Obstáculos no processo de ensino e de aprendizagem de cálculo estequiométrico

The article presents results of a research realized in the city of Belém, Pará with chemistry teachers and students of 2nd year of high school from a public school and one private, by the application of semistructured interviews in order to identify and investigate in Chemistry classes in the main obstacles of the students in relation to student learning Stoichiometric Calculation, and thus, propose a didactic intervention. After quantitative and qualitative analysis was applied a contextualized classroom using teaching a game, aiming at effective learning. The results show that the main difficulty reported by both students and the teachers is related to the calculations present in the content addressed. It is concluded that, after didactic intervention and implementation of a new semistructured interview, the students showed an interest in class, better understanding of the contents so they could effectively build the knowledge object of this studyO artigo apresenta resultados de uma pesquisa realizada no município de Belém-Pará, com professores de Química e alunos do 2° ano do Ensino Médio de uma escola pública e outra privada, por meio da aplicação de entrevistas semiestruturadas com o objetivo de identificar e investigar nas aulas de Química os principais obstáculos dos estudantes em relação ao aprendizado de Cálculo Estequiométrico, e assim, propor uma intervenção didática. Após análise quantitativa e qualitativa aplicou-se uma aula contextualizada utilizando um jogo didático, objetivando uma aprendizagem efetiva. Os resultados mostram que a principal dificuldade relatada tanto pelos discentes quanto pelos docentes está relacionada aos cálculos presentes no conteúdo abordado. Concluiu-se, após a intervenção didática e a aplicação de uma nova entrevista semiestruturada, que os estudantes demonstraram interesse na aula, melhor compreensão do conteúdo e assim puderam construir efetivamente o conhecimento objeto deste estudo

Zeolites: A Theoretical and Practical Approach with Uses in (Bio)Chemical Processes

This review provides a state-of-the-art summary of distributed zeolite technology, as well as identifying strategies to further promote the absorption of these materials in various areas of study. Zeolites are materials that can be synthesized or found in natural rock deposits a with a basic composition consisting in Al, Si, and O. Zeolite’s consideration as a future material is due to many facile synthesis methods to obtain different structures with variations in pore size, surface area, pore volume and physical properties. These methods are developed using the control of relevant synthesis parameters that influences structure formation, such as crystallization temperature, time of aging and/or crystallization, stoichiometric relationships between components of synthesis gel, pH of the medium, and in some cases the type of structure-directing agent. Each method will lead to geometric changes in the framework formation, making possible the formation of typical chemical bonds that are the fingerprint of any zeolitic structure (O-Si-O and Al-O-Si), forming typical acid sites that give specificity in zeolite and allows it to act as a nanoreactor. The specificity is a characteristic that in some cases depends on selectivity, a fundamental property derived of the porosity, mostly in processes that occur inside the zeolite. In processes outside the structure, the surface area is the main factor influencing this property. Moreover, there are many natural sources with adequate chemical composition to be used as precursors. Some of these sources are waste, minimizing the deposition of potential hazardous materials that can be recalcitrant pollutants depending on the environment. Besides its uses as a catalyst, zeolite serves as a support for many bioprocesses; therefore, this review aims to explain relevant aspects in chemical nature, physical properties, main methods of synthesis, main precursors used for synthesis, and relevant applications of zeolites in chemical catalysis and biological processes

Glycerol and Catalysis by Waste/Low-Cost Materials—A Review

The growing global demand for renewable energy sources can be reached using biofuels such as biodiesel, for example. The most used route to produce biodiesel is the transesterification reaction of oils or fats with short-chain alcohols, generating fatty acid esters (biodiesel) and a very important by-product, glycerol (Gly). Gly is widely used in different sectors of the industry, and in order to add value to this by-product, heterogeneous catalysis becomes a relevant tool, whether to transform glycerol into other chemical products of interest or even use it in the production of catalysts. Among the several studies found in the literature, the use of low-cost materials and/or wastes from the most diverse activities to prepare active catalytic materials for the transformation of Gly has been increasingly reported due to its valuable advantages, especially related to the cost of raw materials and environmental aspects. Thus, this brief review article presents the relationship between catalysis, low-cost materials, waste, and glycerol, through different studies that show glycerol being transformed through reactions catalyzed by materials produced from low-cost sources/waste or with the glycerol itself used as a catalyst

INOVAÇÃO PEDAGÓGICA NO CURSO DE ENFERMAGEM: ESTUDO, REFLEXÃO E COLABORAÇÃO PARA UM PROCESSO DE ENSINO-APRENDIZAGEM DE QUALIDADE

Objetivou-se relatar a experiência de estudantes e professores em um projeto de inovação pedagógica desenvolvido no curso de Enfermagem da Universidade Federal do Tocantins. As vivências e ações foram voltadas à promoção do protagonismo do estudante na sua formação, bem como à integração do ensino, pesquisa e extensão no ambiente universitário. Com base na experiência sugere-se uma avaliação conjunta com os demais projetos contemplados em outras áreas do conhecimento, no intuito de aprimorar o programa de inovação pedagógica institucional

University Extension of Elderly Health and Potency for Medical Training

Objective: To present the potential of university extension for medical training, based on the perception of extension workers. Method: This is an exploratory descriptive study, with a qualitative approach, carried out with medical students, former students of the university extension project of the elderly health. Wheels of conversations were made to base empirical production on a semi-structured interview script. The analysis was performed using Fiorin's speech analysis technique. Results: It was possible to verify, in this research, the power of the university extension in the medical training, the impact generated in the accompanied elderly people and the importance of the production of bond. It was also verified the importance of providing students with more projects that can give a return to society and foster in students the need not to stop only the pathology, but mainly to awaken the motivation for a humanized and integral care. Conclusion: The university extension provides an approximation with the community, through the bond and accountability between the academic and the elderly. In addition, it allows to contribute to improve and implant the sense of citizenship in the life of individuals. Key words: Health of the institutionalized elderly, Medicine, Collective Health

Sepse: avaliação da qualidade do atendimento em setor de urgência e emergência: Sepsis: assessment of the quality of emergency and emergency care

A Sepse corresponde à presença de uma disfunção orgânica fatal provocada por uma resposta anormal do hospedeiro a um processo infeccioso, que pode progredir para um choque séptico. No decorrer dessa pesquisa, cuja metodologia foi a revisão integrativa de literatura, foram utilizados artigos científicos publicados em periódicos nacionais entre os anos de 2015 e 2022, retirados da base de dados Medline e Lilacs, sendo buscados a partir dos descritores: “Sepse”, “Qualidade do atendimento” e “Urgência e Emergência”. Com o objetivo de analisar a efetividade das ações de cuidados de Enfermagem aplicadas ao sepse adulto, a partir da análise de dados reunidos nesta revisão integrativa, foi possível concluir que a implantação de protocolos para o tratamento resultou em melhorias significativas nos indicadores de qualidade nos cuidados com a sepse, a exemplo da melhoria do fluxo e de atenção aos pacientes e redução da mortalidade nos setores de urgência e emergência

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK.

BACKGROUND: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. METHODS: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. FINDINGS: Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0-75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4-97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8-80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3-4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. INTERPRETATION: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK

Background A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. Methods This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. Findings Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0–75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4–97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8–80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3–4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. Interpretation ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials