Incorporação de resíduos da indústria do calçado em produtos cerâmicos de construção

Desenvolveu-se um estudo de incorporação de resíduos de couro do sector do calçado em produtos cerâmicos de construção. Resíduos de couro curtido ao crómio de diversas indústrias do calçado foram triturados e incorporados até 5% em peso, na argila de produção de tijolo. Quer os provetes de controlo quer os provetes com incorporação foram submetidos a processos de secagem e cozedura idênticos aos do fabrico de tijolo, efectuando-se ensaios de resistência mecânica (flexão e compressão), eflorescência, determinação do teor em crómio no material ao longo do processo de incorporação e ensaios de lixiviação para análise de crómio nos eluatos. Nos resultados obtidos não se verificaram perdas de crómio por volatilização durante a cozedura e as concentrações de crómio nos eluatos dos ensaios de lixiviação aos provetes incorporados com resíduos são desprezáveis, indicando um processo de estabilização/retenção pelo material cerâmico do constituinte principal que confere perigosidade ao resíduo. Verificou-se uma redução generalizada nas propriedades mecânicas dos provetes-teste, resultante da carbonização do resíduo durante a cozedura, que conduz a um aumento significativo da porosidade do material, sem alterar a sua elasticidade e sem o aparecimento de eflorescências. O decréscimo da massa volúmica dos provetes-teste confere ao material vantagens em termos de isolamento térmico e acústico

Insights into improved ferroelectric and electrocaloric performance of Ba0.85Ca0.15Ti0.9Zr0.1O3 thick films grown by the electrophoretic deposition

Lead-free Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZT) bulk ceramics have recently gained attention as one of the attractive candidates for electrocaloric cooling due to their large heat absorption capacity induced by electro-structural phase transition near room temperature. However, adiabatic temperature change (ΔT) at room temperature in ceramics has been limited by their relatively low dielectric breakdown strength. Thick films, in this respect, possess the advantages of ceramics (volume) and thin films (thickness). In this work, a systematic ferroelectric and electrocaloric investigation of BCZT thick films, fabricated by electrophoretic deposition combined with laser annealing, has been carried out. Laser annealing at an optimized energy density of 398 W/cm2 has resulted in densely packed grain morphology with no compositional heterogeneities. Analysis of the scaling behavior of dynamic hysteresis revealed that ferroelectric domain reversal in BCZT/Pt has good stability and low energy consumption in the saturation region. The present thick films exhibited larger breakdown strength of 294 kV/cm and recoverable energy storage density of ~7.3 J/cm3 , at least five-fold enhancement compared to the bulk which is stable up to a 4 mm bending radius. The indirect electrocaloric measurements displayed parameters such as a ΔT and entropy change (ΔS) of 2.94 K and 3.1 J kg− 1 K− 1 respectively, for 205 kV/cm which are more than two orders increased compared to the bulk. Higher values of ΔT (1.9 K) at 25 ◦C, refrigerant capacity of 249 J/kg, and responsivity of 0.143 K mm/kV for BCZT/Pt film compared to relevant lead-free ferroelectric thick films elucidate the potential use of these films for solid-state refrigeration applications. The work also presents electrophoretic deposition with laser annealing as an alternative technique to widely studied tape-casting of thick films for electrocaloric studies.publishe

Changes in adenosine receptors and neurotrophic factors in the SOD1G93A mouse model of amyotrophic lateral sclerosis: modulation by chronic caffeine

Amyotrophic lateral sclerosis (ALS) is characterized by the progressive degeneration of corticospinal tract motor neurons. Previous studies showed that adenosine-mediated neuromodulation is disturbed in ALS and that vascular endothelial growth factor (VEGF) has a neuroprotective function in ALS mouse models. We evaluated how adenosine (A1R and A2AR) and VEGF (VEGFA, VEGFB, VEGFR-1 and VEGFR-2) system markers are altered in the cortex and spinal cord of pre-symptomatic and symptomatic SOD1G93A mice. We then assessed if/how chronic treatment of SOD1G93A mice with a widely consumed adenosine receptor antagonist, caffeine, modulates VEGF system and/or the levels of Brain-derived Neurotrophic Factor (BDNF), known to be under control of A2AR. We found out decreases in A1R and increases in A2AR levels even before disease onset. Concerning the VEGF system, we detected increases of VEGFB and VEGFR-2 levels in the spinal cord at pre-symptomatic stage, which reverses at the symptomatic stage, and decreases of VEGFA levels in the cortex, in very late disease states. Chronic treatment with caffeine rescued cortical A1R levels in SOD1G93A mice, bringing them to control levels, while rendering VEGF signaling nearly unaffected. In contrast, BDNF levels were significantly affected in SOD1G93A mice treated with caffeine, being decreased in the cortex and increased in spinal the cord. Altogether, these findings suggest an early dysfunction of the adenosinergic system in ALS and highlights the possibility that the negative influence of caffeine previously reported in ALS animal models results from interference with BDNF rather than with the VEGF signaling molecules.info:eu-repo/semantics/publishedVersio

Primeiro registro da broca Homalinotus Depressus L. (Coleoptera: Curculionidae: Cholini) em plantas de cocus nucifera no Estado do Pará.

Resumo 1496-1

How are the portuguese coping with the mandatory confinement by COVID-19?: association between mental health and coping strategies

INTRODUCTION: The global COVID-19 pandemic has had an unprecedented effect on human behaviour and wellbeing. However, researchers have not yet considered how coping responses to stress related to COVID-19 could influence mental health. OBJECTIVES: This study aims to evaluate the mental health status of Portuguese during the national lockdown; examine how study participants cope with stress during the national lockdown; and assess the association between coping and mental health status. METHODS: We cross sectionally analysed data from a convenience sample of 430 adults living in Portugal. Mental health was measured using the five-item Mental Health Inventory. Coping strategies were assessed using the Brief COPE. We examine the univariate associations between mental health status and coping responses. We performed a multiple hierarchical regression analysis controlling for sex and age, to test the predictive importance of coping responses on mental health status. RESULTS: Participants’ mental health was lower than the cut-off point for poor mental health (p<.001). The use of instrumental support, emotional support, self-blame, venting, denial, behavioral disengagement, and substance use were positively significantly associated with mental health, while active coping, positive reframing, acceptance, and humor were negatively significantly associated with mental health. The multiple hierarchical regression analyses showed that sex and age accounted for 6% of the variance of mental health. Coping strategies accounted for an additional and statistically significant 30% of the variance of mental health. CONCLUSIONS: The findings provide support for the impact of the coping strategies on mental health. We encourage future research on the present topic

Seguimento a Longo Prazo da Ablação de Arritmias Ventriculares com Origem na Câmara de Saída Ventricular Baseada em Mapeamento Não Contacto por Balão Multi-Elétrodos

Introduction: The outflow tract (OT) regions of the ventricles are a common location of origin for idiopathic ventricular arrhythmias (VA). Non-contact mapping (NCM) with a multi-electrode balloon catheter Ensite-Array enables three-dimensional reconstruction of the geometry of the cardiac chambers and accurate mapping of the propagation map, based on a single beat analysis, facilitating the ablation and contributing procedure success. Objective: Assessment of the feasibility and long-term outcomes following NCM-guided OT VA ablation. Methods: Single center retrospective analysis of patients admitted for symptomatic OT VA ablation. Demographic and clinical characteristics of patients, procedure data and long-term outcomes were assessed. Results: Fifty-eight patients (79.3% female, age 43.9±17.6 years) were considered, 89.7% without structural heart disease. In 85.7% of the cases left ventricle ejection fraction (LVEF) was preserved (LVEF≥50%), 8.6% had mild systolic dysfunction (LVEF 40%-49%) and 5.7% had moderate systolic dysfunction (LVEF 30%-39%). Twenty-four-hour Holter recording documented sustained VA episodes in 12.1% of the patients, non-sustained VA in 31.0%, and >10 000 premature ventricular complex (PVC)/24 h in 56.9%, with an ECG suggesting right ventricular OT origin in 84.5%. There was total elimination of PVC in 87.9% cases and a significant reduction in 3.4%. During a mean follow-up of 5.5 years, 87.9% patients remained asymptomatic without medication, 12.1% underwent re-ablation due to symptomatic PVC recurrence, and two cases underwent a third successful intervention. Conclusion: Non-contact mapping-guided multi-electrode balloon catheter VA ablation is a highly effective and safe procedure, with a low rate of long-term recurrence.info:eu-repo/semantics/publishedVersio

Geoenvironmental study of gold mining tailings in a circular economy context: Santa Barbara, Minas Gerais, Brazil

We characterized the tailings from the Santa Barbara tailings dam, which is located in Minas Gerais, southeastern Brazil, to: (i) identify its chemical, mineralogical, and metallurgical properties, and (ii) perform an environmental evaluation of the water at the surface of the tailings facility. The potential recovery of elements such as Sb, As, and Au was also considered for potential tailings reuse. The water was alkaline, with maximum pH values of ≈ 10, and contained potentially toxic elements, such as Sb (up to 0.500 mg/L), As (up to 0.080 mg/L), and Cu (up to 20 mg/L). Gold enrichment areas were found in the tailings dam, with concentrations up to 0.5 g/t. Alignment exists among tailings management, demand for critical raw materials, and increased interest in the processing of low-grade ores and mining waste, which is important in the context of the circular economy. They suggest that valorisation of tailings, although challenging, can be achieved by economic recovery of the more valuable metals.This work was funded the Fundação para a Ciência e a Tecnologia (FCT) through projects UIDB/04683/2020, UIDP/04683/2020, Nano-MINENV 029259 (PTDC/CTAAMB/29259/2017), and by AngloGold Ashanti Brazil

Ocorrência de Faustinus apicalis (Faust) (Coleoptera: Curculionidae) e Nealcidion bicristatum (Bates) (Coleoptera: Cerambycidae) em solanáceas no norte do Brasil.

Os besouros Faustinus apicalis (Faust) (Curculionidae) e Nealcidion bicristatum (Bates) (Cerambycidae) foram observados atacando solanáceas no estado do Tocantins, norte do Brasil, nos meses de julho a setembro de 2015. Adultos e larvas de F. apicalis e N. bicristatum foram registrados atacando simultaneamente cultivos comerciais de jiló (Solanum aethiopicum L.) e berinjela (Solanum melongena L.). De acordo com a intensidade do ataque, os besouros causaram injúrias ou a morte das plantas. Larvas de N. bicristatum também foram observadas atacando plantas de jurubeba (Solanum paniculatum L.) localizadas próximas aos cultivos estudados. Este é o primeiro registro de F. apicalis atacando cultivos de berinjela no Brasil, além do primeiro registro de ocorrência de F. apicalis e N. bicristatum no norte do Brasil