scholarly journals Prevention of Airborne Transmission of SARS-CoV-2 by UV-C Illumination of Airflow

COVID ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 602-607
Author(s):  
Richard A. Bowen ◽  
Peter Gilgunn ◽  
Airn E. Hartwig ◽  
Jeff Mullen
Keyword(s):  
Mechanical Ventilator ◽  
Airborne Transmission ◽  
Virus Shedding ◽  
Block Transmission ◽  
Potential Applications ◽  
Uv C

SARS-CoV-2 is frequently transmitted by aerosol, and the sterilization of the virus in airflows has numerous potential applications. We evaluated a UV-C illuminator similar to what might be incorporated into tubing of a mechanical ventilator for its ability to block transmission of the airborne virus from infected to naïve hamsters. Hamsters protected by the UV system were consistently protected from infection, whereas non-protected hamsters uniformly became infected and displayed virus shedding and high burdens of virus in respiratory tissues. The efficiency and speed with which the virus in flowing air was inactivated using this system suggests several applications for mitigating transmission of this virus.

Novel hyperbranched poly(urethane–imide)s with enhanced thermal, mechanical, and UV-shielding properties

2018 ◽  
Vol 31 (2) ◽  
pp. 137-147
Author(s):  
Jun Tian ◽  
Qing Li ◽  
Liji Xiao ◽  
Zushun Xu ◽  
Changfeng Yi
Keyword(s):  
Nitrogen Atmosphere ◽  
Attenuated Total Reflection ◽  
Good Mechanical Property ◽  
X Ray Diffraction ◽  
X Ray ◽  
Uv Shielding ◽  
Hyperbranched Poly ◽  
Potential Applications ◽  
Shielding Properties ◽  
Uv C

A series of novel hyperbranched poly(urethane–imide)s (HBPUIs) was synthesized and derived from as-prepared imide-containing glycol and commercial materials via an A2 + B2 + B3 approach. The chemical and morphological structures of the resulting polymers were evaluated by infrared attenuated total reflection and X-ray diffraction techniques, respectively. Compared with pure HBPU, HBPUIs exhibited better thermal stability with the 10% weight loss temperature of 282–298°C under nitrogen atmosphere, good mechanical property with the tensile strength of 2–19 MPa, and elongation at breaks of 461–896%. Moreover, optical transmissivity of all films was measured and the results showed that they had excellent transparency in the scope of visible light. Meanwhile, the cutoff wavelengths of as-prepared HBPUI films were at around 350 nm, which can block the whole ultraviolet (UV)-C (200–280 nm) and UV-B (280–320 nm), as well as a part of UV-A (320–400 nm). Furthermore, the designed photocatalytic degradation experiment of the methylene blue (MB) confirmed that HBPUI films had good UV-shielding performance with 70% degradation of MB after intense UV irradiation (400 W) for 50 min under the protection of HBPUI film with 14% imide-containing glycol. This endowed HBPUIs with potential applications prospect in UV-shielding materials.

scholarly journals Aerosol Susceptibility of Influenza Virus to UV-C Light

2012 ◽  
Vol 78 (6) ◽  
pp. 1666-1669 ◽  
Author(s):  
James J. McDevitt ◽  
Stephen N. Rudnick ◽  
Lewis J. Radonovich
Keyword(s):  
Influenza Virus ◽  
Relative Humidity ◽  
Influenza A ◽  
Virulent Strain ◽  
Airborne Transmission ◽  
Mortality And Morbidity ◽  
Virus Susceptibility ◽  
Air Disinfection ◽  
Uv C ◽  
Upper Room

ABSTRACTThe person-to-person transmission of influenza virus, especially in the event of a pandemic caused by a highly virulent strain of influenza, such as H5N1 avian influenza, is of great concern due to widespread mortality and morbidity. The consequences of seasonal influenza are also substantial. Because airborne transmission appears to play a role in the spread of influenza, public health interventions should focus on preventing or interrupting this process. Air disinfection via upper-room 254-nm germicidal UV (UV-C) light in public buildings may be able to reduce influenza transmission via the airborne route. We characterized the susceptibility of influenza A virus (H1N1, PR-8) aerosols to UV-C light using a benchtop chamber equipped with a UVC exposure window. We evaluated virus susceptibility to UV-C doses ranging from 4 to 12 J/m2at three relative humidity levels (25, 50, and 75%). Our data show that the Z values (susceptibility factors) were higher (more susceptible) to UV-C than what has been reported previously. Furthermore, dose-response plots showed that influenza virus susceptibility increases with decreasing relative humidity. This work provides an essential scientific basis for designing and utilizing effective upper-room UV-C light installations for the prevention of the airborne transmission of influenza by characterizing its susceptibility to UV-C.

scholarly journals UV-C light completely blocks highly contagious Delta SARS-CoV-2 aerosol transmission in hamsters

2022 ◽  
Author(s):  
Robert Fischer ◽  
Julia Rebecca Port ◽  
Myndi Holbrook ◽  
Kwe Claude Yinda ◽  
Martin Creusen ◽  
...  
Keyword(s):  
Control Measures ◽  
Environmental Strategy ◽  
Airborne Transmission ◽  
Hamster Model ◽  
Medical Control ◽  
Uv C

Behavioral and medical control measures are not effective in containing the spread of SARS-CoV-2. Here we report on the effectiveness of a preemptive environmental strategy using UV-C light to prevent airborne transmission of the virus in a hamster model and show that UV-C exposure completely prevents airborne transmission between individuals.

scholarly journals SARS-CoV-2 disease severity and transmission efficiency is increased for airborne compared to fomite exposure in Syrian hamsters

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Julia R. Port ◽  
Claude Kwe Yinda ◽  
Irene Offei Owusu ◽  
Myndi Holbrook ◽  
Robert Fischer ◽  
...  
Keyword(s):  
Disease Severity ◽  
Transmission Efficiency ◽  
Airborne Transmission ◽  
Disease Manifestation ◽  
Pathogenic Potential ◽  
Virus Shedding ◽  
Syrian Hamsters ◽  
Relative Contribution ◽  
Distinct Disease ◽  
Respiratory Pathology

AbstractTransmission of SARS-CoV-2 is driven by contact, fomite, and airborne transmission. The relative contribution of different transmission routes remains subject to debate. Here, we show Syrian hamsters are susceptible to SARS-CoV-2 infection through intranasal, aerosol and fomite exposure. Different routes of exposure present with distinct disease manifestations. Intranasal and aerosol inoculation causes severe respiratory pathology, higher virus loads and increased weight loss. In contrast, fomite exposure leads to milder disease manifestation characterized by an anti-inflammatory immune state and delayed shedding pattern. Whereas the overall magnitude of respiratory virus shedding is not linked to disease severity, the onset of shedding is. Early shedding is linked to an increase in disease severity. Airborne transmission is more efficient than fomite transmission and dependent on the direction of the airflow. Carefully characterized SARS-CoV-2 transmission models will be crucial to assess potential changes in transmission and pathogenic potential in the light of the ongoing SARS-CoV-2 evolution.

scholarly journals Degradation of acetaminophen in aqueous solution by UV and UV-activated sludge processes

2018 ◽  
Vol 78 (10) ◽  
pp. 2088-2095 ◽  
Author(s):  
Bingjie Xu ◽  
Guoyan Zhan ◽  
Bin Xu ◽  
Haijie Du ◽  
Hang Luo ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Degradation Rate ◽  
Degradation Efficiency ◽  
Wastewater Effluent ◽  
Potential Applications ◽  
Ultraviolet C ◽  
Irradiation Period ◽  
Potential Risks ◽  
Activated Sludge Processes ◽  
Uv C

Abstract Acetaminophen (N-acetyl-p-aminophenol, APAP) is one of the most common antipyretic analgesics used to treat common ailments throughout the world. Recently, APAP has been frequently detected in wastewater effluent and groundwater, resulting in potential risks to the environment. Current methods for eliminating APAP are complicated and cost-prohibitive. This study examined APAP degradation by ultraviolet-C (UV-C) and UV-C irradiation combined with activated sludge (UV/AS) to evaluate potential applications in wastewater treatment. The results of this study indicate that UV-C irradiation reached an APAP degradation efficiency of more than 52% and a degradation rate of 0.0012–0.0013 min−1 during 720 min of exposure, while the initial APAP concentration exhibited only a nominal effect on the degradation rate. However, the UV/AS treatment demonstrated an APAP degradation rate that was 9.6 times the rate of the UV-C-only treatment, with a degradation efficiency of 99% over the same UV irradiation period. The results further indicated that APAP photolysis efficiency was more effective when applied to sterilized AS than when applied to unsterilized AS. Finally, excessive dosage of both AS and humic acid inhibited APAP photolysis efficiency.

scholarly journals SARS-CoV-2 disease severity and transmission efficiency is increased for airborne but not fomite exposure in Syrian hamsters

2020 ◽  
Author(s):  
Julia R. Port ◽  
Claude Kwe Yinda ◽  
Irene Offei Owusu ◽  
Myndi Holbrook ◽  
Robert Fischer ◽  
...  
Keyword(s):  
Disease Severity ◽  
Transmission Efficiency ◽  
Airborne Transmission ◽  
Disease Manifestation ◽  
Pathogenic Potential ◽  
Virus Shedding ◽  
Syrian Hamsters ◽  
Relative Contribution ◽  
Distinct Disease ◽  
Respiratory Pathology

AbstractTransmission of SARS-CoV-2 is driven by contact, fomite, and airborne transmission. The relative contribution of different transmission routes remains subject to debate. Here, we show Syrian hamsters are susceptible to SARS-CoV-2 infection through intranasal, aerosol and fomite exposure. Different routes of exposure presented with distinct disease manifestations. Intranasal and aerosol inoculation caused more severe respiratory pathology, higher virus loads and increased weight loss. Fomite exposure led to milder disease manifestation characterized by an anti-inflammatory immune state and delayed shedding pattern. Whereas the overall magnitude of respiratory virus shedding was not linked to disease severity, the onset of shedding was. Early shedding was linked to an increase in disease severity. Airborne transmission was more efficient than fomite transmission and dependent on the direction of the airflow. Carefully characterized of SARS-CoV-2 transmission models will be crucial to assess potential changes in transmission and pathogenic potential in the light of the ongoing SARS-CoV-2 evolution.

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

Microstructure of laser-irradiated, conducting Kapton polyimide

1995 ◽  
Vol 53 ◽  
pp. 502-503
Author(s):  
D. L. Callahan ◽  
Z. Ball ◽  
H. M. Phillips ◽  
R. Sauerbrey
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Film Surface ◽  
Cross Sectional ◽  
General Utility ◽  
Transmission Electron ◽  
Considerable Debate ◽  
Potential Applications

Ultraviolet laser-irradiation can be used to induce an insulator-to-conductor phase transition on the surface of Kapton polyimide. Such structures have potential applications as resistors or conductors for VLSI applications as well as general utility electrodes. Although the percolative nature of the phase transformation has been well-established, there has been little definitive work on the mechanism or extent of transformation. In particular, there has been considerable debate about whether or not the transition is primarily photothermal in nature, as we propose, or photochemical. In this study, cross-sectional optical microscopy and transmission electron microscopy are utilized to characterize the nature of microstructural changes associated with the laser-induced pyrolysis of polyimide.Laser-modified polyimide samples initially 12 μm thick were prepared in cross-section by standard ultramicrotomy. Resulting contraction in parallel to the film surface has led to distortions in apparent magnification. The scale bars shown are calibrated for the direction normal to the film surface only.

Fabrication and characterization - by High Resolution Electron Microscopy and atom probe microanalysis - of Co-based metallic multilayer films

1990 ◽  
Vol 48 (4) ◽  
pp. 772-773
Author(s):  
Amanda K. Petford-Long ◽  
A. Cerezo ◽  
M.G. Hetherington
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Atom Probe ◽  
Multilayer Films ◽  
Interface Roughness ◽  
Probe Field ◽  
Resolution Electron ◽  
Potential Applications ◽  
Field Ion Microscope

The fabrication of multilayer films (MLF) with layer thicknesses down to one monolayer has led to the development of materials with unique properties not found in bulk materials. The properties of interest depend critically on the structure and composition of the films, with the interfacial regions between the layers being of particular importance. There are a number of magnetic MLF systems based on Co, several of which have potential applications as perpendicular magnetic (e.g Co/Cr) or magneto-optic (e.g. Co/Pt) recording media. Of particular concern are the effects of parameters such as crystallographic texture and interface roughness, which are determined by the fabrication conditions, on magnetic properties and structure.In this study we have fabricated Co-based MLF by UHV thermal evaporation in the prechamber of an atom probe field-ion microscope (AP). The multilayers were deposited simultaneously onto cobalt field-ion specimens (for AP and position-sensitive atom probe (POSAP) microanalysis without exposure to atmosphere) and onto the flat (001) surface of oxidised silicon wafers (for subsequent study in cross-section using high-resolution electron microscopy (HREM) in a JEOL 4000EX. Deposi-tion was from W filaments loaded with material in the form of wire (Co, Fe, Ni, Pt and Au) or flakes (Cr). The base pressure in the chamber was around 8×10−8 torr during deposition with a typical deposition rate of 0.05 - 0.2nm/s.

Progress and perspectives on halide lithium conductors for all-solid-state lithium batteries

2020 ◽  
Vol 13 (5) ◽  
pp. 1429-1461 ◽  
Author(s):  
Xiaona Li ◽  
Jianwen Liang ◽  
Xiaofei Yang ◽  
Keegan R. Adair ◽  
Changhong Wang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Solid State ◽  
Lithium Batteries ◽  
Electrochemical Stability ◽  
Superionic Conductors ◽  
Fundamental Understanding ◽  
Potential Applications ◽  
Synthesis Routes

This review focuses on fundamental understanding, various synthesis routes, chemical/electrochemical stability of halide-based lithium superionic conductors, and their potential applications in energy storage as well as related challenges.

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