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Antimicrobial effect of agents predestined for prevention of contamination IV.
Grätzová, Michaela ; Jílek, Petr (advisor) ; Křivčíková, Lucie (referee)
Author: Michaela Grätzová Title: Antimicrobial effect of agents predestined for prevention of contamination IV Master's thesis Charles university in Prague, Faculty Of Pharmacy Study program: Pharmacy Background In this research we studied the antimicrobial characteristic of paint coats, which had a different concentration of zinc oxide (0%; 4%; 15,2%). We investigated the effect of ultraviolet radiation in antimicrobial activity of paint coats. Methods Bacteria being tested included E. coli, S. aureus and C.albicans. We left the suspension of bacteria in contact with paint coats and we taken samples in defined time intervals. The first part of samples was irradiated by UV radiation for 30 minutes before application of microbial suspension. The second part of samples was irradiated by UV radiation for 30 minutes at the same time with microbial suspension. The third part of samples was not irradiated by UV radiation. The results were evaluated by bacterial colony plate counting. Results The paint coats have antimicrobial activity even without application of UV radiation. UV radiation enhances the antimicrobial properties and activates paint coats. Conclusions We have demonstrated the antimicrobial effects against all of the three species of bacteria. The most antibacterial result was against E...
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Evaluation of oxidative stress markers after intoxication with nerve agents and treatment with acetylcholinesterase reactivators
Mercová, Miroslava ; Opletal, Lubomír (advisor) ; Mladěnka, Přemysl (referee)
53 ABSTRACT Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany and Ecology Candidate: Miroslava Mercová Consultant: Doc. RNDr. Lubomír Opletal, CSc. Title of Thesis: Evaluation of oxidative stress markers after intoxication with nerve agents and treatment with acetylcholinesterase reactivators In this study, the influence of soman poisoning and treatment with atropine and some oximes on redox status in rat erythrocytes, liver and plasma were investigated. Male Wistar rats were divided into eight groups, each of six animals. The first group was exposed to atropine only, the second group to one LD50 of soman and atropine. The groups 3-7 were treated with soman, atropine and one of named oximes (HI-6, trimedoxime, K203) or with their combinations (HI-6 + trimedoxime, HI-6 + K203). The control (eighth) group was treated with saline solution only. To study the markers of oxidative stress the TBARS method (thiobarbituric acid reactive substances), glutathion reductase activity and the FRAP (ferric reducing antioxidant power) method were chosen. There was plasma protein content and acetylcholinesterase activity assessed, too. The experimental data showed significant alterations in followed parameters. The presence of oxidative stress is offset by enhanced...
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Reduction of nitrogen oxides in flue gas on special filter materials
Sirový, Martin ; Jecha, David (referee) ; Jedlička, Filip (advisor)
This thesis deals with the reduction of oxides of nitrogen (NOx) which are part of the exhaust gas combustion devices. The focus is on reduction of NOx by selective catalytic reduction (SCR) and catalyst filtration. The first part of this work deals with the formation of NOx, their hazards and related legislation. The following is an overview of the available technologies to reduce NOx in the flue gas and comparison of this methods. The following section describes the experimental catalytic filtration unit INTEQ II, where the first real experiment selective catalytic reduction of NOx with ammonia was realized. We have verified the operability of the experimental units and achieve up to 80% efficiency SCR. The final section describes the progress of the experiment and its results. It is recommended a few minor adjustments to improve stabile operation of unit INTEQ II.
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Study of manganeese oxides properties by the EQCM method
Pléha, David ; Špičák, Petr (referee) ; Novák, Vítězslav (advisor)
The present work deals with the use of manganese oxide as a catalyst for positive electrode of fuel cells. The theoretical part is to analyze the problem of fuel cells, focusing on lowtemperature fuel cells. Are discussed and the methods of measurement and evaluation of properties of manganese oxide layer. The practical part deals with doping electrolytic manganese dioxide salts of divalent metals and monitoring their behavior in the cyclic voltammetry by the EQCM method.
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Machinable bioceramics prepared by gelcasting method
Kolář, Martin ; Částková, Klára (referee) ; Trunec, Martin (advisor)
In the diploma thesis, overviews of the existing literature focused on the gelcasting method and based on the findings were prepared aqueous slurries of zirconium oxide for gelcasting method. These suspensions were examined for the influence of the content ceramics powder, type and content of dispersants and volume of initiator on viscosity of aqueous suspensions and process of polymerization. Optimum ceramic suspension had 45 vol.% of ceramic powder which was stabilized by 0,5 weight % of dispersant Dolapix CE 64. Polymerization running at room temperature was initiated by 0,175 weight % of ammonium persufate without accelerator. Microstructure of prepared ceramic blanks and sintered bodies was compared with body prepared by isostatic pressing. For the machining tests were prepared blanks in disc-shaped.
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Plasma preparation of metal and oxide layers on ceramic and plastic substrates.
Olejníček, Jiří
Contract research was focused on preparation and optimization of the plasma deposition process of selected thin metal and semiconducting oxide layers with required optical properties. The goal was to prepare transparent color electrochromic films on thermally sensitive substrates, the layers with high refractive index on the surface of pressed plastic structures and shiny metallic films on the porous ceramic masks.\n
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Influence of latent toxoplasmosis on sex ratio and pregnancy progression - search for proximate cause
Kaňková, Šárka ; Flegr, Jaroslav (advisor) ; Votýpka, Jan (referee) ; Calda, Pavel (referee)
The boy-to-girl ratio at birth (secondary sex ratio) is around 1.06 in most populations. The sex ratio may be influenced by many factors, such as stress and immunosuppression, age of parents, parity and sex of preceding siblings. The most common human protozoan parasite in developed countries, Toxoplasma gondii (prevalence 20% - 80%), is known to change the behaviour of its intermediate hosts, thereby increasing the probability of transmission to its definitive host (the cat) by predation. The results of our retrospective cohort study suggest that the presence of Toxoplasma gondii, can influence the secondary sex ratio in humans. Depending on the antibody concentration, the probability of the birth of a boy can increase up to a value of 0.72, which means that for every 260 boys born, 100 girls are born to women with the highest concentration of anti-Toxoplasma antibodies. In accordance with results on human subjects, laboratory mice with toxoplasmosis produced a higher sex ratio than controls, in the early phase of latent infection. Our further results showed that mice in the early phase of latent infection exhibited temporarily increased production of interleukin (IL)-12 and decreased production of IL-10. The mice showed decreased production of IL-2 and nitric oxide and decreased proliferation...
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Hyperfine interactions in maghemite and magnetite particles
Křišťan, Petr ; Štěpánková, Helena (advisor) ; Procházka, Ivan (referee)
Thesis is aimed at studying of magnetic iron oxide particles of submicron and nanoscale dimensions by means of nuclear magnetic resonance (NMR). 57 Fe NMR inves- tigations were carried out in composite bentonite/maghemite with respect to tempera- ture of calcination (Tcalc) during the sample preparation and in magnetite submicron powders with respect to various range of the particles size. One of the main findings is that increasing Tcalc improves resolution in the NMR spectra, which is most likely connected with higher degree of atomic ordering in the spinel structure. Evaluating the integral intensities of NMR spectra allowed us to determine the relative content of maghemite phase in particular samples of the series: the content rapidly grows for Tcalc up to ∼420 deg. An approach to distinguish signal from tetrahedral and octahedral irons was developed and tested on pure maghemite sample. Analysis based on vacancy- distribution models was performed in the spinel structure and the results were compared to the experiment. 57 Fe NMR spectra in submicron magnetite samples were found to differ markedly from spectrum of a single crystal. It was concluded that the investigated powders possess high amount of defects in the crystal structure or contain additional phase (probably closely related to the maghemite phase).
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Bioproduction, Characterization and Application of Selected Biopolymers
Benešová, Pavla ; Pekař, Miloslav (referee) ; Čertík, Milan (referee) ; Márová, Ivana (advisor)
Proposed doctoral thesis deals with microbial production of biopolymers (polysaccharides and polyesters) using renewableble inexpensive resources as carbon and nitrogen source. At first, production of extracellular metabolites, mainly pullulan and poly-L-malic acid, by polymorphic microorganism Aureobasisium pullulans was studied. Further part of thesis was focused on production of bacterial biopolyesters polyhydroxyalkanoates (PHA). PHA are produced in the form of intracellular granules by various bacteria species. During the study of PHA production, sythesis of poly(3-hydroxybutyrate) and technologically significant copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) was investigated as well with regard to waste substrate utilization in biorafinery concept. Spent coffee ground seemed to be applicable waste in biorefinery proces. One of the coffee wastes used for PHA production was spent coffee ground hydrolysate which was converted to PHA by Burkholderia cepacia. Moreover, copolymer of 3HB and 3HV was accumulated when SCGH was used as a sole carbon source, no precursor had to be added. Another coffee waste, which was utillized by Cupriavidus necator H16, is represented by oil extracted from spent coffee grounds. Hydrolysis proces of waste substrates had to be optimized, to reach the highest possible saccharide concentration. Due to the hydrolysis process several toxic compounds can be formed, hence, influence of hydrolysis procesings on polyphenols content in hydrolysates was monitored. Waste substrates were also tested as potentional complex nitrogen source for PHA production. Hydrolysates of cheese whey and chicken feather were used as inexpensive complex nitrogen source for PHA production by C. necator, when waste frying oil was used as a carbon substrate. The finnal part of the thesis is dealing with possibilities how the PHA can be processed into atractive aplication forms. Liposomes with partial content of PHB had been prepared, moreover, for improving of antioxidant activity and antimicrobial effect the waste coffee oil was added. Micro-fibrous PHB materials were prepared for the purposes of water filtration. Higher filtration effectivity was observed when composite PHB fibrous material containing active charcoal or metal oxides was used. Important part of thesis is represented by study of degradation processes of prepared PHA-based aplication forms. Various microorganisms were tested on PHA depolymerases production. Biodegradability of PHA materials was tested in of composting conditions by standard composting test IS/ISO 20200. Changes in mechanical properties of polyurethan, where polyol was partialy replaced by PHB, were tested depending on the exposure of composting condition.
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Determination of kadmium content in plant tissue of Norway Spruce and European Beech after application of cadmium oxide nanoparticles
Svozilová, Eva ; Mikuška,, Pavel (referee) ; Večeřa, Zbyněk (advisor)
The aim of this thesis is to monitor cadmium content in needles of Norway spruce and European beech leaves after controlled exposure to cadmium oxide nanoparticles and evaluate the potential risks of such nanoparticles to plants. Needles and leaves were harvested after a one-week and two-week exposure and prior to analysis of cadmium content, they were modified using relevant procedures. Samples were mineralized in nitric acid using pressurized microwave mineralizer and subsequently analyzed by atomic absorption spectrometry (AAS) with electrothermal atomization of cadmium content. Based on the results AAS analysis the transport of nanoparticles into the plant tissue of studied species was evaluated, comparing the content of cadmium in one week and two weeks experiment in the washed and unwashed samples of needles and leaves.
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