Mössbauer spectroscopy and Rietveld refinement used to analyze stainless steel properties regarding shape memory effect (SME)

The resonant absorption of recoilless -rays, known as Mössbauer Spectroscopy, is an efficient nuclear prospecting technique to structural and magnetic analysis. When studying steels, it is possible to accurately analyze the surface of materials using the Conversion Electron Mössbauer Spectroscopy technique (CEMS) that evaluates the sample’s surface to a depth of 200 nm, and by Conversion X-ray Mössbauer Spectroscopy by (CXMS), which can go deeper and investigate inner layers of steel samples (10 m). In this work, this technique was employed to study the crystallographic reversion (f.c.c.h.c.p.) of  stainless steel shape memory. A hexagonal martensitic phase was induced mechanically through the compression test and the reversion to austenite phase was observed using heat treatment. Mössbauer spectroscopy measurements were carried out using the conversion of electrons, and X-ray with a 57Co source in a rhodium matrix at room temperature and without the external fields. Spectra were analyzed using specific adjustment software. The results indicated great reversal of -martensite. Rietveld refinement analysis was obtained using the XRD data to evaluate possible structural changes occurring during the thermo-mechanical treatment (cycles of deformation followed by heating). Comparison of the Mössbauer spectra and Rietveld refinement are important for understanding the reversal of the martensitic phase. In this case, the crystal structure changes resulted in a shape recovery material, which was deformed beyond its elastic limit.Keywords: Shape memory effect, stainless steel, -martensite, Mössbauer Spectroscopy, Rietveld refinemen

Ultra high molecular weight polyethylene doped with iron through high energy mechanical alloying

Doping polymers with metallic materials can improve significantly its use. Ultra high molecular weight polyethylene is known for its high resistance to abrasion and impact, and also for its friction coefficient, which is significantly lower than that of commercial steel and most polymeric materials. Therefore, this material presents high industrial demand despite its processing difficulty due to its high viscosity. One kind of polymer processing which has been widely used recently is the high energy mechanical alloying. This method provokes significant changes in the material, such as crystalline structure transformation, amorphization, formation of metastable phases, and nanostructuring, among others. In order to investigate the influence of iron dopant in structural characteristics of polymeric matrix, ultra high molecular weight polyethylene were doped with low concentrations (between 0.1 at.% and 1 at.%) of iron using the method of high energy mechanical alloying. The samples composition was characterized by X-Ray Diffraction Mössbauer Spectroscopy. A theoretical molecular modeling was carried out to simulate the iron presence in polymeric cell, which is in good agreement with the experimental results. Therefore, there is evidence that part of the iron promotes a crossed bond between the polymeric chains. Keywords: Ultra high molecular weight polyethylene (UHMWPE), High energy mechanical alloying, Mössbauer Spectroscopy, structural properties

Principais complicações da covid-19 e implicações futuras: revisão integrativa

Objetivo: sintetizar as evidências científicas quanto às principais complicações daCOVID-19, ocorridas durante o período de convalescença, em pacientes adultos eidosos. Método: revisão integrativa, realizada entre março e maio de 2021 nas fontes:US National Library of Medicine National Institutes Database Search of Health,Literatura Latino Americana e do Caribe em Ciências da Saúde, Scopus, CumulativeIndex to Nursing and Allied Health Literature, Web of Science, Excerpta MédicaDatabase. Utilizou-se o Rayyan na seleção e a análise de conteúdo. Resultados:identificaram-se 833 artigos, destes, nove compuseram a amostra. As complicações sãoneurológicas, respiratórias, psiquiátricas, cardiovasculares, nutricionais e musculares.Conclusão: as complicações mais preponderantes da COVID-19 são caracterizadaspelos acometimentos respiratórios e neurológicos, as quais implicam no aumento depacientes descompensados nos serviços de saúde para procedimentos eletivos,aumento dos gastos públicos e na incidência de parada cardíaca extra-hospitalar

Atuação do enfermeiro no atendimento domiciliar ao paciente idoso: revisão integrativa

O tema tem por objetivo  falar  sobre  a  atuação do enfermeiro na assistência domiciliar prestada ao paciente idoso. Utilizou-se a revisão integrativa onde foram selecionadas 18 publicações revisão integrativa por meio de consulta às bases de dados BVS, SciELO. De 38 artigos. Foram incluídos estudos em espanhol, inglês e português, não delimitando data de publicação. Após a leitura minuciosa destas, foi possível identificar três categorias: Gestão do processo de cuidar; Educação à saúde dos familiares cuidadores; Processo de trabalho do enfermeiro no contexto da equipe de saúde. A partir dos resultados obtidos fica evidente a necessidade  do  enfermeiro  de  reconhecer  e  atender o idoso de  forma  integral no contexto do seu domicilio, considerando, também, a promoção à saúde, tendo neste aspecto a importância na atuação do enfermeiro(a) no atendimento domiciliar neste período de vida é muito  importante  para  promover um envelhecimento bem-sucedido

Construção do plano de parto no acompanhamento do pré-natal de risco habitual: uma revisão integrativa

Pesquisar a construção do Plano de parto no acompanhamento do pré-natal em gestantes atendidas na Atenção Primaria a saúde

Convalescent plasma for COVID-19 in hospitalised patients : an open-label, randomised clinical trial

Background: The effects of convalescent plasma (CP) therapy in hospitalised patients with coronavirus disease 2019 (COVID-19) remain uncertain. This study investigates the effect of CP on clinical improvement in these patients. Methods: This is an investigator-initiated, randomised, parallel arm, open-label, superiority clinical trial. Patients were randomly (1:1) assigned to two infusions of CP plus standard of care (SOC) or SOC alone. The primary outcome was the proportion of patients with clinical improvement 28 days after enrolment. Results: A total of 160 (80 in each arm) patients (66.3% critically ill, 33.7% severely ill) completed the trial. The median (interquartile range (IQR)) age was 60.5 (48–68) years; 58.1% were male and the median (IQR) time from symptom onset to randomisation was 10 (8–12) days. Neutralising antibody titres >1:80 were present in 133 (83.1%) patients at baseline. The proportion of patients with clinical improvement on day 28 was 61.3% in the CP+SOC group and 65.0% in the SOC group (difference −3.7%, 95% CI −18.8–11.3%). The results were similar in the severe and critically ill subgroups. There was no significant difference between CP+SOC and SOC groups in pre-specified secondary outcomes, including 28-day mortality, days alive and free of respiratory support and duration of invasive ventilatory support. Inflammatory and other laboratory marker values on days 3, 7 and 14 were similar between groups. Conclusions: CP+SOC did not result in a higher proportion of clinical improvement on day 28 in hospitalised patients with COVID-19 compared to SOC alone

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio