Examination of effects of indoor fires on building structures and people.

The scientific study of the harmful effects of indoor fires on building structures and on the environment is a top issue today. Indoor fires frequently occur all over the world. The goal of our research is to examine the effects of an average room fire on the survival possibility of a trapped person and on the building structure, taking into account features of the Eastern European architecture. First, a computational fluid dynamics (CFD) simulation was performed to examine the change of temperature, oxygen, and carbon monoxide concentration in a selected room in a vacant building used for military training. Based on the results, a 1:1 scale fire experiment was carried out with the parameters used in the simulation. The experiment was repeated once with the same settings. It was observed that without the intervention of firefighters, the temperature in the experiment could have rapidly reached 400 °C, as suggested by the simulation, which could have caused structural damage to the building. Furthermore, after 3 min the carbon monoxide concentration reached 400 ppm in both experiments and the simulation, which is a harmful level to people trapped inside the room. Also, in the experiment there was sufficient oxygen at the ground level with what people can survive 3 min.

Characterization of selenium speciation in selenium-enriched button mushrooms (Agaricus bisporus) and selenized yeasts (dietary supplement) using X-ray absorption near-edge structure (XANES) spectroscopy.

Selenium is an essential trace element for which dietary intake is not sufficient in many parts of the world such as in Europe. Yeast and mushrooms may accumulate considerable amounts of selenium, but the chemical form in mushrooms has not been elucidated yet. Thus, we determined the selenium speciation of selenium-enriched button mushrooms in comparison to that of selenized yeast via Se K-edge XANES spectroscopy. Quantitative analysis of the XANES spectra revealed that the selenium in selenized yeast is mainly present as seleno-methionine but that in selenium-enriched button mushrooms, it is present predominantly as Se-methyl-l-selenocysteine. As this form is highly bioavailable and directly enters the selenium metabolic pool, selenium-enriched mushrooms may be a good food choice to improve selenium intake.

DGGE and T-RFLP analysis of bacterial succession during mushroom compost production and sequence-aided T-RFLP profile of mature compost.

The amount of button mushroom (Agaricus bisporus) harvested from compost is largely affected by the microbial processes taking place during composting and the microbes inhabiting the mature compost. In this study, the microbial changes during the stages of this specific composting process were monitored, and the dominant bacteria of the mature compost were identified to reveal the microbiological background of the favorable properties of the heat-treated phase II mushroom compost. 16S ribosomal deoxyribonucleic acid (rDNA)-based denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP) molecular fingerprinting methods were used to track the succession of microbial communities in summer and winter composting cycles. DNA from individual DGGE bands were reamplified and subjected to sequence analysis. Principal component analysis of fingerprints of the composting processes showed intensive changes in bacterial community during the 22-day procedure. Peak temperature samples grouped together and were dominated by Thermus thermophilus. Mature compost patterns were almost identical by both methods (DGGE, T-RFLP). To get an in-depth analysis of the mature compost bacterial community, the sequence data from cultivation of the bacteria and cloning of environmental 16S rDNA were uniquely coupled with the output of the environmental T-RFLP fingerprints (sequence-aided T-RFLP). This method revealed the dominance of a supposedly cellulose-degrading consortium composed of phylotypes related to Pseudoxanthomonas, Thermobifida, and Thermomonospora.