Quantitative Kinetic Insights from Operando-UV-Vis Spectroscopy: An Application to NH3-SCR of NOx on Cu-CHA Catalysts.

We employ UV-Vis Diffuse Reflectance spectroscopy directly coupled with a packed bed flow reactor to extract quantitative kinetic information. We use as a show-case the CuII/CuI redox dynamics during the reduction half cycle of the NH3-Selective Catalytic Reduction (SCR) on Cu-CHA catalysts. Our measurements enable quantification of the fraction of oxidized Cu, reconstructed by Multivariate Curve Resolution (MCR) together with monitoring of the gas-phase evolution during the reaction. These data both on the dynamics of the gas-phase and of the active site oxidation state have been used to assess the reduction half cycle rate equation and estimate the rate constant. Our results in terms of reaction orders and kinetic constant are in line with previous findings in the literature. Overall, our results demonstrate that the combined analysis of the UV spectra and of the gas-phase dynamics provides converging and unparalleled kinetic insight: this approach effectively resolves ambiguities concerning RHC kinetics and mechanism. More in general, this work provides evidence that operando spectroscopy can be used to extract quantitative kinetic information on catalytic cycles.

Extract from Opuntia ficus-indica cladode delays the Aedes aegypti larval development by inducing an axenic midgut environment.

This study evaluated the effects of acute exposure of Aedes aegypti third instar (L3 ) larvae to the saline extract of Opuntia ficus-indica cladodes on the biological cycle and fertility of the emerging adults. For this, larvae were treated for 24 h with the extract at » LC50 (lethal concentration to kill 50% of larvae), ½ LC50 or LC50 ; the development and reproduction of the emerged adults were evaluated after a recovery period of 9 days. The resistance of proteins in the extract to hydrolysis by L3 digestive enzymes and histomorphological alterations in the larval midgut were also investigated. The extract contained lectin, flavonoids, cinnamic derivatives, terpenes, steroids, and reducing sugars. It showed a LC50 of 3.71% for 48 h. The data indicated mean survival times similar in control and extract treatments. It was observed development delay in extract-treated groups, with a lower number of adults than in control. However, the females that emerged laid similar number of eggs in control and treatments. Histological evaluation revealed absence of bacterial and fungal microorganisms in the food content in midguts from larvae treated with cladode extract. Electrophoresis revealed that three polypeptides in the extract resisted to hydrolysis by L3 digestive proteases for 90 min. The lectin activity was not altered even after 24-h incubation with the enzymes. In conclusion, the extract from O. ficus-indica can delay the development of Ae. aegypti larvae, which may be linked to induction of an axenic environment at larval midgut and permanence of lectin activity even after proteolysis.

Appraising Multinuclear Cu2+ Structure Formation in Cu-CHA SCR Catalysts via Low-T Dry CO Oxidation with Modulated NH3 Solvation.

Cu2+ ions (ZCu2+ (OH)- , Z2 Cu2+ ) are regarded as the NH3 -SCR (SCR=selective catalytic reduction) active site precursors of Cu-exchanged chabazite (CHA) which is among the best available catalysts for the abatement of NOx from Diesel engines. During SCR operation, copper sites undergo reduction (Reduction half-cycle, RHC: Cu2+ →Cu+ ) and oxidation (Oxidaton half-cycle, OHC: Cu+ →Cu2+ ) semi cycles, whose associated mechanisms are still debated. We recently proposed CO oxidation to CO2 as an effective method to probe the formation of multinuclear Cu2+ species as the initial low-T RHC step. NH3 pre-adsorption determined a net positive effect on the CO2 production: by solvating ZCu2+ (OH)- ions, ammonia enhances their mobility, favoring their coupling to form binuclear complexes which can catalyze the reaction. In this work, dry CO oxidation experiments, preceded by modulated NH3 feed phases, clearly showed that CO2 production enhancements are correlated with the extent of Cu2+ ion solvation by NH3 . Analogies with the SCR-RHC phase are evidenced: the NH3 -Cu2+ presence ensures the characteristic dynamics associated with a second order kinetic dependence on the oxidized Cu2+ fraction. These findings provide novel information on the NH3 role in the low-T SCR redox mechanism and on the nature of the related active catalyst sites.

On the Redox Mechanism of Low-Temperature NH3 -SCR over Cu-CHA: A Combined Experimental and Theoretical Study of the Reduction Half Cycle.

Cu-CHA is the state-of-the-art catalyst for the Selective Catalytic Reduction (SCR) of NOx in vehicle applications. Although extensively studied, diverse mechanistic proposals still stand in terms of the nature of active Cu-ions and reaction pathways in SCR working conditions. Herein we address the redox mechanism underlying Low-Temperature (LT) SCR on Cu-CHA by an integration of chemical-trapping techniques, transient-response methods, operando UV/Vis-NIR spectroscopy with modelling tools based on transient kinetic analysis and density functional theory calculations. We show that the rates of the Reduction Half-Cycle (RHC) of LT-SCR display a quadratic dependence on CuII , thus questioning mechanisms based on isolated CuII -ions. We propose, instead, a CuII -pair mediated LT-RHC pathway, in which NO oxidative activation to mobile nitrite-precursor intermediates accounts for CuII reduction. These results highlight the role of dinuclear Cu complexes not only in the oxidation part of LT-SCR, but also in the RHC reaction cascade.

A Trypsin Inhibitor from Moringa oleifera Flowers Modulates the Immune Response In Vitro of Trypanosoma cruzi-Infected Human Cells.

Trypanosoma cruzi causes the lethal Chagas disease, which is endemic in Latin America. Flowers of Moringa oleifera (Moringaceae) express a trypsin inhibitor (MoFTI) whose toxicity to T. cruzi trypomastigotes was previously reported. Here, we studied the effects of MoFTI on the viability of human peripheral blood mononuclear cells (PBMCs) as well as on the production of cytokines and nitric oxide (NO) by T. cruzi-infected PBMCs. Incubation with MoFTI (trypsin inhibitory activity: 62 U/mg) led to lysis of trypomastigotes (LC50 of 43.5 µg/mL) but did not affect the viability of PBMCs when tested at concentrations up to 500 µg/mL. A selectivity index > 11.48 was determined. When T. cruzi-infected PBMCs were treated with MoFTI (43.5 or 87.0 µg/mL), the release of the pro-inflammatory cytokine TNF-α and INF-γ, as well as of NO, was stimulated. The release of the anti-inflammatory cytokine IL-10 also increased. In conclusion, the toxicity to T. cruzi and the production of IL-10 by infected PBMCs treated with MoFTI suggest that this molecule may be able to control parasitemia while regulating the inflammation, preventing the progress of Chagas disease. The data reported here stimulate future investigations concerning the in vivo effects of MoFTI on immune response in Chagas disease.

Insect midgut structures and molecules as targets of plant-derived protease inhibitors and lectins.

The midgut of insects is involved in digestion, osmoregulation and immunity. Although several defensive strategies are present in this organ, its organization and function may be disturbed by some insecticidal agents, including bioactive proteins like lectins and protease inhibitors (PIs) from plants. PIs interfere with digestion, leading to poor nutrient absorption and decreasing amino acid bioavailability. Intake of PIs can delay development, cause deformities and reduce fertility. Ingestion of PIs may lead to changes in the set of proteases secreted in the insect gut, but this response is often insufficient and results in aggravation of the malnutrition status. Lectins are proteins that are able to interact with glycoconjugates, including those linked to cell surfaces. Their effects on the midgut include disruption of the peritrophic matrix, brush border and secretory cell layer; induction of apoptosis and oxidative stress; interference with nutrient absorption and transport proteins; and damaging effects on symbionts. In addition, lectins can cross the intestinal barrier and reach the hemolymph. The establishment of resistant insect populations due to selective pressure resulting from massive use of a bioactive protein is an actual possibility, but this can be minimized by the multiple mode-of-action of these proteins, mainly the lectins. © 2018 Society of Chemical Industry.

Validation of the Brazilian version of the Berg balance scale for patients with Parkinson's disease.

BACKGROUND: Changes in balance occur with the progression of Parkinson's disease (PD). OBJECTIVE: To validate the Brazilian version of the Berg Balance Scale (BBS) for PD patients, determining its reliability and internal consistency and correlating it with PD-specific instruments. METHOD: We evaluated 53 patients (M/F 37/16, mean age+/-SD, 62+/-7.9 years) with PD (mean+/-SD, 7.8+/-4.4 years). Unified Parkinson's Disease Rating Scale (UPDRS), Schwab and England Scale (SandE , Hoehn and Yahr Staging Scale (HY) and BBS were used to assess patients. Statistical analyses for inter-rater reliability, internal consistency and correlations among BBS, UPDRS, SandE and HY were performed. RESULTS: The mean scores+/-SD on UPDRS and BBS were, respectively, 41.6+/-17.8 and 47.2+/-8.2. The median on SandE and HY scales were 80% and 2.5, respectively. The BBS presented a high intra-class correlation coefficient (ICC=0.84) and internal consistency (Cronbrach's alpha=0.92). There was a statistically significant correlation between BBS and disease duration (r(s)= -0.520, p<0.001), UPDRS subscales II and III (r(s)= -0.467, p=0.011; r(s)= -0.374, p=0.046, respectively), stage of disease (HY; r(s)= -0.507, p<0.001) and the activities of daily living (SandE; r(s)=0.492, p<0.001). CONCLUSION: The BBS is a promising tool for the assessment of balance in PD, correlating with the stage of disease and the level of independence.

Validation of the brazilian version of the berg balance scale for patients with parkinson's disease / Validação da versão brasileira da Escala de Equilíbrio de Berg para pacientes com a doença de Parkinson

Background: Changes in balance occur with the progression of Parkinson's disease (PD). OBJECTIVE: To validate the Brazilian version of the Berg Balance Scale (BBS) for PD patients, determining its reliability and internal consistency and correlating it with PD-specific instruments. METHOD: We evaluated 53 patients (M/F 37/16, mean age±SD, 62±7.9 years) with PD (mean±SD, 7.8±4.4 years). Unified Parkinson's Disease Rating Scale (UPDRS), Schwab and England Scale (S&E), Hoehn and Yahr Staging Scale (HY) and BBS were used to assess patients. Statistical analyses for inter-rater reliability, internal consistency and correlations among BBS, UPDRS, S&E and HY were performed. RESULTS: The mean scores±SD on UPDRS and BBS were, respectively, 41.6±17.8 and 47.2±8.2. The median on S&E and HY scales were 80 percent and 2.5, respectively. The BBS presented a high intra-class correlation coefficient (ICC=0.84) and internal consistency (Cronbrach's α=0.92). There was a statistically significant correlation between BBS and disease duration (r s= -0.520, p<0.001), UPDRS subscales II and III (r s= -0.467, p=0.011; r s= -0.374, p=0.046, respectively), stage of disease (HY; r s= -0.507, p<0.001) and the activities of daily living (S&E; r s=0.492, p<0.001). CONCLUSION: The BBS is a promising tool for the assessment of balance in PD, correlating with the stage of disease and the level of independence.

Alterações de equilíbrio ocorrem com a progressão da doença de Parkinson (DP). Objetivo: Validar a versão brasileira da Escala de Equilíbrio de Berg (EEB) para pacientes com DP, determinando a confiabilidade, a consistência interna e correlacionando com instrumentos específicos da DP. MÉTODO: Foram avaliados 53 pacientes (H/M 37/16, idade média±DP, 62±7,9 anos) com DP (media±DP, 7,8±4,4 anos). Escala de Graduação Unificada da Doença de Parkinson (UPDRS), Escala de Schwab e England (S&E), Escala de Estágios de Hoehn e Yahr (HY) e EEB foram utilizadas. Análise estatística para confiabilidade entre examinadores, consistência interna e correlações entre EEB, UPDRS, S&E e HY foram realizadas. RESULTADOS: Os escores médios±DP nas escalas UPDRS e EEB foram, respectivamente, 41,6±17,8 e 47,2±8,2. A mediana nas escalas S&E e HY foram 80 por cento e 2,5. A EEB mostrou ter alto coeficiente de correlação intraclasse (ICC=0,84) e consistência interna (α de Cronbach=0,92). Houve correlação estatisticamente significativa entre EEB e a duração da doença (r s= -0,520, p<0,001), sub-escalas II e III do UPDRS (r s= -0,467, p=0,011; r s= -0,374, p=0,046, respectivamente), estágio da doença (HY; r s= -0,507, p<0,001), com as atividades da vida diária (S&E; r s= 0,492; p<0,001). CONCLUSÃO: A EEB é um instrumento promissor para avaliar o equilíbrio na DP, correlacionando-se com o estágio da doença e o nível de independência.

Abordagem fisioterapêutica na encefalomielite disseminada aguda ADEM: relato de um caso / The physiotherapy in the treatment of acute disseminated encephalomyelitis - (ADEM): case report

Descreve-se um caso de encefalomielite disseminada aguda (ADEM), que é uma doença auto-imune, desmielinizante aguda do sistema nervoso central. O caso apresentado é de uma paciente do sexo feminino, 2 anos de idade, que após um quadro de infecção respiratória evoluiu com atraso do desenvolvimento neurológico, hipotonia de tronco, déficit no controle cervical, hiperreflexia bilateral patelar e de aquileu, hipertonia grau 1 bilateral de bíceps e tríceps braquial, além de tibial anterior. Foi realizada por três meses fisioterapia motora para reduzir o atraso do desenvolvimento neurológico. Após os três meses de tratamento fisioterapêutico, a paciente continuou a apresentar as observações acima e, notou-se melhora na sustentação da cabeça principalmente em decúbito ventral, melhora no controle de tronco, manteve-se na posição sentada com reação de proteção anterior, adotou o rolar para ambos os lados sem ajuda do fisioterapeuta. Sendo assim, pode-se concluir que o estudo de um único caso não foi suficiente para comprovar a eficácia da fisioterapia, o que demonstra a necessidade de estudos mais completos, mas foi importante para sugerir que a abordagem fisioterapêutica pode ser útil no tratamento de pacientes com encefalomielite disseminada aguda (ADEM).

We are reporting a case of an acute disseminated encephalomyelitis (ADEM), which is an autoimmune uncommon inflammatory disease that destroys severely the myelin of the central nervous system. The case we are going to present is of a two years old, female patient that after a picture of a respiratory infection she had a delay on her neurological development, hipotomy ofher trunk, deficit control of her cervical, a deep bilateral reflex of the patellar and of the aquileu, high tonus degree one of the bilateral biceps and triceps bronchial and of the previous tibia. For three month she was under motor physiotherapy to reduce delay of the neurological development. After three months of treatment the patient continued to present a delay in the neurological development and it was noticed that she was able to sustain her head a little better even when she was laying on her stomach, she could control her trunk better when she was seated, she was able to stay seated with the reaction of previous protection, and last but not least she could roll from one side to the other without the help of a physiotherapist. Thus we can conclude that the study of one case is not enough to prove the physiotherapy efficiency, there is the need of more complete studies. We can also say that this case was important to show the need of physiotherapy in the treatment of patients with acute disseminated encephalomyelitis (ADEM).

A "Nitrate Route" for the low temperature "Fast SCR" reaction over a V2O5-WO3/TiO2 commercial catalyst.

A novel mechanism is proposed for the Fast SCR reaction of NH(3), NO and NO(2) at low temperature involving the formation of ammonium nitrate as intermediate and its subsequent reaction with NO as the rate determining step.

Levodopa effect upon functional balance of Parkinson's disease patients.

OBJECTIVE: The aim of this study was to evaluate functional balance in PD patients taking levodopa during their 'on' and 'off' phases. DESIGN: We evaluated 23 PD patients who were manifesting fluctuations of levodopa effect. All patients were assessed by Hoehn-Yahr, UPDRS-III and Schwab-England rating scales and by the Berg functional balance scale during a practically defined 'off' (at least after 12 h the last levodopa intake) and 'on' (the mobile state induced by the drug) phases. RESULTS: Mean scores obtained for all scales showed improvements during the 'on' phase of levodopa and all of the comparisons were statistically significant. Mean scores of Berg scale moved from 31.7 during the 'off' phase to 42.7 during the 'on' phase. Mean UPDRS 'off' and 'on' scores were 50.6 and 32.0, respectively. CONCLUSION: We conclude that Berg functional balance scale is able to detect changes in balance and that levodopa can modify the postural instability of PD patients.

A importancia da abordagem multimodal na fibrose cistica com enfase no desenvolvimento neuropsicomotor

Este estudo foi desenvolvido com base na observacao de cinco criancas portadoras de Fibrose Cistica (FC), na faixa etaria de 0 a 3 anos, com quadro de desnutricao secundaria e frequentes hospitalizacoes. As principais caracteristicas encontradas nestas criancas foram: hipotonia, hipotrofia de membros e uma lentidao nas respostas motoras, o que levantou a hipotese de uma possivel correlacao entre FC e atraso do desenvolvimento neuropsicomotor. Com a realizacao do estudo, esta hipotese foi parcialmente comprovada, visto que o atraso encontrado nao foi decorrente da patologia propriamente dita, mas da influencia da desnutricao e do hospitalismo, associados a variaveis como nivel socio-economico, dinamica familiar e estimulacao ambiental.

A importância da abordagem multimodal na fibrose cística, com ênfase no desenvolvimento neuropsicomotor / The importance of multimodal approach in custic fibrosis, emphasizing neuropsychomotor development

Este estudo foi desenvolvido com base na observaçäo de cinco crianças portadoras de Fibrose Cística (FC), na faixa etária de 0 a 3 anos, com quadro de desnutriçäo secundaria e frequentes hospitalizaçöes. As principais caracteristicas encontradas nestas crianças foram: hipotonia, hipotrofia de membros e uma lentidäo nas respostas motoras, o que levantou a hipótese de uma possível correlaçäo entre FC e atraso do desenvolvimento neuropsicomotor. Com a realizaçäo do estudo, esta hipótese foi parcialmente comprovada, visto que o atraso encontrado näo foi decorrente da patologia propriamente dita, mas da influência da desnutriçäo e do hospitalismo, associados a variáveis como nível sócio-econômico, dinâmica familiar e estimulaçäo ambiental