Stability of SARS-CoV-2 in cold-chain transportation environments and the efficacy of disinfection measures.

Background: Low temperature is conducive to the survival of COVID-19. Some studies suggest that cold-chain environment may prolong the survival of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and increase the risk of transmission. However, the effect of cold-chain environmental factors and packaging materials on SARS-CoV-2 stability remains unclear. Methods: This study aimed to reveal cold-chain environmental factors that preserve the stability of SARS-CoV-2 and further explore effective disinfection measures for SARS-CoV-2 in the cold-chain environment. The decay rate of SARS-CoV-2 pseudovirus in the cold-chain environment, on various types of packaging material surfaces, i.e., polyethylene plastic, stainless steel, Teflon and cardboard, and in frozen seawater was investigated. The influence of visible light (wavelength 450 nm-780 nm) and airflow on the stability of SARS-CoV-2 pseudovirus at -18°C was subsequently assessed. Results: Experimental data show that SARS-CoV-2 pseudovirus decayed more rapidly on porous cardboard surfaces than on nonporous surfaces, including polyethylene (PE) plastic, stainless steel, and Teflon. Compared with that at 25°C, the decay rate of SARS-CoV-2 pseudovirus was significantly lower at low temperatures. Seawater preserved viral stability both at -18°C and with repeated freeze-thaw cycles compared with that in deionized water. Visible light from light-emitting diode (LED) illumination and airflow at -18°C reduced SARS-CoV-2 pseudovirus stability. Conclusion: Our studies indicate that temperature and seawater in the cold chain are risk factors for SARS-CoV-2 transmission, and LED visible light irradiation and increased airflow may be used as disinfection measures for SARS-CoV-2 in the cold-chain environment.

Two-stage cascade configurations based on ejectors for ultra-low temperature refrigeration with natural refrigerants

Research in ultra-low temperature refrigeration applications has intensified in recent years after the appearance of vaccines in response to the COVID-19 pandemic. There are few current technologies for this low-temperature range, with reduced energy performance and high global warming potential refrigerants. This work analyses the introduction of the ejector in two-stage cascade cycles for ultra-low temperature refrigeration. The proposal includes the assessment of the behaviour of the ejector while implementing it in a single stage or simultaneously in both stages. The study is carried out with refrigerants R-290 in the high-temperature stage and R-170 in the low-temperature stage since these are natural refrigerants with very low global warming potential. The results show that the ejector is a component that causes improvements in the cycle when placed in the high-temperature and low-temperature stages. On the other hand, changing evaporation and condensation temperatures, the evaporation temperature is more critical regarding cycle energy performance. With the results obtained, a cascade cycle with an ejector in both stages is proposed, obtaining a 21% higher coefficient of performance than the standard cascade cycle. Also, the cycle with the ejector in both stages causes an improvement of 13.6% compared to the previous generation's refrigerants (R-23 and R-507A) in the same cycle. The carbon footprint analysis shows that this cycle emits less than half of the equivalent CO2 than actual cycles for ultra-low temperatures, also with a new refrigerant like R-472A. © 2023 The Author(s)

High-Intensity Ultraviolet-C Irradiation Efficiently Inactivates SARS-CoV-2 Under Typical Cold Chain Temperature.

SARS-CoV-2 contaminated items in the cold chain becomes a threat to public health, therefore the effective and safe sterilization method fit for the low temperature is needed. Ultraviolet is an effective sterilization method while its effect on SARS-CoV-2 under low-temperature environment is unclear. In this research, the sterilization effect of high-intensity ultraviolet-C (HIUVC) irradiation against SARS-CoV-2 and Staphylococcus aureus on different carriers at 4 °C and - 20 °C was investigated. The results showed that dose of 15.3 mJ/cm2 achieved more than 3 log reduction of SARS-CoV-2 on gauze at 4 °C and - 20 °C. The vulnerability of coronavirus to HIUVC under - 20 °C was not significantly different than those under 4 °C. Four models including Weibull, biphasic, log-linear tail and log linear were used to fit the survival curves of SARS-CoV-2 and Staphylococcus aureus. The biphasic model fitted best with R2 ranging from 0.9325 to 0.9878. Moreover, the HIUVC sterilization correlation between SARS-CoV-2 and Staphylococcus aureus was established. This paper provides data support for the employment of HIUVC under low-temperature environment. Also, it provides a method of using Staphylococcus aureus as a marker to evaluate the sterilization effect of cold chain sterilization equipment.

Exposure of low-temperature plasma after vaccination in tongue promotes systemic IgM induction against spike protein of SARS-CoV-2.

COVID-19 has been pandemic since 2020 with persistent generation of new variants. Cellular receptor for SARS-CoV-2 is angiotensin-converting enzyme 2 (ACE2), where transmembrane serine protease-2 (TMPRSS2) is essential for viral internalization. We recently reported abundant expression of ACE2 and TMPRSS2 in the oral cavity of humans and mice. Therefore, oral cavity may work for COVID-19 infection gates. Here we undertook to evaluate whether vaccination in the tongue harbors any merit in comparison to subcutaneous injection. Low-temperature plasma (LTP) is the fourth physical state of matters with ionization above gas but at body temperature. LTP provides complex chemistry, eventually supplying oxidative and/or nitrosative stress on the interface. LTP-associated cellular death has been reported to cause apoptosis and/or ferroptosis. However, there is few data available on immunogenicity retention after LTP exposure. We therefore studied the effect of LTP exposure after the injection of keyhole limpet hemocyanin (KLH) or spike 2 protein of SARS-CoV-2 to the tongue of six-week-old male BALB/c mice, compared to subcutaneous vaccination. Whereas LTP did not change the expression of ACE2 and TMPRSS2 in the tongue, repeated LTP exposure after tongue vaccination significantly promoted systemic and specific IgM production at day 11. In contrast, repeated LTP exposure after subcutaneous vaccination of KLH decreased systemic IgM production. Of note, tongue injection produced significantly higher titer of IgM and IgG in the case of KLH. In conclusion, LTP significantly reinforced humoral immunity by IgM after tongue injection. Vaccination to the tongue can be a novel strategy to acquire immediate immunity.

Two-stage cascade configurations based on ejectors for ultra-low temperature refrigeration with natural refrigerants

Research in ultra-low temperature refrigeration applications has intensified in recent years after the appearance of vaccines in response to the COVID-19 pandemic. There are few current technologies for this low-temperature range, with reduced energy performance and high global warming potential refrigerants. This work analyses the introduction of the ejector in two-stage cascade cycles for ultra-low temperature refrigeration. The proposal includes the assessment of the behaviour of the ejector while implementing it in a single stage or simultaneously in both stages. The study is carried out with refrigerants R-290 in the high-temperature stage and R-170 in the low-temperature stage since these are natural refrigerants with very low global warming potential. The results show that the ejector is a component that causes improvements in the cycle when placed in the high-temperature and low-temperature stages. On the other hand, given the change in evaporation and condensation temperatures, the evaporation temperature is more critical regarding cycle energy performance. With the results obtained, a cascade cycle with an ejector in both stages is proposed, obtaining a 21% higher coefficient of performance than the standard cascade cycle. Also, the cycle with the ejector in both stages causes an improvement of 13.6 % compared to the previous generation's refrigerants (R-23 and R-507A) in the same cycle. The carbon footprint analysis shows that this cycle emits less than half of the equivalent CO2 than actual cycles for ultra-low temperatures, also with a new refrigerant like R-472A.

A novel infrared forehead thermometer with ambient temperature compensation for body temperature measurement in low-temperature environment

Body temperature screening and measurement using infrared forehead thermometer (IFT), a non-contact thermometer, is an important method to prevent the spread of COVID-19 at present. However, low accuracy and unreliability of current IFT due to ambient temperature effect prevent it application in most of low-temperature environment. The aim of this study was to measure the body temperature accurately using IFT in low-temperature environment. A novel IFT with broad working temperature range and ambient temperature compensation was designed and fabricated, and the performance was evaluated. Also an ambient temperature compensation method based on Bluetooth module was introduced to improve the accuracy of body temperature measurement for the first time. The experiment results demonstrated that the laboratory indication error and repeatability in test mode of this developed IFT were all below 0.2℃ in ambient temperature range of (3~35) ℃. While the extended uncertainty for laboratory indication error was less than 0.1℃ (k=2). Compared with the contact electronic clinical thermometer, the difference of body temperature was improved within the scope of (-0.3~+0.3)℃ in low-temperature measurement environment. All the results showed that the IFT fabricated in this paper is sufficient and competent for body temperature screening and clinical body temperature measurement in most of low-temperature environment. © 2022 SPIE.

An Optimization of COVID-19 Vaccine Distribution in Canada Based on the VRP Model

SARS-Cov-2, or COVID-19, is a new emergent human-transmitting disease, which has caused a worldwide pandemic crisis affecting every aspect of our life. With the latest medical enhancements, vaccines from numerous medical companies (Pfizer, Moderna, Sinovac, etc.) have been proven effective in controlling the hospitalization and deaths caused by COVID-19. Cold-chain transportation of vaccines is a crucial part of providing vaccination. The standard procedure is to store vaccines at low temperatures, around 2°C to 8°C, during any time of transportation. However, due to the uncertainty in this process, a well-developed, monitored cold-chain logistics network is demanded. This paper explores the optimization of the contributing factors, involving data analysis and applied mathematical models, focusing on a case study of the Ontario, Canada area. The simulated results provide a general concept and indication for the administrators and regulators to design and achieve a suitable and fair distribution of vaccines.

Investigating the microbial inactivation effect of low temperature high pressure carbon dioxide and its application in frozen prawn (Penaeus vannamei).

During the pandemic of coronavirus disease 2019, the fact that frozen foods can carry the relevant virus raises concerns about the microbial safety of cold-chain foods. As a non-thermal processing technology, high pressure carbon dioxide (HPCD) is a potential method to reduce microbial load on cold-chain foods. In this study, we explored the microbial inactivation of low temperature (5-10 °C) HPCD (LT-HPCD) and evaluated its effect on the quality of prawn during freeze-chilled and frozen storage. LT-HPCD treatment at 6.5 MPa and 10 °C for 15 min could effectively inactivate E. coli (99.45%) and S. aureus (94.6%) suspended in 0.85% NaCl, SARS-CoV-2 Spike pseudovirus (>99%) and human coronavirus 229E (hCoV-229E) (>1-log virus tilter reduction) suspended in DMEM medium. The inactivation effect of LT-HPCD was weakened but still significant when the microorganisms were inoculated on the surface of food or package. LT-HPCD treatment at 6.5 MPa and 10 °C for 15 min achieved about 60% inactivation of total aerobic count while could maintain frozen state and quality of prawn. Moreover, LT-HPCD treated prawn exhibited significant slower microbial proliferation and no occurrence of melanosis compared with the untreated samples during chilled storage. A comprehensive quality investigation indicated that LT-HPCD treatment could maintain the color, texture and sensory of prawn during chilled or frozen storage. Consequently, LT-HPCD could improve the microbial safety of frozen prawn while maintaining its original quality, and could be a potential method for food industry to improve the microbial safety of cold-chain foods.

Conferences

First he examined the interactions between the lingering effects of the COVID-19 pandemic and current economic and social transformations. In light of the session in his honour, Dr George Harlow (American Museum of Natural History, New York, USA) chronicled the history of his career, in which he built collections, organised exhibitions and performed geological fieldwork around the world while researching jade, ruby, etc. Pamir rubies formed at unusually low pressures (minimum of 1–1.2 kbar) and a temperature of approximately 760°C. Wim Vertriest (Gemological Institute of America [GIA], Bangkok, Thailand) and co-authors reviewed the identification of low-temperature heat treatment of gem corundum (i.e. up to about 1200°C, which starts causing damage to rutile ‘silk’ inclusions). In another presentation, Dr Dutrow and co-authors investigated the origin determination of Cu-bearing tourmaline using statistical analyses of LIBS and electron microprobe data.

The effect of COVID-19 restrictions on atmospheric new particle formation in Beijing

During the COVID-19 lockdown, the dramatic reduction of anthropogenic emissions provided a unique opportunity to investigate the effects of reduced anthropogenic activity and primary emissions on atmospheric chemical processes and the consequent formation of secondary pollutants. Here, we utilize comprehensive observations to examine the response of atmospheric new particle formation (NPF) to the changes in the atmospheric chemical cocktail. We find that the main clustering process was unaffected by the drastically reduced traffic emissions, and the formation rate of 1.5 nm particles remained unaltered. However, particle survival probability was enhanced due to an increased particle growth rate (GR) during the lockdown period, explaining the enhanced NPF activity in earlier studies. For GR at 1.5–3 nm, sulfuric acid (SA) was the main contributor at high temperatures, whilst there were unaccounted contributing vapors at low temperatures. For GR at 3–7 and 7–15 nm, oxygenated organic molecules (OOMs) played a major role. Surprisingly, OOM composition and volatility were insensitive to the large change of atmospheric NOx concentration;instead the associated high particle growth rates and high OOM concentration during the lockdown period were mostly caused by the enhanced atmospheric oxidative capacity. Overall, our findings suggest a limited role of traffic emissions in NPF.

Vaccine Development in Global Pandemic Time

Introduction Pfizer-BioNTech collaboration started in 2018 in order to develop mRNA flu vaccine. Because of the covid19 pandemic the two companies started to focus on mRNA vaccine development for the prevention of covid19 infection. In March they signed the Letters of Intent. Initially there were four vaccine candidates including unmodified mRNA, nucleoside-modified mRNA and self-amplifying mRNA. For further development the nucleoside- modified mRNA was chosen. In April Phase 1/2 study was completed in Germany and in May in the USA. Two 30 μg doses 3 weeks apart induced neutralizing antibody titers comparable to natural infection and strong CD4+ and CD8+ Tcell responses were observed. Phase 2b/3 clinical trial started in July involving more than 43.000 participants in 153 sites. The result showed 95% efficacy with mild and moderate local and systemic events. For safety reason all participants will be followed for 2 years after the second dose. Based on rolling review regulatory agencies were able to approve within a short period of time in December 2020, first MHRA in UK, then FDA authorized for Emergency Use and EMA granted Conditional Marketing Authorization on 21 December 2021 for 16 years old and older. The first shipments were sent all European countries on 27 December. Direct shipments to vaccination centers on ultra-low temperature (minus 9060 degree of centigrade) using dry ice. Each thermal shipping container has a temperature monitoring device. All shipments are tracked via GPS monitoring device to ensure end-to-end distribution within required temperatures. In May EMA granted an extension of indication for covid-19 vaccine to include in children aged 12-15. The effect of vaccine was investigated in 2260 children aged 12-15, about half of them received dummy injection. Of the 1,005 children receiving the vaccine, none developed COVID-19 compared to 16 children out of the 978 who received the dummy injection. This means that, in this study, the vaccine was 100% effective at preventing COVID-19. The most common side effects in children aged 12 to 15 are similar like those in people aged 16 and above. They include pain at the injection site, tiredness, headache, muscle and joint pain, chills and fever. These effects are usually mild or moderate and improve within a few days from the vaccination. EMA granted approval for booster dose (third dose) for immune weakened people 28 days after the second dose, and 6 months after the second dose for 18 years of age and older. Approval is based on the clinical program evaluating the safety, tolerability and immunogenicity of a booster dose of covid-19 vaccine. A booster dose of the vaccine elicited significantly higher neutralizing antibody titers against the initial SARS-CoV-2 virus (wild type), as well as the Beta and Delta variants, when compared with the levels observed after the two-dose primary series. The reactogenicity profile within seven days after the booster dose was typically mild to moderate, and the frequency of reactions was similar to or lower than after dose two. The efficacy is this trial was 95,6%. In October 2021 FDA authorized for emergency use of covid-19 for children 5 through 111 years of age. For this age group, the vaccine is to be admin-istered in a two-dose regimen of 10 μg (0,2 ml) doses given 21 days apart. EUA is supported by clinical data showing a favorable safety profile and high vaccine efficacy of 90.7% in children 5 through 11 years of age during a period when Delta was the prevalent strain. In 2021 we have already distributed 1,8B doses to 146 countries by end of September. In 2022 we plan to distribute 4B doses. (Figure Presented).

Life-Cycle Assessment of Power-to-Liquid Kerosene Produced from Renewable Electricity and CO2 from Direct Air Capture in Germany

Decarbonization of the aviation sector is crucial to reaching the global climate targets. We quantified the environmental impacts of Power-to-Liquid kerosene produced via Fischer-Tropsch Synthesis from electricity and carbon dioxide from air as one broadly discussed alternative liquid jet fuel. We applied a life-cycle assessment considering a well-to-wake boundary for five impact categories including climate change and two inventory indicators. Three different electricity production mixes and four different kerosene production pathways in Germany were analyzed, including two Direct Air Capture technologies, and compared to fossil jet fuel. The environmental impacts of Power-to-Liquid kerosene varied significantly across the production pathways. E.g., when electricity from wind power was used, the reduction in CO2-eq. compared to fossil jet fuel varied between 27.6–46.2% (with non-CO2 effects) and between 52.6–88.9% (without non-CO2 effects). The reduction potential regarding CO2-eq. of the layout using low-temperature electrolysis and high-temperature Direct Air Capture was lower compared to the high-temperature electrolysis and low-temperature Direct Air Capture. Overall, the layout causing the lowest environmental impacts uses high-temperature electrolysis, low-temperature Direct Air Capture and electricity from wind power. This paper showed that PtL-kerosene produced with renewable energy could play an important role in decarbonizing the aviation sector.

Variations in Sulfur and Nitrogen Oxidation Rates in Summer Aerosols from 2014 to 2020 in Wuhan, China

To date, research regarding the changes of the sulfur and nitrogen rates in Wuhan during the summer is limited. In this study, we analyzed the air quality in Wuhan, China, using water-soluble ion, gaseous precursor, and weather data. A Spearman correlation analysis was then performed to investigate the temporal changes in air quality characteristics and their driving factors to provide a reference for air pollution control in Wuhan. The results indicate that SO2 in the atmosphere at Wuhan undergoes secondary conversion and photo-oxidation, and the conversion degree of SO2 is higher than that of NO2. During the summers of 2016 and 2017, secondary inorganic atmospheric pollution was more severe than during other years. The fewest oxidation days occurred in summer 2020 (11 days), followed by the summers of 2017 and 2014 (25 and 27 days, respectively). During the study period, ion neutralization was the strongest in summer 2015 and the weakest in August 2020. The aerosols in Wuhan were mostly acidic and NH4+ was an important neutralizing component. The neutralization factors of all cations showed little change in 2015. K+, Mg2+, and Ca2+ level changes were the highest in 2017 and 2020. At low temperature, high humidity, and low wind speed conditions, SO2 and NO2 were more easily converted into SO42− and NO3−.

Continuous Disinfection of Airborne Pathogens Using Far UV-C KRCL∗Microplasma Lamp for Personal Protection

Microplasma lamps based on the confinement of a weakly-ionized, low-temperature plasma in a microscale cavity have been found to be ideal for far UV-C radiation at 222 nm (KrCl ∗ excimer). During the last several years, researchers have demonstrated that far UV-C 222 nm efficiently kills airborne pathogens (coronaviruses) with minimal risk of harm to human skin or eyes. Therefore, the data support the premise that far UV-C 222 nm from a KrCl∗ excimer emission in the microplasma flat lamp can be used safely in occupied spaces. In particular, ACGIH recently increased the allowed human exposure levels at 222 nm more than seven times. 1 © 2022 IEEE.

A Literature Review of the Kalina Cycle and Trends

The demand for electricity and power has been increasing with the increase of the population of the world. The Covid-19 Pandemic has affected the way of life of human beings starting last year. The pandemic and economic downturn also affected the electricity demand of the world, but this is only short-term. Once the lockdowns around the world ease and back to normal situation begin, demand for power and electricity shall continue to grow. The century-old Rankine cycle has been the basis for power plants widely used today. However, a modified Rankine cycle known as the Kalina cycle has been proving more efficient than the standard Rankine cycle and might be able to provide the additional power needed in medium and low-temperature sources and waste heat recovery. This paper look into the development of the Kalina cycle and the trends that might be of use for the global electricity requirement.

The 2022 Plasma Roadmap: low temperature plasma science and technology

The 2022 Roadmap is the next update in the series of Plasma Roadmaps published by Journal of Physics D with the intent to identify important outstanding challenges in the field of low-temperature plasma (LTP) physics and technology. The format of the Roadmap is the same as the previous Roadmaps representing the visions of 41 leading experts representing 21 countries and five continents in the various sub-fields of LTP science and technology. In recognition of the evolution in the field, several new topics have been introduced or given more prominence. These new topics and emphasis highlight increased interests in plasma-enabled additive manufacturing, soft materials, electrification of chemical conversions, plasma propulsion, extreme plasma regimes, plasmas in hypersonics, data-driven plasma science and technology and the contribution of LTP to combat COVID-19. In the last few decades, LTP science and technology has made a tremendously positive impact on our society. It is our hope that this roadmap will help continue this excellent track record over the next 5â€"10 years. [ FROM AUTHOR] Copyright of Journal of Physics: D Applied Physics is the property of IOP Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Is it correct to name DESs deep eutectic solvents?

Recent years of research and development have brought frequently used terms for new types of green solvents to the lexicon of scientists. This can lead to terminological inaccuracies. In particular, different names are being used for the same types of solvents: Deep Eutectic Solvents (DES);Natural Deep Eutectic Solvents;Low-Transition Temperature Mixtures;Low-Melting Mixtures. It would, therefore, be appropriate to eliminate certain inaccuracies and to use simplification, which means using the general term “Low-Temperature Transition Mixtures” or introducing the term “DES-like mixtures”.

Secondary PM2.5 decreases significantly less than NO2 emission reductions during COVID lockdown in Germany

This study estimates the influence of anthropogenic emission reductions on the concentration of particulate matter with a diameter smaller than 2.5 µm (PM2.5) during the 2020 lockdown period in German metropolitan areas. After accounting for meteorological effects, PM2.5 concentrations during the spring 2020 lockdown period were 5 % lower compared to the same time period in 2019. However, during the 2020 pre-lockdown period (winter), PM2.5 concentrations with meteorology accounted for were 19 % lower than in 2019. Meanwhile, NO2 concentrations with meteorology accounted for dropped by 23 % during the 2020 lockdown period compared to an only 9 % drop for the 2020 pre-lockdown period, both compared to 2019. SO2 and CO concentrations with meteorology accounted for show no significant changes during the 2020 lockdown period compared to 2019. GEOS-Chem (GC) simulations with a COVID-19 emission reduction scenario based on the observations (23 % reduction in anthropogenic NOx emission with unchanged anthropogenic volatile organic compounds (VOCs) and SO2) are consistent with the small reductions of PM2.5 during the lockdown and are used to identify the underlying drivers for this. Due to being in a NOx-saturated ozone production regime, GC OH radical and O3 concentrations increased (15 % and 9 %, respectively) during the lockdown compared to a business-as-usual (BAU, no lockdown) scenario. Ox (equal to NO2+O3) analysis implies that the increase in ozone at nighttime is solely due to reduced NO titration. The increased O3 results in increased NO3 radical concentrations, primarily during the night, despite the large reductions in NO2. Thus, the oxidative capacity of the atmosphere is increased in all three important oxidants, OH, O3, and NO3. PM nitrate formation from gas-phase nitric acid (HNO3) is decreased during the lockdown as the increased OH concentration cannot compensate for the strong reductions in NO2, resulting in decreased daytime HNO3 formation from the OH + NO2 reaction. However, nighttime formation of PM nitrate from N2O5 hydrolysis is relatively unchanged. This results from the fact that increased nighttime O3 results in significantly increased NO3, which roughly balances the effect of the strong NO2 reductions on N2O5 formation. Ultimately, the only small observed decrease in lockdown PM2.5 concentrations can be explained by the large contribution of nighttime PM nitrate formation, generally enhanced sulfate formation, and slightly decreased ammonium. This study also suggests that high PM2.5 episodes in early spring are linked to high atmospheric ammonia concentrations combined with favorable meteorological conditions of low temperature and low boundary layer height. Northwest Germany is a hot-spot of NH3 emissions, primarily emitted from livestock farming and intensive agricultural activities (fertilizer application), with high NH3 concentrations in the early spring and summer months. Based on our findings, we suggest that appropriate NOx and VOC emission controls are required to limit ozone, and that should also help reduce PM2.5. Regulation of NH3 emissions, primarily from agricultural sectors, could result in significant reductions in PM2.5 pollution.