Solid-state dewetting of ultra-thin Au films on SiO2 and HfO2.

Ultra-thin Au films with thickness (h) ranging from 0.5 to 6.0 nm were deposited at room temperature (RT) by means of e-beam evaporation on SiO2 and HfO2. Due to the natural solid-state dewetting (SSD) of the as-deposited films, Au nanoparticles (NPs) were formed on the substrates. By properly adjusting the h value, the size and the density of the Au NPs can be finely tuned. For h = 0.5 nm, spherical-like Au NPs with diameter below 5 nm and density in the order of 10(12) Au NPs cm(-2) were obtained without any additional thermal treatment independently from the substrate. The dependence of the Au NPs characteristics on the substrate starts to be effective for h ≥ 1.0 nm where the Au NPs diameter is in the 5-10 nm range and the density is around 10(11) Au NPs cm(-2). The effect of a subsequent high temperature (400-800 °C) annealing in N2 atmosphere on the Au NPs was investigated as well. For h ≤ 1.0 nm, the Au NPs characteristics evidenced an excellent thermal stability. Whereas the thermal treatment affects the cristallinity of the Au NPs. For the thicker films (2.0 ≤ h ≤ 6.0 nm), the thermal treatment becomes effective to induce the SSD. The proposed methodology can be exploited for the synthesis of Au NPs with diameter below 10 nm on different substrates at RT.

Exclusive jejunal and ileal lesions due to blunt trauma.

The exclusive jejunal and ileal lesion due to blunt trauma is a rare and potentially lethal condition. The small intestine is the most damaged organ in penetrating abdominal injuries, although its isolated injury in blunt abdominal trauma is rare and difficult to diagnosed. There are no characteristic signs nor symptoms in the exclusive jejunal and ileal lesions due to abdominal contusions which result in high morbidity and mortality rates since a late diagnosis is done despite advanced auxiliary diagnostic methods available. Considering these facts, the aim of the present work is to study the prognosis of patients suffering from this type of injury due to abdominal trauma, taking into consideration the time elapsed between the trauma and its diagnosis and the importance of its early surgical correction.

Leucemia de celulas cabeludas ("hairy cell") e manifestacoes osteoarticulares. / Hairy cell leukemia and osteoarticular manifestations

Os autores, fundamentados em dados da literatura, bem como na experiencia pessoal tentaram pesquisar, nas leucemias de celulas "cabeludas", as alteracoes osteoarticulares encontradas nas leucemias. Os resultados encontrados mostraram ausencia dessas lesoes. Entretanto, ressaltam prudencia numa afirmativa definitiva, em razao do numero pequeno de casos