Affinity capillary electrophoretic study of K+/Na+ selectivity of hexaarylbenzene-based polyaromatic receptor

Affinity capillary electrophoretic (ACE) study has proved the selectivity of hexaarylbenzene-based polyaromatic receptor (R) for K+ ion over Na+ ion. The apparent binding constants of the R complexes with K+ and Na+ ions were determined from the dependence of effective electrophoretic mobility of R on the concentration of the above alkali metal ions in the background electrolyte using a non-linear regression analysis. The apparent binding constants (Kb) of the K-R+ and Na–R+ complexes in methanolic medium were evaluated as log Kb = 3.20 ± 0.22 for the K–R+ complex, and log Kb≅−0.7 for the Na–R+ complex

Mono-\u3cem\u3eN\u3c/em\u3e-acyl-2,6-diaminopimelic Acid Derivatives: Analysis by Electromigration and Spectroscopic Methods and Examination of Enzyme Inhibitory Activity

Thirteen mono-N-acyl derivatives of 2,6-diaminopimelic acid (DAP)—new potential inhibitors of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE; EC 3.5.1.18)—were analyzed and characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies and two capillary electromigration methods: capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC). Structural features of DAP derivatives were characterized by IR and NMR spectroscopies, whereas CZE and MEKC were applied to evaluate their purity and to investigate their electromigration properties. Effective electrophoretic mobilities of these compounds were determined by CZE in acidic and alkaline background electrolytes (BGEs) and by MEKC in acidic and alkaline BGEs containing a pseudostationary phase of anionic detergent sodium dodecyl sulfate (SDS) or cationic detergent cetyltrimethylammonium bromide (CTAB). The best separation of DAP derivatives, including diastereomers of some of them, was achieved by MEKC in an acidic BGE (500 mM acetic acid [pH 2.54] and 60 mM SDS). All DAP derivatives were examined for their ability to inhibit catalytic activity of DapE from Haemophilus influenzae (HiDapE) and ArgE from Escherichia coli (EcArgE). None of these DAP derivatives worked as an effective inhibitor of HiDapE, but one derivative—N-fumaryl, Me-ester-DAP—was found to be a moderate inhibitor of EcArgE, thereby providing a promising lead structure for further studies on ArgE inhibitors

N,N′-Diethyl-N,N′-diphenyl­pyridine-2,6-dicarboxamide

The asymmetric unit of the title compound, C23H23N3O2, contains two mol­ecules in both of which, one amide N atom is in a syn position with respect to the pyridine N atom, while the other amide N atom is in an anti position (the syn--anti conformation). There are minor conformational differences between the two mol­ecules, as reflected in the Npyridine—C—C—Namide torsion angles of −44.9 (3) and 136.0 (2)° for one mol­ecule and 43.5 (3) and −131.1 (2)° for the other mol­ecule. However, the two mol­ecules show significant differences in the orientation of an ethyl group, with corresponding C—C—N—C torsion angles of 86.6 (3)° for one mol­ecule and 79.6 (3)° for the other mol­ecule. In the crystal, mol­ecules are linked by weak C—H⋯O hydrogen bonds, forming a three-dimensional supra­molecular network

Comparison of two dimensional computer codes on the case study of the flow computation of the river Bolska near Gomilsko

V diplomski nalogi so z dvodimenzijskimi programi PCFLOW2D, MIKE 21 ter MIKE Flood izvedeni izračuni z različnimi pretoki za reko Bolsko pri Gomilskem. Na začetku sta opisana vodotoka Bolska in Trnavca ter računsko območje, ki je bilo modelirano. Izveden je bil tudi terenski ogled območja, da se je nato lažje določilo različne koeficiente. V nadaljevanju so opisane teoretične osnove računanja pri uporabljenih programih ter priprava računskega modela za posamezne programe. Na podlagi zahtevnosti vnosa računskega modela ter dobljenih rezultatov so na koncu podane prednosti in slabosti posameznih programov ter analizirane razlike v izračunanih poljih hitrosti in globinah.In this diploma thesis, I carried out calculations of various flows for the Bolska river below the town of Gomilsko by two-dimensional programmes PCFLOW 2D, MIKE 21, and MIKE Flood. In the beginning, the Bolska and Trnavca watershed and modelled calculation domain are described. I also performed site surveys of the area in order to define various coefficients more effectively. Moreover, the background of the calculation of specific programmes and the preparation of the calculation model for individual programme is briefly described. Based on the complexity of the input of the calculation model and the obtained results, I finally set out the advantages and weaknesses of each programme and analysed the differences of calculated velocity fields and water depths

Developement of cretit rating in the debt crises - the situation of Italy

The thesis is primarily focused on the methodology of credit rating and characteristic aspects of each of the evaluated areas. The knowledge acquired in the first part are then applied in the second part to the situation of Italy during the debt crisis. The thesis is aimed to the developement of sovereign rating of the country. Whitin selected topic I am focused on the evaluation criteria and I poin out the qualitative and quantitative characteristics of this process. Sub-goal of the thesis is to determine the role of rating agencies in the developement of the global financial crisis, which caused the recession and was gradually transformed into a debt crisis

Investigation of peptide complexes with small cations and cyclodextrins by capillary affinity electrophoresis

Capillary affinity electrophoresis was applied to quantitative evaluation of the strength of the complexes of i) valinomycin, macrocyclic dodecadepsipeptide ionophore, with small cations (ammonium and alkali metal ions, Li+, Na+, K+, Rb+ and Cs+) in methanol, and ii) enantiomers of dipeptide beta-alanyl-D,L-tyrosine and its derivatives with a chiral selector, 2 hydroxypropyl-beta-cyclodextrin (2-HP-beta-CD), in water

Návrh provozní diagnostiky hydraulického obvodu zvedcího a nakládacího zařízení montovaného na nákladní automobily

Import 20/04/2006Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta strojní. Katedra (338) hydromechaniky a hydraulických zařízen

Recent applications of capillary electrophoresis to analysis and physicochemical characterization of peptides

Recent developments in the methodology of capillary electrophoresis are presented with respect to their application to analysis, separation and physicochemical characterization of biologically active peptides. New strongly acidic/basic classical and isoelectric background electrolytes were applied to high-sensitive analysis and high-efficient separations of structurally related peptides, such as insect oostatic and antimicrobial peptides, phosphinic pseudopeptides and tryptic peptide fragments of proteins from native and genetically modified maize species

Separace a charakterizace stereoizomerů peptidů a pseudopeptidů kapilární elektroforézou

Capillary zone electrophoresis has been applied to separation of diastereomers of phosphinic pseudopeptides in achiral media, and to separation of enantiomers of antimicrobial dipeptide beta-alanyl-L,D-tyrosine in chiral media using beta-cyclodextrin as chiral selector