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Foram avaliados os níveis de exposição e dos efeitos causados por emissões na atmosfera de mercúrio metálico proveniente de casas compradoras de ouro na população do Município de Poconé, Estado de Mato Grosso. O projeto foi desenvolvido através da comparação da morbidade referida, dos exames clínicos e da análise dos teores de mercúrio na urina de três grupos populacionais. As análises dos teores de mercúrio na urina mostraram diferenças altamente significativas entre os grupos centro e periferia em comparação ao grupo-controle. Entrevistas com as pessoas que apresentavam teores elevados evidenciaram que a exposição no centro da cidade poderia ser proveniente das casas compradoras de ouro e, no caso da periferia, poderia ter ocorrido exposição através da queima de amálgamas no interior das residências. Os dados de morbidade referida apresentaram proporções maiores de queixas entre os moradores do centro em comparação aos outros grupos e também maior número de alterações no exame clínico. Conclui-se que há maiores exposição e efeitos à saúde devido ao mercúrio metálico entre pessoas pertencentes aos primeiros dois grupos.

Different zirconia porous layers were produced on zirconia dense zirconia substrates by slip casting using powder with different mean sizes: 40 μm (Z40), 70 μm (Z70), and 100 μm (Z100). The dynamic and static coefficients of friction against bovine femoral bone, mimicking the implantation process, were conducted using a ball‐on‐flat reciprocating sliding tribometer under 3 N of normal load. Additionally, the porous layers were assessed with regard to their low temperature degradation (aging). Results revealed that the porous layers were able to keep their integrity during the sliding testes against bone, with no zirconia particles being transferred to the bone. Results did not show significant differences (p > 0.05) in kinetic and static COF values for Z40, Z70, Z100, and GRAD specimens, ranging from 0.53 to 0.77 and 0.65 to 0.90, respectively. The aging tests revealed that all surfaces were prone to low temperature degradation (~49% of monoclinic content after 18 h). In conclusion, the cohesive integrity of the layers and relatively high COF observed reveled that zirconia porous layers may be considered for replacing the current implant surfaces, and are expected to improve their primary stability. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1113–1121, 2019. [ABSTRACT FROM AUTHOR]

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Abstract: Titanium and its alloys have been widely used in many engineering areas due to their properties. Despite having a high implant‐tissue osseointegration time, Ti6Al4V has been extensively used in prosthesis and articular implants. To promote a faster bone ingrowth and consequently reduce the implant fixation time, the addition of a bioactive phase to form a biocomposite seems to be an excellent solution. Because of their bioactivity and similarity in composition with the human bone, HAp and β‐TCP are two of the most widely used calcium phosphates in biomedical applications. To guarantee a strong adhesion of the previous bioactive materials in the implants surface, samples of Ti6Al4V, Ti6Al4V+HAp (10 vol %) and Ti6Al4V+β‐TCP (10 vol %) TCP were processed by the hot pressing technique. Tribological tests against Al2O3, lubricated in PBS at 37°C were carried out on a ball‐on‐flat reciprocating sliding geometry. Loads in the range of 3 N to 30 N were applied and their effect on the friction behavior and wear resistance of the tested materials was evaluated. Values of the coefficient of friction as well as the wear rate tend to increase with the addition of a bioactive phase to the Ti alloy. Micrographs of the worn surfaces showed that abrasion and plastic deformation are the prevailing wear mechanisms in the studied tribosystems. For biocomposites, particularly in the case of Ti6Al4V+HAp, pull‐out of bioactive particle clusters has a determinant role on the tribological response, increasing both the friction coefficient and the specific wear rate. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1010–1016, 2018. [ABSTRACT FROM AUTHOR]