Physio-chemical characterization of three-component co-amorphous systems generated by a melt-quench method

The purpose of this work was to evaluate the possibility of creating a ternary co-amorphous system and to determine how the properties of a co-amorphous material are altered by the addition of a selected third component. Piroxicam and indomethacin form a stable co-amorphous with the Tg above room temperature. The third component added was selected based on tendency to crystallise (benzamide, caffeine) or form amorphous (acetaminophen, clotrimazole) on cooling. Generated co-amorphous systems were characterised with TGA, HSM, DSC, FTIR, and XRD. Stable ternary co-amorphous systems were successfully generated, which was confirmed using XRD, DSC and FTIR analysis. In all cases, Tg of the ternary system was lower than the Tg of the binary system, although higher than that of the individual third compound. Upon storage for 4 weeks all created ternary systems showed significantly smaller variation in Tg compared to the binary system. Stable three-component co-amorphous systems can be generated via melt quench method using either a crystalline or amorphous third component. Addition of third component can alter the Tg of co-amorphous system and in all cases created more stable co-amorphous system upon storage. Physical parameters may not be sufficient in predicting the resulting Tg, therefore knowledge of chemical interaction must be brought into equation as well

Caracterização de aço inoxidável ASTM 138 (CrNiMo) e biocompatibilidade em parafusos de fixação de próteses

Este trabalho tem por objetivo realizar o uma análise da composição dos ele-mentos químicos dos parafusos para fixação de próteses, fabricados com aço inoxidável ASTM F138 (CrNiMo). Um parafuso para fixação de próteses quando inserido no orga-nismo humano, sofre desgastes corrosivos. O método Microscopia Eletrônica de Varre-dura (MEV) e espectroscopia de raios X por dispersão em energia (EDS), analisaram a morfologia e os elementos químicos que compõem a estrutura do parafuso de fixação de próteses. Os resultados obtidos foram comparados e analisados com as normas ASTM F138.</jats:p

Análise da biocompatibilidade de parafusos de fixação de próteses de fêmur em liga de titânio ASTM F136

A área de biomateriais passa por uma constante evolução, pois a cada ano que se passa novos biomateriais são desenvolvidos visando redução de custo, osseointegração, biocompatibilidade entre outros fatores. Neste trabalho tem por objetivo a realização da análise da composição química dos parafusos de fixação de prótese de fêmur, fabricados em liga de titânio ASTM 136. A utilização de ligas de titânio em aplicações ortopédicas, odontológicas e aeronáuticas tem aumentado nas últimas décadas. As propriedades características da liga ASTM 136 conferem boa resistência à corrosão aplicada em meios biológicos com alto grau de biocompatibilidade. Para realizar a análise dos elementos químicos que fazem parte da composição dos parafusos de fixação da prótese foram utilizados o Microscópio Eletrônico de Varredura (MEV) e a espectroscopia de raios X por dispersão em energia (EDS). Com os ensaios finalizados, os resultados foram comparados com a norma ASTM F136. Os parafuso apresentaram uma grande quantidade de Carbono e Nitrogênio, deste modo, houve um aumento da dureza do parafuso realizando uma mudança no comportamento das propriedades plásticas, fazendo com que elas diminuíssem.</jats:p

Comparison of function of passive modular exoskeletons for analysis of abduction movement and horizontal abduction of the upper limb

Stroke is one of the biggest problems of the health system in Brazil and in the world: not only due to high health costs, but also due to the treatment that does not guarantee a complete functional recovery. About 25% of the patients do not survive, and almost half of the survivors have a functional limitation of the upper and / or lower limbs. In the human body, the skeletal structure provides mechanical support for movements. On the shoulder, we find the greatest amount of degrees of articular freedom of the body - it allows arm movements in almost all directions, as well as in different angles. Compromising any of your movements directly affects autonomy in activities of daily living. The tracking of movements of the shoulder girdle and upper limbs accompanied by biomechanical assessments in the performance of activities of daily living provides support for rehabilitation. This measurement, however, is a complex activity due to the number of interdependent joints and movements. The objective of this research is to compare the readings performed on two passive exoskeletons, which measure three-dimensionally the movement of the abduction / adduction and lateral abduction joints. To acquire the signals in the mechanical structure of the equipment, a reading system by a position sensor (encoder) is placed. The acquired signals are treated with a computational tool. The data are presented in real time, with visual feedback on joint movements. In the tests performed, the exoskeleton had no mechanical limitations that prevented the measurement of movements. Keywords. Upper limb, Exoskeleton, Measurement system.</jats:p