Autonomous Thermal-Oxidative Composition Inversion and Texture Tuning of Liquid Metal Surfaces.

Droplets capture an environment-dictated equilibrium state of a liquid material. Equilibrium, however, often necessitates nanoscale interface organization, especially with formation of a passivating layer. Herein, we demonstrate that this kinetics-driven organization may predispose a material to autonomous thermal-oxidative composition inversion (TOCI) and texture reconfiguration under felicitous choice of trigger. We exploit inherent structural complexity, differential reactivity, and metastability of the ultrathin (∼0.7-3 nm) passivating oxide layer on eutectic gallium-indium (EGaIn, 75.5% Ga, 24.5% In w/w) core-shell particles to illustrate this approach to surface engineering. Two tiers of texture can be produced after ca. 15 min of heating, with the first evolution showing crumpling, while the second is a particulate growth above the first uniform texture. The formation of tier 1 texture occurs primarily because of diffusion-driven oxide buildup, which, as expected, increases stiffness of the oxide layer. The surface of this tier is rich in Ga, akin to the ambient formed passivating oxide. Tier 2 occurs at higher temperature because of thermally triggered fracture of the now thick and stiff oxide shell. This process leads to inversion in composition of the surface oxide due to higher In content on the tier 2 features. At higher temperatures (≥800 °C), significant changes in composition lead to solidification of the remaining material. Volume change upon oxidation and solidification leads to a hollow structure with a textured surface and faceted core. Controlled thermal treatment of liquid EGaIn therefore leads to tunable surface roughness, composition inversion, increased stiffness in the oxide shell, or a porous solid structure. We infer that this tunability is due to the structure of the passivating oxide layer that is driven by differences in reactivity of Ga and In and requisite enrichment of the less reactive component at the metal-oxide interface.

Perfil y manejo del trauma torácico en un hospital regional / Management of thoracic trauma in a chilean regional hospital

El trauma constituye la principal causa de muerte en la población menor a 40 años. Un 25 por ciento de ellos, como consecuencia de una lesión torácica. El objetivo del presente trabajo es conocer y caracterizar biodemográficamente la población afectada por trauma toráxico que consulta en el Hospital Base de Osorno. Se analizaron retrospectivamente los registros clínicos de 94 pacientes con traumatismos torácicos, atendidos en el Servicio de Urgencias y Cirugía, entre enero 2003 y junio de 2004, cuyos diagnósticos de egreso fueron codificados según la Clasificación Internacional de Enfermedades (CIE 10). El 91 por ciento de los accidentados correspondió al sexo masculino, con un promedio de edad de 29,6 años (rango de 8 a 85 años). El 28 por ciento de los pacientes sufrió un traumatismo abierto, en el 96 por ciento por arma blanca. La complicación más frecuente fue un hemoneumotórax. El tratamiento en orden de frecuencia fue: médico (52 por ciento), pleurotomía percutánea con tubo (35 por ciento) y toracotomía (7 por ciento). Esta última, en el caso de hemotórax masivos y heridas penetrantes cardíacas. El período promedio de estada fue de 2.5 días, prolongándose a 5,9 días en pacientes con pleurotomía, 10 días en caso de toracotomía y hasta 14, cuando requirió estar en la Unidad de Terapia Intensiva. En un 23 por ciento hubo fracaso de la pleurotomía percutánea, correspondiendo en un 14 por ciento a drenaje inadecuado, un 5,8 por ciento a empiema pleural y un 3 por ciento a hemotórax retenido. En conclusión, nuestro manejo es similar al del medio nacional. Sin embargo, destaca una elevada frecuencia de morbilidad asociada a la realización de la pleurotomía percutánea.

Liver abscess of hydatid origin: clinical features and results of aggressive treatment.

BACKGROUND: Cyst infection and subsequent liver abscess formation are complications of liver echinococcosis. Traditionally, this condition has been treated by simple drainage, a procedure associated with unsatisfactory postoperative evolution. METHODS: The present paper examines a series of cases involving infected liver echinococcal cysts. Surgery was performed at the Temuco Regional Hospital after assessment was made of general and liver laboratory parameters, chest X-ray and abdominal ultrasound were performed and antibiotic treatment was administered. The procedure consisted of surgical drainage, parasite material extirpation and pericystic membrane resection with surrounding healthy liver parenchyma. The morbidity and mortality rate, hospital stay and evidence of recurrent hydatid disease were evaluated. RESULTS: Forty-nine patients (21 male and 28 female), with a median age of 45 years (range 16-84 years), with infected cysts measuring 14 cm in ultrasonographical diameter (range 5-30 cm) were operated on. In the majority of cases, liver abscesses were located in the right lobe (37 patients, 75.4%) and the most frequent computed tomography scan pattern was heterogeneous (40 patients, 81.6%). The median hospital stay was 5 days, the median follow-up period was 32 months (range 2-91 months) and perioperative morbidity was 24.4%. Surgical complications were verified in five patients (10.2%) and medical complications occurred in seven cases (14.3%). No recurrence of hydatid disease was observed. Mortality was 2% (one patient). CONCLUSIONS: Good results were obtained when hydatid liver abscesses were treated aggressively.