Observed Reductions in the Infectivity of Bioaerosols Containing Bovine Coronavirus Under Repetitively Pulsed RF Exposure.

OBJECTIVE: The purpose of the present study is to investigate the inactivation of bioaerosols containing Bovine Coronavirus, BCoV, under repetitively pulsed radio frequency (RF) electromagnetic exposure. METHODS: These experiments were performed in a waveguide containing a flowing aerosol stream and were limited to a single RF waveform: ∼2 µs square envelope, 5.6 GHz, 4.8 kHz repetition rate. Aerosol streams were exposed to RF electric field amplitudes in the range of 41.9 +/-6.2 kV/m. Under laminar flow conditions, 75% of the total collected aerosol stream spends 0.85 seconds or less in the RF exposure region. RESULTS: Application of the RF waveform changed mean survival rate of the aerosolized BCoV by -0.58 decades (roughly a 74% reduction) and impacted the variance and standard deviation of the experimental results, with the RF exposure data showing an 800% increase in variance and 196% increase in standard deviation over the control results. Experimental results were compared to those from an analytic electromagnetic-heating inactivation model. CONCLUSION: The comparison indicated the feasibility that the observed reduction in BCoV survival rate might be due to a combination of thermal effects and non-thermal electric field effects. SIGNIFICANCE: Developing better insight into the mechanisms of inactivation is important for understanding the potential limits of efficacy for this method. Additionally, these results contribute an important baseline for the impact of electromagnetic fields on aerosolized pathogens.

Feeling Socially Connected and Focusing on Growth: Relationships With Wellbeing During a Major Holiday in the COVID-19 Pandemic.

Numerous major holidays celebrate socially gathering in person. However, in major holidays that happened during the pandemic, desires to nurture relationships and maintain holiday traditions often conflicted with physical distancing and other measures to protect against COVID-19. The current research sought to understand wellbeing during American Thanksgiving in 2020, which happened 8months into the COVID-19 pandemic, after months of physical distancing and stay-at-home orders. American Thanksgiving is a major holiday not limited to any religion. We asked 404 American adults how they spent Thanksgiving Day and to report on their experiences of that day. Predictors of wellbeing that we drew from self-determination theory were satisfaction of the fundamental needs for social connection (relatedness), for doing what one really wants (autonomy), and feeling effective (competence). The predictors of wellbeing that we drew from regulatory focus theory were a focus on growth (promotion), and a focus on security (prevention). We found that feeling socially connected and focusing on growth related most strongly to wellbeing. Additionally, participants who saw even one other person face-to-face reported significantly higher relatedness satisfaction, promotion focus, and wellbeing than those who did not. Our research could help construct persuasive messages that encourage nurturing close relationships at major holidays while remaining safe against the virus.

Nonlinear transmission line-driven apparatus for short-pulse microwave exposure of aerosolized pathogens.

A system capable of exposing a flowing aerosol stream to short duration (2-4 ns), high-power RF waveforms is described. The system utilizes a C-band gyromagnetic nonlinear transmission line source having peak power outputs ranging as high as 80 kW at a center frequency of 4.2 GHz. RF electric field magnitudes of up to 280 kV/m ± 17% are achieved within the aerosol flow region of the RF exposure apparatus.

Apparatus for controlled microwave exposure of aerosolized pathogens.

A set of three apparatus enabling RF exposure of aerosolized pathogens at four chosen frequencies (2.8 GHz, 4.0 GHz, 5.6 GHz, and 7.5 GHz) has been designed, simulated, fabricated, and tested. Each apparatus was intended to operate at high power without leakage of RF into the local environment and to be compact enough to fit within biocontainment enclosures required for elevated biosafety levels. Predictions for the range of RF electric field exposure, represented by the complex electric field vector magnitude, that an aerosol stream would be expected to encounter while passing through the apparatus are calculated for each of the chosen operating frequencies.