published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

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With the goal of developing Schiff base macrocycles with conjugation extended over multiple aromatic rings, new phenanthrene and triphenylene-containing bis(salicylates) were synthesized. A convenient route to 3,6,9,10-tetraalkoxy-2,7-diiodophenanthrene was developed. This compound has been found to be a useful precursor for Pd-catalyzed cross-coupling reactions. Macrocycles were synthesized by Schiff base condensation of the phenanthrene and triphenylene precursors. Reaction of smaller phenanthrene and triphenylene bis(salicylates) with 1,2-dialkoxy-4,5-phenylenediamine afforded macrocycles in poor yield and purity, but formation of the macrocycle was confirmed by mass spectrometry. Condensation of larger phenanthrene ethynylene bis(salicylates) with phenylenediamines formed [3+3] Schiff base macrocycles in good yield and could be purified through recrystallization. These two large macrocycles were weakly luminescent, and showed decrease in intensity of emission in solution over time. Addition of nitroaromatic compounds to solutions of the macrocycles caused quenching of luminescence, but Stern-Volmer constants could not be determined. One of the macrocycles aggregates in solution and shows some order in the solid state. Association constants for self-assembly of this macrocycle in chloroform were determined, and aggregation was found to be enthalpically driven and entropically disfavoured. Both large macrocycles can complex metals, but low solubility prevents thorough characterization of the metal complexes. Phenanthrene-containing poly(phenyleneethynylene)s (PPEs) and poly(phenylenevinylene)s (PPVs) were synthesized via the Sonogashira and Heckcouplings, respectively. The PPEs had high molecular weight and both polymers were extremely luminescent with OF = 70% for the PPE and OF = 59% for the PPV. These polymers show potential for use in solar cells and nitroaromatic sensors . Dithienylsalphen monomers were made using 4-(2-thienyl)salicylaldehyde and 5-(2-thienyl)salicylaldehyde. These monomers were coordinated to Ni(II), Cu(II) and vanadyl, and tested for electropolymerization. Conjugated dithienylsalphen monomers polymerize poorly, while non-conjugated dithienylsalphen monomers form good films through electropolymerization. Ultraviolet-visible spectroscopy confirmed extended conjugation in N,N '-phenylenebis(4-(2-thienyl)salicylideneimine).

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Magistro darbe yra suformuluojama teisingai pasirinktų alternatyviųjų investicijų strategija ir jos veiklos pagristumas, išanalizuoti ir susisteminti įvairių Lietuvos ir užsienio autorių teoriniai investicijų vertinimo metodai, pateikti atskirų metodų privalumai ir trūkumai vertinant investicijų pagrindimą, išanalizuota valstybės politika investavimo klausimais ir teisinio šios sferos reguliavimo padėtis. Pateiktas UAB “GARDI DUONA” planuojamų investicijų atsipirkimo periodas, kai vykdomos investicijos. Pasirinktos šios alternatyvos: pastato ar patalpų pirkimas, pastato statyba, pastato ar patalpų nuoma. Investicijų pasirinktų alternatyvų efektyvumas vertinamas pagal dažniausiai naudojamus jautrumo analizės investicijų efektyvumo vertinimo metodus: grynąj�� dabartinę vertę (NPV), atsipirkimo periodą (Nok), vidinę grąžos normą (IRR), modifikuotą vidinę grąžos normą (MIRR) ir rentabilumą (U). Atlikus metodų analizę patvirtinama autorės suformuluota mokslinio tyrimo hipotezė, kad įmonėje priimamus sprendimus dėl investicijų pagrįstumo sąlygoja ne pavieniai rodikliai, o skaičiuojamų rodiklių nuoseklumas ir tarpusavio sąveika. / In this thesis work the proper chosen alternative investment strategy and its business substantiation are formulated, analysed and systemized theoretical investment methods of various authors of Lithuania and abroad, submitted advantages and disadvantages of separate methods by evaluating substantiation of investment; analysed the position of government politics under investment questions and legal regulation. In this work also is analysed the planned investments’ payback period of GARDI DUONA, UAB when investments are made and they are not. These alternatives are chosen: purchasing of building or accommodation, rent of building or accommodation. The effectiveness of chosen alternatives of investment is evaluating according to commonly used effectiveness evaluation methods of sensitivity analysis investment: NVP, Nok, IRR, MIRR and U.

During HIV-1 assembly, the Gag structural protein specifically encapsidates two copies of viral genomic RNA in the form of a dimer. An RNA stem-loop structure (SL1) in the 5' untranslated region, known as the dimerization initiation site (DIS), is important for dimerization and packaging of HIV-1 genomic RNA; however, the mechanisms involved are not fully understood. The major goal of this PhD study was to further understand HIV-1 RNA dimerization, and to study the role of the Gag protein in the dimerization and packaging processes. Despite the known involvement of the DIS in RNA dimerization, DIS-mutated viruses still contain significant levels of dimerized RNA, and electron microscopy studies suggest that the RNA molecules are linked at the extreme 5' end. We show here that RNA sequences on both sides of the DIS are also required for HIVA genome dimerization, suggesting that multiple RNA elements are involved. We have also examined the contribution of specific amino acids within Gag to the dimerization and packaging processes. Previous work showed that partial deletion of the DIS impacted on viral replication capacity, but could largely be corrected by compensatory point mutations within Gag. To further elucidate the mechanism(s) of these compensatory mutations, we generated DIS mutants lacking the entire SL1, or only the SL1 loop sequences, and combined these deletions with various combinations of compensatory mutations. Analysis of virion-derived RNA showed that the relevant mutant viruses contained increased levels of spliced viral RNA compared to wild type, indicating that a defect in genome packaging specificity was present. However, this defect was corrected by our compensatory mutations, and a T121 substitution in p2 was shown to be solely responsible for this activity. These results suggest that the p2 spacer peptide plays a critical role in the specific packaging of viral genomic RNA. In summary, these findings provide new insig

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