Biochemical and morphological characterization of freshwater microalga Tetradesmus obliquus (Chlorophyta: Chlorophyceae).

Tetradesmus is a microalgal genus with biotechnological potential due to its rapid production of biomass, which is plenty in proteins, carbohydrates, lipids, and bioactives. However, its morphology and physiology need to be determined to guide better research to optimize the species cultivation and biocompounds processing. Thus, this study describes the biochemistry and morphology of the strain Tetradesmus obliquus BR003, isolated from a sample of freshwater reservoirs in a Brazilian municipality. In the T. obliquus BR003 dry biomass, we identified 61.6% unsaturated fatty acids, and 3.4% saturated fatty acids. Regarding other compounds, 28.50 ± 1.47 g soluble proteins/100 g, 0.14 ± 0.009 g carotenoids/100 g, 0.76 ± 0.013 g chlorophyll a/100 g, and 0.42 ± 0.015 g chlorophyll b/100 g with a chlorophyll a/b ratio of 1.8 were detected. The main chemical elements found were S, Mg, and P. The cells of BR003 were elliptically curved at the ends and without appendages. Histochemical tests showed carbohydrates distributed in the cytoplasm and pyrenoids, some lipid droplets, and proteins. The cytoplasm is rich in vacuoles, rough endoplasmic reticulum, mitochondria, and chloroplasts. The nucleus has a predominance of decondensed chromatin, and the cell wall has three layers. Chloroplasts have many starch granules and may be associated with a spherical central pyrenoid. To the best of our knowledge, this was the first biochemical description combined with ultrastructural morphological characterization of the strain T. obliquus BR003, grown under standard conditions, to demonstrate specific characteristics of the species.

Handmade face mask can be sterilized without compromising their efficacy / Máscara facial artesanal pode ser esterilizada sem comprometer sua eficácia / La mascarilla facial hecha a mano se puede esterilizar sin comprometer su eficácia

Background and Objectives: COVID-19 caused by SARS-CoV-2 is transmitted by contact, droplets and aerosols. The World Health Organization recommends the mandatory use of surgical masks for health professionals and encourages countries to adhere to their use, en masse, in order to minimize the transmission of the virus. Since the lack of this personal protective equipment is a cause for concern, the objective of this study was to evaluate the characteristics of facial masks regarding (i) the mechanical properties of elongation, rupture stress and resistance to air passage and (ii) the morphometric properties of thickness, fiber diameter and pore distribution after autoclave sterilization. Methods: The masks were made in TNT Spunbonded (100% polypropylene, 60 g/m2 ), autoclaved at 70 ºC for 5 minutes and stored in plastic films at room temperature. Then, the mechanical properties were determined in an Instron universal testing machine and Gurley type automatic densimeter and the morphometric properties in a semi-automatic thickness gauge and scanning electron microscope. Results: It was observed that a cycle of sterilization of facial masks, by moist heat under pressure, increased the blanket's stiffness, did not produce physical damage and did not reduce the blanket's barrier capacity. Conclusion: The sterilization of face masks made of TNT can be considered a strategy to increase safety in their production and use.(AU)

Justificativa e Objetivos: A COVID-19 causada pelo SARS-CoV-2 é transmitida pelo contato, por gotículas e por aerossóis. A Organização Mundial da Saúde recomenda a obrigatoriedade do uso de máscaras cirúrgicas aos profissionais da saúde e incentiva os países a aderirem ao seu uso, em massa, a fim de minimizar a transmissibilidade do vírus. Posto que a falta desse equipamento de proteção individual causa preocupação, o objetivo deste trabalho foi avaliar as características de máscaras faciais quanto (i) às propriedades mecânicas alongamento, tensão de ruptura e resistência a passagem de ar e (ii) às propriedades morfométricas espessura, diâmetro das fibras e distribuição de poros após esterilização em autoclave. Métodos: As máscaras foram confeccionadas em TNT Spunbonded (100% polipropileno, 60 g/m2), autoclavadas a 70 ºC por 5 minutos e armazendadas em filmes plásticos a temperatura ambiente. Na sequência, as propriedades mecânicas foram determinadas em máquina de teste universal Instron e densímetro automático tipo Gurley e as propriedades morfométricas em medidor de espessura semiautomático e microscópio eletrônico de varredura. Resultados: Observou-se que um ciclo de esterilização das máscaras faciais, por calor úmido sob pressão, promoveu o aumento da rigidez da manta, não produziu danos físicos e não diminuiu a capacidade de barreira da manta. Conclusão: A esterilização de máscaras faciais confeccionadas em TNT pode ser considerada uma estratégia para aumentar a segurança na sua produção e uso.(AU)

Antecedentes y objetivos: El COVID-19 causado por el SARS-CoV-2 se transmite por contacto, gotitas y aerosoles. La Organización Mundial de la Salud recomienda el uso obligatorio de mascarillas quirúrgicas para los profesionales de la salud y alienta a los países a adherirse a su uso, en masa, con el fin de minimizar la transmisión del virus. Dado que la falta de este equipo de protección personal es motivo de preocupación, el objetivo de este estudio fue evaluar las características de las máscaras faciales en cuanto a (i) las propiedades mecánicas de elongación, tensión de rotura y resistencia al paso del aire y (ii) la morfometría propiedades de espesor, diámetro de fibra y distribución de poros después de la esterilización en autoclave. Métodos: Las máscaras se fabricaron en TNT Spunbonded (100% polipropileno, 60 g / m2), se esterilizaron en autoclave a 70 ºC durante 5 minutos y se almacenaron en películas plásticas a temperatura ambiente. Posteriormente, se determinaron las propiedades mecánicas en una máquina de ensayo universal Instron y densímetro automático tipo Gurley y las propiedades morfométricas en un medidor de espesor semiautomático y microscópio electrónico escaneando.Resultados: Se observó que un ciclo de esterilización de mascarillas faciales, por calor húmedo a presión, incrementó la rigidez de la manta, no produjo daño físico y no redujo la capacidad barrera de la manta. Conclusión: La esterilización de mascarillas faciales fabricadas con TNT puede considerarse una estrategia para aumentar la seguridad en su producción y uso.(AU)

Effects of inclined treadmill training on functional and cardiovascular parameters of stroke patients: study protocol for a randomized controlled trial.

BACKGROUND: Treadmill training has been widely used for gait recovery after stroke. Gait re-establishment is one of the main objectives of rehabilitation programs after stroke, aiming to acquire more functional patterns and increase walking speed, along with improvement in cardiovascular function. The aim of this study is to evaluate the effects of a treadmill gait training protocol on functional and cardiovascular variables in patients with chronic stroke. METHODS: A single-blind randomized clinical trial will be conducted. The sample will consist of 36 patients, who will be allocated in three groups: control group (n = 12), experimental group 1 (n = 12), and experimental group 2 (n = 12). The intervention will occur for 6 consecutive weeks, three times a week, 30 min each session, in all groups. The control group will perform a treadmill gait training without inclination, experimental group 1 will perform a treadmill gait training with anterior inclination of 5%, and experimental group 2 will perform a treadmill gait training with anterior inclination of 10%. All participants will be assessed for sample characterization measures, gait speed, functional capacity, systemic arterial blood pressure, heart rate, peripheral oxygen saturation, exercise capacity, neuromuscular torque, and quality of life. Evaluations of outcome measures will occur at the end of the interventions (post-training) and after 1 month and 1 year after the end of the interventions (short- and long-term follow-up). Statistical analysis will be performed descriptively and inferentially. Alpha equals 5% will be considered for inferential analysis. Mixed analysis of variance with repeated measures will be used to compare outcome measures between groups and between baseline, post-training, and follow-up. Normality test (Shapiro-Wilk) and subsequently t test (or Mann-Whitney) will be used to compare groups during the same training session. DISCUSSION: It is believed that treadmill training, especially treadmill training with anterior inclination, may result in improved exercise capacity in patients with stroke, reduced blood pressure and heart rate values, and an improvement in functional parameters with increased gait speed, functional capacity, quadriceps muscle torque, and quality of life. TRIAL REGISTRATION: Registration in Brazilian Registry of Clinical Trials (ReBEC) identifier RBR-5ffbxz , date of registration October 25 2017.