O3 dissolved in water (or ozonized water) has been considered a potent antimicrobial agent, and this study aimed to test this through microbiological and in vitro assays. The stability of O3 was accessed following modifications of the physicochemical parameters of water, such as the temperature and pH, with or without buffering. Three concentrations of O3 (0.4, 0.6, and 0.8 ppm) dissolved in water were tested against different microorganisms, and an analysis of the cytotoxic effects was also conducted using the human ear fibroblast cell line (Hfib). Under the physicochemical conditions of 4 °C and pH 5, O3 remained the most stable and concentrated compared to pH 7 and water at 25 °C. Exposure to ozonized water resulted in high mortality rates for Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus faecalis, and Candida albicans. Scanning electron micrograph images indicate that the effects on osmotic stability due to cell wall lysis might be one of the killing mechanisms of ozonized water. The biocidal agent was biocompatible and presented no cytotoxic effect against Hfib cells. Therefore, due to its cytocompatibility and biocidal action, ozonized water can be considered a viable alternative for microbial control, being possible, for example, its use in disinfection processes.

To control infectious diseases such as the severe acute respiratory syndrome coronavirus (Covid-19) that caused the current pandemic, disinfection measures are essential. Among building measures, disinfection chambers can help to decrease the transmission rate through the sanitizing capacity of the disinfectant used, which can thereby clean surfaces or humans. Out of existing biocides, ozone is considered one of the safest for humans, but one of the most powerful oxidizers, making the substance a better alternative as the biocidal solution in disinfection chambers. Analyses were carried out by using all patented documents related to disinfection chambers that used ozone as a disinfectant. A Derwent Innovation Index (DII) database search was undertaken to find these patents. Patent prospecting resulted in 620 patent documents that were divided into 134 patent families. There was no technology related to protective barriers for individuals, and the majority of patents in the retrieved data aimed at sterilizing medical devices and surfaces. Given that the specific Cooperative Patent Classification (CPC) code for ozone dissolved in liquid was used in the methodology search, but not included among the 10 most used codes in the patents, the use of ozonized water may be an innovative approach in the technology landscape of sterilization chambers.

No abstract

The development of new approaches for the decontamination of surfaces is important to deal with the processes related to exposure to contaminated surfaces. Therefore, was evaluated the efficacy of a disinfection technology using ozonized water (0.7–0.9 ppm of O3) on the surfaces of garments and accessories of volunteers, aiming to reduce the spread of microbial pathogens in the workplace and community. A Log10 microbial reduction of 1.72–2.40 was observed between the surfaces tested. The microbial reductions remained above 60% on most surfaces, and this indicated that the disinfection technology was effective in microbial log reduction regardless of the type of transport used by the volunteers and/or their respective work activities. In association with the evaluation of efficacy, the analysis of the perception of use (approval percentage of 92.45%) was fundamental to consider this technology as an alternative for use as a protective barrier, in conjunction with other preventive measures against microbiological infections, allowing us to contribute to the availability of proven effective devices against the spread of infectious agents in the environment.

The use of personal protective equipment (PPE) has been considered the most effective way to avoid the contamination of healthcare workers by different microorganisms, including SARS-CoV-2. A spray disinfection technology (chamber) was developed, and its efficacy in instant decontamination of previously contaminated surfaces was evaluated in two exposure times. Seven test microorganisms were prepared and inoculated on the surface of seven types of PPE (respirator mask, face shield, shoe, glove, cap, safety glasses and lab coat). The tests were performed on previously contaminated PPE using a manikin with a motion device for exposure to the chamber with biocidal agent (sodium hypochlorite) for 10 and 30s. In 96.93% of the experimental conditions analyzed, the percentage reduction was >99% (the number of viable cells found on the surface ranged from 4.3x106 to <10 CFU/mL). The samples of E. faecalis collected from the glove showed the lowest percentages reduction, with 86.000 and 86.500% for exposure times of 10 and 30 s, respectively. The log10 reduction values varied between 0.85 log10 (E. faecalis at 30 s in glove surface) and 9.69 log10 (E. coli at 10 and 30 s in lab coat surface). In general, E. coli, S. aureus, C. freundii, P. mirabilis, C. albicans and C. parapsilosis showed susceptibility to the biocidal agent under the tested conditions, with >99% reduction after 10 and 30s, while E. faecalis and P. aeruginosa showed a lower susceptibility. The 30s exposure time was more effective for the inactivation of the tested microorganisms. The results show that the spray disinfection technology has the potential for instant decontamination of PPE, which can contribute to an additional barrier for infection control of healthcare workers in the hospital environment.

To mitigate the loss of efficiency of photovoltaic modules, protective films of polyethylene terephthalate with tin doped indium oxide (PET / ITO) may be a viable alternative. Thus, the article presents a review on the effect of the accumulation of dirt in photovoltaic modules and on the state of the art involving protective films made of PET / ITO. The review started in 2019 with a predominance of articles published abroad and in international journals. The results show that there are several studies on the effect of dirt on photovoltaic systems, but these are studies that do not take into account the comparison between studies done in the laboratory and in adverse conditions of the external environment such as rain, wind and film degradation.

Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, is a problem of fetal erythrocyte hemolysis. This may happen due to the sensitization of maternal antibodies through the placental route. It is the pathology most frequently found in neonatal patients. Approximately 98% of maternal alloimmunization cases by erythrocyte antigens are due to the RhD factor. Phototherapy is the first choice in the treatment of neonatal jaundice. Blood transfusion is the therapy instituted for the treatment of severe neonatal disease. This study aimed to develop an automated device for performing the blood transfusion procedure. The method was developed in four stages: (1) Literature review about the search for theoretical references based on scientific articles and textbooks on transfusion therapy in the newborn; (2) Elaboration of the device consisted of items related to its assembly and structuring; (3) Operation of the medical device, including specific schedules related to the execution of the procedure; (4) Performing tests with simulating the purpose of volume replacement in the total cycle performed in the exsanguine transfusion procedure. The results showed that it was possible to assemble, reproduce, and implement the automation of the device developed for the exsanguine transfusion procedure in a practical. Also, the procedure presented security and effectiveness in the clinical treatment related to HDN.

Resumo: O uso de sistemas energia solar fotovoltaica cresce consideravelmente em todo o mundo. Pesquisas mostram que os módulos fotovoltaicos (FV) são consideravelmente afetados pela existência de poeira e sua deposição nas superfícies dos módulos, levando à redução da eficiência do sistema. Este trabalho tem como objetivo desenvolver um estudo, utilizando a Dinâmica dos Fluidos Computacional (CFD), sobre o uso de jatos de ar para promover o arrasto das partículas de poeira, removendo-as da superfície de módulos. Um modelo foi desenvolvido utilizando uma análise Euleriana, baseada em parâmetros físicos, a fim de descobrir a velocidade do ar para promover o arraste da poeira. Através do uso do software ANSYS CFX 17.1, foi possível realizar a montagem e simulação do modelo e adquirir dados importantes.