Airflow detailed analysis through a face mask using the schlieren technique.

This work presents an exhaustive visualization of the airflow expulsed by a person while breathing, talking, exhaling, and blowing inside a closed room wearing a disposable face mask like those used in hospitals for patient protection and those who care for them. An optical schlieren experimental arrangement was used to obtain some of the relevant physical characteristics of the airflow, such as its refractive index gradient, the distribution of temperature, and the associated velocity field for all the tests developed. We tested three face masks, one of the surgical types and the others of the N95 series with denominations KN95 and 3MN95 (Aura TC-84A-8590). The results show appreciable differences between the masks evaluated; the surgical mask was the one that allowed the most abrupt output airflow through it in the field of view of the experimental setup. However, were also found some differences in the performance of the KN95 and 3MN95 masks. The KN95 face mask had the best performance since it expulsed to its surroundings the lowest airflow with different physical properties to the input airflow. The results obtained are relevant since it was possible to estimate the expulsed airflow velocity as a function of the distance for every face mask tested, which allows for understanding its filtering capacity by restricting the flow of potential pathogens from the mouth or nose of one person to another. Undoubtedly, the airflow behavior determination around a face mask can help to reduce the risk of spreading infectious airborne particles.

Surface guided radiation therapy with an innovative open-face mask and mouth bite: patient motion management in brain stereotactic radiotherapy.

INTRODUCTION: To guarantee treatment reproducibility and stability, immobilization devices are essential. Additionally, surface-guided radiation therapy (SGRT) serves as an accurate complement to frameless stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) by aiding patient positioning and real-time monitoring, especially when non-coplanar fields are in use. At our institute, we have developed a surface-guided SRS (SG-SRS) workflow that incorporates our innovative open-face mask (OM) and mouth bite (MB) to guarantee a precise and accurate dose delivery. METHODS: This study included 40 patients, and all patients were divided into closed mask (CM) and open-face mask (OM) groups according to different positioning flow. Cone beam computed tomography (CBCT) scans were performed, and the registration results were recorded before and after the treatment. Then Bland-Altman method was used to analyze the consistency of AlignRT-guided positioning errors and CBCT scanning results in the OM group. The error changes between 31 fractions in one patient were recorded to evaluate the feasibility of monitoring during treatment. RESULTS: The median of translation error between stages of the AlignRT positioning process was (0.03-0.07) cm, and the median of rotation error was (0.20-0.40)°, which were significantly better than those of the Fraxion positioning process (0.09-0.11) cm and (0.60-0.75)°. The mean bias values between the AlignRT guided positioning errors and CBCT were 0.01 cm, - 0.07 cm, 0.03 cm, - 0.30°, - 0.08° and 0.00°. The 31 inter-fractional errors of a single patient monitored by SGRT were within 0.10 cm and 0.50°. CONCLUSIONS: The application of the SGRT with an innovative open-face mask and mouth bite device could achieve precision positioning accuracy and stability, and the accuracy of the AlignRT system exhibits excellent constancy with the CBCT gold standard. The non-coplanar radiation field monitoring can provide reliable support for motion management in fractional treatment.

Cosmetic attributes (oiliness reduction and firmness) from face masks composed of red, green and black clays / Atributos cosméticos (redução de oleosidade e melhora de firmeza) de máscaras faciais compostas por argilas vermelha, verde e preta

The appearance of skin strongly influences people´s self-esteem and well-being. Among the characteristics that affect the most, we can cite acne and wrinkles. Therefore, minimizing those characteristics by using cosmetics has important value for the consumer. Nowadays, there is a demand for natural ingredients, mainly concerning cosmetic products. The use of clays in beauty care is old, with therapeutic uses since Prehistory. There is an essential advantage in using clays for cosmetic purposes, as it is a low-cost, environmentally friendly, natural, and abundant ingredient, which is chemically inert with a low level of toxicity (when in adequate conditions), easy to apply and remove, dries, and hardens fast. In this research work, we aimed at developing and investigating the effect of formulations containing red, green, and black clays as active components in oiliness reduction, and firmness and elasticity improvement in vivo, as well as characterizing clays mineralogically. All clays presented different compositions. Black clay was the one with the simplest mineralogic content, lowest density, and smallest particle size. It was the richest in Si and Al. Green clay presented expandable smectite and the highest density. Red clay presented the largest particle average size and was the richest in iron content. By thermal analysis, clays presented two characteristic events: the water loss (dehydration) and the dihydroxylation of kaolinite, turning into meta kaolinite. In Sebumetry, clays showed a significant reduction of skin oiliness on the forehead in both concentrations after 2h of contact compared to control, baseline, and placebo. However, after 4h (2h after removal), no significant difference was observed with the control. In the Cutometry, clays did not present significant efficacy in skin firmness and elasticity improvement when compared to control and placebo sites, thus, further studies should be performed comparing the efficacy of different vehicles with dispersed clays. Finally, clay mask formulations were developed with black, red, and green clay dispersed in an oil-free gel vehicle, which proved to be adequate for oily skin

A aparência da pele influencia fortemente autoestima e o bem-estar das pessoas. Dentre as características que mais afetam podemos citar acne e rugas. Portanto, minimizar estas características com o uso de cosméticos tem um valor importante para o consumidor. Atualmente existe uma procura por ingredientes naturais, principalmente no que diz respeito a produtos cosméticos. O uso das argilas nos cuidados de beleza é antigo, com usos terapêuticos desde a Pré-História. Há uma vantagem essencial na utilização de argilas para fins cosméticos, pois é um ingrediente de baixo custo, ecologicamente correto, natural, e abundante, que é quimicamente inerte e tem baixo nível de toxicidade (quando usado em condições adequadas), fácil de aplicar e remover, seca, e endurece rapidamente. Neste trabalho de pesquisa, objetivamos desenvolver e investigar o efeito de formulações contendo argilas vermelha, verde e preta como componentes ativos na redução da oleosidade e na melhoria da firmeza e elasticidade in vivo, bem como caracterizar mineralogicamente as argilas. Todas as argilas apresentaram diferentes composições. A argila preta foi a de conteúdo mineralógico mais simples, mais baixa densidade, e menor tamanho de partícula. Foi a mais rica em Si e Al. A argila verde apresentou esmectita expansível e mais alta densidade. A argila vermelha apresentou o maior tamanho médio de partícula e foi a mais rica em ferro. Segundo a análise térmica, as argilas apresentaram dois eventos característicos: a perda de água (desidratação) e a desidroxilação da caulinita, transformando-se em meta-caulinita. Na Sebumetria, as argilas demonstraram significativa redução na oleosidade da pele na testa em ambas as concentrações após 2h de contato comparada ao controle, basal e placebo. Porém, após 4h (2h após remoção), nenhuma diferença significativa foi observada com o controle. Na Cutometria, as argilas não apresentaram Eficácia significativa na melhora da firmeza e elasticidade quando comparadas aos sítios controle e placebo, portanto, mais estudos devem ser realizados comparando a eficácia de diferentes veículos com argilas dispersas. Finalmente, as formulações de máscaras de argilas foram desenvolvidas com argilas preta, vermelha e verde dispersas em um veículo em gel livre de oleosidade, o qual provou ser adequado para pele oleosa

Face Mask and Tear Film Stability: A Pilot Study of the Objective Measurement of Tear Break-Up Time.

(1) Background: Mask-associated dry eye (MADE) has been associated with increased dry eye symptoms, apparently due to reduced tear break-up time (TBUT). This study aimed to determine the short-term impact of surgical face mask (FM) on tear film stability by measuring non-invasive tear break-up time (NIBUT). (2) Methods: Twenty-six healthy participants had NIBUT evaluated without FM, with surgical FM and with a surgical FM secured to the skin with adhesive tape (TFM). NIBUT-first was measured with Keratograph 5M (K5M, Oculus, Wetzlar, Germany). Each participant had NIBUT measured in four sessions on four consecutive days. Session 1: without FM vs. with FM. Session 2: with FM vs. without FM. Session 3: without FM vs. with TFM. Session 4: with TFM vs. without FM (3). The time between each measured setting was 2 min. Results: The mean ± SD NIBUT without FM was 8.9 ± 3.7, with FM 10.2 ± 4.1, and with TFM 8.4 ± 3.8 s. No significant differences were observed in NIBUT in any of the evaluated settings: without FM vs. with FM (p = 0.247), without FM vs. with TFM (p = 0.915), and with FM vs. with TFM (p = 0.11). (4) Conclusions: This study did not find a significant short-term effect of FM on NIBUT. Other variables or longer periods of exposure might trigger the symptoms and ocular surface alterations in MADE.

Multiclass Mask Classification with a New Convolutional Neural Model and Its Real-Time Implementation.

The world has been greatly affected by the COVID-19 pandemic, causing people to remain isolated and decreasing the interaction between people. Accordingly, various measures have been taken to continue with a new normal way of life, which is why there is a need to implement the use of technologies and systems to decrease the spread of the virus. This research proposes a real-time system to identify the region of the face using preprocessing techniques and then classify the people who are using the mask, through a new convolutional neural network (CNN) model. The approach considers three different classes, assigning a different color to identify the corresponding class: green for persons using the mask correctly, yellow when used incorrectly, and red when people do not have a mask. This study validates that CNN models can be very effective in carrying out these types of tasks, identifying faces, and classifying them according to the class. The real-time system is developed using a Raspberry Pi 4, which can be used for the monitoring and alarm of humans who do not use the mask. This study mainly benefits society by decreasing the spread of the virus between people. The proposed model achieves 99.69% accuracy with the MaskedFace-Net dataset, which is very good when compared to other works in the current literature.

Facial mask acute effects on affective/psychological and exercise performance responses during exercise: A meta-analytical review.

Background: Face masks are widely used during the COVID-19 pandemic as one of the protective measures against the viral infection risk. Some evidence suggests that face mask prolonged use can be uncomfortable, and discomfort can be exacerbated during exercise. However, the acute responses of mask-wearing during exercise on affective/psychological and exercise performance responses is still a topic of debate. Purpose: To perform a systematic review with meta-analysis of the acute effects of mask-wearing during exercise on affective/psychological and exercise performance responses in healthy adults of different/diverse training status. Methods: This review (CRD42021249569) was performed according to Cochrane's recommendations, with searches performed in electronic (PubMed, Web of Science, Embase, SportDiscus, and PsychInfo) and pre-print databases (MedRxiv, SportRxiv, PsyArXiv, and Preprint.Org). Syntheses of included studies' data were performed, and the RoB-2 tool was used to assess the studies' methodological quality. Assessed outcomes were affective/psychological (discomfort, stress and affective responses, fatigue, anxiety, dyspnea, and perceived exertion) and exercise performance time-to-exhaustion (TTE), maximal power output (POMAX), and muscle force production] parameters. Available data were pooled through meta-analyses. Results: Initially 4,587 studies were identified, 36 clinical trials (all crossover designs) were included. A total of 749 (39% women) healthy adults were evaluated across all studies. The face mask types found were clothing (CM), surgical (SM), FFP2/N95, and exhalation valved FFP2/N95, while the most common exercises were treadmill and cycle ergometer incremental tests, beyond outdoor running, resistance exercises and functional tests. Mask-wearing during exercise lead to increased overall discomfort (SMD: 0.87; 95% CI 0.25-1.5; p = 0.01; I2 = 0%), dyspnea (SMD: 0.40; 95% CI 0.09-0.71; p = 0.01; I2 = 68%), and perceived exertion (SMD: 0.38; 95% CI 0.18-0.58; p < 0.001; I2 = 46%); decreases on the TTE (SMD: -0.29; 95% CI -0.10 to -0.48; p < 0.001; I2 = 0%); without effects on POMAX and walking/running distance traveled (p > 0.05). Conclusion: Face mask wearing during exercise increases discomfort (large effect), dyspnea (moderate effect), and perceived exertion (small effect), and reduces the TTE (small effect), without effects on cycle ergometer POMAX and distance traveled in walking and running functional tests. However, some aspects may be dependent on the face mask type, such as dyspnea and perceived exertion. Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021249569], identifier [CRD42021249569].

Prevention of COVID-19 superspreading events in buses boarded by presymptomatic cases.

INTRODUCTION: COVID-19 superspreader events have occurred when symptomatic individuals without wearing face masks boarded buses. OBJECTIVE: To report the risk of superspreader events when presymptomatic individuals boarded buses to-gether with unvaccinated passengers, but with non-pharmacological preventive interventions being maintained. METHODS: Prospec-tive study of health personnel transported in buses to a COVID-19 vaccination center for two weeks. Open windows, correct use of face masks and exclusion of symptomatic individuals were mandatory. Prospective surveillance identified workers with COVID-19 within 14 days after vaccination. Each asymptomatic passenger of buses where cases were identified was monitored for a similar time period. Voluntary screening results were available for workers who were tested in the month before or after vaccination. RESULTS: 1,879 workers boarded 65 buses. On-board time ranged from three to eight hours. Twenty-nine cases of COVID-19 and four asymptomatic cases were identified among 613 passengers of 21 buses. Median time between vaccina-tion and COVID-19 symptoms onset was six days. One case of suspected transmission on a bus was identi-fied. CONCLUSIONS: Strict nonpharmacological preventive interventions substantially reduced the risk of COVID-19 super-spreader events in buses boarded by presymptomatic individuals.

ANTECEDENTES: Ha ocurrido superpropagación de COVID-19 cuando individuos sintomáticos sin uso de cubrebocas abordaron autobuses. OBJETIVO: Reportar el riesgo de superpropagación cuando individuos presintomáticos abordaron autobuses junto con pasajeros no vacunados pero se mantuvieron intervenciones preventivas no farmacológicas. MATERIAL Y MÉTODOS: Estudio prospec­tivo de personal de salud transportado durante dos semanas en autobuses a un centro de vacunación contra COVID-19. Fue obligatorio llevar ventanas abiertas, uso correcto de cubrebocas y exclusión de personas con síntomas. La vigilancia prospectiva identificó a trabajadores con COVID-19 los 14 días siguientes a la vacunación. Cada pasajero asintomático de autobuses donde se detectaron casos fue vigilado durante un periodo de tiempo similar. Los resultados de tamizaje voluntario estuvieron disponibles para los trabajadores que se realizaron prueba el mes previo o el siguiente a la vacunación. RESULTADOS: 1879 trabajadores abordaron 65 autobuses. El tiempo a bordo varió de tres a ocho horas. Veintinueve casos de COVID-19 y 4 casos asintomáticos fueron identificados entre 613 pasajeros de 21 autobuses. La mediana de tiempo entre la vacunación y el inicio de síntomas en casos de COVID-19 fue de seis días. Fue identificado un caso de transmisión sospechada en autobús. CONCLUSIONES: Las intervenciones preventivas no farmacológicas estrictas redujeron sustancialmente el riesgo de superpropagación de COVID-19 en autobuses ocupados por individuos presintomáticos.

Moral Disengagement, Dark Triad and Face Mask Wearing during the COVID-19 Pandemic.

Not wearing a face mask, despite the sanitary recommendation, represented a public health risk during the COVID-19 pandemic. For this reason, the aim of the study was to determine the mediating role of moral disengagement in the relationship between the dark triad and face mask wearing during the second wave of the pandemic. We worked with a sample made up of 534 adults, who were administered the Dirty Dozen Dark test, the Moral Disengagement Mechanisms Scale and a questionnaire on the frequency of use of face masks. The results showed that moral disengagement mediates the effect of each trait of the dark triad (Machiavellianism, psychopathy and narcissism) on the use of face masks. It is concluded that those who possess any of the dark personality traits morally disengage in order not to use a face mask, exercising a reckless behavior of the possible contagion of COVID-19 to others.

Development of mask design as personal protective equipment through 3D printing.

This project aimed to develop an innovative mask design, aided by 3D printing technology that was able to protect its wearers against virus infection. The project was motivated with the intention of helping to fight Covid-19, but that its use was extensive as an option to N95 and similar masks, already on the market, even after the pandemic. Whose main design objective was that the mask had a sealing efficiency based on a half-face mask and that it could be used in conjunction with masks made of antiviral fabrics, such as, for example, a surgical mask that has its filtering capacity already tested and approved and, which would be the filter element of the mask. The mask was also intended to be reusable so that it could be washed for cleaning, with only the fabric filter element being disposable.

Effectiveness and adherence to closed face shields in the prevention of COVID-19 transmission: a non-inferiority randomized controlled trial in a middle-income setting (COVPROSHIELD).

BACKGROUND: The use of respiratory devices can mitigate the spread of diseases such as COVID-19 in community settings. We aimed to determine the effectiveness of closed face shields with surgical face masks to prevent SARS-CoV-2 transmission in working adults during the COVID-19 pandemic in Bogotá, Colombia. METHODS: An open-label non-inferiority randomized controlled trial that randomly assigned participants to one of two groups: the intervention group was instructed to wear closed face shields with surgical face masks, and the active control group was instructed to wear only surgical face masks. The primary outcome was a positive reverse transcription polymerase chain reaction test, IgG/IgM antibody test for SARS-CoV-2 detection, or both during and at the end of the follow-up period of 21 days. The non-inferiority limit was established at - 5%. RESULTS: A total of 316 participants were randomized, 160 participants were assigned to the intervention group and 156 to the active control group. In total, 141 (88.1%) participants in the intervention group and 142 (91.0%) in the active control group completed the follow-up. PRIMARY OUTCOME: a positive SARS-CoV-2 test result was identified in one (0.71%) participant in the intervention group and three (2.1%) in the active control group. In the intention-to-treat analysis, the absolute risk difference was - 1.40% (95% CI [- 4.14%, 1.33%]), and in the per-protocol analysis, the risk difference was - 1.40% (95% CI [- 4.20, 1.40]), indicating non-inferiority of the closed face shield plus face mask (did not cross the non-inferiority limit). CONCLUSIONS: The use of closed face shields and surgical face masks was non-inferior to the surgical face mask alone in the prevention of SARS-CoV-2 infection in highly exposed groups. Settings with highly active viral transmission and conditions such as poor ventilation, crowding, and high mobility due to occupation may benefit from the combined use of masks and closed face shields to mitigate SARS-CoV-2 transmission. TRIAL REGISTRATION: ClinicalTrials.gov NCT04647305 . Registered on November 30, 2020.

Prevención de eventos de superpropagación de COVID-19 en autobuses que transportaron pacientes presintomáticos / Prevention of COVID-19 superspreader events in buses boarded by presymptomatic patients

Resumen Introducción: Ha ocurrido superpropagación de COVID-19 cuando individuos sintomáticos sin uso de cubrebocas abordaron autobuses. Objetivo: Reportar el riesgo de superpropagación cuando individuos presintomáticos abordaron autobuses junto con pasajeros no vacunados, pero se mantuvieron intervenciones preventivas no farmacológicas. Métodos: Estudio prospectivo de personal de salud transportado durante dos semanas en autobuses a un centro de vacunación contra COVID-19. Fue obligatorio llevar ventanas abiertas, uso correcto de cubrebocas y exclusión de personas con síntomas. La vigilancia prospectiva identificó a trabajadores con COVID-19 los 14 días siguientes a la vacunación. Cada pasajero asintomático de autobuses donde se detectaron casos fue vigilado durante un periodo similar. Los resultados de tamizaje voluntario estuvieron disponibles para los trabajadores que se realizaron prueba el mes previo o el siguiente a la vacunación. Resultados: 1879 trabajadores abordaron 65 autobuses. El tiempo a bordo varió de tres a ocho horas. Veintinueve casos de COVID-19 y cuatro casos asintomáticos fueron identificados entre 613 pasajeros de 21 autobuses. La mediana de tiempo entre la vacunación y el inicio de síntomas de COVID-19 fue de seis días. Fue identificado un caso de transmisión sospechada en autobús. Conclusiones: Las intervenciones preventivas no farmacológicas estrictas redujeron sustancialmente el riesgo de superpropagación de COVID-19 en autobuses ocupados por individuos presintomáticos.

Abstract Introduction: COVID-19 superspreader events have occurred when symptomatic individuals without wearing face masks boarded buses. Objective: To report the risk of superspreader events when presymptomatic individuals boarded buses together with unvaccinated passengers, but with non-pharmacological preventive interventions being maintained. Methods: Prospective study of health personnel transported in buses to a COVID-19 vaccination center for two weeks. Open windows, correct use of face masks and exclusion of symptomatic individuals were mandatory. Prospective surveillance identified workers with COVID-19 within 14 days after vaccination. Each asymptomatic passenger of buses where cases were identified was monitored for a similar time period. Voluntary screening results were available for workers who were tested in the month before or after vaccination. Results: 1,879 workers boarded 65 buses. On-board time ranged from three to eight hours. Twenty-nine cases of COVID-19 and four asymptomatic cases were identified among 613 passengers of 21 buses. Median time between vaccination and COVID-19 symptoms onset was six days. One case of suspected transmission on a bus was identified. Conclusions: Strict nonpharmacological preventive interventions substantially reduced the risk of COVID-19 superspreader events in buses boarded by presymptomatic individuals.

Deep transfer learning for the recognition of types of face masks as a core measure to prevent the transmission of COVID-19.

The use of face masks in public places has emerged as one of the most effective non-pharmaceutical measures to lower the spread of COVID-19 infection. This has led to the development of several detection systems for identifying people who do not wear a face mask. However, not all face masks or coverings are equally effective in preventing virus transmission or illness caused by viruses and therefore, it appears important for those systems to incorporate the ability to distinguish between the different types of face masks. This paper implements four pre-trained deep transfer learning models (NasNetMobile, MobileNetv2, ResNet101v2, and ResNet152v2) to classify images based on the type of face mask (KN95, N95, surgical and cloth) worn by people. Experimental results indicate that the deep residual networks (ResNet101v2 and ResNet152v2) provide the best performance with the highest accuracy and the lowest loss.

Self-perceived and self-reported breath odour and the wearing of face masks during the COVID-19 pandemic.

OBJECTIVES: To assess the self-perception of breath odour (SPBO) and oral hygiene habits (OHHs) while the wearing of face masks during the COVID-19 pandemic. SUBJECTS AND METHODS: This cross-sectional study included 4647 individuals who answered a structured questionnaire containing demographic, medical and dental variables and self-perceived breath odour. Variables associated with changes in self-perceived breath odour, self-perceived halitosis and changes in OHHs were assessed through multivariate logistic regression. RESULTS: Changes in self-perceived breath odour were reported by 1572 individuals and were associated with smoking, systemic conditions, dry mouth, tongue coating, the period of face mask use and its interaction with prior thinking of having bad breath. Likewise, 645 individuals started to consider having bad breath. This was associated with the interaction between prior family/friends saying they have bad breath and period of face mask use. Changes in OHHs were strongly associated with changes in SPBO and starting to consider having bad breath. CONCLUSION: Changes in one's SPBO was associated with the wearing of face masks and was significant for changes in OHHs. Findings may be important to guide comprehensive preventive and therapeutic strategies in relation to oral health care.

Impact on COVID-19 morbidity and mortality according to the regulations on the use of face mask.

INTRODUCTION: Currently, the face mask represents an incomparable symbol whose value went from clinical work to impacting the containment of the spread of SARS-CoV-2, although it has become an element of discord in the general population. OBJECTIVE: To establish the impact of face mask use policies on COVID-19 morbidity and mortality. METHODS: Face mask use policy variables, obtained from the website of the #Masks4All scientific movement, were associated with the number of infections, deaths and flattening of the curve published by the Johns Hopkins University resource center and EndCoronavirus.org. RESULTS: Face mask use policies were universal (required in shops, restaurants, public transport), partial (recommended, required in any public place) and absent. Associations of the face mask use policy with total cases (p = 0.01), cases per million (p = 0.04) and deaths per million population (p = 0.02) were statistically significant. Associations of the variables with the epidemiological curve trend were also statistically significant (p = 0.00). CONCLUSION: The recommendation for face mask widespread use is a measure with sufficient scientific support to reduce the number of COVID-19-related infections and deaths.

INTRODUCCIÓN: Actualmente, la mascarilla representa un símbolo incomparable cuyo valor pasó del trabajo clínico a impactar en la contención de la propagación del virus SARS-CoV-2; se convirtió en un elemento de discordia en la población general. OBJETIVO: Establecer el impacto de las políticas de uso de mascarilla en la morbimortalidad por COVID-19. MÉTODOS: Se asociaron las variables de política de uso de cubrebocas, obtenidas de la página web del movimiento científico #Masks4All, con el número de contagios, muertes y aplanamiento de la curva publicados por el centro de recursos de la Universidad Johns Hopkins y EndCoronavirus.org. RESULTADOS: Las políticas de uso de mascarilla fueron de tipo universal (requerido en tiendas, restaurantes, transporte público), parcial (recomendado, requerido en cualquier lugar público) y ausente. Las asociaciones de la política de uso de mascarilla con casos totales (p = 0.01), casos por millón (p = 0.04) y muertes por millón de habitantes (p = 0.02) resultaron estadísticamente significativas. Las asociaciones de las variables con la tendencia de la curva epidemiológica también resultaron estadísticamente significativas (p = 0.00). CONCLUSIÓN: La recomendación del uso generalizado de mascarilla es una medida con suficiente respaldo científico para reducir el número de contagios y muertes por COVID-19.

Tolerancia a la prueba ergométrica graduada al utilizar barbijo o tapaboca / Exercise Testing Tolerance when Using Face Mask

RESUMEN Introducción: es poco conocida la tolerancia al ejercicio con el uso de barbijo. Objetivo: investigar tolerancia al barbijo en ergometrías (PEG). Material y métodos: estudio multicéntrico con PEG con barbijo. Resultados: 118 PEG (62 cinta, 56 cicloergómetro), 68 hombres, edad 46,74 ± 16,7 años. Setenta (59,3%) completaron PEG con barbijo, 48 (40,7%) debieron retirarlo: 17 en cinta (27,4%), 31 (55,4%) en bicicleta (p = 0,002). Porcentaje de frecuencia cardíaca al retirar barbijo con respecto a máxima alcanzada: 94,5±5,35%. Edad de quienes retiraron barbijo: 42,69±17,35 años y de quienes toleraron: 49,51 ± 15,88 (p = 0,003). Saturación basal: 97,46 ± 1,01%; en esfuerzo máximo con barbijo: 96,58 ± 1,37% (p <0,0001). Al retirar barbijo, saturación de 97,06 ± 1,35% (p < 0.0001). Edad menor y uso de cicloergómetro fueron predictores de no tolerar el barbijo. Conclusiones: la mayoría completó el ejercicio máximo con barbijo. La intensidad de ejercicio al retirar el barbijo fue alta. La saturación cayó en ejercicio con barbijo, aunque sin repercusión clínica.

ABSTRACT Background: Tolerance to exercise with the use of face mask is not well known. Objective: The aim of this study was to investigate the tolerance of exercise parameters during exercise stress testing (EST) while wearing a face mask. Methods: Multicenter study of EST while wearing face mask. Results: 118 ESTs (62 on treadmill, 56 on cycle ergometer), 68 men, age 46.74 ± 16.7 years. Seventy patients (59.3%) completed the EST wearing a face mask, and 48 (40.7%) removed it; 17 patients (27.4%) were on treadmill and 31 (55.4%) on cycle ergometer (p = 0.002). Percentage of maximum predicted heart rate attained when the patients removed their face mask: 94.5 ± 5.35%. Age of those who removed the face mask: 42.69 ± 17.35 years and of those who tolerated the face mask: 49.51 ± 15.88 years (p = 0.003). Baseline SpO2 was 97.46 ± 1.01% and 96.58 ± 1.37% on peak exercise wearing face mask (p < 0.0001). SpO2 when the face mask was removed: 97.06 ± 1.35% (p <0.0001). Younger age and use of cycle ergometer were predictors of intolerance to face mask. Conclusion: Most patients completed peak exercise with face mask. Exercise intensity was high when the face mask was removed. Oxygen saturation dropped during exercise with face mask without clinical impact.

A Sociodemographic Profile of Mask Use During the COVID-19 Outbreak Among Young and Elderly Individuals in Brazil: Online Survey Study.

BACKGROUND: Sociodemographic variables may impact decision making regarding safety measures. The use and selection of adequate face masks is a safety and health measure that could help minimize the spread of COVID-19 infection. OBJECTIVE: This study aims to examine sociodemographic variables and factors relating to COVID-19 that could impact decision making or the choice to use or not use face masks in the prevention and care of a possible COVID-19 infection among a large sample of younger and older Brazilian people. METHODS: An online survey composed of 14 closed-ended questions about sociodemographic variables and COVID-19 was used. A total of 2673 participants consisted of Brazilian people (aged ≥18 years) from different states of Brazil and were grouped according to age (≤59 years and ≥60 years). To compare the variables of interest (associated with wearing a face mask or not), chi-square and likelihood ratio tests were used (with P<.05 being significant). RESULTS: Most of the participants in both groups were women from the southeast region who had postgraduate degrees. Approximately 61% (1452/2378) of individuals aged ≤59 years and 67.8% (200/295) of those aged ≥60 years were not health professionals. In the group aged ≤59 years, 83.4% (1983/2378) did not show COVID-19 signs and symptoms, and 97.3% (2314/2378) were not diagnosed with COVID-19. In the older adult group, 92.5% (273/295) did not show signs and symptoms of COVID-19, and 98.3% (290/295) were not diagnosed with the disease. The majority of the participants in both groups reported using face masks, and their decision to use face masks was influenced by the level of education and their occupation as a health professional. CONCLUSIONS: Younger and older adults have worn face masks during the COVID-19 outbreak. It is difficult to measure how much of a positive impact this attitude, habit, and behavior could have on the degree of infection and spread of the disease. However, it can be a positive indicator of adherence to the population's security and safety measures during the pandemic.

The importance of nonmedical face masks in the general population during the COVID-19 pandemic. A narrative review / La importancia de las mascarillas no médicas en la población general durante la pandemia de COVID-19. Una revisión narrativa

Abstract: The COVID-19 pandemic is a new and great challenge that medicine has had to face. Scientific evidence is growing rapidly and one of the aspects that has generated controversy is the role that the use of non-medical face masks can play when trying to stop the dissemination of cases. This narrative review examines the possible transmission mechanisms of the SARS-COV-2 virus, making emphasis on the role of aerosols, the history of their use inside and outside the hospital environment, the mechanisms by which they offer protection, as well as the efficiency in laboratory test where it is shown that face mask made with several layers of hybrid materials are more effective, and the beneficial impact that they have demonstrated in the general population. Evidence shows its widespread use helps reduce infection by decreasing the transmission of infectious droplets and aerosols, emphasizing that these results are superior when its use is more generalized. Given that it's impossible to provide the entire population with a medical face mask, public policies should be implemented in order to ensure the generalized use of non-medical face masks, along with hygiene strategies, social distance, avoiding closed places and contact tracking.

Resumen: La pandemia de COVID-19 es un nuevo y gran reto al que la medicina se ha tenido que enfrentar. La información científica crece rápidamente y uno de los aspectos que ha generado controversia es el posible papel que puede jugar el uso generalizado de los cubrebocas no médicos para tratar de detener la diseminación de casos. En esta revisión narrativa se examinan los posibles mecanismos de transmisión del virus SARS-CoV-2 con énfasis en el papel de los aerosoles, la historia de su uso dentro y fuera del medio hospitalario; se revisan los mecanismos por los que ofrecen protección, la eficiencia en pruebas de laboratorio donde se demuestra que los cubre bocas de varias capas de materiales híbridos son más eficaces, y el impacto benéfico que han demostrado en la población general. La evidencia demuestra que su uso generalizado ayuda a reducir los contagios al disminuir la transmisión de gotas y aerosoles infecciosos, y el resultado es superior mientras más generalizado es su empleo. Ante la imposibilidad de dotar a toda la población con cubre bocas médicos, se deben adoptar políticas públicas para el uso generalizado de cubre bocas no médicos de un diseño adecuado, junto con estrategias de higiene, distancia social, evitar lugares cerrados y seguimiento de contactos

Impacto en la morbimortalidad por COVID-19 según las regulaciones del uso de mascarilla / Impact on COVID-19 morbidity and mortality according to the regulations on the use of face mask

Resumen Introducción: Actualmente, la mascarilla representa un símbolo incomparable cuyo valor pasó del trabajo clínico a impactar en la contención de la propagación del virus SARS-CoV-2; se convirtió en un elemento de discordia en la población general. Objetivo: Establecer el impacto de las políticas de uso de mascarilla en la morbimortalidad por COVID-19. Métodos: Se asociaron las variables de política de uso de cubrebocas, obtenidas de la página web del movimiento científico #Masks4All, con el número de contagios, muertes y aplanamiento de la curva publicados por el centro de recursos de la Universidad Johns Hopkins y EndCoronavirus.org. Resultados: Las políticas de uso de mascarilla fueron de tipo universal (requerido en tiendas, restaurantes, transporte público), parcial (recomendado, requerido en cualquier lugar público) y ausente. Las asociaciones de la política de uso de mascarilla con casos totales (p = 0.01), casos por millón (p = 0.04) y muertes por millón de habitantes (p = 0.02) resultaron estadísticamente significativas. Las asociaciones de las variables con la tendencia de la curva epidemiológica también resultaron estadísticamente significativas (p = 0.00). Conclusión: La recomendación del uso generalizado de mascarilla es una medida con suficiente respaldo científico para reducir el número de contagios y muertes por COVID-19.

Abstract Introduction: Currently, the face mask represents an incomparable symbol whose value went from clinical work to impacting the containment of the spread of SARS-CoV-2, although it has become an element of discord in the general population. Objective: To establish the impact of face mask use policies on COVID-19 morbidity and mortality. Methods: Face mask use policy variables, obtained from the website of the #Masks4All scientific movement, were associated with the number of infections, deaths and flattening of the curve published by the Johns Hopkins University resource center and EndCoronavirus.org. Results: Face mask use policies were universal (required in shops, restaurants, public transport), partial (recommended, required in any public place) and absent. Associations of the face mask use policy with total cases (p = 0.01), cases per million (p = 0.04) and deaths per million population (p = 0.02) were statistically significant. Associations of the variables with the epidemiological curve trend were also statistically significant (p = 0.00). Conclusion: The recommendation for face mask widespread use is a measure with sufficient scientific support to reduce the number of COVID-19-related infections and deaths.

Decontamination of N95 respirators against SARS-CoV-2: A scoping review.

OBJECTIVES: This scoping review aimed to map and compile the available evidence regarding the effectiveness of decontaminating N95 respirators against the novel coronavirus (SARS-CoV-2). DATA: We selected studies written in English assessing or discussing the decontamination strategies of N95 respirators against SARS-CoV-2. Two independent researchers performed the search and study screening. A descriptive analysis was carried out considering the study design of the included studies. SOURCES: PubMed, SCOPUS, and Preprint platforms (bioRxiv and medRxiv). STUDY SELECTION: We included 55 reports from PubMed and SCOPUS. Nine articles were letters to the editors, 21 were in vitro studies, 16 were literature reviews, and 9 were classified as other study designs. We included 37 preprints. Two articles were letters to the editors, 24 were in vitro studies, 3 were literature reviews, and 8 were classified as other study designs. In general, vaporized hydrogen peroxide and ultraviolet irradiation were the strategies most cited and most promising. However, there is a lack of evidence and consensus related to the best method of N95 respirator decontamination. CONCLUSION: The evidence regarding decontamination strategies of N95 respirators against SARS-CoV-2 remains scarce. Vaporized hydrogen peroxide and ultraviolet irradiation seem to be the current standard for N95 respirator decontamination. CLINICAL SIGNIFICANCE: Vaporized hydrogen peroxide and ultraviolet irradiation appear to be the most promising methods for N95 respirator decontamination.

Nondepolarizing muscle relaxant improves direct laryngoscopy view with no effect on face mask ventilation / Relaxantes musculares não despolarizantes melhoram a visibilidade em laringoscopia direta sem efeito sobre a ventilação via máscara facial

Abstract Background: Difficult or impossible face mask ventilation complicated with difficult tracheal intubation during anesthesia induction occurs in 0.4% of adult anesthesia cases, possibly leading to life-threatening complications. Because of such catastrophes, muscle relaxants have been recommended to be administered after confirming adequate face mask ventilation without a solid scientific validation of this principal. Methods: In this observational study, the ease of ventilation and the scores of direct laryngoscopy views before and after administration of cisatracurium were assessed in ninety young healthy adults, without anesthetic risks and without foreseen difficult intubation and who were scheduled for general elective surgeries. Results: Before muscle relaxation, 43 patients (48%) were Cormack Grade I, while the remaining 47 patients (52%) were either Cormack Grade II (28 patients, 31%) or Cormack Grade II (19 patients, 21%). Following muscle relaxation with cisatracurium, the number of patients with Cormack Grade I significantly increased from 43 patients (48%) to 65 patients (72%) (p = 0.0013). Only 1 patient out of 19 patients (5%) improved his Cormack grade from Grade III to Grade I while 16 out 19 patients (84%) improved their Cormack grade from Grade III to Grade II after the use of cisatracurium. The quality of face mask ventilation did not differ with and without muscle relaxants in all patients. Conclusion: The use of cisatracurium in healthy young adults undergoing general elective surgeries with no anticipated difficult endotracheal intubation had no effect on the quality of face mask ventilation despite resulting in a quantifiable improvement in the laryngeal view.

Resumo Justificativa: A ventilação difícil ou impossível via máscara facial complicada pela intubação traqueal difícil durante a indução da anestesia ocorre em 0,4% dos casos de anestesia em adultos, possivelmente leva a complicações fatais. Devido a tais catástrofes, recomendou-se que a administração de relaxantes musculares seja feita após a confirmação de ventilação adequada via máscara facial, sem uma validação científica sólida dessa conduta. Métodos: Neste estudo observacional, a facilidade de ventilação e os escores de visibilidade em laringoscopia direta antes e após a administração de cisatracúrio foram avaliados em 90 adultos jovens e saudáveis, sem riscos anestésicos e sem intubação difícil prevista, agendados para cirurgias eletivas gerais. Resultados: Antes do relaxamento muscular, 43 pacientes (48%) eram Cormack Grau I, enquanto os 47 (52%) restantes eram ou Cormack Grau II (28, 31%) ou Cormack Grade III (19, 21%). Após o relaxamento muscular com cisatracúrio, o número de pacientes com Cormack Grau I aumentou significativamente de 43 (48%) para 65 (72%) (p = 0,0013). Apenas um paciente (5%) dos 19 melhorou sua classificação de Cormack do Grau III para o Grau I, enquanto 16 dos 19 (84%) melhoraram suas classificações de Cormack do Grau III para o grau II após o uso de cisatracúrio. A qualidade da ventilação via máscara facial não diferiu com ou sem relaxantes musculares em todos os pacientes. Conclusão: O uso de cisatracúrio em adultos jovens saudáveis submetidos a cirurgias eletivas gerais sem intubação traqueal difícil prevista não teve efeito sobre a qualidade da ventilação via máscara facial, mesmo resultando em melhora quantificável da visibilidade da laringe.