Fast inactivation of coronavirus in filtering-facepiece respirators in a reflective cylindrical UV-C chamber.

Objective: We report on the development and characterization of a UV-C (λ  =  200 - 280 nm, λpeak = 254 nm) chamber designed for the rapid disinfection of N95 class filtering-facepiece respirators contaminated with SARS-CoV-2 coronaviruses. The device was evaluated against Betacoronavirus strain MHV-3 and its virucidal capacity was evaluated as a function of different applied UV-C doses (UV-C exposure times of 60 s, 120 s, 180 s, and 240 s) using two types of respirators geometry (shell and two-panel shapes, 3M 8801 H and 9920 H, respectively), at eight points of the respirators. Background: Most chemical disinfection methods are not recommended for N95 masks. UV-C light provided by UVGI lamps (254 nm) is an effective physical agent against viruses and bacteria due to direct photochemical harming effect on DNA/RNA, and can provide rapid disinfection for personal protective equipment such as N95/PFF2 masks. Results: The device reached a mean elimination rate of 99.9999% of MHV-3 inoculated into all the assessed different points on the tested PFF2 respirator models in a UV-C cycle of just 60 s. Statistical analysis performed through Person´s chi-square test showed no correlation between the viral infectivity reduction and the viral inoculation point (p = 0.512) and the tested respirator models (p = 0.556). However, a correlation was found between the exposure time and the viral infectivity reduction (p = 0.000*), between UV-C and no UV-C exposure. All the tested UV-C exposure times (60 s, 120 s, 180 s, and 240 s) provided the same reduction in infection rates. Therefore, 60 s was confirmed as the minimum exposure time to achieve a 99.9999% or 6 Log reduction in MHV-3 coronavirus infection rates in the PFF2 samples tested in the device. Conclusions: We conclude that the assessed UV-C chamber for the inactivation of MHV-3 coronavirus in N95/PFF2 standard masks can be a promising tool for effective and rapid disinfection of coronaviruses, including SARS-CoV-2 virus.

Premature or Small for Gestational Age Discrimination: International Multicenter Trial Protocol for Classification of the Low-Birth-Weight Newborn Through the Optical Properties of the Skin.

BACKGROUND: A low birth weight is an independent risk factor for adverse infant outcomes and a predictor of chronic disease in adulthood. In these situations, differentiating between prematurity and small for gestational age (SGA) or simultaneous conditions is essential to ensuring adequate care. Such diagnoses, however, depend on reliable pregnancy dating, which can be challenging in developing countries. A new medical optoelectronic device was developed to estimate gestational age (GA) at birth based on newborn skin reflection. OBJECTIVE: This study will aim to evaluate the device's ability to detect prematurity or SGA, or both conditions simultaneously as well as predict short-term pulmonary complications in a cohort of low-birth-weight newborns. METHODS: This study protocol was designed for a multicenter cohort including referral hospitals in Brazil and Mozambique. Newborns weighing 500-2500 g will be eligible for inclusion with the best GA available, considering the limited resources of low-income countries. Comparator-GA is based on reliable last menstrual period dating or ultrasound assessment before 24 weeks' gestation. Estimated GA at birth (Test-GA) will be calculated by applying a novel optoelectronic device to the newborn's skin over the sole. The average difference between Test-GA and Comparator-GA will be analyzed, as will the percentage of newborns who are correctly diagnosed as preterm or SGA. In addition, in a nested case-control study, the accuracy of skin reflection in the prediction of prematurity-related respiratory problems will be evaluated. The estimated required sample size is 298 newborns. RESULTS: Teams of health professionals were trained, and standard operating procedures were developed following the good practice guidelines for the clinical investigation of medical devices for human participants. The first recruitment started in March 2019 in Brazil. Data collection is planned to end in December 2020, and the results should be available in March 2021. CONCLUSIONS: The results of this clinical study have the potential to validate a new device to easily assess postnatal GA, supporting SGA identification when pregnancy dating is unreliable or unknown. TRIAL REGISTRATION: ReBec: RBR-33rnjf; http://www.ensaiosclinicos.gov.br/rg/RBR-33rnjf/. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/16477.

Analysis of low-level laser transmission at wavelengths 660, 830 and 904 nm in biological tissue samples.

BACKGROUND: In recent decades, low-level laser therapy (LLLT) has occupied a prominent position and has been studied in various fields of knowledge, and your effects have been widely observed in studies about numerous tissues, such as tendons, peripheral nerves, cutaneous tissue, bone, and muscle, in different fields of knowledge. PURPOSE: To analyze the power transmitted by low-level laser therapy (LLLT) to different tissue samples by using distinct wavelengths. METHODS: Skin samples of rat (n = 7, 1.17-1.63 mm) and pig (n = 10; 1.20-2.30 mm); pig fat (n = 10; 2.71-14.01 mm) and pig muscle (n = 10; 1.91-8.91 mm) were analyzed and interposed between the emitter and the power analyzer sensor. All the samples were irradiated sequentially three times, at five equidistant points and average power levels of 35.34(±1.03), 32.40(±0.70), and 42.32(±0.82) mW, for the wavelengths 660, 830, and 904 nm, respectively. Transmitted radiation was measured with a power analyzer connected to a laser emitter. Statistical analysis was performed with a Shapiro-Wilk test followed by ANOVA with Tukey's post hoc test, with a significance level of 5%. RESULTS: The transmitted power of LLLT on skin, fat, and muscle of tissues decreases with the increase of thicknesses, presenting minor attenuation on rat skin, pig fat, and pig muscle for 904 nm. The pig skin has the slight attenuation for 830 nm. CONCLUSION: The LLLT should be applied after considering the transmission loss taking place in different anatomical structures, following the Beer-Lambert law and attenuation coefficient presented for more practical application in many fields.

A quantitative cross-sectional analysis of the melanin index in the skin of preterm newborns and its association with gestational age at birth.

BACKGROUND: Estimation of gestational age (GA) is important to make timely decisions and provide appropriate neonatal care. Clinical maturity scales to estimate GA have used skin texture and color to assess maturity at birth facing situations of the uncertainty of pregnancy dating. The size and darkness of the areola around the nipple to grade skin characteristics are based on visual appearance. The melanin index (M-Index) is an optical skin parameter related to the melanin content in the tissue. This study is aimed to associate the M-Index of the skin with the GA. METHODS: A cross-sectional study evaluated 80 newborns at birth. A photometer device quantified the skin pigmentation on the areolae, forearms, and soles. Paired average differences of M-Index were compared among the three body sites. The skin M-Indexes were compared between subgroups of newborns until 34 weeks or with 34 and more. RESULTS: The skin over the areola had the highest values of M-Index compared with the forearm or sole areas (P < .001 for both). Infants with a GA between 34 and <37 weeks had higher M-Index values over the areola than the group with a GA with 24 to <34 weeks: 41.7 (8.9) and 38.3 (10.5) median (IQR), P = .005. CONCLUSIONS: The measurable M-Index values have the potential to improve physical evaluation in assessing GA at birth.

Prematurity detection evaluating interaction between the skin of the newborn and light: protocol for the preemie-test multicentre clinical trial in Brazilian hospitals to validate a new medical device.

INTRODUCTION: Recognising prematurity is critical in order to attend to immediate needs in childbirth settings, guiding the extent of medical care provided for newborns. A new medical device has been developed to carry out the preemie-test, an innovative approach to estimate gestational age (GA), based on the photobiological properties of the newborn's skin. First, this study will validate the preemie-test for GA estimation at birth and its accuracy to detect prematurity. Second, the study intends to associate the infant's skin reflectance with lung maturity, as well as evaluate safety, precision and usability of a new medical device to offer a suitable product for health professionals during childbirth and in neonatal care settings. METHODS AND ANALYSIS: Research protocol for diagnosis, single-group, single-blinding and single-arm multicenter clinical trial with a reference standard. Alive newborns, with 24 weeks or more of pregnancy age, will be enrolled during the first 24 hours of life. Sample size is 787 subjects. The primary outcome is the difference between the GA calculated by the photobiological neonatal skin assessment methodology and the GA calculated by the comparator antenatal ultrasound or reliable last menstrual period (LMP). Immediate complications caused by pulmonary immaturity during the first 72 hours of life will be associated with skin reflectance in a nested case-control study. ETHICS AND DISSEMINATION: Each local independent ethics review board approved the trial protocol. The authors intend to share the minimal anonymised dataset necessary to replicate study findings. TRIAL REGISTRATION NUMBER: RBR-3f5bm5.