National Repository of Grey Literature 28 records found  1 - 10nextend  jump to record: Search took 0.02 seconds. 

Study of allelopathic effects in species of Impatiens genus (Impatiens L.)
KREJČOVÁ, Jana
All three jewelweeds species (Impatiens. L.)contain series of secondary metabolites from category of phenolic substances, e.g. naphthoquinones. This substances belong to allelochemicals, they can to affect germinability and growth of other plants. The extracts from jewelweeds (leaves, roots) and their fractions can to affect negatively germinability and growth of the chosen weed's seeds. Knowledges of allelopathic effects in jewelweeds species on other plants might be of important impact on ecological farming in the implementing of alternative herbicides.

Influence of E/P copolymer composition on impact copolymer properties
Dostálová, Dagmar ; Kučera, František (referee) ; Buráň, Zdeněk (advisor)
Houževnatý E/P kopolymer se vyrábí polymerací v plynné fázi, která je katalyzovaná Ziegler–Nattovými katalyzátory. Tento materiál s výbornými mechanickými vlastnostmi je používán v mnoha průmyslových odvětvích, např. v automobilovém průmyslu na výrobu nárazníků aut a palubních desek. Jeho vlastnosti závisí na chemické struktuře, která byla zkoumána pomocí metod DSC, SSA, 13C NMR, ATREF a FTIR. Výsledky analýz byly porovnány s mechanickými vlastnostmi vzorků - modulem pružnosti v ohybu a nízkoteplotní vrubovou houževnatostí dle Charpyho. Pro studium vlivu složení na mechanické vlastnosti bylo použito 5 různých vybraných vzorků houževnatého kopolymeru E/P s různým poměrem ethylenu a propylenu v kopolymerní fázi, které byly frakcionovány pomocí o-xylenové extrakce za účelem rozdělení materiálu na krystalickou část, složenou z krystalického E/P kopolymeru a PP, a amorfní část, tvořenou E/P kaučukem. Získané frakce i původní vzorky byly následně analyzovány výše uvedenými metodami.

Study of atmospheric aerosol in Brno and Šlapanice
Mikuška, Pavel ; Vojtěšek, Martin ; Křůmal, Kamil ; Večeřa, Zbyněk
Contribution deals with comparison of chemical composition of atmospheric aerosols (size fraction PM1) and identification of emission sources of aerosols in large (Brno) and small city (Šlapanice).

The synthesis of thiamacrocycles and the study of their properties
Nejedlý, Jindřich ; Kroutil, Jiří (referee) ; Starý, Ivo (advisor)
The aim of this work is the study of a simple method of preparing macrocyclic ligands for complexation of fullerenes. Necessary attribute of those ligands is their construction of electron-rich building blocks, which are prerequisite for π-π interactions with electron- deficiency fullerene spherical systems. Tetrathiafulvalene (TTF) is a known electron-rich system and for this reason, 2,3-bis(butylthio)-6,7-bis(2-kyanoethylthio)- tetrathiafulvalene was chosen as a basic building block. The protecting cyanoethyl group in this derivative can be removed by the acting of a base and thus generated thiolate function group is used in alkylation reactions of bis(bromomethyl)aryls. In reactions of these two components of bifunctional alkylation reactions was produced (in addition to the prevalent oligomeric products) a mixture of macrocycles with different sizes, the number of included building units was marked as [2 +2], [3 +3] and [4 +4] macrocycles. Reactions of TTF derivative with 4,4'- bis(bromomethyl)biphenyl and 4,4'-bis(bromomethyl)diphenylether have been performed. Column chromatography fractions of cyclic products were in both cases analyzed by gel permeation chromatography, NMR spectroscopy. The performed study has shown, that an equipoise to the simplicity of the synthetic protocol are low yields of...

Study of the storage temperature influence on the weight of eye drops
Strážnická, Julie ; Šklubalová, Zdeňka (advisor) ; Šnejdrová, Eva (referee)
Charles University in Prague, Faculty of Pharmacy in Hradci Králové Department of: Pharmaceutical technology Consultant: Doc. PharmDr. Zdenka Šklubalová, Ph.D. Student: Julie Strážnická Title of Thesis: Study of the storage temperature influence on the weight of eye drops Eye drops are a conventional dosage form for a topical application of ophthalmic drugs. Even a size of an applied drop, being influenced by many factors, significantly affects bioavailability of the drug. The object of the thesis was research into an effect of storage temperature, the residual volume of the preparation ranging from 1 to 5 ml, and the dispensing angle on the weight of commercial eye drops. Based on the results, storage temperature 8řC and/or 25řC, respectively, and the residual volume did not significantly affect the weight of the eye drop. The significant effect of the dispensing angle on the drop weight was influenced due to the wetting of a dropper tip. With a dispensing angle of 90ř, an average weight of the drop was 30 mg for the non-wetted dropper tip, while an average weight of the drop approximately 35 mg was noted for the wetted dropper tip. Decreasing the dispensing angle from 90ř to 45ř from the horizontal resulted in significant increase in the weight of drop to 37 mg due to the formation of a drop from...

The study of effect of selenium on proliferation of cell lines isolated from colorectal carcinoma
Žmolilová, Hana ; Szotáková, Barbora (advisor) ; Šimůnek, Tomáš (referee)
Selenium is an essential trace element that is an integral part of many proteins, with catalytic and structural functions. The antioxidant properties of some selenoproteins, such as glutathione peroxidase, may be particularly important in having influence on carcinogenesis. Selenium exists in different chemical forms - inorganic (selenite, selenate) and organic forms (selenoaminoacids, selenoproteins). The bioavailability and cancer chemoprotective activity of selenium depend on the concentration and the chemical form in which it is present. I studied the effect of L-Selenomethionine and Se-methyl-L-selenocysteine on proliferation in three colorectal cell lines with different malignant potential (HT 29, SW 480, SW 620). Proliferation was measured by BrdU - ELISA with chemiluminiscent detection.

Extraction of beta-Sitosterol from the Stinging Nettle Root with Supercritical CO2
Sajfrtová, Marie ; Bártlová, Milena ; Sovová, Helena
The stinging nettle root contains both polar and non-polar biologically active substances. beta-Sitosterol (BS), the most important component of its neutral lipids, is active in the root extracts used for various alternative medicine treatments, including the reduction of enlarged prostate. Dry roots contaning 0.28 g/kg BS were extracted with CO2 at pressure 12-60 MPa and temperature 40-80 C. Though the maximum yield of BS was only 89 %, its concentration in extract was increased by 13 % compared to the extraction with hexane. Changing vials where the CO2 extract was collected, fractions with double and higher BS concentration could be obtained. The fractionation was simulated using a mathematical kinetic model of multicomponent extraction.
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Study of interspecies differences in plasma protein binding of 18F-labeled radiopharmaceuticals
Nováková, Dana ; Lázníček, Milan (advisor) ; Bárta, Pavel (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Mgr. Dana Nováková Consultant: Prof. PharmDr. Ing. Milan Lázníček, CSc. Title of Thesis: Study of interspecies differences in plasma protein binding of 18 F-labeled radiopharmaceuticals In this thesis, the binding ability of three radiopharmaceuticals containing radionuclide 18 F to the plasma proteins was examined in bovine, pig, human and rat plasma, and the interspecies comparison was performed. Examined radiopharmaceuticals included 18 F-FDG, 18 F-fluorocholine and 18 F-thymidine. The two main methods used are equilibrium dialysis and ultrafiltration. These methods are based on separation of free ligand from the linked component. During the separation, semi-permeable membrane and special filters (AMICON and VIVASPIN) were used for equilibrium dialysis and ultrafiltration, respectively. Free fraction of drugs is considered to be an important parameter for the availability of the drug distribution into the tissues and cells, interaction with receptors, excretion and metabolism. All experiments were carried out at the physiological temperature of 37řC. Obtained results indicate low plasma protein binding of the three radiopharmaceuticals in all studied species, which suggests...

Evaluation of energetic byproducts via selected ecotoxicity tests
Král, Petr ; Modlitbová, Pavlína (referee) ; Zlámalová Gargošová, Helena (advisor)
The topic of bachelor thesis is the study of ecotoxicity of energetic byproducts generated from the power industry. The theoretical part is focused on current problems concerning waste ecotoxicity testing namely on needs of ecotoxicity testing not only in terrestric but also in aquatic arrangement. In practical part selected energetic byproduct were evaluated via Acute toxicity test and Avoidance test on soil organism earthworm (Eisenia fetida) and Plant root growth inhibition test on letuce and onion (Lactuca sativa a Allium cepa). Luminescent bacteria test on Vibrio fischeri was also used. Obtained results served for evaluation of potential ecotoxicity of energetic byproducts discussion. It was found that test in contact arrangement is very important for complex evaluation of negative effects of matrices entering the ecosystem. Also the importance of test on luminescent bacteria Vibrio fischeri is not negligible, because provides additional information of effects on representatives of destruents as an important ecosystem function part.

Resuspension chamber as a tool for determination of resuspendable fraction of soil and street dust
Civiš, Martin ; Hovorka, Jan (advisor) ; Ždímal, Vladimír (referee) ; Střižík, Michal (referee)
A purpose-built cylindrical resuspension chamber (V=0.437 m3 , S=0.35 m2 , S/V=8.38) was used for the dispersion of samples of soil and various kinds of dust. The samples were studied from the point of view of the number and mass distribution of aerosol particles which could affect the concentration of atmospheric aerosol. The samples were taken from lignite, power plant flue ash and from overburden soil in the North Bohemian surface mine Nastup. The individual samples were pneumatically dispersed inside the chamber under defined temperature-humidity conditions (20řC and relative humidity (RH) 50 %). An APS (Aerodynamic Particle Sizer) processing provided us with average size distributions of particle mass and number. Lignite and flue ash probably have the greatest potential impact on the concentration of atmospheric aerosol in the studied locality. The amount of the resuspended mass of the samples varied between 0.001 % (overburden soil) and 0.32 % (mine road). The lignite and flue ash samples were then analyzed by gravimetric methods using the HI (Harvard Impactor) and the SCI (Sioutas Cascade Impactor). The flue ash contained higher amounts of fine particles than the lignite. Subsequent chemical analysis by electron microscope of the filters with deposits of power plant flue ash showed that the PM2.5...