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The pharmacokinetics of the oxime acetylcholinesterase reactivator K869
Hojná, Anna ; Váňová, Nela (advisor) ; Bavlovič Piskáčková, Hana (referee)
Co-administration of oxime reactivators of AChE together with atropine and diazepam is the basic strategy for the pharmacological treatment of organophosphate (OP) poisoning. The aim is to develop such oxime, that would be effective against a wide range of OPs and simultaneously, that would penetrate the central nervous system. Bispyridinium oximes are among the structures with the most efficient acetylcholinesterase reactivation. However, they are charged molecules that poorly cross the blood-brain barrier. Researchers try to modify these molecules to be more lipophilic thus, enhancing their central effect. One of the possible approaches is to substitute the basic structure of the reactivator with suitable functional groups. K869 is an asymmetric bispyridinium oxime whose pyridinium ring is substituted by two chlorine atoms. An HPLC-UV method was developed and optimized for the determination of oxime K869 in plasma and kidneys. Since oxime K869 is a permanently charged molecule, ion- pair chromatography was applied, in which the molecule becomes uncharged with the addition of an ion-pairing agent (1 mM octane sulfonic acid) to the aqueous components of the mobile phase (citrate-phosphate buffer). It was then separated in a reverse chromatographic mode in isocratic elution mode where acetonitrile...
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THE EFFECTS OF HIGH TEMPERATURE HELIUM GAS ON THE FRACTURE BEHAVIOUR OF ODS MA957
Rozumová, L. ; Hojná, A. ; Kalivodová, J. ; Bublíková, P. ; Hadraba, Hynek ; Di Gabriele, F.
Oxide-dispersion-strengthened steel (ODS) MA957 has been studied as a candidate material for Tritium Breeding Blanket for fusion reactors with helium coolant, where temperatures 250-650 degrees C are expected. Helium is one of type as primary coolant in High Temperature Reactor and Gas Cooled Fast Reactor with working temperature 500-1000 degrees C. \n\nThis work presents results of the study of behaviour of ODS (MA957) under influence of high temperature helium environment. Microstructure of the material and the interaction with He was investigated. The average exposure temperature was held at 720 degrees C. Subsequently, the surface changes were determined. Impact testing and material surfaces were studied in detail by means of SEM and TEM microscopy. It is essential to understand the He effect on microstructure and mechanical properties of structural materials since the He embrittlement in TBB may be significant.
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Embrittlement of ferritic 14%Cr ODS steel in air and in Pb/Pb-Bi coolants at elevated temperatures
Hadraba, Hynek ; Dlouhý, Ivo ; Hojná, A. ; Di Gabriele, F.
The work was focused to describing influence of long-time high-temperature exposition of the ferritic 14%Cr ODS steel to the liquid Pb and Pb-Bi metals environments. The steel was during exposition in the liquid Pb and Pb-Bi at 600°C and 550°C respectively depleted from Cr and Ti formed with Pb and Bi the surface oxide scale. In addition the isothermal ageing of the steel at 650°C caused precipitates coarsening and porosity development by dislocation annealing in the bulk of the steel. Tensile and impact bend tests reveals outstanding embrittlement of the isothermally aged ODS steel and the steel after exposition to the liquid Pb and Pb-Bi compared with the steel in as-received state.
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