RESUMO
Thin, nano-porous, highly adherent layers of anodised aluminium formed on the surface of titanium alloys are being developed as coatings for metallic surgical implants. The layers are formed by anodisation of a 1-5 microm thick layer of aluminium which has been deposited on substrate material by electron beam evaporation. The surface ceramic layer so produced is alumina with 6-8 wt % phosphate ions and contains approximately 5 x 10(8) cm(-2) pores with a approximately 160 nm average diameter, running perpendicular to the surface. Mechanical testing showed the coatings' shear and tensile strength to be at least 20 and 10 MPa, respectively. Initial cell/material studies show promising cellular response to the nano-porous alumina. A normal osteoblastic growth pattern with cell number increasing from day 1 to 21 was shown, with slightly higher proliferative activity on the nano-porous alumina compared to the Thermanox control. Scanning electron microscopy (SEM) examination of the cells on the porous alumina membrane showed normal osteoblast morphology. Flattened cells with filopodia attaching to the pores and good coverage were also observed. In addition, the pore structure produced in these ceramic coatings is expected to be suitable for loading with bioactive material to enhance further their biological properties.
Assuntos
Materiais Biocompatíveis , Cerâmica/química , Titânio/química , Ligas , Alumínio/química , Proliferação de Células , Corantes/farmacologia , Elétrons , Humanos , Íons , Teste de Materiais , Microscopia Eletrônica de Varredura , Osteoblastos/citologia , Osteoblastos/metabolismo , Oxazinas/farmacologia , Oxirredução , Propriedades de Superfície , Fatores de Tempo , Xantenos/farmacologiaRESUMO
We studied 60 children, aged 12 months to 8 yr, undergoing plastic surgery under general anaesthesia supplemented by regional anaesthesia. Patients were allocated randomly to have the laryngeal mask airway removed either on awakening or while anaesthetized. Subsequent observation of respiratory factors and oxygen saturation showed a significant difference between the groups for coughing (P < 0.001), with a greater incidence (17 of 33) in the awake group compared with those from whom the laryngeal mask airway was removed while anaesthetized (two of 27). There were no differences in the incidences of laryngospasm, desaturation (< 95%) and excess salivation between the groups. Removed of the laryngeal mask airway during deep anaesthesia reduced coughing in the immediate postoperative period.
