Physical and chemical properties of orthodontic brackets after 12 and 24 months: in situ study

Objective: The aim of this article was to assess how intraoral biodegradation influenced the surface characteristics and friction levels of metallic brackets used during 12 and 24 months of orthodontic treatment and also to compare the static friction generated in these brackets with four different methods of the ligation of orthodontic wires. Material and Methods: Seventy premolar brackets as received from the manufacturer and 224 brackets that were used in previous orthodontic treatments were evaluated in this experiment. The surface morphology and the composition of the deposits found in the brackets were evaluated with rugosimetry, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Friction was analyzed by applying tensile tests simulating sliding mechanics with a 0.019x0.025" steel wire. The static friction levels produced by the following ligation methods were evaluated: loosely attached steel ligature around all four bracket wings, steel ligature attached to only two wings, conventional elastomeric ligation around all 4 bracket wings, and non-conventional Slide® elastomeric ligature. Results: The results demonstrated the presence of biodegradation effects such as corrosion pits, plastic deformation, cracks, and material deposits. The main chemical elements found on these deposits were Carbon and Oxygen. The maximum friction produced by each ligation method changed according to the time of intraoral use. The steel ligature loosely attached to all four bracket wings produced the lowest friction levels in the new brackets. The conventional elastic ligatures generated the highest friction levels. The metallic brackets underwent significant degradation during orthodontic treatment, showing an increase in surface roughness and the deposit of chemical elements on the surface. Conclusion: The levels of static friction decreased with use. The non-conventional elastic ligatures were the best alternative to reduce friction

Decision-making on the optimum timing for nitrogen fertilization on sugarcane ratoon

Low efficiency of nitrogen from fertilizers is a major concern worldwide, threatening the sustainability of sugarcane production. The N use efficiency (NUE) by sugarcane can be improved by adopting better fertilizing management practices, reducing environmental impacts. This work evaluated the effects of varying N rates and time of application on stalks and sugar yield in ratoon harvested early in the crop season. The experimental design was a randomized block in a 2 × 4 factorial design and a control (no N) with five replications, including two application times (45 or 90 DAH – days after harvest) and four N rates (50, 100, 150, or 200 kg N ha–1). The time of N fertilizer application promoted differences in stalk yield, as the cumulative yield of two harvests was increased by 8 % (15 Mg ha–1) at 45 DAH when compared to the application at 90 DAH. The application performed at 45 DAH augmented sugar yield by 10 % (2.8 Mg ha–1 of sugar) in relation to 90 DAH. The N rates that promoted the highest sugarcane yield were, respectively, 122 and 144 kg N ha–1 in the first and second crop cycles. The average economical rates obtained for the first and second agricultural cycles were, respectively, 104 and 127 kg N ha–1, demonstrating that the gains by applying high amounts of fertilizers (rates above 150 kg N ha–1) may not cover the investment

Impact of MELD allocation policy on survival outcomes after liver transplantation: a single-center study in northeast Brazil

OBJECTIVE: To analyze the impact of model for end-stage liver disease (MELD) allocation policy on survival outcomes after liver transplantation (LT). INTRODUCTION: Considering that an ideal system of grafts allocation should also ensure improved survival after transplantation, changes in allocation policies need to be evaluated in different contexts as an evolutionary process. METHODS: A retrospective cohort study was carried out among patients who underwent LT at the University of Pernambuco. Two groups of patients transplanted before and after the MELD allocation policy implementation were identified and compared using early postoperative mortality and post-LT survival as end-points. RESULTS: Overall, early postoperative mortality did not significantly differ between cohorts (16.43% vs. 8.14%; p = 0.112). Although at 6 and 36-months the difference between pre-vs. post-MELD survival was only marginally significant (p = 0.066 and p = 0.063; respectively), better short, medium and long-term post-LT survival were observed in the post-MELD period. Subgroups analysis showed special benefits to patients categorized as nonhepatocellular carcinoma (non-HCC) and moderate risk, as determined by MELD score (15-20). DISCUSSION: This study ensured a more robust estimate of how the MELD policy affected post-LT survival outcomes in Brazil and was the first to show significantly better survival after this new policy was implemented. Additionally, we explored some potential reasons for our divergent survival outcomes. CONCLUSION: Better survival outcomes were observed in this study after implementation of the MELD criterion, particularly amongst patients categorized as non-HCC and moderate risk by MELD scoring. Governmental involvement in organ transplantation was possibly the main reason for improved survival

Distribución geográfica de la hemoglobinopatía recién nacida en Teresina, PiauíDistribución geográfica de la hemoglobinopatía recién nacida en Teresina, Piauí

O presente estudo busca determinar a distribuição geográfica de hemoglobinas variantes HbS, HbC, HbD, bem como pacientes diagnosticados com doença falciforme em um laboratório de saúde pública no município de Teresina - Piauí a partir do programa de triagem neonatal. Foi realizado um estudo de caráter descritivo, transversal, observacional e retrospectivo com abordagem quantitativa, baseando-se por meio de dados secundários fornecidos pelo Laboratório Central de Saúde Pública do Estado do Piauí (LACEN-PI). Foram analisados os bancos de dados da triagem neonatal tendo como amostra todos os recém-nascidos que realizaram o teste de triagem neonatal na rede de coleta conveniada no período de janeiro de 2018 a agosto de 2019. Cerca de 17.236 amostras foram analisadas do município de Teresina (25,3% total analisado) e organizadas de acordo com as zonas administrativas municipal. Este estudo permitiu traçar um mapa no município teresinense mostrando as zonas que apresentam maior incidência de hemoglobinopatias.The present study aims to determine the geographical distribution of HbS, HbC, HbD variant hemoglobins, as well as patients diagnosed with sickle cell disease in a public health laboratory in the municipality of Teresina - Piauí, based on the neonatal screening program. A descriptive, cross-sectional, observational and retrospective study with a quantitative approach was conducted, based on secondary data provided by the Central Public Health Laboratory of the State of Piauí (LACEN-PI). The neonatal screening databases were analyzed, and all newborns who underwent the neonatal screening test in the agreed collection network from January 2018 to August 2019 were sampled. About 17,236 samples were analyzed from the municipality of Teresina (25,3% total analyzed) and organized according to the municipal administrative zones. This study allowed us to draw a map in the municipality of teresinense showing the areas with the highest incidence of hemoglobinopathies.El presente estudio tiene como objetivo determinar la distribución geográfica de las hemoglobinas variantes HbS, HbC, HbD, así como a los pacientes diagnosticados con enfermedad de células falciformes en un laboratorio de salud pública en el municipio de Teresina - Piauí, según el programa de detección neonatal. Se realizó un estudio descriptivo, transversal, observacional y retrospectivo con un enfoque cuantitativo, basado en datos secundarios proporcionados por el Laboratorio Central de Salud Pública del Estado de Piauí (LACEN-PI). Se analizaron las bases de datos de detección neonatal y se tomaron muestras de todos los recién nacidos que se sometieron a la prueba de detección neonatal en la red de recolección acordada desde enero de 2018 hasta agosto de 2019. Se analizaron alrededor de 17.236 muestras del municipio de Teresina (25,3% total analizado) y organizado según las zonas administrativas municipales. Este estudio nos permitió dibujar un mapa en el municipio de teresinense que muestra las áreas con mayor incidencia de hemoglobinopatías

A model for the prediction of the punching resistance of steel fibre reinforced concrete slabs centrically loaded

With the aim of contributing for the development of design guidelines capable of predicting with high accuracy the punching resistance of steel fibre reinforced concrete (SFRC) flat slabs, a proposal is presented in the present paper and its predictive performance is assessed by using a database that collects the experimental results from 154 punching tests. The theoretical fundaments of this proposal are based on the critical shear crack theory proposed by Muttoni and his co-authors. The proposal is capable of predicting the load versus rotation of the slab, and attends to the punching failure criterion of the slab. The proposal takes into account the recommendations of the most recent CEB-FIP Model Code for modelling the post-cracking behaviour of SFRC. By simulating the tests composing the collected database, the good predictive performance of the developed proposal is demonstrated.Fundação para a Ciência e a Tecnologia (FCT

Pharmaceutical development of tablets containing a spray-dried optimized extract from Lippia origanoides H. B. K.: influence of excipients and toxicological assessment

Lippia origanoides is a honey shrub which has showed hypotensive potential assessed by in vivo studies. The aim of this work is the development of a pharmaceutical formulation composed by an optimized extract obtained from aerial parts of L. origanoides. The quantification of the naringenin marker in the dry extract and tablets developed was performed, as well as the assessment of the oral acute toxicity in rats. The hydroalcoholic extract of L. origanoides was spray-dried with the addition of colloidal silicon dioxide (Lo-HAE/CSD), and then applied in the preparation of eight different lots of tablets. The influence of the diluent (cellulose or babassu mesocarp), the presence of binder, and the percentage of lubricant, as well as organoleptic and physicochemical characteristics were screened. For the quantification of the marker content both in Lo-HAE/CSD and in the tablets, an analytical curve of the naringenin standard was fitted, and the samples were then analyzed in UFLC. The toxicological assessment was performed in female Wistar rats according to the Acute Toxic Class Method from OECD. The developed tablets produced meet acceptable macroscopic characteristics, and the presence of babassu as diluent provided improved physicochemical properties. The best content of Lo-HAE/CSD in the tablet (100.27%) was identified for the lot containing babassu, composed by 1.0% magnesium stearate, without PVP binder in its formulation. Moreover, Lo-HAE/CSD showed no signs of toxicity. Therefore, the babassu mesocarp powder is a promising pharmaceutical excipient for the development of herbal tablets containing the Lippia origanoides extract

Impact of MELD allocation policy on survival outcomes after liver transplantation: a single-center study in northeast Brazil

OBJECTIVE: To analyze the impact of model for end‐stage liver disease (MELD) allocation policy on survival outcomes after liver transplantation (LT). INTRODUCTION: Considering that an ideal system of grafts allocation should also ensure improved survival after transplantation, changes in allocation policies need to be evaluated in different contexts as an evolutionary process. METHODS: A retrospective cohort study was carried out among patients who underwent LT at the University of Pernambuco. Two groups of patients transplanted before and after the MELD allocation policy implementation were identified and compared using early postoperative mortality and post‐LT survival as end‐points. RESULTS: Overall, early postoperative mortality did not significantly differ between cohorts (16.43% vs. 8.14%; p = 0.112). Although at 6 and 36‐months the difference between pre‐ vs. post‐MELD survival was only marginally significant (p = 0.066 and p = 0.063; respectively), better short, medium and long‐term post‐LT survival were observed in the post‐MELD period. Subgroups analysis showed special benefits to patients categorized as non‐hepatocellular carcinoma (non‐HCC) and moderate risk, as determined by MELD score (15‐20). DISCUSSION: This study ensured a more robust estimate of how the MELD policy affected post‐LT survival outcomes in Brazil and was the first to show significantly better survival after this new policy was implemented. Additionally, we explored some potential reasons for our divergent survival outcomes. CONCLUSION: Better survival outcomes were observed in this study after implementation of the MELD criterion, particularly amongst patients categorized as non‐HCC and moderate risk by MELD scoring. Governmental involvement in organ transplantation was possibly the main reason for improved survival

Encefalite de Rasmussen de início tardio: relato de caso

A encefalite de Rasmussen é uma síndrome rara, imunomediada, que afeta principalmente a faixa pediátrica. Cursa com epilepsia focal farmacorresistente, acometimento motor e cognitivo. No relato de caso temos uma paciente que apresentou crises convulsivas focais de difícil controle mais tardiamente, aos 15 anos, com déficits motor e cognitivo discretos. A RM de crânio mostrou atrofia cortical mais significativa em hemisfério esquerdo. O diagnóstico foi difícil de ser realizado, tendo em vista ser uma doença rara e a manifestação tardia ser atípica, no entanto foi possível após realização do EEG, que foi característico da doença

Population-based seroprevalence of SARS-CoV-2 and the herd immunity threshold in Maranhão

OBJECTIVE: To estimate the seroprevalence of SARS-CoV-2 in the state of Maranhão, Brazil. METHODS: A population-based household survey was performed, from July 27, 2020 to August 8, 2020. The estimates considered clustering, stratification and non-response. Qualitative detection of IgM and IgG antibodies was performed in a fully-automated Elecsys® Anti-SARS-CoV-2 electrochemiluminescence immunoassay on the Cobas® e601 analyzer (Roche Diagnostics). RESULTS: In total, 3,156 individuals were interviewed. Seroprevalence of total antibodies against SARS-CoV-2 was 40.4% (95%CI 35.6-45.3). Population adherence to non-pharmaceutical interventions was higher at the beginning of the pandemic than in the last month. SARS-CoV-2 infection rates were significantly lower among mask wearers and among those who maintained social and physical distancing in the last month compared to their counterparts. Among the infected, 26.0% were asymptomatic. The infection fatality rate (IFR) was 0.14%, higher for men and older adults. The IFR based on excess deaths was 0.28%. The ratio of estimated infections to reported cases was 22.2. CONCLUSIONS: To the best of our knowledge, the seroprevalence of SARS-CoV-2 estimated in this population-based survey is one of the highest reported. The local herd immunity threshold may have been reached or might be reached soon.OBJECTIVE: To estimate the seroprevalence of SARS-CoV-2 in the state of Maranhão, Brazil. METHODS: A population-based household survey was performed, from July 27, 2020 to August 8, 2020. The estimates considered clustering, stratification and non-response. Qualitative detection of IgM and IgG antibodies was performed in a fully-automated Elecsys® Anti-SARS-CoV-2 electrochemiluminescence immunoassay on the Cobas® e601 analyzer (Roche Diagnostics). RESULTS: In total, 3,156 individuals were interviewed. Seroprevalence of total antibodies against SARS-CoV-2 was 40.4% (95%CI 35.6-45.3). Population adherence to non-pharmaceutical interventions was higher at the beginning of the pandemic than in the last month. SARS-CoV-2 infection rates were significantly lower among mask wearers and among those who maintained social and physical distancing in the last month compared to their counterparts. Among the infected, 26.0% were asymptomatic. The infection fatality rate (IFR) was 0.14%, higher for men and older adults. The IFR based on excess deaths was 0.28%. The ratio of estimated infections to reported cases was 22.2. CONCLUSIONS: To the best of our knowledge, the seroprevalence of SARS-CoV-2 estimated in this population-based survey is one of the highest reported. The local herd immunity threshold may have been reached or might be reached soon