National Repository of Grey Literature 56 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Polymeric nanofibrous carriers for local application of hydrophobic drugs - studying of the drug release profiles by HPLC
Hampejsová, Zuzana ; Bosáková, Zuzana (advisor) ; Pacáková, Věra (referee) ; Marie Tlusťáková, Marie (referee)
Immunosupresive and cytostatic drugs have many serious side effects which are dose dependent. Local application of drugs prolongs and increases the concentration of drug in the target place and, therefore, may reduce their serious side effects. Polymeric fiber carrier could be used as drug delivery system for local application. Polylactide (PLA) micro/nanofibers containing hydrophobic drugs (immunosupresive drug cyclosporine A and cytostatic drug paclitaxel) were prepared to study this potential medicinal application. Poly(ethylene)glycols (PEG) of various molecular weight (6, 20 and 35 kDa) were incorporated to the structure of fibers to improve compatibility of PLA-drug system and influence the release profiles of hydrophobic drugs. For the systematic development of these materials, it is important to describe the context of the preparation of nanofibers, their morphology and drug release profiles. Therefore, HPLC methods with tandem mass spectrometric or UV detection were optimized and validated to determinate the influence of composition of nanofibers on release kinetics of drugs to different medium (phosphate buffer, hydrogels). The nanofibers with added PEG released significantly higher amounts of drugs and prolonged the release time, compared to the fibers containing only drugs. A multiple...
Chromatographic characterization of polyaniline-coated stationary phases
Taraba, Lukáš ; Křížek, Tomáš (advisor) ; Pacáková, Věra (referee) ; Srbek, Jan (referee)
(EN) This dissertation thesis is focused on physicochemical and chromatographic characterization of polyaniline-coated stationary phases. In the first part, surfaces of bare silica and octadecyl silica sorbents were modified by in-situ chemical polymerization of aniline hydrochloride and their subsequent systematic characterization was performed by using the linear solvation energy relationship approach in the HILIC mode of capillary LC. In addition, several common physicochemical techniques were used to characterize properties of these altered materials. The modified sorbents were then packed into capillary columns. The retention interactions taking place between solute and the separation system were evaluated on the basis of retention data of a number of various solutes. The results showed that polyaniline coating had a significant effect on the retention promoting interactions of both polyaniline-coated stationary phases. The assumed mixed-mode retention mechanism was proven for both the stationary phases. The second part dealt with investigation of the separation potential of polyaniline- coated silica stationary phase in different chromatographic modes. The retention factor curves of structurally similar solutes were constructed as a function of organic modifier portion in the mobile phase....
Utilization of mass spectrometry for analysis of biologically active compounds
Kaliba, David ; Jelínek, Ivan (advisor) ; Pacáková, Věra (referee) ; Smrček, Stanislav (referee)
This PhD thesis provides a commented set of four publications. These publications are focused on capillary electrophoresis, liquid chromatography, and UV/Vis spectrometry used to study complexes of rhenium with aromatic ligands. The methods of mass spectrometry with soft ionization techniques, 1 H and 13 C nuclear magnetic resonance, and infrared spectrometry were used for structural characterization of the individual complexes. The complexes were synthetized in reactions of the rhenium precursor tetrabutylammonium tetrachlorooxorhenate with the corresponding ligand under both aerobic and anaerobic conditions. In the course of the research, it was revealed that the prepared complexes (with Re in the oxidation number +V and +VI) are unstable and their oxidation numbers change to another more stable form (Re+VII ). Sub-projects which were successfully implemented during the research were as follows:  Design and successful realization of the process of synthesis of selected rhenium complexes with aromatic ligands 1,2-dihydroxybenzene, 1,2,3-trihydroxybenzene, and 2,3-dihydroxynaphthalene in reactions with and without air access, and their structural characterization by ESI-MS, APPI- MS, LDI-MS, ESI-MS/MS, NMR, and IR.  ESI-MS SRM and UV/Vis time studies of the behaviour of primary rhenium complexes...
Analysis of biologically active substances by modern separation methods
Bierhanzl, Václav Matěj ; Čabala, Radomír (advisor) ; Pacáková, Věra (referee) ; Sýkora, David (referee)
The thesis is dedicated to the phospholipids and their polar headgroups analysis by gas chromatography, capillary electrophoresis and mass spectrometry. Phospholipids are the most important polar lipids and they are classified into phospholipid classes according to their phosphorylated groups. Phospholipids can be found in cell membranes and the changes in their ratio are monitored to research the impact of external conditions on cells. Actually thin layer chromatography is still used for phospholipid class ratio analyses. It is not suitable for microbiological research due to its time demandingness. The presented compendium of papers engaged in phospholipid classification is targeted on Bacillus subtilis strain, which produces potential antibiotics with detergent effect - surfactin. Published methods can be used for research of optimal conditions for producing microbe cultivation. Because non-polar parts of the phospholipid molecule (fatty acids) can affect the analysis methods on spliced polar headgroups have to be designed. Capillary electrophoresis and gas chromatography methods were developed and the latter one was further optimized for simultaneous analysis with fatty acids. Additional part deals with an alternative approach which consists in direct injection on mass spectrometer of intact...
Hybridly stabilized arc as a tool for biomass gasification and the degradation of water-soluble organic compounds
Hlína, Michal ; Pacáková, Věra (advisor) ; Jelínek, Ivan (referee) ; Pekárek, Stanislav (referee)
(EN) A plasma torch (the source of plasma) with Gerdien arc was utilized as the source of energy in a reactor for gasification of biomass and for the degradation of organic compounds dissolved in water circling around the arc where the dissolved compounds are exposed to an intensive ultraviolet radiation. Thermal plasmas have electrons, ions and neutrals in thermal equilibrium and are quite often characterized by higher pressures and temperatures than nonthermal plasmas. Therefore, thermal plasmas generally carry a huge amount of energy which can be employed for heating and subsequent gasification of various types of materials. Thermal plasma gasification reactors are operated at higher temperatures than conventional reactors which results in a very good composition with a high percentage of hydrogen and carbon monoxide in produced synthetic gas. Spruce sawdust and spruce pellets were gasified at feeding rates up to 60 kg/h. Oxidizing media such as water, carbon dioxide, oxygen or their mixtures had to be added to the reactor during experiments to avoid the formation of solid carbon. The compositions of produced gas significantly corresponded to calculated compositions and the produced gas was of high quality - hydrogen content approximately 45 % vol., carbon monoxide approximately 48 % vol., a...
Development of Methods for High-Throughput Enrichment of Glycoproteins and Glycopeptides Employing Multiple Lectin Affinity Chromatography/Tandem Mass Spectrometry
Maděra, Milan ; Pacáková, Věra (advisor) ; Feltl, Ladislav (referee) ; Foret, František (referee) ; Kučerová, Zdenka (referee)
5 CONCLUSIONS This thesis surrrnrarizes the development of a multimethodological analýical approach employing microcolumn lectin affi1t1,9fuom1tography coupled to highir".otu,to; separation and dete9tion techniques, in order to facilitate the enrichmení of glyco-proteins aná giycopeptioes originating from small quantities of real samples. This is u"toauy a sipificant-ítep towara satis$'ing the demands of contemporary glycoproteomics, which rely orirurt *a small scale analyses, allowing the identification of low abundant protein components' The overď conclusions and contribution to the contemporaÍy scierrce are drawn in tbree followine chaoters. 5.1 combining Lectin Microcolumns with High-Resolution separation Techniques for Enrichment of Glycoproteins and Glycopeptides This section describes coupling small-scďe lectin aÍfinity chromatograpby on-line to high- resolution separation and detection techniques, with the utiliý of a microcolumn loaded with a lectin immobilized onto macroporous silica. Experimental results, involving optimization of coupling procedure, fabrication of lectin microcolumns, verification of tteir Uin&ng efficiency and their possibility of interfacing on-line with nano LC-MS/]víS, me summarizžd into thé following conclusions; o optimized coupling procedure involved resuspending only 125...
Determination of persistent organohalogen pollutants using GC/MS/MS methods
Grabic, Roman ; Pacáková, Věra (advisor) ; Ševčík, Jiří (referee) ; Matisová, Eva (referee)
Conclusions o MSiMS methods for analysis of PCDD/Fs, PCBs, OCPs, and PBDES were develoPed o GC separations were optimized for MS/MS detection methods o GC/MS/MS optimized methods were validated. o Limits of quantification at level 0.1 - I pg/pl were achieved. o Linear response over four orders of magnitude was achieved except for some OCPs. o The selectivity of methods is better or comparable with a reference HRMS method' o Cost of GC/MS/MS analysis is significantly lower comPared to GC/HRMS o Developed methods were successfully applied for o Human blood, milk and adipose tissue analysis o Studies of de novo synthesis and destruďion of halogenated POP o In vitro study of PCB accumulation in human cells o List of application is enclosed Page 12
The survey of xenobiotics for toxicological and pharmaceutical purposes
Bořek-Dohalský, Václav ; Feltl, Ladislav (advisor) ; Pacáková, Věra (referee) ; Fischer, Jan (referee) ; Majstřík, Viktor (referee)
L INTRODUCTION Processes in the nature and also in the human organism are affected by conditions of its running. People are notably affecting their living con- ditions both positively and unfortunately negatively. The environment is exposed to countless human interventions - social impacts, influence of physical factors and chemical compounds. The chemical products belong into many conquests of the modern civilization, which are inherent part of our life. Except their benefit they could also have the negative effect in many cases. Acquiring data for new chemical compounds that are extraneous to organisms (xenobiotics) is difficult, but it is much more difficult to describe the effect of xenobiot- ics onto the living organisms. Toxicology deals with the adverse effects of these compounds; pharmacology is the practice of searching for their bene- ficial effects. My PhD thesis looks at both of these branches. I was en- gaged in possibilities of alternative testing of the acute toxicity of binary mixtures and possibilities of predicting the acute toxicity using the phys- icochemical descriptors of these mixtures in terms of toxicology. In the section covering pharmacology I worked on the development and valida- tion of analytical methods for the determination of drugs in a biological matrix. I' IL lI lfr' ffi...

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