|
|
Study of organs of mice in inhalation experiments
Vrlíková, Lucie ; Diviš, Pavel (referee) ; Dočekal, Bohumil (advisor)
The diploma thesis is devoted to study potential risks for living organisms resulting from inhalation of nanoparticles of chosen heavy metals. The main aim of this work is the investigation of organs from experimental white mice after their guided inhalation of lead nanoparticles. The samples of liver and lungs from these animals are taken in time periods during the inhalation experiments and processed by specific methods for their evaluation. After pressurized microwave assisted decomposition of selected samples of mice organs in high purity concentrated nitric acid the content of lead is determined by atomic absorption spectrometry with electrothermal atomization. Furthermore, the changes are monitored using the microscopy of histological slides stained with hematoxylin-eosin. The results of both approaches are evaluated and compared within the frame of this work.
|
|
|
New resin gels for application in DGT technique
Trávníčková, Jana ; Řezáčová, Veronika (referee) ; Dočekal, Bohumil (advisor)
Diffusive gradients in thin films technique (DGT) is a simple preconcetration method for in situ determination of labile metal ions in aquatic systems. It eliminates contamination problems associated with the sampling and transport into the laboratory. The DGT technique is based on a simple device that accumulates metal ions on a cation-exchange resin, immobilized in thin layer of hydrogel, after passage through the diffusion layer. The cation-exchanger, usually Chelex 100, is selective for binding free or weakly complexed metal ions in solution. This diploma thesis deals with the characterization of a new resin gel based on ion exchanger with anchored thiol-functional groups, Spheron-Thiol, for DGT technique. This new binding agent with a high selectivity for „heavy“ metal ions could provide more information on the labile metal species in water systems. The performance of DGT technique with utilization of Spheron-Thiol resin was investigated by the determination of Cd, Cu, Ni and Pb under laboratory conditions. Due to the strong adsorption of copper to the Spheron-Thiol, it is necessary to decompose the resin gel in nitric acid prior to the determination. New resin gel provides reliable information of trace metal concentrations within the pH range 6 – 8 typical for natural waters. The effect of competitive ligands, iminodiacetic and humic acids, on Cd, Cu, Ni a Pb sorption on Spheron-Thiol and Chelex 100 resin gels was determined.
|
|
|
Investigation of Miniature Devices for Collection of Hydride Forming Elements in Atomic Spectrometry Methods
Krejčí, Pavel ; Čelechovská, Olga (referee) ; Janoš, Pavel (referee) ; Otruba, Vítězslav (referee) ; Dočekal, Bohumil (advisor)
Capability of a prototype of miniature collection device based on a strip of the molybdenum foil for collecting hydride forming elements (As, Se, Sb and Bi) was studied. The device was combined with a miniature hydrogen diffusion flame for detection by atomic absorption spectrometry. The conditions for trapping and subsequent vaporization of analytes of interest were optimized. A twin-channel hydride generation system was used for study of mutual interference effects of co-generated hydride forming elements. The influence of modification of the molybdenum surface with noble metals - Rh, Pt and Ir on trapping and vaporization processes was also studied and changes of microstructure of the foil surface after modification were investigated using scanning electron microscope equipped with energy dispersive x-ray analyzer and electron backscattered diffraction system. Complementary radiotracer and radiography experiments were performed in order to determine trapping efficiency and to assess the spatial distribution of collected analytes within the device. Practical application of the method was demonstrated on determination of antimony in water samples at trace level. Possibility of multi-element analysis was demonstrated by combining the collection device with atomization and excitation of the analyte in microwave induced plasma and with detection by atomic emission spectrometry method. The results of the experiments proved that tested miniature collection device is capable of trapping analytes that form volatile hydrides. This device can be coupled to various types of atomizers, typically used in spectrometry methods. Thus, very sensitive and specific detection of hydride forming elements can be performed.
|
|
|
Modification of Diffusive Gradient in Thin Films Technique for Characterization of Environmental Systems
Gregušová, Michaela ; Sommer, Lumír (referee) ; Janoš, Pavel (referee) ; Dočekal, Bohumil (advisor)
Diffusive gradient in thin film technique (DGT) represents a relatively new approach for in situ determinations of labile metal-species in aquatic systems. The DGT device passively accumulates labile species from the solution while deployed in situ, and therefore contamination problems associated with conventional collection and filtration procedures are eliminated. This study deals with a possible modification of DGT technique. The key of using DGT technique for speciation analysis of metals is to find out suitable binding phase and diffusion layer. The new resin gel based on Spheron Oxin (5 sulphophenyl-azo-8-hydroxyquinoline) ion exchanger with a higher selectivity to trace metals than Chelex 100 could potentially provide more information on metals speciation in aquatic systems. The performance of this new binding phase was tested for the determination of Cd, Cu, Ni, Pb and U under laboratory conditions. The hydrogel layer based on poly(2-hydroxyethyl methacrylate) was synthesized and tested as a new diffusion gel for application in DGT technique.
|
|
|
GENE EXPRESSION AND IMMUNOLOGICAL RESPONSE IN MICE EXPOSED TO ZnO NANOPARTICLES
Rössner ml., Pavel ; Vrbová, Kristýna ; Strapáčová, S. ; Rössnerová, Andrea ; Ambrož, Antonín ; Brzicová, Táňa ; Líbalová, Helena ; Javorková, Eliška ; Zajícová, Alena ; Holáň, Vladimír ; Kulich, P. ; Večeřa, Zbyněk ; Mikuška, Pavel ; Coufalík, Pavel ; Křůmal, Kamil ; Čapka, Lukáš ; Dočekal, Bohumil ; Šerý, Omar ; Machala, M. ; Topinka, Jan
We analyzed gene expression changes in the lungs and the immunological response in splenocytes of mice exposed by inhalation of ZnO nanoparticles - NP. Adult female ICR mice were treated for three days and three months, respectively. Analysis of differential expression in genes involved in oxidative stress was conducted using quantitative RT-PCR. The potential immunotoxic and immunomodulatory effects of ZnO NP were analyzed by phenotyping and cytokine production by splenocytes after three months exposure. Three days exposure resulted in down-regulation of GCLC, GSR, HMOX-1, NQO-1, NF-kB2, PTGS2 and TXNRD1 mRNA expression, three months exposure increased the expression of these genes. Three months exposure caused a significant decrease in the percentage of granulocytes in the spleen cells, and affected the production of IL-10 and IL-6 by lipopolysaccharide-stimulated leukocytes. In summary, our study revealed changes in the expression of genes involved in the oxidative stress response following acute ZnO NP exposure. Subchronic ZnO NP exposure induced immunomodulatory effects in the spleen.
|
|
|
Effect of inhaled metal oxide nanoparticles on organs of exposed mice
Mikuška, Pavel ; Večeřa, Zbyněk ; Dočekal, Bohumil ; Čapka, Lukáš ; Křůmal, Kamil ; Coufalík, Pavel ; Moravec, Pavel ; Buchtová, Marcela ; Míšek, Ivan ; Vrlíková, Lucie ; Smutná, Tereza ; Dumková, J. ; Hampl, A. ; Fictum, P.
Adult mice were continuously exposed to metal oxide nanoparticles for different time intervals. At the end of experiment, mice organs (lung, brain, kidney, liver and spleen) were collected for chemical, biochemical, histological and electron microscopical analyses.
|
|
|
Investigation of Miniature Devices for Collection of Hydride Forming Elements in Atomic Spectrometry Methods
Krejčí, Pavel ; Čelechovská, Olga (referee) ; Janoš, Pavel (referee) ; Otruba, Vítězslav (referee) ; Dočekal, Bohumil (advisor)
Capability of a prototype of miniature collection device based on a strip of the molybdenum foil for collecting hydride forming elements (As, Se, Sb and Bi) was studied. The device was combined with a miniature hydrogen diffusion flame for detection by atomic absorption spectrometry. The conditions for trapping and subsequent vaporization of analytes of interest were optimized. A twin-channel hydride generation system was used for study of mutual interference effects of co-generated hydride forming elements. The influence of modification of the molybdenum surface with noble metals - Rh, Pt and Ir on trapping and vaporization processes was also studied and changes of microstructure of the foil surface after modification were investigated using scanning electron microscope equipped with energy dispersive x-ray analyzer and electron backscattered diffraction system. Complementary radiotracer and radiography experiments were performed in order to determine trapping efficiency and to assess the spatial distribution of collected analytes within the device. Practical application of the method was demonstrated on determination of antimony in water samples at trace level. Possibility of multi-element analysis was demonstrated by combining the collection device with atomization and excitation of the analyte in microwave induced plasma and with detection by atomic emission spectrometry method. The results of the experiments proved that tested miniature collection device is capable of trapping analytes that form volatile hydrides. This device can be coupled to various types of atomizers, typically used in spectrometry methods. Thus, very sensitive and specific detection of hydride forming elements can be performed.
|
|
|
Modification of Diffusive Gradient in Thin Films Technique for Characterization of Environmental Systems
Gregušová, Michaela ; Sommer, Lumír (referee) ; Janoš, Pavel (referee) ; Dočekal, Bohumil (advisor)
Diffusive gradient in thin film technique (DGT) represents a relatively new approach for in situ determinations of labile metal-species in aquatic systems. The DGT device passively accumulates labile species from the solution while deployed in situ, and therefore contamination problems associated with conventional collection and filtration procedures are eliminated. This study deals with a possible modification of DGT technique. The key of using DGT technique for speciation analysis of metals is to find out suitable binding phase and diffusion layer. The new resin gel based on Spheron Oxin (5 sulphophenyl-azo-8-hydroxyquinoline) ion exchanger with a higher selectivity to trace metals than Chelex 100 could potentially provide more information on metals speciation in aquatic systems. The performance of this new binding phase was tested for the determination of Cd, Cu, Ni, Pb and U under laboratory conditions. The hydrogel layer based on poly(2-hydroxyethyl methacrylate) was synthesized and tested as a new diffusion gel for application in DGT technique.
|
|
|
Study of organs of mice in inhalation experiments
Vrlíková, Lucie ; Diviš, Pavel (referee) ; Dočekal, Bohumil (advisor)
The diploma thesis is devoted to study potential risks for living organisms resulting from inhalation of nanoparticles of chosen heavy metals. The main aim of this work is the investigation of organs from experimental white mice after their guided inhalation of lead nanoparticles. The samples of liver and lungs from these animals are taken in time periods during the inhalation experiments and processed by specific methods for their evaluation. After pressurized microwave assisted decomposition of selected samples of mice organs in high purity concentrated nitric acid the content of lead is determined by atomic absorption spectrometry with electrothermal atomization. Furthermore, the changes are monitored using the microscopy of histological slides stained with hematoxylin-eosin. The results of both approaches are evaluated and compared within the frame of this work.
|
|
|
New resin gels for application in DGT technique
Trávníčková, Jana ; Řezáčová, Veronika (referee) ; Dočekal, Bohumil (advisor)
Diffusive gradients in thin films technique (DGT) is a simple preconcetration method for in situ determination of labile metal ions in aquatic systems. It eliminates contamination problems associated with the sampling and transport into the laboratory. The DGT technique is based on a simple device that accumulates metal ions on a cation-exchange resin, immobilized in thin layer of hydrogel, after passage through the diffusion layer. The cation-exchanger, usually Chelex 100, is selective for binding free or weakly complexed metal ions in solution. This diploma thesis deals with the characterization of a new resin gel based on ion exchanger with anchored thiol-functional groups, Spheron-Thiol, for DGT technique. This new binding agent with a high selectivity for „heavy“ metal ions could provide more information on the labile metal species in water systems. The performance of DGT technique with utilization of Spheron-Thiol resin was investigated by the determination of Cd, Cu, Ni and Pb under laboratory conditions. Due to the strong adsorption of copper to the Spheron-Thiol, it is necessary to decompose the resin gel in nitric acid prior to the determination. New resin gel provides reliable information of trace metal concentrations within the pH range 6 – 8 typical for natural waters. The effect of competitive ligands, iminodiacetic and humic acids, on Cd, Cu, Ni a Pb sorption on Spheron-Thiol and Chelex 100 resin gels was determined.
|
guest ::
RSS feed.