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1.
National Journal of Clinical Anatomy ; 10(1):1-4, 2021.
Article in English | EMBASE | ID: covidwho-20241556
2.
Avances en Odontoestomatologia ; 39(1):42-48, 2023.
Article in Spanish | EMBASE | ID: covidwho-20234681

ABSTRACT

The oral cavity houses a large number of microorganisms that are potential pathogens, such as cytome-galovirus, hepatitis B virus (HBV), hepatitis C virus, herpes simplex virus types 1 and 2, human immuno-deficiency virus, mycobacterium tuberculosis and currently with the appearance of the SARS COV-2 that causes covid-19, the dental community must take stricter measures in its protection protocols against diseases. To evaluate its germicidal efficacy, ultraviolet light was applied with different exposure times on the alginate dental impressions, immediately after having taken the impression, which when it came into contact with the oral cavity of the patient is contaminated. As a result, a decrease in size and quantity of the bacterial colonies was observed in most of the samples in which the UV LED light was applied at 10 and 15 minutes of exposure. Some samples showed less bacterial growth even after 5 minutes of exposure. All this confirms its germicidal capacity thanks to its 245 nm ultraviolet spectrum that affects the DNA and RNA chain of microorganisms since it is the wavelength of maximum absorption of its molecule, eliminating its reproductive and survival capacity. The advantages it offers such as its small size, easy to handle and install, that it does not require constant maintenance, low acquisition cost;its constant high intensity light that does not generate any increase in temperature, makes it an excellent disinfectant auxiliary that can be incorporated into dental clinics.Copyright © 2023, Ediciones Avances S.L.. All rights reserved.

3.
Aims Microbiology ; 9(3):431-443, 2023.
Article in English | Web of Science | ID: covidwho-20231397

ABSTRACT

To minimize health risks, surrogates are often employed to reduce experiments with pathogenic microorganisms and the associated health risk. Due to structural similarities between the enveloped RNA -viruses SARS-CoV-2 and Phi6, the latter has been established as a nonpathogenic coronavirus surrogate for many applications. However, large discrepancies in the UV log-reduction doses between SARS-CoV-2 and Phi6 necessitate the search for a better surrogate for UV inactivation applications. A literature study provided the bacteriophage PhiX174 as a potentially more suitable nonpathogenic coronavirus surrogate candidate. In irradiation experiments, the sensitivity of PhiX174 was investigated upon exposure to UV radiation of wavelengths 222 nm (Far-UVC), 254 nm (UVC), 302 nm (broad-band UVB), 311 nm (narrow-band UVB) and 366 nm (UVA) using a plaque assay. The determined log-reduction doses for PhiX174 were 1.3 mJ/cm2 @ 222 nm, 5 mJ/cm2 @ 254 nm, 17.9 mJ/cm2 @ 302 nm, 625 mJ/cm2 @ 311 nm and 42.5 J/cm2 @ 366 nm. The comparison of these results with published log-reduction doses of SARS-CoV-2 in the same spectral region, led to the conclusion that the bacteriophage PhiX174 exhibits larger log-reduction doses than SARS-CoV-2, nevertheless, it is a better UV-surrogate at 222 nm (Far-UVC), 254 nm (UVC) and 302 nm (UVB) than the often applied Phi6.

4.
International Journal of Infectious Diseases ; 130:S104-S104, 2023.
Article in English | Academic Search Complete | ID: covidwho-2324510

ABSTRACT

COVID-19 pandemic affected the entire globe and resulted in millions of deaths. Besides human-to-human respiratory droplets transmission, contact with aerosol-infected surfaces is an important way of transmitting this virus. The virus can be detected on many surfaces for a long time, in aerosols for at least 3 hours, and on plastic surfaces for up to 72 hours. Hence, it is crucial to determine how to disinfect the environment. Several biocidal agents have been used to clean the environment. Apart from biocidal agents, ultraviolet (UV) irradiation had also been used for environmental disinfection. However, there are several UV sources and systems with different wavelengths were used for disinfection and there was a wide range of effectiveness in disinfection with different modules. Thus, it was necessary to comprehensively review the current understanding of UV light used in disinfection to advise regarding UV light for environmental disinfection. Using the keywords COVID-19, UV light, and disinfection from 2020 to 2022, we searched various databases for articles online. We found various devices that had been studied for disinfection of SARS-CoV-2 with UV, such as monochromatic UV-C lamps, UV-LED light, broad- spectrum UV light devices, and excimer lamps. As a monochromatic UV source, different types of lamps were reported to have an excellent effect on disinfection, with the most common wavelength used for disinfection being 254 nm. As a broad-spectrum wavelength light, which is from 200 to 280 nm, one- minute exposure is enough to cause a 3 log10 reduction of viral load, which means 99.97% in disinfection. UV light are effective in coronavirus disinfection. Compared with the chemical agent, it is more environmentally friendly. To apply the UV light to environmental disinfection, five minutes is enough to reach 99.99% disinfection of the SARS-CoV-2 virus, for broad-spectrum wavelength light placed within one meter from the target surface. [ FROM AUTHOR] Copyright of International Journal of Infectious Diseases is the property of Elsevier B.V. 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.)

5.
British Medical Bulletin ; 144(1):1-2, 2022.
Article in English | EMBASE | ID: covidwho-2320171
6.
Chinese Journal of Dermatology ; 53(3):159-164, 2020.
Article in Chinese | EMBASE | ID: covidwho-2293391

ABSTRACT

Health professions preventing and controlling coronavirus disease 2019 are prone to skin and mucous membrane injuries, which may cause acute and chronic dermatitis, secondary infections and aggravation of underlying skin diseases. This is a consensus of Chinese experts on measures and advice on hand cleaning- and medical glove-related hand protection, mask-and goggles-related face protection, ultraviolet-related protection, as well as eye, nasal and oral mucosa, outer ear and hair protection. It is necessary to strictly follow standards on wearing protective equipment and specifications on sterilizing and cleaning. Both insufficient and excessive protection will adversely affect the skin and mucous membrane barrier. At the same time, using moisturizing products is highly recommended to achieve better protection.Copyright © 2020 by the Chinese Medical Association.

7.
19th China International Forum on Solid State Lighting and 8th International Forum on Wide Bandgap Semiconductors, SSLCHINA: IFWS 2022 ; : 228-230, 2023.
Article in English | Scopus | ID: covidwho-2306504

ABSTRACT

Recent studies in the epidermis have shown that Far-UVC (200-230nm) is a promising candidate against Novel Coronavirus (SARS-Cov-2) with little DNA damage. Due to the consideration that conventional Far-UVC KrCl excilamps may emit 200-230 nm radiation (typically 222-nm peak wavelength) but with some harmful UV radiation beyond 230 to 280 nm, a novel design of Far-UVC KrCl excilamps with the filter and reflector is introduced to reduce the harmful UV radiation from 10.9% to 2.5% at the cost of 30%~40% reduction in the total irradiance. In our study, the radiant characteristics and service life of the novel Far-UVC KrCl excilamps of 40~75 Watt (electrical power) with 222-nm peak wavelength were investigated. The service life was assessed under aging at the ambient temperatures (Ta) of 25 and 85 for 500 hours, respectively. The results showed that both the ambient temperature and the root mean square of current (Irms) into the excilamps have a substantial effect on the lifetime of the KrCl excilamps. Furthermore, although no significant change of the off-nominal emission ratio existed during the lifetime test, it was observed that the high ambient temperature has a negative effect on the filtering of the harmful radiation. © 2023 IEEE.

8.
Water (Switzerland) ; 15(7), 2023.
Article in English | Scopus | ID: covidwho-2306223

ABSTRACT

UV-LED irradiation has attracted attention in water and wastewater disinfection applications. However, no studies have quantitatively investigated the impact of light intensity on the UV dosage for the same magnitude of disinfection. This study presents a powerful 280 nm UV-LED photoreactor with adjustable light intensity to disinfect municipal wastewater contaminated with E. coli, SARS-CoV-2 genetic materials and others. The disinfection performance of the 280 nm LED was also compared with 405 nm visible light LEDs, in terms of inactivating E. coli and total coliforms, as well as reducing cATP activities. The results showed that the UV dose needed per log reduction of E. coli and total coliforms, as well as cATP, could be decreased by increasing the light intensity within the investigated range (0–9640 µW/cm2). Higher energy consumption is needed for microbial disinfection using the 405 nm LED when compared to 280 nm LED. The signal of SARS-CoV-2 genetic material in wastewater and the SARS-CoV-2 spike protein in pure water decreased upon 280 nm UV irradiation. © 2023 by the authors.

9.
Bulletin of the American Meteorological Society ; 104(3):623-630, 2023.
Article in English | ProQuest Central | ID: covidwho-2298113

ABSTRACT

Presentations spanned a range of applications: the public health impacts of poor air quality and environmental justice;greenhouse gas measuring, monitoring, reporting, and verification (GHG MMRV);stratospheric ozone monitoring;and various applications of satellite observations to improve models, including data assimilation in global Earth system models. The combination of methane (CH4), carbon dioxide (CO2), carbon monoxide (CO), and NO2 retrievals can improve confidence in emissions inventories and model performance, and together these data products would be of use in future air quality management tools. The ability to retrieve additional trace gases (e.g., ethane, isoprene, and ammonia) in the thermal IR along with those measured in the UV–Vis–NIR region would be extremely useful for air quality applications, including source apportionment analysis (e.g., for oil/natural gas extraction, biogenic, and agricultural sources). Ground-level ozone is one of six criteria pollutants for which the EPA sets National Ambient Air Quality Standards (NAAQS) to protect against human health and welfare effects.

10.
Photodiagnosis and Photodynamic Therapy ; Conference: ABSTRACTS of the Nancy Meeting 2022. Nancy France. 41 (no pagination), 2023.
Article in English | EMBASE | ID: covidwho-2296899

ABSTRACT

The Covid-19 epidemic has been the most consequential global health crisis since the era of the influenza pandemic of 1918 [1]. Due to its high spreading rate, the virus disseminated across the world in a very short time span, forcing the World Health Organization to declare Covid-19 a global pandemic after just 3 months from the first reported case in China. At the beginning of the pandemic, when no vaccines were available, people entrust their safety to very few devices such as personal protective equipment (face masks, shields, and gloves), lock-down, and social distancing. The lack of alternative and not conventional techniques to suppress the spread of airborne epidemics among humans has pushed the research to develop new antiviral devices. The SAVE-US project (Suppression of Airborne Viral Epidemic Spread by UV-Light Barriers) aims at developing and demonstrating an innovative antimicrobial device based on 222nm-radiation. As known from the literature, the UVC radiation (200-280 nm) is the most effective wavelength for the inactivation of viruses and bacteria, corresponding to the DNA and RNA absorption peaks, but may also be mutagenic. For this reason, UVC-light sterilization is commonly performed in the absence of living organisms. Radiation in the far-UVC, especially at 222 nm, has been recently investigated because it shows a good antimicrobial efficacy, tested already on both bacteria [2] and virus [3] models including coronavirus, with very limited risks to human health. The low risk is associated to the small penetration depth of 222 nm light (a few mum): the energy is absorbed by the superficial stratum corneum of the skin that contains dead cells, with negligible irradiation of the underlying live tissue [4]. We will present the first version of a new prototype of 222 nm-illuminator and some preliminary results on its characterization;the presented device will be used in successive in vitro and in vivo experiments with SARS-CoV-2 virus. The device embeds a far-UVC lamp emitting at 222 nm, optical filters, and the controlling electronics. We show results on the spatial homogeneity of the emission intensity and the dependence on the lamp-virus distance. We also report on the ozone production due to absorption of far-UVC light from molecular oxygen naturally present in the air in order to evaluate its safety for human being and to properly evaluate its photo-killing efficacy.Copyright © 2023

11.
Photodiagnosis and Photodynamic Therapy ; Conference: ABSTRACTS of the Nancy Meeting 2022. Nancy France. 41 (no pagination), 2023.
Article in English | EMBASE | ID: covidwho-2295388

ABSTRACT

Despite the gradual return to pre-pandemic conditions, the spreading of COVID-19 (SARS-CoV-2) left several open issues. Nowadays it is know that airborne infections, including COVID-19, are conveyed by particles having the size of >5 mum (droplets) and <5 mum (droplets nuclei), ejected by coughing and sneezing [1]. While droplets undergo to dehydration and precipitation, droplet nuclei persist in air for long time after their ejection, contributing to infection spreading. Actual prevention strategies are based on non-pharmaceutical interventions act to reduce droplets diffusion and spacing from Personal Protective Equipment, such as facial masks, and social distancing measure. Nevertheless, for the new endemic phase of COVID-19 the development of new strategies for airborne infections' containment becomes unavoidable. In this project, we propose a new device for the suppression of Airborne Viral Aerosols designed to work in situations with constrained geometries (e.g. public transportation, offices, waiting rooms etc.) not allowing social distancing. The device, devised to perform photokilling of viral aerosols in air in presence of humans, has its core in an UV illumination system operating at 222 nm. It is know from literature that UV radiation alters the genetic material of viruses and bacteria whose maximum absorption wavelengths are in the far-UV range (UVC, 100-280 nm), the most effective for sterilization [2]. Differently from the operative wavelength of most commercial systems (254 nm), the higher tissue absorption prevents the 222 nm radiation to travel over the very first epidermal layers [3] constituting a minor health risk for applications in presence of people. The device combines the UV illumination system with a vertical flux of air that conveys exhaled particles to the light source and controls humidity and temperature, crucial parameters for virus diffusion. After its development, the device prototype will be tested in model experiments. Initially, its safety will be verified by monitoring in particular the UVC-induced ozone production. Then, in vitro photokilling experiments will be performed in two steps: (i) on a layer of immobilized SARS-Cov-2 virus act to obtain optimal UV doses for an effective sterilization;(ii) on SARS-Cov-2 aerosol models. For this last experiment, a model viral aerosol miming the characteristics of cough and sneeze particles will be preliminary studied and supported by synthetic data to characterize the optical properties of the reference scenario. The resulting information will be crucial for the final design of the device itself. As a last step, we will test the device in in vivo experiments. An air flux, harvesting exhaled air by infected mice, will be illuminated by the device and will be sent to healthy mice. Finally, the infectiveness of exhaled air after the UV treatment will be evaluated, providing more information for further applications in the presence of humans.Copyright © 2023

12.
12th International Conference on Manufacturing Engineering and Processes, ICMEP 2022 ; : 11-23, 2023.
Article in English | Scopus | ID: covidwho-2275051

ABSTRACT

The world is currently experiencing a crisis, caused by SARS-CoV-2 and a viral mutation. Given this, the mechatronic system is proposed that allows disinfecting contaminated surfaces. This device makes it possible to disinfect polyethylene terephthalate (PET) bottles by applying short-wave UVC rays from 200 to 280 nm, which generates a germicidal effect. The machine consists of a UVC chamber, transport, and a control system. For this, the methodology of the Association of German Engineers (VDI 2206) was used, taking into account the Inventor, TIA Portal, and Factory IO software, managing to develop the system whose light-emitting diodes inside the camera project type C ultraviolet light, camera protected by strips of plastic sheet (ABS) acrylonitrile butadiene styrene anti-ultraviolet light that blocks the projection wave up to 98% of the radiation;the recycled PET bottles are moved through a linear conveyor belt that supports a maximum weight of 200 kg, controlled by a control panel. Obtaining the results in this research focused on the design of the prototype, with a feasible structural system thanks to its maximum efficiency in the disinfection process. It is concluded that it is feasible to design a machine that projects ultraviolet rays to disinfect recycled PET bottles to eliminate viruses, parasites, fungi, and bacteria. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

13.
Izvestiya. Atmospheric and Oceanic Physics, suppl. 1 ; 58:S42-S51, 2022.
Article in English | ProQuest Central | ID: covidwho-2280569

ABSTRACT

In this paper we consider the effect of heliogeophysical activity on the COVID-19 epidemic associated with the spread of the SARS-CoV-2 coronavirus in Moscow. An analysis of official data on the course of the pandemic has provided evidence of the effect of heliogeophysical activity on the spread of an infectious disease. The pandemic arose during the winter when solar activity was minimal and ultraviolet radiation was at its lowest. The study showed a significant relation between the infectious process and geomagnetic activity: periods of outbreaks in the number of infections and deaths correlated with periods of a decrease in geomagnetic activity lasting several months. The impact of magnetospheric storms and substorms on the human body during a pandemic is also considered. It is shown that, during the minimum of solar activity during periods of geomagnetic disturbances lasting from one to several days, both the number of infections and the number of deaths additionally and statistically significantly increase. Evidence of a direct or indirect effect of solar activity on the occurrence of outbreaks of infectious diseases is important from the viewpoint of understanding the emergence and development of epidemics.

14.
Wuli Xuebao/Acta Physica Sinica ; 72(4), 2023.
Article in Chinese | Scopus | ID: covidwho-2258961

ABSTRACT

AlGaN-based deep-ultraviolet light-emitting diodes (DUV LEDs) are widely used in sterilization, sensing, water purification, medical treatment, non-line of sight (NLOS) communication and many other fields. Especially it has been reported that the global novel coronavirus (COVID-19) can be effectively inactivated by the DUV light with a wavelength below 280 nm (UVC) within a few seconds, which has also attracted great attention. However, the external quantum efficiency (EQE) of UVC LED is still at a low level, generally not more than 10%. As an important component of EQE, internal quantum efficiency (IQE) plays a crucial role in realizing high-performance DUV-LED. In order to improve the IQE of AlGaN-based DUV-LED, this work adopts an electron blocking layer (EBL) structure based on InAlGaN/AlGaN superlattice. The results show that the superlattice EBL structure can effectively improve the IQE compared with the traditional single-layer and double-layer EBL structure for the DUV-LED. On this basis, the optimization method based on JAYA intelligent algorithm for LED structure design is proposed in this work. Using the proposed design method, the InAlGaN/AlGaN superlattice EBL structure is further optimized to maximize the LED' s IQE. It is demonstrated that the optimized superlattice EBL structure is beneficial to not only the suppression of electron leakage but also the improvement of hole injection, leading to the increase of carrier recombination in the active region. As a result, the IQE of the DUV-LED at 200 mA injection current is 41.2% higher than that of the single-layer EBL structure. In addition, the optimized structure reduces IQE at high current from 25% to 4%. The optimization method based on intelligent algorithm can break through the limitation of the current LED structure design and provide a new method to improve the efficiency of AlGaN-based DUV-LED. © 2023 Chinese Physical Society.

15.
Iranian Journal of Veterinary Medicine ; 13(3):251-259, 2023.
Article in English | EMBASE | ID: covidwho-2250867

ABSTRACT

BACKGROUND: Gammacoronaviruses, which are single-stranded, positive-sense RNA viruses, are responsible for a wide variety of existing and emerging diseases in birds. The Gammacoronaviruses primarily infect avian hosts. OBJECTIVE(S): This study aimed to investigate the genetic diversity of Gammacoronaviruses in quail population in Iran. METHOD(S): In the period from 2016 to 2018, samples from 47 quail flocks with or without enteric signs, were collected from four provinces in Iran. RESULT(S): Gammacoronavirus was detected in samples of 4 flocks by using RT-PCR and characterized by N gene sequencing. The isolates formed a distinct group from other Gamma- coronaviruses groups CONCLUSION(S): The finding suggests the existence of a novel Gammacoronavirus circulating in quail farms. The phylogenetic relationship of the isolates concerning different sequences and geographical regions displayed complexity and diversity. The present study is the first detection of Gammacoronavirus in quail farms in Iran. Further studies are required and should include the isolation and experimental studies of Gammacoronaviruses in Iran.Copyright © 2019.

16.
British Journal of Dermatology ; 187(Supplement 1):218, 2022.
Article in English | EMBASE | ID: covidwho-2278801

ABSTRACT

Owing to the COVID-19 pandemic, there has been an increased effort to find new approaches to prevent airborne transmission of diseases. One of these approaches is the use of far ultraviolet C (far-UVC) irradiation. Far-UVC is emitted at 222 nm by KrCl excimer lamps and has been shown to inactivate many pathogens, including human coronaviruses, under laboratory conditions. Studies so far suggest that human skin can tolerate even extremely high doses of filtered far-UVC without the induction of erythema or significant DNA damage, unlike existing germicidal ultraviolet lamps, which typically emit at 254 nm. Far-UVC could therefore potentially be used safely to reduce effectively airborne transmission in public spaces. However, if that was to happen, it would be important that the general public understood the risks and benefits of far-UVC. The aims of this study were to carry out a survey to assess current public knowledge and understanding of far-UVC, with a view to the subsequent development of a public engagement activity to raise awareness and address safety concerns about the use of far-UVC. The survey was developed in-house and was distributed to the general public through the use of social media and the results showed that only 32.4% of respondents had previously heard of far-UVC vs. 64.9% having heard of UVC. Despite this, after being given a short (< 200 words) page of information about far- UVC, the majority of participants said that they would feel safer in public spaces if far-UVC was used vs. how they feel currently. Participants were then asked if they would support use of far-UVC in hospitals, public leisure spaces such as shops and cafes, public transport and their own workplaces. In all scenarios, the majority of participants said they would support far-UVC use, with < 10% of responses for each scenario being an outright 'no'. Of people who answered 'no' or 'not sure' to these questions, most cited reasons such as not having enough information or still not being convinced of its safety. These responses highlight the need for public engagement in this field, in order to raise awareness and to allow the general public to be better informed, with respect to the anticipated benefits and the safety of far-UVC irradiation use for disinfection purposes.

17.
Science of the Total Environment ; Part 2. 858 (no pagination), 2023.
Article in English | EMBASE | ID: covidwho-2277905

ABSTRACT

Students spend nearly one third of their typical day in the school environment, where they may be exposed to harmful air pollutants. A consolidated knowledge base of interventions to reduce this exposure is required for making informed decisions on their implementation and wider uptake. We attempt to fill this knowledge gap by synthesising the existing scientific literature on different school-based air pollution exposure interventions, their efficiency, suitability, and limitations. We assessed technological (air purifiers, HVAC - Heating Ventilation and Air Conditioning etc.), behavioural, physical barriers, structural, school-commute and policy and regulatory interventions. Studies suggest that the removal efficiency of air purifiers for PM2.5, PM10, PM1 and BC can be up to 57 %, 34 %, 70 % and 58 %, respectively, depending on the air purification technology compared with control levels in classroom. The HVAC system combined with high efficiency filters has BC, PM10 and PM2.5 removal efficiency up to 97 %, 34 % and 30 %, respectively. Citizen science campaigns are effective in reducing the indoor air pollutants' exposure up to 94 %. The concentration of PM10, NO2, O3, BC and PNC can be reduced by up to 60 %, 59 %, 16 %, 63 % and 77 %, respectively as compared to control conditions, by installing green infrastructure (GI) as a physical barrier. School commute interventions can reduce NO2 concentration by up to 23 %. The in-cabin concentration reduction of up to 77 % for PM2.5, 43 % for PNC, 89 % for BC, 74 % for PM10 and 75 % for NO2, along with 94 % reduction in tailpipe emission of total particles, can be achieved using clean fuels and retrofits. No stand-alone method is found as the absolute solution for controlling pollutants exposure, their combined application can be effective in most of the scenarios. More research is needed on assessing combined interventions, and their operational synchronisation for getting the optimum results.Copyright © 2022 The Authors

18.
Environ Res ; 228: 115796, 2023 07 01.
Article in English | MEDLINE | ID: covidwho-2251023

ABSTRACT

The relation between meteorological factors and COVID-19 spread remains uncertain, particularly with regard to the role of temperature, relative humidity and solar ultraviolet (UV) radiation. To assess this relation, we investigated disease spread within Italy during 2020. The pandemic had a large and early impact in Italy, and during 2020 the effects of vaccination and viral variants had not yet complicated the dynamics. We used non-linear, spline-based Poisson regression of modeled temperature, UV and relative humidity, adjusting for mobility patterns and additional confounders, to estimate daily rates of COVID-19 new cases, hospital and intensive care unit admissions, and deaths during the two waves of the pandemic in Italy during 2020. We found little association between relative humidity and COVID-19 endpoints in both waves, whereas UV radiation above 40 kJ/m2 showed a weak inverse association with hospital and ICU admissions in the first wave, and a stronger relation with all COVID-19 endpoints in the second wave. Temperature above 283 K (10 °C/50 °F) showed a strong non-linear negative relation with COVID-19 endpoints, with inconsistent relations below this cutpoint in the two waves. Given the biological plausibility of a relation between temperature and COVID-19, these data add support to the proposition that temperature above 283 K, and possibly high levels of solar UV radiation, reduced COVID-19 spread.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , SARS-CoV-2 , Temperature , Italy/epidemiology , Meteorological Concepts , Humidity
19.
Journal of Pharmaceutical and Biomedical Analysis ; 223, 2023.
Article in English | Scopus | ID: covidwho-2245767

ABSTRACT

A fast procedure obtained by the combination of fabric phase extraction (FPSE) with high performance liquid chromatography (HPLC) has been developed and validated for the quantification of favipiravir (FVP) in human plasma and breast milk. A sol-gel polycaprolactone-block-polydimethylsiloxane-block-polycaprolactone (sol-gel PCAP-PDMS-PCAP) coated on 100% cellose cotton fabric was selected as the most efficient membrane for FPSE in human plasma and breast milk samples. HPLC-UV analysis were performed using a RP C18 column under isocratic conditions. Under these optimezed settings, the overall chromatographic analysis time was limited to only 5 min without encountering any observable matrix interferences. Following the method validation procedure, the herein assay shows a linear calibration curve over the range of 0.2–50 µg/mL and 0.5–25 µg/mL for plasma and breast milk, respectively. The method sensitivities in terms of limit of detection (LOD) and limit of quantification (LOQ), validated in both the matrices, have been found to be 0.06 and 0.2 µg/mL for plasma and 0.15 and 0.5 µg/mL for milk, respectively. Intraday and interday precision and trueness, accordingly to the International Guidelines, were validated and were below 3.61% for both the matrices. The herein method was further tested on real samples in order to highlight the applicability and the advantage for therapeutic drug monitoring (TDM) applications. To the best of our knowledge, this is the first validated FPSE-HPLC-UV method in human plasma and breast milk for TDM purposes applied on real samples. The validated method provides fast, simple, cost reduced, and sensitive assay for the direct quantification of favipiravir in real biological matrices, also appliyng a well-known rugged and cheap instrument configuration. © 2022 Elsevier B.V.

20.
Journal of Hazardous Materials ; 443, 2023.
Article in English | Scopus | ID: covidwho-2242953

ABSTRACT

This study focuses on characterizing microplastics and non-microplastics released from surgical masks (SMs), N95 masks (N95), KN95 masks (KN95), and children's masks (CMs) after simulating sunlight aging. Based on micro-Raman spectrum analysis, it was found that the dominant particles released from masks were non-microplastics (66.76–98.85%). Unfortunately, CMs released the most microplastics, which is 8.92 times more than SMs. The predominant size range of microplastics was 30–500 µm, and the main polymer types were PP and PET. Compared with the whole SMs, the microplastic particles released from the cutting-SMs increased conspicuously, which is 12.15 times that of the whole SMs. The main components of non-microplastics include β-carotene, microcrystalline cellulose 102, and eight types of minerals. Furthermore, non-microplastics were mainly fibrous and fragmented in appearance, similar to the morphology of microplastics. After 15 days of UVA-aging, the fibers of the face layers had cracks to varying degrees. It was estimated that these four types of masks can release at least 31.5 trillion microplastics annually in China. Overall, this study demonstrated that the masks could release a large quantity of microplastics and non-microplastics to the environment after sunlight aging, deserving urgent attention in the future study. © 2022 Elsevier B.V.

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