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dubna, Czech Republic

Kucera J.,Research Center Rez Ltd. | Kofronova K.,Police of the Czech Republic
Journal of Radioanalytical and Nuclear Chemistry | Year: 2011

Autopsy of 29-year old woman suspicious of committing suicide by the ingestion of As2O3 yielded contradictory findings. All pathological findings as well as clinical symptoms suggested acute poisoning, while a highly elevated As level of 26.4 μg g-1 in her hair collected at the autopsy, which was determined with inductively coupled plasma mass spectrometry indicated chronic poisoning. To elucidate this discrepancy, instrumental neutron activation analysis (INAA) with proven accuracy was performed of another set of sectioned hair samples. Levels of As found by INAA in the range of 0.16-0.26 μg g-1 excluded chronic poisoning, because the person died after approximately 14 h after the As2O 3 ingestion. Two reasons for the discordant As results obtained by ICP-MS and INAA are considered: (1) accidental, non-removed contamination of hair on the As2O3 ingestion; (2) erroneous performance of ICP-MS. © 2010 Akadémiai Kiadó, Budapest, Hungary. Source

Vaisocherova-Lisalova H.,Academy of Sciences of the Czech Republic | Visova I.,Academy of Sciences of the Czech Republic | Ermini M.L.,Academy of Sciences of the Czech Republic | Springer T.,Academy of Sciences of the Czech Republic | And 6 more authors.
Biosensors and Bioelectronics | Year: 2016

Recent outbreaks of foodborne illnesses have shown that foodborne bacterial pathogens present a significant threat to public health, resulting in an increased need for technologies capable of fast and reliable screening of food commodities. The optimal method of pathogen detection in foods should: (i) be rapid, specific, and sensitive; (ii) require minimum sample preparation; and (iii) be robust and cost-effective, thus enabling use in the field. Here we report the use of a SPR biosensor based on ultra-low fouling and functionalizable poly(carboxybetaine acrylamide) (pCBAA) brushes for the rapid and sensitive detection of bacterial pathogens in crude food samples utilizing a three-step detection assay. We studied both the surface resistance to fouling and the functional capabilities of these brushes with respect to each step of the assay, namely: (I) incubation of the sensor with crude food samples, resulting in the capture of bacteria by antibodies immobilized to the pCBAA coating, (II) binding of secondary biotinylated antibody (Ab2) to previously captured bacteria, and (III) binding of streptavidin-coated gold nanoparticles to the biotinylated Ab2 in order to enhance the sensor response. We also investigated the effects of the brush thickness on the biorecognition capabilities of the gold-grafted functionalized pCBAA coatings. We demonstrate that pCBAA-compared to standard low-fouling OEG-based alkanethiolate self-assemabled monolayers-exhibits superior surface resistance regarding both fouling from complex food samples as well as the non-specific binding of S-AuNPs. We further demonstrate that a SPR biosensor based on a pCBAA brush with a thickness as low as 20nm was capable of detecting E. coli O157:H7 and Salmonella sp. in complex hamburger and cucumber samples with extraordinary sensitivity and specificity. The limits of detection for the two bacteria in cucumber and hamburger extracts were determined to be 57CFU/mL and 17CFU/mL for E. coli and 7.4×103CFU/mL and 11.7×103CFU/mL for Salmonella sp., respectively. In addition, we demonstrate the simultaneous detection of E. coli and Salmonella sp. in hamburger sample using a multichannel SPR biosensor having appropriate functional coatings. © 2016 Elsevier B.V. Source

Michalek L.,VSB - Technical University of Ostrava | Grega M.,AGH University of Science and Technology | Leszczuk M.,AGH University of Science and Technology | Bryk D.,AGH University of Science and Technology | And 3 more authors.
Communications in Computer and Information Science | Year: 2014

The INACT tool is designed to be used by police forces in cases of prosecution for the production, distribution, and possession of child pornography (CP). The INACT tool is being developed under the INDECT research project. We performed a statistical assessment of results in order to determine success and performance in the process of searching. We focused on the size of the confidence interval, which is based on the values of first hit times. The aim of the experiments was to confirm that the INACT application is functional and performs well enough to be used by police forces in searching for CP. The paper also describes progress in the development of the INACT application with respect to the indexing and searching of movies. © Springer International Publishing Switzerland 2014. Source

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