Dependence on relative humidity in the formation of reactive oxygen species in water droplets

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(12)

Опубликована: Март 15, 2024

Water microdroplets (7 to 11 µm average diameter, depending on flow rate) are sprayed in a closed chamber at ambient temperature, whose relative humidity (RH) is controlled. The resulting concentration of ROS (reactive oxygen species) formed the microdroplets, measured by amount hydrogen peroxide (H 2 O ), determined nuclear magnetic resonance (NMR) and spectrofluorimetric assays after droplets collected. results found agree closely with one another. In addition, hydrated hydroxyl radical cations (•OH-H 3 + ) recorded from using mass spectrometry superoxide anions (•O − radicals (•OH) electron paramagnetic spectroscopy. As RH varies 15 95%, H shows marked rise factor about 3.5 going 50%, then levels off. By replacing water deuterium oxide (D O) but keeping gas surrounding O, spectrometric analysis demonstrates that air plays dominant role producing other ROS, which accounts for variation RH. increases, droplet evaporation rate decreases. These two facts help us understand why viruses both survive better low values, as indoor wintertime, disinfected more effectively higher summertime, thus explaining recognized seasonality airborne viral infections.

Язык: Английский

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Recent advancements in the measurement of pathogenic airborne viruses

Journal of Hazardous Materials, Год журнала: 2021, Номер 420, С. 126574 - 126574

Опубликована: Июль 5, 2021

Air-transmissible pathogenic viruses, such as influenza viruses and coronaviruses, are some of the most fatal strains spread rapidly by air, necessitating quick stable measurements from sample air volumes to prevent further diseases take appropriate steps rapidly. Measurements airborne generally require their collection into liquids or onto solid surfaces, with subsequent hydrosolization then analysis using growth method, nucleic-acid-based techniques, immunoassays. can also be performed in real time without sampling, where species-specific determination is disabled. In this review, we introduce recent advancements measurement viruses. Air sampling technologies for viral aerosols reviewed, special focus on effects damage sampled measurements. Measurement an interdisciplinary research area that requires understanding both aerosol technology biotechnology effectively address issues. Hence, review expected provide useful guidelines regarding virus detection methods particular applications.

Язык: Английский

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Estimating the impact of indoor relative humidity on SARS-CoV-2 airborne transmission risk using a new modification of the Wells-Riley model

Building and Environment, Год журнала: 2021, Номер 205, С. 108278 - 108278

Опубликована: Авг. 23, 2021

A novel modified version of the Wells-Riley model was used to estimate impact relative humidity (RH) on removal respiratory droplets containing SARS-CoV-2 virus by deposition through gravitational settling and its inactivation biological decay; effect RH susceptibility not considered. These effects were compared with achieved increased ventilation rate outdoor air. Modeling performed assuming that infected person talked continuously for 60 120 min. The results modeling showed infection risk depended size range virus-laden droplets. 0.5 ACH, change between 20% 53% predicted have a small risk, while at 6 ACH this had nearly no effect. On contrary, increasing from decrease half which is remarkably larger RH. It thus concluded more beneficial reducing airborne levels than changing indoor

Язык: Английский

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The physics of respiratory particle generation, fate in the air, and inhalation

Nature Reviews Physics, Год журнала: 2022, Номер 4(11), С. 723 - 734

Опубликована: Авг. 31, 2022

Язык: Английский

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Mango anthracnose disease: the current situation and direction for future research

Frontiers in Microbiology, Год журнала: 2023, Номер 14

Опубликована: Авг. 24, 2023

Mango anthracnose disease (MAD) is a destructive of mangoes, with estimated yield losses up to 100% in unmanaged plantations. Several strains that constitute

Язык: Английский

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Airborne virus transmission via respiratory droplets: Effects of droplet evaporation and sedimentation

Current Opinion in Colloid & Interface Science, Год журнала: 2021, Номер 55, С. 101471 - 101471

Опубликована: Май 30, 2021

Язык: Английский

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Modeling the impact of indoor relative humidity on the infection risk of five respiratory airborne viruses

Scientific Reports, Год журнала: 2022, Номер 12(1)

Опубликована: Июль 7, 2022

With a modified version of the Wells-Riley model, we simulated size distribution and dynamics five airborne viruses (measles, influenza, SARS-CoV-2, human rhinovirus, adenovirus) emitted from speaking person in typical residential setting over relative humidity (RH) range 20-80% air temperature 20-25 °C. Besides transformation virus-containing droplets due to evaporation, respiratory absorption, then removal by gravitational settling, model also considered mechanism ventilation. The trend magnitude RH impact depended on virus. For rhinovirus adenovirus humidifying indoor 20/30 50% will be increasing infection risk, however, this risk increase negligible for weak adenovirus. Humidification have potential benefit decreasing only influenza when there is large decrease 20 50%. Regardless dry solution composition, humidification overall via long-range transmission SARS-CoV-2. Compared at constant ventilation rate, rate moderate levels 0.5 → 2.0 h

Язык: Английский

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Review of factors affecting virus inactivation in aerosols and droplets

Journal of The Royal Society Interface, Год журнала: 2024, Номер 21(215)

Опубликована: Июнь 1, 2024

The inactivation of viruses in aerosol particles (aerosols) and droplets depends on many factors, but the precise mechanisms are not known. system involves complex physical biochemical interactions. We reviewed literature to establish current knowledge about these identify gaps. identified 168 relevant papers grouped results by following factors: virus type structure, or droplet size, temperature, relative humidity (RH) evaporation, chemical composition droplet, pH atmospheric composition. These factors influence dynamic microenvironment surrounding a virion thus may affect its inactivation. Results indicate that experience biphasic decay as carrier aerosols undergo evaporation equilibrate with air, their final state (liquid, semi-solid solid) RH. Virus stability, RH temperature interrelated, effects multifaceted still completely understood. Studies impact stability have raised new questions require further exploration. frequent practice studying large culture media limit our understanding for transmission, so we encourage use physiologically size future research.

Язык: Английский

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Development of a dual point humidity sensor using POF based on twisted fiber structure

Scientific Reports, Год журнала: 2024, Номер 14(1)

Опубликована: Май 10, 2024

The humidity has often been measured through a single point sensor. Where, the could be varied at different locations as well depending on environmental conditions. present paper developed dual measuring sensor by using polymer optical fiber (POF) based illuminating fiber. sensor's basic structure is to twist two fibers and bend them certain radius. However, cascading of twisted micro (TMB-1 TMB-2). twisting couples light from one another side coupling method. An increase in level leads change reflective index, which helps get variation coupled intensity. To measure humidity, sensors are placed into control chamber random positions. power reading significantly linear when increases 30 80%. fast response about 1 s recovery time 4 s. Furthermore, chemical coating applied improve sensitivity. Between 80% range both TMB-1 TMB-2 have appropriate sensitivity detection limits, 680.8 nW/% 763.9 1.37% 1.98%, respectively. variable positions, points well-stable, easy, straightforward, uses less expensive

Язык: Английский

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Mechanisms controlling the transport and evaporation of human exhaled respiratory droplets containing the severe acute respiratory syndrome coronavirus: a review

Environmental Chemistry Letters, Год журнала: 2023, Номер 21(3), С. 1701 - 1727

Опубликована: Фев. 22, 2023

Transmission of the coronavirus disease 2019 is still ongoing despite mass vaccination, lockdowns, and other drastic measures to control pandemic. This due partly our lack understanding on multiphase flow mechanics that droplet transport viral transmission dynamics. Various models evaporation have been reported, yet there limited knowledge about influence physicochemical parameters respiratory droplets carrying severe acute syndrome 2. Here we review effects initial size, environmental conditions, virus mutation, non-volatile components dispersion, stability. We present experimental computational methods analyze transport, factors controlling evaporation. Methods include thermal manikins, techniques, aerosol-generating nucleic acid-based assays, antibody-based polymerase chain reaction, loop-mediated isothermal amplification, field-effect transistor-based assay, discrete gas-phase modeling. Controlling turbulence, ventilation, ambient temperature, relative humidity, size distribution, components, mutation. Current results show medium-sized droplets, e.g., 50 µm, are sensitive humidity. Medium-sized experience delayed at high increase airborne lifetime travel distance. By contrast, low quickly shrink nuclei follow cough jet. Virus inactivation within a few hours generally occurs temperatures above 40 °C, presence particles in aerosols impedes

Язык: Английский

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