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Milín, Czech Republic

Klouda K.,State Office for Nuclear Safety | Matheisova H.,Republic Services | Weisheitelova M.,National Institute for Nuclear
Wood Research | Year: 2014

Sedimented dusts representing potentially risky waste were obtained by technological processing (grinding) of nine selected exotic woods. This article describes macroscopic properties of the dusts, their microscopic structure and thermal stability (TGA and DSC analysis), depending on the type of the wood, size and shape of particles, effects of extractable wood components on the stability, biological activity of the dusts and their behavior after their exposure to ionizing radiation.

Lasch P.,Robert Koch Institute | Wahab T.,Public Health Agency of Sweden | Weil S.,Austrian Agency for Health and Food Safety | Palyi B.,National Center for Epidemiology | And 11 more authors.
Journal of Clinical Microbiology | Year: 2015

In the case of a release of highly pathogenic bacteria (HPB), there is an urgent need for rapid, accurate, and reliable diagnostics. MALDI-TOF mass spectrometry is a rapid, accurate, and relatively inexpensive technique that is becoming increasingly important in microbiological diagnostics to complement classical microbiology, PCR, and genotyping of HPB. In the present study, the results of a joint exercise with 11 partner institutions from nine European countries are presented. In this exercise, 10 distinct microbial samples, among them five HPB, Bacillus anthracis, Brucella canis, Burkholderia mallei, Burkholderia pseudomallei, and Yersinia pestis, were characterized under blinded conditions. Microbial strains were inactivated by high-dose gamma irradiation before shipment. Preparatory investigations ensured that this type of inactivation induced only subtle spectral changes with negligible influence on the quality of the diagnosis. Furthermore, pilot tests on nonpathogenic strains were systematically conducted to ensure the suitability of sample preparation and to optimize and standardize the workflow for microbial identification. The analysis of the microbial mass spectra was carried out by the individual laboratories on the basis of spectral libraries available on site. All mass spectra were also tested against an in-house HPB library at the Robert Koch Institute (RKI). The averaged identification accuracy was 77% in the first case and improved to>93% when the spectral diagnoses were obtained on the basis of the RKI library. The compilation of complete and comprehensive databases with spectra from a broad strain collection is therefore considered of paramount importance for accurate microbial identification. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Kolinska R.,National Institute of Public Health | Spanelova P.,National Institute of Public Health | Drevinek M.,National Institute for Nuclear | Hrabak J.,Charles University | Zemlickova H.,National Institute of Public Health
Folia Microbiologica | Year: 2015

Strains of genus Citrobacter (152 isolates from 1950 to 1988 deposited in the Czech National Collection of Type Cultures, Prague) were re-classified using biological and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) methods. One-hundred thirty-six strains (ca. 90 %) were identified to the species level using the biological method with evaluation by Farmer matrix. MALDI-TOF MS exhibited better identification capability, the data being more compact; the method was unambiguously successful in typing 145 (95 %) strains. Comparison of the results of identification by the two methods revealed differences (for 12 samples) in identified species which, considering all biochemical and/or MS characteristics, could be attributed to the natural variability of strains and close relation of the misidentified species (all of them belonged to the Citrobacter freundii complex). Taking into account all the above data, both methods can be considered reliable; however, the MALDI-TOF MS exhibits higher accuracy, efficiency, and rapidity. © 2014, Institute of Microbiology, Academy of Sciences of the Czech Republic, v.v.i.

Slezakova M.,National Radiation Protection Institute, Czech Republic | Navratilova Rovenska K.,National Radiation Protection Institute, Czech Republic | Tomasek L.,National Radiation Protection Institute, Czech Republic | Holecek J.,National Institute for Nuclear
Radiation Protection Dosimetry | Year: 2013

In this paper, repeated measurements of radon progeny concentration in dwellings in the Czech Republic are described. Two distinct data sets are available: one based on present measurements in 170 selected dwellings in the Central Bohemian Pluton with a primary measurement carried out in the 1990s and the other based on 1920 annual measurements in 960 single-family houses in the Czech Republic in 1992 and repeatedly in 1993. The analysis of variance model with random effects is applied to data to evaluate the variability of measurements. The calculated variability attributable to repeated measurements is compared with results from other countries. In epidemiological studies, ignoring the variability of measurements may lead to biased estimates of risk of lung cancer. © The Author 2012. Published by Oxford University Press. All rights reserved.

Cusack M.,Czech Institute of Chemical Process Fundamentals | Talbot N.,Czech Institute of Chemical Process Fundamentals | Ondracek J.,Czech Institute of Chemical Process Fundamentals | Minguillon M.C.,CSIC - Institute of Environmental Assessment And Water Research | And 5 more authors.
Atmospheric Environment | Year: 2015

Measurements of PM10, PM2.5 and PM1 and particle number concentration and size distribution were measured for 24 h on a platform of the Prague underground metro in October 2013. The three PM fractions were analysed for major and minor elements, secondary inorganic aerosols (SIA) and total carbon (TC). Measurements were performed both when the metro was inoperative and closed to the public (referred to as background), and when the metro was in operation and open to passengers. PM concentrations were elevated during both periods, but were substantially increased in the coarse fraction during hours when the metro was in operation. Average PM concentrations were 214.8, 93.9 and 44.8 μg m-3 for PM10, PM2.5 and PM1, respectively (determined gravimetrically). Average particle number concentrations were 8.5 × 103 cm-3 for background hours and 11.5 × 103 cm-3 during operational hours. Particle number concentrations were found to not vary as significantly as PM concentrations throughout the day. Variations in PM were strongly governed by passing trains, with highest concentrations recorded during rush hour. When trains were less frequent, PM concentrations were shown to fluctuate in unison with the entrance and exit of trains (as shown by wind velocity measured on the platform). PM was found to be highly enriched with iron, especially in the coarse fraction, comprising 46% of PM10 (98.9 μg m-3). This reduces to 6.7 μg m-3 during background hours, proving that the trains themselves were the main source of iron, most probably from wheel-rail mechanical abrasion. Other enriched elements relative to background hours included Ba, Cu, Mn, Cr, Mo, Ni and Co, among others. Many of these elements exhibited a similar size distribution, further indicating their sources were common and were attributed to train operations. © 2015 Elsevier Ltd.

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