of COVID-19 infection.* -
  • Results showed that individuals with both high T-cell and antibody responses had the lowest risk of infection, while those with only an antibody response also had a strong protective effect.* -
  • The findings highlight that antibody responses are more crucial for protection against SARS-CoV-2 compared to T-cell responses, suggesting potential implications for public health policies related to COVID-19.*
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