Abstract In this work the behavior of NiO-PrO2-ZrO2 catalysts containing various nickel loadings was evaluated in the partial oxidation of methane and oxidative-reforming reactions of methane. The catalysts were characterized by X-Ray Diffraction Analysis (in situ-XRD), Temperature Programmed Reduction (H2-TPR), Scanning Electron Microscopy (SEM/EDX) and Adsorption-Desorption of nitrogen (BET area). The reactions were carried out at 750 °C and 1 atm for 5 hours. The catalysts were studied with different nickel content: 0, 5, 10 and 15% (related to total weight of catalyst, wt%). In both reactions, the catalyst containing the mixture of the three oxides (NiO/PrO2/ZrO2) with 15% nickel (15NiPrZr catalyst) showed the best activity for the conversion of the reactants into Syngas and showed high selectivity for H2 and CO. The results suggest that the promoter PrO2 and the Niº centers are in a good proportion in the catalyst with 15% Ni. Our results showed that low nickel concentrations in the catalyst led to high metallic dispersion; however, very low nickel concentrations did not favor the methane transformation into Syngas. The catalyst containing only NiO/ZrO2 in the mixture was not sufficient for the catalysis. The presence of the promoter PrO2 was very important for the catalysis of the POM.

INTRODUÇÃO: A utilização da via radial tem reconhecida eficácia em reduzir complicações hemorrágicas na intervenção coronária percutânea (ICP). Nas síndromes coronárias agudas (SCAs), o crossover (transição) entre a heparina de baixo peso molecular e a heparina não-fracionada aumenta o risco hemorrágico após ICP por via femoral. O objetivo deste estudo foi comparar a incidência de sangramentos em pacientes com SCA submetidos a ICP por via radial de acordo com a ocorrência, ou não, do crossover da terapia com heparina. MÉTODOS: Estudo observacional de pacientes com SCA submetidos a ICP por via radial, divididos em grupos A (no qual ocorreu crossover) e B (sem crossover). Os eventos hemorrágicos foram classificados conforme os critérios do GUSTO; para os sangramentos da via de acesso radial, foram utilizados os critérios do EASY. RESULTADOS: Foram incluídos 140 pacientes consecutivos, 74 pacientes no grupo A e 66 pacientes no grupo B, com média de idade de 59,7 ± 9,4 anos, 72,8% do sexo masculino e 21,4% diabéticos. Ocorreram seis casos de complicações hemorrágicas (4,3%), sendo duas (1,4%) classificadas pelo GUSTO como moderadas (uma hemorragia digestiva e um sangramento femoral após balão intra-aórtico) e quatro (2,9%), como leves (hematomas com diâmetro < 5 cm). Na comparação entre os grupos, sangramentos moderados ocorreram em 1,3% no grupo A e em 1,5% no grupo B (P = 0,49) e sangramentos leves, em 2,7% e em 3,1% nos grupos A e B, respectivamente (P = 0,37). CONCLUSÕES: Nesta casuística de pacientes com SCA submetidos a ICP pela via radial, foi observada baixa incidência de sangramentos, sendo a maioria das complicações hemorrágicas decorrente de pequenos hematomas da via de acesso. O crossover da terapia com heparina não conferiu risco aumentado de sangramentos após ICP pela via radial.

BACKGROUND: Radial access is effective in reducing bleeding complications in percutaneous coronary interventions (PCI). In acute coronary syndromes (ACS), the crossover from low molecular weight to unfractioned heparin increases the risk of bleeding after transfemoral PCI. The aim of this study was to evaluate the incidence of bleeding in patients with ACS undergoing PCI using the radial approach according to the occurrence or not of crossover of heparin therapy. METHODS: Observational study of patients with ACS undergoing PCI using the radial access, divided into groups: A (with crossover) and B (without crossover). Bleeding events were classified according to GUSTO criteria; EASY criteria were used for bleeding events in the radial access. RESULTS: We included 140 consecutive patients, 74 in group A and 66 in group B, with mean age of 59.7 ± 9.4 years, 72.8% were male, and 21.4% diabetic. There were six cases of bleeding complications (4.3%), and two (1.4%) were classified by GUSTO as moderate (one digestive bleeding and one femoral bleeding after intraaortic balloon pump), and four (2.9%) were classified as mild (hematomas with diameter < 5 cm). In the comparison between groups, moderate bleeding occurred in 1.3% in group A and 1.5% in group B (P = 0.49) and mild bleedings in 2.7% and 3.1% in groups A and B, respectively (P = 0.37). CONCLUSIONS: In this cohort of patients with ACS undergoing PCI using the radial access, a low incidence of bleeding events was observed, and most of these bleeding complications resulted from small hematomas of the access route. Crossover of heparin therapy did not increase the risk of bleeding after transradial PCI.

INTRODUÇÃO: O escore SYNTAX foi desenvolvido como ferramenta para graduar a complexidade angiográfica da doença arterial coronária em pacientes com acometimento de três vasos e/ou com lesão de tronco. Avaliamos seu papel em predizer desfechos clínicos após intervenção coronária percutânea (ICP) em pacientes não-selecionados, tratados na prática diária de um hospital de referência. MÉTODOS: Análise de pacientes submetidos a ICP entre março e setembro de 2009 e acompanhados por até 12 meses. Os pacientes foram divididos em tercis de acordo com o escore SYNTAX. O desfecho primário foi composto de eventos cardíacos adversos maiores (ECAM) - óbito, infarto agudo do miocárdio não-fatal e revascularização do vaso-alvo. O desempenho do escore SYNTAX em predizer ECAM foi avaliado pela curva ROC (Receiver Operator Characteristic). RESULTADOS: Foram incluídos 234 pacientes com escore SYNTAX médio de 11,6 ± 6,2 pontos. O tercil I apresentou escore SYNTAX < 9 (média de 5,9); o tercil II, > 9 e < 13 (média de 10,8); e o tercil III, > 13 (média de 18,3). No seguimento clínico de 7,2 ± 4,9 meses, a incidência de ECAM foi maior no tercil III em comparação com os tercis I e II (2,5% vs. 6,4% vs. 14,1%; P = 0,0075). A curva ROC mostrou área sob a curva de 0,667 (P = 0,012), indicando moderada capacidade de prever a ocorrência de ECAM nessa população. CONCLUSÕES: O escore SYNTAX mostrou ser útil em prever a ocorrência de ECAM em pacientes pós-ICP tratados na prática clínica diária.

BACKGROUND: The SYNTAX score was developed as an angiographic tool to grade the complexity of coronary artery disease in patients with three-vessel and/or left main disease. We evaluated its role in predicting clinical outcomes after percutaneous coronary intervention (PCI) in non-selected patients, treated in the daily clinical practice of a reference center. METHODS: Analysis of patients undergoing PCI from March to September 2009 and followed-up for up to 12 months. Patients were divided in tertiles according to the SYNTAX score. The primary endpoint included major adverse cardiac events (MACE) - death, non-fatal acute myocardial infarction and target-vessel revascularization. The ability of the SYNTAX score in predicting MACE was assessed by the ROC (Receiver Operator Characteristic) curve. RESULTS: Two hundred and thirty-four patients with a mean SYNTAX score of 11.6 ± 6.2 points were included. Tertile I had a SYNTAX score < 9 (average 5.9); tertile II, > 9 and < 13 (average 10.8); and tertile III, > 13 (average 18.3). In the clinical follow-up of 7.2 ± 4.9 months, the incidence of MACE was greater in tertile III when compared to tertiles I and II (2.5% vs. 6.4% vs. 14.1%; P = 0.0075). The ROC curve showed an area under the curve of 0.667 (P = 0.012) indicating a moderate ability to anticipate the occurrence of MACE in this population. CONCLUSIONS: The SYNTAX score proved to be seful in predicting the occurrence of MACE after PCI in real world patients.