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Abstract An accepted murine analogue for the environmental behavior of human SARS coronaviruses was aerosolized in microdroplets of its culture media and saliva to observe the decay of its airborne infectious potential under relative humidity (RH) conditions relevant to conditioned indoor air. Contained in a dark, 10 m3 chamber maintained at 22°C, murine hepatitis virus (MHV) was entrained in artificial saliva particles that were aerosolized in size distributions that mimic SARS-CoV-2 virus expelled from infected humans’ respiration. As judged by quantitative PCR, more than 95% of the airborne MHV aerosolized was recovered from microdroplets with mean aerodynamic diameters between 0.56 and 5.6 μm. As judged by its half-life, calculated from the median tissue culture infectious dose (TCID50), saliva was protective of airborne murine coronavirus through a RH range recommended for conditioned indoor air (60% < RH < 40%; average half-life = 60 minutes). However, its average half-life doubled to 120 minutes when RH was maintained at 25%. Saliva microaerosol was dominated by carbohydrates, which presented hallmarks of vitrification without efflorescence at low RH. These results suggest that dehydrating carbohydrates can affect the infectious potential coronaviruses exhibit while airborne, significantly extending their persistence under the drier humidity conditions encountered indoors.
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Electrical properties of human saliva as a function of time monitored using a SARS-CoV-2 microfabricated sensor
A metamaterial composed of diamond-shaped (70 m X 35 m) copper patches was designed and used to detect nanoparticles with 0.75-1.1 terahertz transmission spectroscopy. Deoxyribonucleic acid (DNA) bases adenine, thymine, cytosine, and guanine were detected and identified. Cytosine showed 1.7 dB higher absorption around 0.975 THz than the other bases. SARS-CoV-2 infected saliva showed different spectrum and -10 dB higher absorption than uninfected saliva over 0.75-1.1 THz. Other nanoparticles consisting of 100-500 nm antimony, carbon black, zeolite aluminosilicate molecular sieves), Terfenol-D (Tb0.3 Dy0.7Fe2), Cu2S, Ag2S, dust collected from bench tops, 10-100 m size diamond particles, red polystyrene beads, iron particles and graphene sheets were also tested. Sensor sensitivity for uninfected saliva was 0.3 dB/ng and for infected saliva was 0.8 dB/ng. The metamaterial surface studied here enables detection of airborne particles larger than 10 m in diameter.
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- Award ID(s):
- 2030359
- PAR ID:
- 10379546
- Date Published:
- Journal Name:
- Proceedings of IEEE Sensors
- ISSN:
- 2168-9229
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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