Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 68
Filter
Add filters

Year range
1.
Frontiers of Environmental Science & Engineering ; 17(3), 2023.
Article in English | ProQuest Central | ID: covidwho-2027649

ABSTRACT

The COVID-19 pandemic remains ever prevalent and afflicting—partially because one of its transmission pathways is aerosol. With the widely used central air conditioning systems worldwide, indoor virus aerosols can rapidly migrate, thus resulting in rapid infection transmission. It is therefore important to install microbial aerosol treatment units in the air conditioning systems, and we herein investigated the possibility of combining such filtration with UV irradiation to address virus aerosols. Results showed that the removal efficiency of filtration towards f2 and MS2 phages depended on the type of commercial filter material and the filtration speed, with an optimal velocity of 5 cm/s for virus removal. Additionally, it was found that UV irradiation had a significant effect on inactivating viruses enriched on the surfaces of filter materials;MS2 phages had greater resistance to UV-C irradiation than f2 phages. The optimal inactivation time for UV-C irradiation was 30 min, with higher irradiation times presenting no substantial increase in inactivation rate. Moreover, excessive virus enrichment on the filters decreased the inactivation effect. Timely inactivation is therefore recommended. In general, the combined system involving filtration with UV-C irradiation demonstrated a significant removal effect on virus aerosols. Moreover, the system is simple and economical, making it convenient for widespread implementation in air-conditioning systems.

2.
International Journal of Molecular Sciences ; 23(17):9991, 2022.
Article in English | ProQuest Central | ID: covidwho-2023754

ABSTRACT

Carbohydrate antigen 199 (CA199) is a serum biomarker which has certain value and significance in the diagnosis, prognosis, treatment, and postoperative monitoring of cancer. In this study, a lateral flow immunoassay based on europium (III) polystyrene time-resolved fluorescence microspheres (TRFM-based LFIA), integrated with a portable fluorescence reader, has been successfully establish for rapid and quantitative analysis of CA199 in human serum. Briefly, time-resolved fluorescence microspheres (TRFMs) were conjugated with antibody I (Ab1) against CA199 as detection probes, and antibody II (Ab2) was coated as capture element, and a “TRFMs-Ab1-CA199-Ab2” sandwich format would form when CA199 was detected by the TRFM-based LFIA. Under the optimal parameters, the detection limit of the TRFM-based LFIA for visible quantitation with the help of an ultraviolet light was 4.125 U/mL, which was four times lower than that of LFIA based on gold nanoparticles. Additionally, the fluorescence ratio is well linearly correlated with the CA199 concentration (0.00–66.0 U/mL) and logarithmic concentration (66.0–264.0 U/mL) for quantitative detection. Serum samples from 10 healthy people and 10 liver cancer patients were tested to confirm the performances of the point-of-care application of the TRFM-based LFIA, 20.0 U/mL of CA199 in human serum was defined as the threshold for distinguishing healthy people from liver cancer patients with an accuracy of about 60%. The establishment of TRFM-based LFIA will provide a sensitive, convenient, and efficient technical support for rapid screening of CA199 in cancer diagnosis and prognosis.

3.
Catalysts ; 12(8):829, 2022.
Article in English | ProQuest Central | ID: covidwho-2023197

ABSTRACT

The transmission of pathogens via surfaces poses a major health problem, particularly in hospital environments. Antimicrobial surfaces can interrupt the path of spread, while photocatalytically active titanium dioxide (TiO2) nanoparticles have emerged as an additive for creating antimicrobial materials. Irradiation of such particles with ultraviolet (UV) light leads to the formation of reactive oxygen species that can inactivate bacteria. The aim of this research was to incorporate TiO2 nanoparticles into a cellulose-reinforced melamine-formaldehyde resin (MF) to obtain a photocatalytic antimicrobial thermoset, to be used, for example, for device enclosures or tableware. To this end, composites of MF with 5, 10, 15, and 20 wt% TiO2 were produced by ultrasonication and hot pressing. The incorporation of TiO2 resulted in a small decrease in tensile strength and little to no decrease in Shore D hardness, but a statistically significant decrease in the water contact angle. After 48 h of UV irradiation, a statistically significant decrease in tensile strength for samples with 0 and 10 wt% TiO2 was measured but with no statistically significant differences in Shore D hardness, although a statistically significant increase in surface hydrophilicity was measured. Accelerated methylene blue (MB) degradation was measured during a further 2.5 h of UV irradiation and MB concentrations of 12% or less could be achieved. Samples containing 0, 10, and 20 wt% TiO2 were investigated for long-term UV stability and antimicrobial activity. Fourier-transform infrared spectroscopy revealed no changes in the chemical structure of the polymer, due to the incorporation of TiO2, but changes were detected after 500 h of irradiation, indicating material degradation. Specimens pre-irradiated with UV for 48 h showed a total reduction in Escherichia coli when exposed to UV irradiation.

4.
Antioxidants ; 11(8):1591, 2022.
Article in English | ProQuest Central | ID: covidwho-2023091

ABSTRACT

Electron transfer plays a crucial role in ROS generation in living systems. Molecular oxygen acts as the terminal electron acceptor in the respiratory chains of aerobic organisms. Two main mechanisms of antioxidant defense by exogenous antioxidants are usually considered. The first is the inhibition of ROS generation, and the second is the trapping of free radicals. In the present study, we have elucidated both these mechanisms of antioxidant activity of glycyrrhizin (GL), the main active component of licorice root, using the chemically induced dynamic nuclear polarization (CIDNP) technique. First, it was shown that GL is capable of capturing a solvated electron, thereby preventing its capture by molecular oxygen. Second, we studied the effect of glycyrrhizin on the behavior of free radicals generated by UV irradiation of xenobiotic, NSAID—naproxen in solution. The structure of the glycyrrhizin paramagnetic intermediates formed after the capture of a solvated electron was established from a photo-CIDNP study of the model system—the dianion of 5-sulfosalicylic acid and DFT calculations.

5.
Drug Development and Delivery ; 22(4):18-23, 2022.
Article in English | Scopus | ID: covidwho-2012508
6.
The Science Teacher ; 90(1):34-37, 2022.
Article in English | ProQuest Central | ID: covidwho-2012095

ABSTRACT

While it should be common practice to talk about climate change throughout the curriculum (NGSS Lead States 2013), only addressing climate when it comes up in other classes results in students graduating high school still unable to articulate the causes or effects of climate change as well as what needs to be done to address the problem (Monroe, Oxarart, and Plate 2013;Reid 2019;Schreiner, Henriksen, and Kirkeby Hansen 2005). Even if building climate change into other science classes was an effective strategy for teaching climate science, students would still not have gained climate literacy because CCE should also incorporate societal effects and climate justice (Stapleton 2019). Students were encouraged to submit their projects to the potentially interested groups or organizations (e.g., Department of Transportation or city planning commission) once complete. Because climate change misconceptions abound (McNeil and Vaughn 2012), we identified common misconceptions ahead of time and provided tools to prevent or resolve these noncanonical understandings. Instead of telling students that the two can be confused, we start by discussing the ozone hole (because they are already familiar with it) and how ozone interacts with UV radiation before even mentioning the greenhouse effect and carbon dioxide interacting with infrared radiation.

7.
Chinese Journal of Evidence-Based Medicine ; 22(8):932-947, 2022.
Article in Chinese | EMBASE | ID: covidwho-2006473

ABSTRACT

Objective To evaluate the evidence of the experience with medical sewage treatment procedures in medical institutions in China. Methods Databases including CNKI, WanFang Data, PubMed, Web of Science, and EBSCO were electronically searched to collect studies on the medical sewage treatment process, flow, and specifications in medical institutions in China. We used the quality evaluation system to classify and grade the experiences based on the principles and methods of evidence-based science and performed a descriptive analysis. Results After the SARS pandemic in 2003, China systematically established and standardized the technical criteria of medical sewage treatment and discharge. Moreover, a prevention system for the epidemic using medical sewage was constructed, which guaranteed that the quality of medical sewage treatment and discharge would meet the criteria and protect the citizens, and the technical specifications of medical sewage treatment would progress and increase strictly. At present, medical sewage treatment in medical institutions in China was based on mechanical and biological methods, and disinfection was mainly performed using chlorine and its compounds, ozone, and ultraviolet light. Conclusion The COVID-19 pandemic requires a higher quality of medical sewage treatment and discharge criteria for medical institutions in China. To meet these criteria, all medical institutions in China should check, replace, and update their old facilities;strengthen personnel training and effectively ensure the quality of medical sewage treatment.

8.
Pediatrics ; 149, 2022.
Article in English | EMBASE | ID: covidwho-2003054

ABSTRACT

Background: The COVID-19 pandemic had placed constraints on cardiopulmonary resuscitation (CPR), including early intubation, minimizing bag-valve mask ventilation1, and using protective equipment and barriers during resuscitation. Patient barrier devices have been introduced in emergency departments and operating rooms, consisting of plastic drapes over the patient9, or the use of an acrylic box.2 Both of these adjuncts reduce aerosolization of oropharyngeal particles from the patient, and can facilitate video-based intubation.2,3 However, it is unknown whether these devices help or hinder the ultimate resuscitation quality in cardiopulmonary arrest patients. Our specific question addresses the effect of a patient barrier device and COVID-19 resuscitation recommendations on resuscitation quality. We hypothesize that a simple patient barrier consisting of a plastic drape reduces healthcare worker (HCW) contamination without affecting resuscitation quality. Methods: This was a single-center randomized controlled pilot trial, in which in-hospital teams of 4 to 6 HCWs were randomized to either use a plastic drape (intervention) or no plastic drape (control) for a simulated adolescent cardiopulmonary arrest. The manikin was modified to emanate simulated viral particles (GloGerm®, Moab, UT) from the trachea detectable using ultraviolet light. Teams managed a cardiopulmonary arrest until intubation, using Personal Protective Equipment (PPE) and PALS/ACLS algorithms. Data were captured via arbitrated video review. Resuscitation data included time-to-bagging, time-to-intubation, and chest compression quality metrics - depth, rate, and lean. Contamination data were collected visually, marking the number of PPE equipment with visible fluorescence. Mean NASA-TLX and NOTECHS scores measured workload and team performance. Descriptive and univariate statistics were used to determine differences between intervention and control teams. Results: Fifteen simulations were conducted from 2020 to 2021;one was excluded from analysis as a performance outlier, leaving 7 intervention vs. 7 control teams. Scenarios lasted an average of 10.4+/- 3 minutes. Time-to-bagging, time-to-intubation, and intubation duration were not different between groups (72.1+/-22.4 vs 56.7+/-30.9 sec, 536+/-289 vs 544+/-127 sec, 78.9+/-73.0 vs 95.7+/-113 sec, p>0.3), and CPR quality for mean depth, rate, and lean were also not different (36.1+/-11.6 vs 30.9+/-13.2 cm, 108+/-13 vs 112+/-8/min, 8.7+/-5.2 vs 4.5+/-4.3 cm, p>0.14). Contamination rates were lower for the intubating physician (2.3+/-0.5 vs 4.1+/-0.9 surfaces, p<0.001) and for all participants (2.8+/-0.7 vs 3.7+/-0.9 surfaces, p=0.05) when using a barrier. No other contamination rate changes were observed. Participants noted no differences in team performance (22.4+/-1.6 vs 20.8+/-1.8, p=0.5) but a slight trend towards higher workload with the plastic barrier (+9.5+/-7.7 vs -0.1+/-11.5, p=0.09). Conclusion: The use of a plastic drape as a patient barrier appears to reduce simulated virus contamination for HCWs, particularly for the intubation physician during a simulated cardiopulmonary arrest without affecting resuscitation performance. Perceived workload increases with the drape, and further studies are needed to substantiate these findings in larger samples and in different settings.

9.
Journal of the Intensive Care Society ; 2022.
Article in English | EMBASE | ID: covidwho-1997280

ABSTRACT

Background: Current personal protective equipment (PPE) practices in UK intensive care units involve “sessional” use of long-sleeved gowns, risking nosocomial infection transmitted via gown sleeves. Data from the first wave of the COVID19 pandemic demonstrated that these changes in infection prevention and control protocols were associated with an increase in healthcare associated bloodstream infections. We therefore explored the use of a protocol using short-sleeved gowns with hand and arm hygiene to reduce this risk. Methods: ICU staff were trained in wearing short-sleeved gowns and using a specific hand and arm washing technique between patients (experimental protocol). They then underwent simulation training, performing COVID-19 intubation and proning tasks using either experimental protocol or the standard (long-sleeved) control protocol. Fluorescent powder was used to simulate microbial contamination, detected using photographs under ultraviolet light. Teams were randomised to use control or experimental PPE first. During the simulation, staff were questioned on their feelings about personal safety, comfort and patient safety. Results: Sixty-eight staff and 17 proning volunteers were studied. Experimental PPE completely prevented staff contamination during COVID-19 intubation, whereas this occurred in 30/67 staff wearing control PPE (p =.003, McNemar). Proning volunteers were contaminated by staff in 15/17 control sessions and in 1/17 with experimental PPE (p =.023 McNemar). Staff comfort was superior with experimental PPE (p<.001, Wilcoxon). Their personal safety perception was initially higher with control PPE, but changed towards neutrality during sessions (p <.001 start, 0.068 end). Their impressions of patient safety were initially similar (p =.87), but finished strongly in favour of experimental PPE (p <.001). Conclusions: Short-sleeved gowns with hand and forearm cleansing appear superior to sessional long-sleeved gowns in preventing cross-contamination between staff and patients.

10.
Indoor and Built Environment ; 2022.
Article in English | EMBASE | ID: covidwho-1997264

ABSTRACT

COVID-19 has alerted us about the need to quantify the effect of different environmental factors on the concentration distribution of bioaerosols. An experimental investigation was carried out to evaluate the effect of environmental factors, including air temperature, relative humidity, airflow speed and ultraviolet (UV) radiation, on the potential dispersion risk of bioaerosols in an enclosed space by tracking the Serratia marcescens as the tiny organisms. Research results indicated that the concentration of bioaerosols is the highest at the indoor air temperature of 25°C among the tested conditions (20°C, 25°C, 30°C and 35°C). The particle size of bioaerosols can be influenced by temperature, resulting in changes in the amount of settling. Increasing relative humidity from 50% to 80% and airflow speed from 1.5 m/s to 2.2 m/s have a negative impact on the dispersion of bioaerosols as the amount of particle settlement increases accordingly. As for the UV radiation parameters, a better disinfection efficiency was achieved at a radiation distance of 40 cm in the tested range of 20–50 cm and a radiation exposure time of 30 min in the tested range of 10–50 min. This study delivered novel data for the concentration distribution of bioaerosol under different environmental factors for creating a safe indoor environment.

11.
Iranian Journal of Dermatology ; 25(1):53-59, 2022.
Article in English | EMBASE | ID: covidwho-1988810

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic, the scale of its damage to all sectors, and its high rate of mortality urgently called all scientists and researchers into action to find solutions that can mitigate its multi-dimensional burden. As of October 1st, 2021, COVID-19 has claimed more than 4.5 million lives and infected more than 200 million individuals. Therefore, every small effort that can positively contribute to the alleviation of the disease and its spread can tremendously help minimize the damage. The application of light as a therapeutic agent has been effective since the beginning of civilization. During the last century, artificial light and its combination with other chemical substances to fight microorganisms have been applied substantially in many domains, such as therapeutics and immunomodulation. In this review, we present the scalable application of light as an antimicrobial and immunomodulatory agent and its potential in fighting COVID-19 and in mitigating its damages by representing the recent developments in this area.

12.
Biomedical and Pharmacology Journal ; 15(2):717-727, 2022.
Article in English | EMBASE | ID: covidwho-1979716

ABSTRACT

Covid-19 was mainly treated by a broad-spectrum antiviral called Remdesivir. A truncated cone molecular structure of Hydroxypropyl-ß-cyclodextrin can enhance the solubility and cellular uptake of the poorly soluble drug's through biological membranes. This study aimed to synthesize, characterize, observe cellular uptake and evaluate the cytotoxicity of remdesivirhydroxypropyl-ß-cyclodextrin (RDV-HPßCD) inclusion complex. The RDV-HPßCD inclusion complex was synthesized by the solvent evaporation method. Furthermore, the inclusion complex characteristic was evaluated by ultraviolet-visible (UV-Vis) spectrophotometry;particle size analyzer (PSA);Fourier infrared spectrophotometry (FTIR);X-ray diffraction (XRD);and differential scanning calorimetry (DSC). Further, fluorescence microscopy was used to evaluate the cellular uptake and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used in the cytotoxicity study. In the UV-Vis spectrum, both the inclusion complex and pure remdesivir showed a maximum peak at 246 nm. The inclusion complex has a particle size of 1697 ± 738.02 nm with -22.4 ± 1.58 mV of zeta potential. Shifted FTIR spectrum, broad XRD peak, and broad DSC thermogram peak at 72.93 °C indicated the successful formation of the RDV-HPßCD inclusion complex. Furthermore, cellular uptake observation of RDV-HPßCD inclusion complex conjugated to FITC showed better intensity inside the Vero cell than pure remdesivir conjugated to FITC. Further, Inclusion complex showed higher cell viability than pure remdesivir at a certain concentration.

13.
Biomedical Optics Express ; 13(8):4429-4444, 2022.
Article in English | EMBASE | ID: covidwho-1978816

ABSTRACT

RNA viruses are ubiquitous in nature, many of which can cause severe infectious syndromes to humanity, e.g., the SARS-CoV-2 virus. Ultraviolet (UV) radiation has been widely studied for inactivating various species of microorganisms, including viruses. The most applicable UV light for viruses ranges from 200nm to 280nm in wavelength, i.e., UVC. More recently, the synergy of UVA light with UVC has been studied in disinfecting bacteria in polluted water. However, little attention has been paid to studying viral inactivation by coupled UVC and UVA LEDs. The necessity of such research is to find an effective and economical solution for the LEDs of these two bands. Along this track, we attempt to tackle two major challenges. The first is to find a suitable viral surrogate that can safely be used in ordinary labs. In this aspect, lentivirus is commonly used as a genetic vector and has been selected to surrogate RNA viruses. Another is to determine the effective dosage of the coupled UVC and UVA light. To this end, the surrogate lentivirus was irradiated by 280nm (UVC) LEDs, 365nm (UVA) LEDs, and their combination at various doses. Survival rates were detected to compare the efficacy of various options. Moreover, the viral RNA damage was detected by RT-qPCR to disclose the mechanism of viral death. The results have shown that for the same duration of irradiation, the effect of the full-power 280nm LEDs is equivalent to that of the half-power 280nm LEDs combined with a suitable radiant power of the 365nm LEDs. The observations have been further confirmed by the effect of damaging the viral RNA by either the 280nm or 365nm light. In conclusion, the experimental results provide clear evidence of alleviating the requirement of UVC LEDs in viral inactivation by substituting them partially with UVA LEDs.

14.
FEBS Open Bio ; 12:167-168, 2022.
Article in English | EMBASE | ID: covidwho-1976642

ABSTRACT

Systemic mycoses are fungal diseases attacking the body through an internal organ. They are the cause of increasing morbidity rates, especially among the immunocompromised population (e.g. with HIV), but also exist as a co-infection in patients with COVID-19. Nowadays, the 'life-saving/last chance' drug (and a poison to humans), Amphotericin B (AmB), is the representative of nonaromatic heptaene macrolides. However, previously obtained data indicate significantly higher antifungal activity of the aromatic heptaene subgroup (AHM), which is unfortunately correlated with their high mammalian toxicity. The undertaken studies concern Partricin and Candicidin complexes as the main representatives of AHMs. Three aromatic heptaene macrolides: Partricin A, Partricin B and Candicidin D were isolated from fermentation broths of S. aureofaciens and S. griseus, respectively, by initial purification, followed by selected chromatographic techniques such as centrifugal partitioning chromatography (CPC) and prep-HPLC. Later on, they were subjected to controlled chromophore geometry change (cis-trans to all-trans) via photochemical isomerization, using UV light of k = 365 nm. The obtained all-trans isomers, regarded as aromatic analogues of AmB, were tested for in vitro selective toxicity indexes (STIs) towards C. albicans cells versus human erythrocyte model. Due to the diminished hemotoxicity of the all-trans isomers - which were maintaining most of their fungicidal power - the obtained STIs were very promising and far better than for AmB (previously published in: J.Górska et al. (2021) Int. J. Mol. Sci. 22). Hence, the all-trans AHMs bear a great potential to be weaponized on the antifungal battlefield. Nevertheless, since individual AHMs are commercially unavailable and difficult to obtain due to their complex nature, our studies will focus on facilitation of the isolation process and further improvement of their STIs, mainly through rational, structural modifications.

15.
ASHRAE Transactions ; 128:340-347, 2022.
Article in English | ProQuest Central | ID: covidwho-1970581

ABSTRACT

The wavelength band of200-280 nm of UV-C radiation generated by the Ultraviolet Germicidal Irradiation (UVGI) system can destroy the reproduction ability of microorganisms. Severalfactors related to UVfixtures, HVAC layout, and the resulting airflow flow patterns can affect the performance of upper-room UVGI applications. With the help of Computational Fluid Dynamics (CFD) analyses, this study systematically evaluates the impact of UV-C intensities on the effectiveness of an upper room UVGI system. It shows that the addition of even a small amount of UV-C energy in the upper region of space can significantly reduce the probability of infection as predicted by the Wells-Riley model. Increasing the UV-C output shows a further reduction in the infection probability, although with a diminishing impact. A further investigation is necessary to evaluate the effect of airflow patterns on the performance of UVGI systems. These studies demonstrate that CFD analyses can help optimize the performance of UVGI systems to minimize the probability of infection in indoor spaces.

16.
Enfermedades Infecciosas y Microbiologia ; 41(2):67-72, 2021.
Article in Spanish | EMBASE | ID: covidwho-1965355

ABSTRACT

introduction. The hospital surfaces can contribute to secondary cross contamination, through the hands of health care personnel or contaminated material. It has been necessary to develop ambiental automatic decontamination equipment without the problems related with manual disinfection. material and method. An analytical, prospective, cross-sectional study was carried out, to evaluate the the efficacy and effectiveness of ambiental decontamination at the hospital, with ultraviolet radiation of a 245 nm wavelength equipment, on two semi critical areas, meant for clinical attention to patients with sars-cov-2 infection, with pre and post intervention sampling. 2-stage study to evaluate efficiency and effectiveness. results. In stage 1 (efficacy evaluation) atcc reference strains were sown, subsequently intervention with uv radiation was carried out, the growth of microorganisms was 0/3 in the micas, that is;it was possible to eliminate the bacterial load in 100% (3 samples). In stage 2 (evaluation of effectiveness), microbiological samples were taken from 15 clinic sites under baseline conditions, it was found that there was growth of microorganisms on 12/15 surfaces prior to intervention. After decontamination with uv radiation, the growth of microorganisms was 4/15 in the micas, bacterial elimination was achieved in 73.34% of the sampled surfaces and the bacterial load persisted in 26.66% of the sampled areas. After the decontamination intervention through uv light, a significant bacterial count elimination was achieved (Chi Square test p = 0.0002). conclusions. The decontamination process with uv light in closed spaces with equipment that emits radiation with a wavelength of 254 nm for 30 minutes was an effective intervention to reduce and eliminate the bacterial load from hospital surfaces.

17.
Zdravniski Vestnik ; 91(5/6):255-261, 2022.
Article in English | CAB Abstracts | ID: covidwho-1964492

ABSTRACT

Slovenia is one of the countries that have been most affected by the autumn/winter 2020/21 wave of the COVID-19 pandemic regarding the incidence and excess mortality among the general population as well as regarding the incidence among health care workers and nursing personnel. The World Health Organization has underestimated the importance of the airborne spread of SARS-CoV-2 and the recommended safety measures have not been entirely sufficient. When people breathe, talk, sing, cough, or sneeze, they emit respiratory droplets of various sizes, most of which are always smaller than 1 m. Respiratory droplets smaller than 5 m stay airborne in indoor spaces for a long time and travel over distances much longer than 2 m. Thus, an infected person in an indoor environment creates an infectious aerosol that may infect other people without close interpersonal contact. This short review presents the mathematical model and internet application by authors from the Massachusetts Institute of Technology for calculating the safe time before probable airborne infection occurs in indoor spaces. The importance of ventilation, air filtration, air humidity, and air disinfection by ultraviolet light is briefly discussed. The principles of preventing the airborne spread of SARS-CoV-2 are summarized.

18.
Proceedings of the Latvian Academy of Sciences ; 76(3):357-360, 2022.
Article in English | ProQuest Central | ID: covidwho-1963316

ABSTRACT

The recent COVID-19 pandemic has made important changes to the everyday practice of anaesthetists. Current research has shown that the virus spreads via respiratory droplets and aerosolisation. The aim of this study was to examine the extent of contact contamination, droplet spread and aerosolisation, which may occur with normal breathing and intubation in a mannequin study. In the first experiment, an Ambu bag was attached to the simulation mannequin’s trachea and an atomiser device was placed into the mannequin’s pharynx. This model simulated normal ventilation as 0.5 ml of luminescent fluid was sprayed through the atomiser. In the second experiment, the mannequin was intubated with a videolaryngoscope while spraying 0.5 ml of luminescent fluid through the atomiser, after which the laryngoscope was removed. The spread of the luminescent aerosol cloud after three full breaths, droplet spread and contact contamination were visualised using ultraviolet light. The extent of spread was evaluated using a 4-point Likert scale (0 to 3) by two observers. Each of the experiments was repeated five times. For the first experiment, aerosol formation, droplet spread and contact contamination were 2.5 (2–3), 1 (0–1), 0 (0–1) points. In the second experiment, aerosol formation, droplet spread and contact contamination were 0.5 (0–1), 1 (0–1), 3 (2–3) points, accordingly. Noticeable contact contamination occurs during laryngoscopy and removal of the laryngoscope, whereas droplet contamination with laryngoscopy and normal breathing is minimal. Normal breathing leads to significant aerosol formation.

19.
Journal of Investigative Dermatology ; 142(8):B9, 2022.
Article in English | EMBASE | ID: covidwho-1956226

ABSTRACT

Indoor tanning using ultraviolet (UV) radiation increases skin cancer risk. However, there is little objective information on when or where indoor tanning is used. We aimed to evaluate tanning salon geography and patterns of use using objective data rather than self-report. We used data from SafeGraph, a company that combines smartphone location data and proprietary geographic data. Our dataset included aggregate, anonymous data from January 1, 2018-December 31, 2020. We developed and validated an algorithm (positive predictive value 92.6%) to identify businesses offering UV indoor tanning. We evaluated tanning salon locations, number of tanning salons per state population, and foot traffic patterns by visits per month, per day of the week, and per hour of the day. Our algorithm identified 7412 businesses as tanning salons. Of those, 2795 (37.7%) had foot traffic data available. The highest concentrations of tanning salons were in Midwestern states. We found peaks in the spring (April) of 2018 and 2019, a slightly later peak (June) in 2020, and a short-term decrease in tanning salon visits during the early phases of the COVID-19 pandemic (March-May 2020). Visits were most frequent during weekdays (Monday-Friday). Peak times of day were 12pm-3pm. Our study has limitations: it includes only a small portion of the US population (approximately 10% of mobile devices) and we could not account for indoor tanning outside of tanning salons. Indoor tanning is a known carcinogen, but the majority of information on use is based on cross-sectional surveys. Our study represents new information for public health strategies to decrease exposure to this carcinogen.

20.
AIMS Microbiology ; 8(3):279-292, 2022.
Article in English | Scopus | ID: covidwho-1954193

ABSTRACT

For SARS-CoV-2 disinfection systems or applications that are based on UVC, UVB or UVA irradiation, it would be desirable to have a SARS-CoV-2 surrogate for tests and development, which does not require a laboratory with a high biosafety level. The bacteriophage Phi 6, an enveloped RNA virus like coronaviruses, is an obvious candidate for such a surrogate. In this study, UVC, UVB and UVA log-reduction doses for Phi6 are determined by plaque assay. Log-reduction doses for SARS-CoV-2 are retrieved from a literature research. Because of a high variability of the published results, median log-reduction doses are determined for defined spectral ranges and compared to Phi6 data in the same intervals. The measured Phi6 log-reduction doses for UVC (254 nm), UVB (311 nm) and UVA (365 nm) are 31.7, 980 and 14 684 mJ/cm2, respectively. The determined median log-reduction doses for SARS-CoV-2 are much lower, only about 1.7 mJ/cm2 within the spectral interval 251–270 nm. Therefore, Phi6 can be photoinactivated by all UV wavelengths but it is much less UV sensitive compared to SARS-CoV-2 in all UV spectral ranges. Thus, Phi6 is no convincing SARS-CoV-2 surrogate in UV applications. © 2022 the Author(s), licensee AIMS Press.

SELECTION OF CITATIONS
SEARCH DETAIL