RESUMO Este é o primeiro estudo a investigar a contaminação por mercúrio (Hg) em espécies de felinos na Amazônia brasileira. Foram coletadas 26 amostras de pelo de felinos selvagens de quatro espécies (Puma concolor, Panthera onca, Leopardus pardalis e Leopardus wiedii) ocorrendo nas reservas de desenvolvimento sustentável Mamirauá e Amanã, no estado do Amazonas. As amostras foram coletadas de espécimes de museu, exceto cinco amostras de P. onca obtidas de indivíduos capturados em vida livre. As concentrações de Hg variaram de 0,12 a 48,1 µg g-1. Não houve diferença significativa entre a concentração de Hg no pelo de espécimes de museu e de indivíduos vivos de P. onca. Houve variação significativa entre espécies, sendo que P. onca e L. pardalis tiveram concentrações significativamente mais altas, o que pode estar relacionado a fatores como dieta e hábitat.

ABSTRACT This is the first study to investigate mercury (Hg) contamination in felid species in the Brazilian Amazon. We collected 26 fur samples from wild felids of four species (Puma concolor, Panthera onca, Leopardus pardalis and Leopardus wiedii) occurring in the Mamirauá and Amanã sustainable development reserves, in the state of Amazonas. Samples were from museum specimens, except for five P. onca samples collected from free-living individuals. Total Hg concentrations ranged from 0.12 to 48.1 µg g-1. Concentrations of Hg did not differ significantly between museum specimens and live individuals of P. onca, but varied significantly among species, with significantly higher concentrations for P. onca and L. pardalis, which could be related to factors such as diet and habitat.

Abstract Nanocomposite based on high density polyethylene (HDPE) and layered zirconium phosphate organically modified with octadecylamine (ZrPOct) was obtained through melt processing. The ZrPOct was synthesized by precipitation and modified by suspension and sonication procedures. The initial and maximum degradation temperatures (Tonset and Tmax) were increased. A slight decrease of crystallinity degree was detected. Reduction of elastic modulus and elongation at break were noticed. The lamellar spacing was increased (3.3 times higher). The storage modulus decreased and low field nuclear magnetic resonance (LFNMR) revealed an increasing of molecular mobility. The presence of octadecylamine enhanced the entrance of HDPE in the ZrPOct galleries. Several characteristics of HDPE were changed indicating that intercalation was successful. All results indicated that partially intercalated and/or exfoliated nanocomposite was achieved.