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The role of dispersion medium on nanoparticle aggregation and size in biological systems
Červená, Tereza ; Rössnerová, Andrea ; Závodná, Táňa ; Vrbová, Kristýna ; Sikorová, Jitka ; Topinka, Jan ; Rössner ml., Pavel
The use of nanomaterials (NMs) in different areas has been rising for more than a decade. Along with this growth, there is visible development of different testing tools and approaches for measuring the actual size of nanomaterials in biological systems. Test conditions during in vitro toxicological assays are different from the standard conditions under which nanomaterials are characterized and careful evaluation of results is needed. The unique properties and range variety of NMs require the close look how the NMs behave in different dispersion medium over time. In this study we present the results of five types of well-characterized NMs (TiO2: NM-101 and NM-103, SiO2: NM-200, Ag: NM-300K and NM-302) of specific size and shape. The hydrodynamic size and Zeta potentials in suspensions were measured using a dynamic light scattering technique (DLS) (Zetasizer Nano ZS, Malvern, UK). The DLS method is suitable for spherical particles, nevertheless, all samples were measured in order to obtain a rough insight into agglomerate formation in the medium. NM300, NM302, and NM200 aggregated rapidly in the media, thus the cells would be most likely exposed to settled big aggregates then small clusters or individual particles. More stable NMs (NM100 and NM103) showed slight grow along with cultivation time or concentration corresponding to cluster formation. Cells exposed to those NMs would be in contact with small clusters and aggregates of NMs. Measured zeta potentials fluctuated around the stability limit corresponding to observed aggregation.
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Ekonomická analýza společnosti DŘEVO-MÁLEK s. r. o.
Červená, Tereza
The Bachelor Thesis deals with an economic analysis of DŘEVO – MÁLEK, s. r. o. for the selected reference period of 2013 – 2017. The main objective of the thesis was to assess the economic situation of the company, which is active in the forestry and timber sector, using the financial statements of the company’s financial accounting. The thesis evaluates the developments in the absolute indicators in the asset and capital structure and the developments in the absolute indicators of the profit and loss account. To analyse the financial situation of the company, ratio indicators of the financial analysis were applied with the emphasis put on assessing the dynamics of the developments in the important economic indicators by means of an elementary characterisation of the time series. Finally, the thesis evaluates the economic situation of the enterprise and provides proposals for improving the situation of the enterprise.
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GENOTOXICITY OF NANOMATERIALS IN BEAS-2B CELLS ANALYZED BY THE IN VITRO MICRONUCLEUS ASSAY
Rössnerová, Andrea ; Červená, Tereza ; Brzicová, Táňa ; Vrbová, Kristýna ; Sikorová, Jitka ; Topinka, Jan ; Rössner ml., Pavel
The tremendous increase of the use of nanomaterials (NMs) has been witnessed during the last decade in many areas of human life including the chemical industry, cosmetics, biomedicine or food technology. The variety of NMs, their unique properties, almost ubiquitous presence and the size range of 1-100 nm raised the interest of toxicologists. The evaluation of the frequency of micronuclei (MN) as a result of the genotoxic events is a broadly utilized and well-established approach in in vitro studies for testing the risk of chemical exposure. Nevertheless, properties of the NMs give rise to the questions concerning the optimal methodological variants of the MN assay. \n\nIn our study, five types of well-characterized NMs (TiO2: NM-101 and NM-103, SiO2: NM-200, Ag: NM-300K and NM-302) of specific size, shape, or e.g. dimensions of aggregates were involved in the genotoxicity testing using four variants of protocols differing in the time of NM exposure, application of cytochalasin-B combined with simultaneous and delayed co-treatment with nanoparticles (NPs). Bronchial epithelial cells (BEAS-2B) were used in this study to fulfil these tasks. Presence of NPs was controlled by transmission electron microscopy (TEM). \n\nObtained results showed the different genotoxic potential of the various TiO2 and Ag NMs (NM-101< NM-103 and NM-300K> NM-302, respectively). Comparison of all testing strategies revealed, that the level of DNA damage can differ based on the time of exposure and the methodological approach. In general, using cytochalasin-B led most frequently to the increase of the genotoxic potential of the tested NMs.
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The use of BEAS-2B cell line for micronucleus assay in genetic toxicology
Červená, Tereza ; Rössner, Pavel (advisor) ; Rubeš, Jiří (referee)
This thesis deals with the application of BEAS-2B cell line for micronucleus assay in genetic toxicology. It is divided into two main parts: a) theoretical introduction to the analysis and search for suitable models for testing the impact of air pollution and manufactured nanoparticles, b) practical part that describes the results of micronuclei induction by polycyclic aromatic hydrocarbons (PAHs), extractable organic matter (EOM) from diesel exhaust particles obtained from emissions of three types of fuel and engineered nanoparticles. BEAS-2B cell line is a nonmalignant human model of lung epithelium which seems to be suitable for micronucleus assay. This assay is commonly used for determining the genotoxicity of various substances to wide variety of cell cultures and also in human studies. In this thesis, the following substances were tested: benzo[a]pyrene, 3-nitrobenzanthrone and 1-nitropyrene as carcinogenic PAHs commonly found in polluted air; EOMs from exhaust particles of 100 % diesel fuel, a blend of diesel fuel and 30 % of biodiesel, 100 % biodiesel and two types of engineered nanoparticles (TiO2 and Ag). The cells were treated with the compounds for 28, 48 and 72 hours. The results confirm the suitability of BEAS-2B cell line as a model for testing the genotoxicity of substances under...
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The use of DNA analysis in kinship studies and investigation of distant biological relationship of people
Červená, Tereza ; Šimková, Halina (advisor) ; Korabečná, Marie (referee)
AJ The thesis deals with the possibilities and problems of DNA analysis in its use in kinship studies and investigation of distant biological relationship of people. It presents a summary of useful DNA markers with a focus on linking autosomal markers and lineage markers - mtDNA and Y-STR; characterizes the typical heredity of individual types of markers and explains the basic principles of interpretation of their analysis. The research also deals with computer software exploited in statistical calculations; case studies, specific examples of the use of DNA analysis in kinship studies and investigation of distant biological relationship of people are also included at the final section. Key words DNA analysis, genealogy, kinship study, STR, SNP, DNA marker
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Dendrological survey of selected vegetation in the property of Blatná city
Červená, Tereza ; Janeček, Vladimír (advisor) ; Bažant, Václav (referee)
Trees and green areas have always had in general a positive effect to human beeings. Our ancestors were very well aware of this fact during building and widening cities and therefore they created various forms of parks, gardens or alleys. Although these did not correspond to a form as we know it nowadays they still fulfilled the various social or environmental functions. It was important to take care about this greenery and always keep an overview. This aspect became more important as time goes by. This diploma thesis aims to evaluate the status of selected assets of the greenery in the town of Blatna. The status is based on the dendrology revision. During the revision the basic dendrology and qualitative values were identified. Within this work I would like to propose some measures and other following steps and modifications which should help to increase the attractiveness of some less used areas and improved the related green functions. The valuation of the five the most valuable specimens was conducted according to the methodology AOPK ČR. The project created in AutoCAD software which should serve and help to visualize the monitored areas is the last outcome of this paper.
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