Structure–properties relationships in fibre drawing of bioactive phosphate glasses

New bioactive phosphate glasses suitable for continuous fibre production are investigated in this work. The structure of both bulk and fibres from Na2O–CaO–MgO–P2O5 glasses has been studied by means of Raman and 31P and 23Na nuclear magnetic resonance spectroscopies, and the structural results have been correlated with the mechanical properties of the fibres and the dissolution rate of the bulk glasses. It has been observed that the mechanical properties of the phosphate glass fibres are influenced by the glass network connectivity, while the dissolution rates are governed by the Qi speciation of the PO4 units. As seen in previous studies, molar volume seems to play an important role in the fragility behaviour of phosphate glasses. Here, a lower molar volume resulting from the increase in the oxygen packing density hinders the cooperative flow of the PO4 units throughout the glass network and, therefore, causes a reduction in the kinetic fragility

Artroplastia total de disco cervical com prótese de Bryan: resultados clínicos e funcionais Artroplastía cervical total con prótesis de Bryan: resultados clínicos y funcionales Cervical total disc arthroplasty with Bryan disc: clinical and functional outcomes

OBJETIVO: Avaliar resultados da artroplastia total disco cervical com a prótese de Bryan para tratamento da cervicobraquialgia (radiculopatia) e da mielopatia compressiva. MÉTODOS: No período de 2002 a 2007, a equipe da CECOL operou 65 pacientes. Somente 28 pacientes foram localizados em 2010 para uma nova coleta de dados. Foi feita avaliação pré e pós-operatória, utilizando-se o questionário CSOQ (Cervical Spine Outcomes Questionnaire). Os critérios de Odom foram utilizados somente na avaliação pós-operatória. Ambos foram traduzidos e adaptados para cultura local. RESULTADOS: Houve melhora funcional e sintomática significativa na maioria dos pacientes. A atenuação da dor cervical (axial) e braquial (radicular) foi semelhante. Os critérios Odom indicaram 82,1% de bons e ótimos resultados, 10% satisfatórios e 7% ruins. Houve apenas uma complicação (3%), que foi revertida com a artrodese anterior. CONCLUSÕES: A artroplastia total de disco cervical demonstrou ser um método seguro e eficaz para tratamento de casos selecionados de hérnia de disco cervical associada a radiculopatia e/ou mielopatia a curto e médio prazo.<br>OBJETIVO: Evaluar los resultados de la artroplastia discal cervical con la prótesis de Bryan para el tratamiento del radiculopatía y compresión de la médula espinal (mielopatía). MÉTODOS: El equipo de CECOL ha operado 65 pacientes en el período de 2002 a 2007. Sólo 28 pacientes fueron localizados en 2010 para una nueva recolección de datos. La evaluación pre y postoperatoria se realizó mediante un cuestionario CSOQ (Cervical Spine Outcomes Questionnaire). Los criterios de Odom sólo fueron utilizados en la evaluación postoperatoria. Ambos fueron traducidos y adaptados a la cultura local. RESULTADOS: Hubo una mejora significativa sintomática y funcional en la mayoría de los pacientes. La atenuación del dolor de cuello (axial) y braquial (radicular) fue similar. Los criterios Odom demostraron 82,1% de resultados buenos y excelentes, 10% satisfactorios y el 7% malos. Hubo sólo una complicación (3%), que se revirtió con artrodesis anterior. CONCLUSIONES: La artroplastia discal cervical ha demostrado ser un método seguro y eficaz para el tratamiento de casos seleccionados de hernia de disco cervical asociada a la radiculopatía y/o a compresión de la médula espinal en el corto y mediano plazo.<br>OBJECTIVE: To evaluate results of cervical disc arthroplasty with the Bryan prosthesis for treatment of cervicobrachial pain (radiculopathy) and spinal cord compression (myelopathy). METHODS: From 2002 to 2007, the CECOL surgical staff has operated 65 patients. Only 28 patients were found in 2010 to a new data collection. The pre- and post-operative evaluation was conducted using the CSOQ questionnaire (Cervical Spine Outcomes Questionnaire). Odom criteria were used only in the postoperative evaluation. Both were translated and adapted to local culture. RESULTS: There was a significant symptomatic and functional improvement in most patients. The reduction of neck pain (axial) and brachial pain (radicular) was similar. Odom criteria showed 82.1% good and excellent results, 10% satisfactory and 7% poor. There was only one complication (3%) which was reversed with anterior arthrodesis. CONCLUSIONS: The total cervical disc arthroplasty has proved to be a safe and effective method to treat selected cases of cervical disc herniation with radiculopathy and/or myelopathy in the short and medium term