Search results for "helat"
showing 4 items of 364 documents
Complex formation of copper(II) and cadmium(II) with pectin and polygalacturonic acid in aqueous solution. An ISE-H + and ISE-Me 2+ electrochemical s…
2012
The acid-base properties of pectin and its ability to complex with copper(II) or cadmium(II) were quantitatively determined in order to define the ability of this natural polyelectrolyte to sequester metal ions. Potentiometric measurements carried out at different ionic strengths (0.1 - 0.7 mol L-1, in Na+ ionic medium) allowed us to define the acid-base properties of pectin together with the dependence of the protonation constants on ionic strength and to calculate the protonation constant at infinite dilution. The formation of complex species between pectin and copper(II) or cadmium(II) was investigated potentiometrically (using H+, Cu2+ and Cd2+ Ion Selective Electrodes, ISEs) in NaNO3 a…
Uz vēža šūnām mērķēti alfa daļiņu emiteri, jauna kompleksējoša savienojuma sintēzes metodes izstrāde
2015
Vēzis ir viena no mūsdienu medicīnas svarīgākajām problēmām. Mērķēta alfa-terapija, kas izmanto pie bioloģiskiem nesējiem piesaistītus α-daļiņas emitējošus radionuklīdus un tiek mērķēta selektīvi uz malignajām šūnām, ir veids, kā iznīcināt atsevišķas vēža šūnas, pat ja tās ir izkaisītas pa visu organismu. Šī darba mērķis ir apkopot informāciju par α-emiteru izmantošanu onkoterapijā, kā arī akcentēt galvenos farmācijas un ķīmijas saskares punktus uz audzēja šūnām mērķētu radiofarmaceitisko vielu izstrādē. Darba teorētiskajā daļā apkopota zinātniskajā literatūrā pieejamā informācija par α emiteriem, to pieejamību, darbības principu, priekšrocībām un potenciālajām iespējām onkoterapijā. Sniegt…
Metabotropic glutamate receptors activate phospholipase D in astrocytes through a protein kinase C-dependent and Rho-independent pathway.
2003
Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors that mediate phospholipase D (PLD) activation in brain, but the mechanism underlying this response remains unclear. Here we used primary cultures of astrocytes as a cell model to explore the mechanism that links mGluRs to PLD. Glutamate activated both phospholipase C (PLC) and PLD with equal potency and this effect was mimicked by L-cysteinesulfinic acid, a putative neurotransmitter previously shown to activate mGluRs coupled to PLD, but not PLC, in adult brain. PLD activation by glutamate was dependent on Ca(2+) mobilization and fully blocked by both protein kinase C (PKC) inhibitors and PKC down-regulation, suggesti…
Synthesis and characterization of Zwitterionic Zn(II) and Cu(II) coordination compounds with ring-substituted 2,2′-biimidazole derivatives
2016
Zwitterionic coordination compounds with strongly asymmetrical charge distribution were synthesized and characterized. Ring-substituted biimidazoles were used as the primary ligands for Zn and Cu compounds. Formation of Zwitterionic coordination compound was found to be strongly dependent on the pH of the reaction medium as well as on the ring and nitrogen substituents of the ligand. Reaction of the Df-R2biim (Df-R2biim = 2,2′-bi-1R-imidazole-5,5′-dicarboxaldehyde, R = Me, Et or Pr) with ZnCl2 in neutral conditions led to binuclear compounds [Zn2Cl4(Df-R2biim)2] with two bridging ligands (1a–c). Reaction with CuCl2·2H2O gave neutral mononuclear compound [CuCl2(Df-Me2biim)] (1d) with chelati…