National Repository of Grey Literature 45 records found  previous11 - 20nextend  jump to record: Search took 0.00 seconds. 
Influence of inhaled manganese oxides nanoparticles on mass of internal organs in mice
Zeman, T. ; Dočekal, Bohumil ; Mikuška, Pavel ; Buchtová, Marcela ; Míšek, Ivan ; Šerý, Omar ; Večeřa, Zbyněk
Results of the statistical analysis of a long-term inhalation experiment on laboratory mice are presented. During 17 weeks of the experiment, the experimental group was exposed to inhaled manganese oxides nanoparticles. Manganese oxides (MnO center dot Mn2O3) nanoparticles (MnONPs) were synthesized continuously via aerosol route in a hot wall tube flow reactor using a thermal decomposition of metal organic precursor manganese(II) acetylacetonate in the flow tube reactor (in vertical position) at temperature 750 degrees C in the presence of 30 vol% of oxygen. The concentration of produced MnONPs at the reactor output was in the range 1-3 x 10(7) particles/cm(3) and the size of generated nanoparticles MnO center dot Mn2O3 was in the range 7-50 nm. Before entering the inhalation chamber, MnONPs in the mixture of N-2, O-2 and air (at total flow rate of 3 L/min) were further diluted using filtrated humidified air (20 L/min) at temperature 21 degrees C resulting in the MnONPs concentration 2 x 10(6) particles/cm(3). At regular time intervals the mass of selected internal organs of mice from both experimental and control group was assessed. It has been proven that inhaled nanoparticles are able to influence the mass of internal organs of mice. Statistically significantly lower mass of kidneys, liver and spleen and higher mass of pancreas have been found in the experimental group compared to the control group.
Influence of inhaled manganese oxides nanoparticles on mass of internal organs in mice
Zeman, T. ; Dočekal, Bohumil ; Mikuška, Pavel ; Buchtová, Marcela ; Míšek, Ivan ; Šerý, Omar ; Večeřa, Zbyněk
Results of the statistical analysis of a long-term inhalation experiment on laboratory mice are presented. During 17 weeks of the experiment, the experimental group was exposed to inhaled manganese oxides nanoparticles. Manganese oxides (MnO.Mn2O3) nanoparticles (MnONPs) were synthesized continuously via aerosol route in a hot wall tube flow reactor using a thermal decomposition of metal organic precursor manganese(II)acetylacetonate in the flow tube reactor (in vertical position) at temperature 750 °C in the presence of 30 vol% of oxygen. The concentration of produced MnONPs at the reactor output was in the range 1-3 × 107 particles/cm3 and the size of generated nanoparticles MnO.Mn2O3 was in the range 7-50 nm. Before entering the inhalation chamber, MnONPs in the mixture of N2, O2 and air (at total flow rate of 3 L/min) were further diluted using filtrated humidified air (20 L/min) at temperature 21 °C resulting in the MnONPs concentration 2 × 106 particles/cm3. At regular time intervals the mass of selected internal organs of mice from both experimental and control group was assessed. It has been proven that inhaled nanoparticles are able to influence the mass of internal organs of mice. Statistically significantly lower mass of kidneys, liver and spleen and higher mass of pancreas have been found in the experimental group compared to the control group.
Atomic absorption spectrometry
Dočekal, Bohumil
Atomic absorption spectrometry is one of the most useful methods applied in trace element analysis, particularly due to high sensitivity and due to relatively low investment and operational costs. This method enables to determine up to 60 elements, metals and metalloids, within a wide concentration range from ug.l-1 to tenth of g.l-1. The contribution deals with fundamental principles of the method and instrumentation, including light sources, optical systems and modern background correction techniques. It systematically describes flame and flameless atomization and sample introduction techniques. Basic analytical parameters of the method, detection power, sensitivity, dynamic working range, standardization approaches, methodology, quality control and assurance are also discussed.
Inhalation of nanoparticles MnxOy
Mikuška, Pavel ; Večeřa, Zbyněk ; Dočekal, Bohumil
Contribution deals with inhalation of nanoparticles MnxOy by small experimental animals and with study of Mn allocation in organs of exposed mice. Content of Mn in organs of exposed mice was compared with content of Mn in organs of control mice that were not exposed to inhalation of MnxOy nanoparticles.
Characterization of atmospheric particulate matter by diffusive gradient in thin film (DGT) technique
Gregušová, Michaela ; Dočekal, Bohumil
In this study, characteristics of heavy metal contamination in road dust collected from urban area with heavy traffic in Brno, Czech Republic was investigated. The DGT probes were exposed in aqueous suspensions of particulate matter for different time periods to monitor responses of the sample matter. The road dust and DGT sorption gels were decomposed by microwave assisted extraction and analyzed by inductively coupled plasma mass spectrometry for estimation of trace metals contents. The results revealed that the traffic appears to be responsible for the high levels of Cu, Pb, Ni and Sb and also that DGT technique, as alternative to conventional extraction procedures is a useful tool for characterization of metals mobility.
New modification of diffusive gradient in thin film technique (DGT) for determination of metals in sediments
Gregušová, Michaela ; Dočekal, Bohumil
The diffusive gradient in thin film (DGT) technique has been used for measuring fluxes and concentrations of labile metal species in waters, soils and sediments. The DGT probes offer a number of advantages over other conventional monitoring techniques as grab sampling, by reducing the errors of sample storage and transportation. Spatially resolved DGT responses were indicative of local redistribution of uranium in naturally uranium poor and rich sediments.
Morfologie‚ chemická a toxikologická charakteristika pouličního prachu a suspendovaných prachových částic‚ včetně určení zdrojů původu
Centrum dopravního výzkumu, v.v.i., Brno ; Del favero, David ; Dočekal, Bohumil ; Večeřa, Zbyněk ; Mikuška, Pavel ; Ličbinský, Roman ; Huzlík, Jiří ; Adamec, Vladimír
Cílem řešení projektu je prohloubení znalostí a získání nových poznatků o chování, složení, morfologii a zdrojích pouličního prachu, a tím i suspendovaných pevných částic na lokalitách zatížených mobilními zdroji znečištění. Hodnocení vlivu látek vyskytujících se v ovzduší na sledovaných lokalitách (Brno - Kotlářská, Ostrava - Bartovice) jak z pohledu životního prostředí (toxikologické testy), tak zdraví člověka (odhad zdravotních rizik shodně označují ve sledovaných faktorech za více zatíženou lokalitu Brno Bartovice, i když druhou lokalitu nelze označit za vyhovující. Odhad celkového individuálního karcinogenního rizika je vyšší než uznávaná zdravotně bezpečná hodnota na všech sledovaných lokalitách.
Morphology, chemical and toxicological characterisation of road dust and particulate matter including sources apportionment: Final report - summary
Adamec, Vladimír ; Huzlík, Jiří ; Ličbinský, Roman ; Effenberger, Karel ; Mikuška, Pavel ; Večeřa, Zbyněk ; Dočekal, Bohumil ; Vojtěšek, Martin
Project brought new scientific results in the field of chemical composition, physical and toxicological characterization of street dust and particulate matter. Chemical analyses and statistical methods including receptor modelling result in identification their sources.
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Unique exposure system for the whole body inhalation experiments with small animals
Večeřa, Zbyněk ; Mikuška, Pavel ; Dočekal, Bohumil ; Vojta, Šimon ; Míšek, Ivan ; Moravec, Pavel ; Smolík, Jiří
The especially inhalation chamber is constructed for chronic exposure studies of small animals to nanoparticles under strictly controlled conditions in frame of project „Study of transport of inhalated nano-sized particles (Pb, Cd) and their allocation in organs“. The inhalation chamber builds from a glass and stainless steel and makes possible long-term inhalation procedures (up to 60 days, 24 hours/day) with up to four discrete groups of mice population (up to 60 individuals each) or of rats population (up to 20 individuals each) under controlled illumination, temperature, relative humidity, doses (0.5 x 106 - 5 x 106 particles/cm3) and size (10-60 nm) of nano-sized particles which are synthesized via aerosol route in a hot wall tube flow reactor using metal organic precursors.
Characterization of a new 8-hydroxyquinoline modifed resin gel for DGT technique
Gregušová, Michaela ; Dočekal, Bohumil
This study deals with a new resin gel based on Spheron-Oxin® ion exchanger with anchored specific groups of 8-hydroxyquinoline for DGT technique. The performance of this new binding phase was tested for determination of Cd, Cu, Ni, Pb and U under laboratory conditions. The new binding phase with a higher selectivity to race metal species than Chelex 100 could potentially provide more information on metals speciation in aquatic systems.

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