In this study, the effects of incorporating recycled photopolymer-plate residues from a packaging flexography process into polyester-glass fiber composites were examined. Ternary composites with an unsaturated polyester matrix with elastomer particles from recycled photopolymer-plate residues were evaluated using two types of glass fibers: in the forms of a fabric with bidirectional fibers and a blanket with multidirectional fibers. The composites were prepared by hand lay-up lamination using different rubber contents (0, 2.5, 5, and 10 wt% based on the polyester resin mass fraction), and were characterized for their void content, flexural and impact strengths, and dynamic mechanical properties. Primary results indicated that the incorporation of the rubber particles increased the difficulty of lamination, while promoting greater void formation with higher filler content. The rubber particles decreased the impact resistance properties but did not reduce the flexural strength or storage modulus, indicating that despite the elastomeric composition, this residue from the photopolymer plates showed a reinforcing rather than toughening character.

Abstract: Thermal analysis is a powerful tool to predict the composition and thermal stability of different materials. In this work, thermogravimetric analysis of Cedrela odorata, Marmaroxylon racemosum and Tectona grandis was carried out at four different heating rates (5°C·min-1, 10°C·min-1, 20°C·min-1 and 40°C·min-1) in a non-isothermal condition. The degradation kinetics was evaluated based on Flynn-Wall-Ozawa and Criado methods. The half-life time of wood degradation reaction was also studied. The wood thermal degradation process in an oxidizing atmosphere can be divided in dehydration, devolatilization, and combustion. The kinetic results revels apparent activation energy values of 130-240 kJ·mol-1 for Tectona grandis, 150-191 kJ·mol-1 for Marmaroxylon racemosum and 188-205 kJ·mol-1 for Cedrela odorata, when conversion values ranged from 0,1-0,5. The most probable degradation mechanism for wood species studied is a diffusion model based on a three-dimensional diffusion. Cedrela odorata presented the lowest reaction half-life time while Marmaroxylon racemosum showed the highest. On the basis of these results, it can be concluded that Flynn-Wall-Ozawa and Criado methods associated with half-life time of reaction may contribute to better understand the wood degradation before use it in polymer composites.

RESUMO: Na doença renal crônica (DRC), a hipertensão arterial é uma das complicações mais comuns, que pode estar associada a liberação dos peptídeos natriuréticos e a hipertrofia ventricular no homem. Em cães os peptídeos natriuréticos são estudados como biomarcadores cardíacos, mas ainda se desconhece sua função em cães com DRC. Desta forma, este estudo teve como objetivo relacionar a concentração sérica de peptídeo natriurético B aos achados de pressão arterial, eletrocardiográficos, eletrolíticos, hematológicos e bioquímicos séricos e urinários em cães nos distintos estágios da DRC. Foram constatadas diferenças significativas na relação de proteína creatinina urinária (UPC, p=0,006), anemia, creatinina e uréia sérica (p<0,001) nos grupos de doentes renais comparado com saudáveis. Apesar das variações de pressão arterial, amplitude e intervalo QRS e fósforo não serem significativas, foi observada tendência de alteração desses valores com o avanço da doença. Não foi observado correlação entre BNP (peptídeo natriurético cerebral) e DRC.

ABSTRACT: In chronic kidney disease (CKD) hypertension is one of the most common complications that may be associated with the release of natriuretic peptides and ventricular hypertrophy in humans. In dogs the natriuretic peptides are studied as cardiac biomarkers, but still unaware their function in dogs with CKD. Thus, this study aimed to relate the serum natriuretic peptide B with blood pressure findings, electrocardiographic, electrolyte, blood and serum and urinary biochemistry in dogs in different stages of CKD. Significant differences were found in urinary protein to creatinine ratio (UPC, p=0.006), anemia, serum creatinine and urea (p<0.001) in the group of patients with renal disease compared with the healthy group. Despite the variation in blood pressure, amplitude and QRS interval and phosphorus are not significant, a tendency for alterations of these values was observed with the advance of the disease. There was no correlation between BNP and CKD.

RESUMO: A anemia crônica é umas das complicações mais graves da doença renal crônica, contribuindo para a morbidade e mortalidade causada pela doença; Portanto, a avaliação citológica da medula óssea é necessária para monitorar a progressão da anemia. Assim, esse estudo objetivou correlacionar a anemia em cães em diferentes estágios da doença renal crônica aos achados de bioquímica sérica, mielograma e concentração sérica de eritropoietina. Sessenta e três cães foram agrupados de acordo com a classificação da International Renal Interest Society (IRIS) em estágios 1, 2, 3 e 4. Foram realizadas análises hematológicas, bioquímicas séricas e urinárias, e dosagem sérica de eritropoetina para comparação com os achados medulares obtidos por citologia aspirativa do manúbrio. Os achados citológicos de hipoplasia eritróide foram descritos em 93,65% dos cães, e a anemia foi observada em 84,1% dos cães. Os resultados hematológicos foram correlacionados com azotemia (p<0,05). Concluiu-se que a hipoplasia eritróide teve associação com a anemia persistente em cães em todas as fases de doença renal crônica, com deficiência de ferro em cães em fases iniciais e com a destruição periférica dos eritrócitos causada pela azotemia.

ABSTRACT: Chronic anaemia is one of the most severe complications of chronic kidney disease, contributing to morbidity and mortality caused by the disease; therefore, bone marrow cytological evaluation is needed to monitor the progression of anaemia. This study aimed to correlate the anaemia in dogs at different stages of chronic kidney disease with their serum biochemistry, myelogram results and serum erythropoietin findings. Sixty-three dogs were grouped according to International Renal Interest Society (IRIS) classification in stages 1, 2, 3 and 4. Haematologic, serum and urinary biochemistry and serum erythropoietin were performed for comparison with the findings of bone marrow cytology obtained by aspiration of the manubrium. Cytological findings for erythroid hypoplasia were described in 93.65% of dogs, and the anaemia was observed in 84.1% of them. The haematological findings were correlated with azotaemia (p<0.05). It was concluded that the erythroid hypoplasia has correlation with persistent anaemia in dogs at all stages of chronic kidney disease, with iron deficiency in dogs in the early stages and with peripheral destruction of erythrocytes caused by azotaemia.

O poli(fluoreto de vinilideno) (PVDF) é um polímero semicristalino contendo uma fase amorfa e uma cristalina. Essa característica é importante para o preparo de membranas assimétricas, pois a fase cristalina tem grande influência na formação da estrutura da membrana e a fase amorfa na porosidade. Membranas de PVDF foram preparadas pelo processo de inversão de fases e avaliadas quanto à permeabilidade e morfologia, bem como o efeito do tratamento térmico. Foram comparadas as seguintes membranas: membrana sem tratamento térmico, membrana com tratamento térmico e membrana comercial. Ensaios de resistência química, fluxo permeado de água a várias pressões, difusão de íons, Microscopia Eletrônica de Varredura (MEV), Calorimetria Exploratória Diferencial (DSC) e Análise Termogravimétrica (TGA) foram realizados para verificar o comportamento das membranas.

Poly(Vinylidene Fluoride) (PVDF) is a semicrystalline polymer containing an amorphous and a crystalline phase. This characteristic is important for the preparation of asymmetric membranes, because the crystalline phase has great influence on the membranes structure, while the amorphous phase affects the porosity. PVDF membranes were prepared by the phase inversion process, which were then evaluated with regard to permeability and morphology, as well as the thermal treatment effect. The following membranes were compared: without thermal treatment, with thermal treatment and commercially-available membrane. The analysis of chemical resistance, water permeability flux to different pressures and diffusion of ions, in addition to studies with Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA), were performed to investigate the membranes properties.