Developments in nanowire scanning electrochemical - atomic force microscopy (SECM-AFM) probes

Since its introduction, SECM-AFM has gained recognition as an extremely useful tool for a wide variety of analytical and imaging applications. We have developed a probe fabrication method that uses single-walled carbon nanotube bundles as a structural template for the formation of a nanowire at the apex of an AFM tip. Subsequent insulation of the probe and cutting across the nanowire yields a disc electrode of well-defined geometry. The probe apex geometry results in topographic information being obtained without causing damage to the electrode by contacting the substrate. Also, by placing the electrode at the apex, electric force imaging can also be realized. The probes are demonstrated to accurately identify active sites and locally generated species by combined topographic and electrochemical measurements on the sub-micron scale. The influence of the probe geometry on the diffusion of species from micrometer scale active sites will also be considered

High lift function of the pteroid bone and forewing of pterosaurs

The pteroid bone is a rod-like element found only in pterosaurs, the flying reptiles of the Mesozoic. It articulated at the wrist, and supported a membranous forewing in front of the inner part of the wing spar. The function of this bone, particularly its orientation, has been much debated. It is widely believed that it pointed towards the body, and that the forewing was relatively narrow. An alternative hypothesis states that it was directed forwards during flight, resulting in a much broader forewing that acted as a leading edge flap. We tested scale models in a wind tunnel to determine the aerodynamic consequences of these conflicting hypotheses, and found that performance is greatly improved if the pteroid is directed forwards: the lift : drag ratios are superior and the maximum lift is exceptionally high in comparison with conventional aerofoils. This high lift capability may have enabled even the largest pterosaurs to take off and land without difficulty

Le artroprotesi modulari nella chirurgia oncologica

Il ginocchio \ue8 la sede pi\uf9 frequentemente coinvolta nei tumori primitivi dello scheletro (60%), soprattutto a livello del femore distale. L\u2019osteosarcoma, il sarcoma di Ewing ed il condrosarcoma sono le neoplasie maligne primitive pi\uf9 comuni in questa sede. Tra le lesioni benigne ricordiamo il tumore a cellule giganti, la cisti aneurismatica ed il condroblastoma. L\u2019et\ue0 pi\uf9 colpita \ue8 quella degli adolescenti e dei giovani adulti