Bio-decontamination of water and surfaces contaminated by bacteria (Salmonella typhimurium) was investigated in two types of positive DC discharges in atmospheric pressure air, in needle-to-plane geometry: the streamer corona and its transition to a novel regime called transient spark with short high current pulses of limited energy. Both generate cold non-equilibrium plasma. Electro-spraying of the treated water through the needle electrode was applied for the first time and resulted in fast bio-decontamination. Experiments providing separation of various biocidal plasma agents, along with the emission spectra and coupled with oxidation stress measurements in the cell membranes helped better understanding of the mechanisms of microbial inactivation. The indirect exposure of contaminated surfaces to neutral active species was almost as efficient as the direct exposure to the plasma, whereas applying only UV radiation from the plasma had no biocidal effects. Radicals and reactive oxygen species were identified as dominant biocidal agents.

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Time irreversibility is a characteristic feature of non-equilibrium, complex systems such as the cardiovascular control mediated by the autonomic nervous system (ANS). Time irreversibility analysis of heart rate variability (HRV) and blood pressure variability (BPV) represents a new approach to assess cardiovascular regulatory mechanisms. The aim of this paper was to assess the changes in HRV and BPV irreversibility during the active orthostatic test (a balance of ANS shifted towards sympathetic predominance) in 28 healthy young subjects. We used three different time irreversibility indices-Porta's, Guzik's and Ehler's indices (P%, G% and E, respectively) derived from data segments containing 1000 beat-to-beat intervals on four timescales. We observed an increase in the HRV and a decrease in the BPV irreversibility during standing compared to the supine position. The postural change in irreversibility was confirmed by surrogate data analysis. The differences were more evident in G% and E than P% and for higher scale factors. Statistical analysis showed a close relationship between G% and E. Contrary to this, the association between P% and G% and P% and E was not proven. We conclude that time irreversibility of beat-to-beat HRV and BPV is significantly altered during orthostasis, implicating involvement of the autonomous nervous system in its generation.

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