Avulsión del tubérculo tibial asociada a epifisiólisis proximal de tibia

Las lesiones de la tuberosidad tibial anterior son fracturas poco frecuentes que se presentan generalmente en adolescentes. Su extensión fisaria hacia la cortical posterior constituye un hecho infrecuente. Algunos autores consideran necesaria la modificación de la clasifícacion de Watson-Jones añadiéndole un tipo IV. Se presenta un caso de epifisiólisis proximal de tibia asociada a avulsión del tubérculo tibial, se discute dicha clasificación, el mecanismo de producción y revisión de la literaturaFractures of the anterior tibial tubercle are uncommon lesions, adolescents being more frequently affected. Physeal extension through the posterior tibial cortical bone is rare. Some authors have suggested that a new type IV can be added to the Watson-Jones classiflcation. In this paper, we report a case with epiphysiolisis of the proximal tibia associated to an avulsion fracture of the anterior tibial tubercle. The Watson-Jones classiflcation, the mechanism of injury are discussed together a review of the literature

Probing the viability of oxo-coupling pathways in iridium-catalyzed oxygen evolution

[Image: see text] A series of Cp*Ir(III) dimers have been synthesized to elucidate the mechanistic viability of radical oxo-coupling pathways in iridium-catalyzed O(2) evolution. The oxidative stability of the precursors toward nanoparticle formation and their oxygen evolution activity have been investigated and compared to suitable monomeric analogues. We found that precursors bearing monodentate NHC ligands degraded to form nanoparticles (NPs), and accordingly their O(2) evolution rates were not significantly influenced by their nuclearity or distance between the two metals in the dimeric precursors. A doubly chelating bis-pyridine–pyrazolide ligand provided an oxidation-resistant ligand framework that allowed a more meaningful comparison of catalytic performance of dimers with their corresponding monomers. With sodium periodate (NaIO(4)) as the oxidant, the dimers provided significantly lower O(2) evolution rates per [Ir] than the monomer, suggesting a negative interaction instead of cooperativity in the catalytic cycle. Electrochemical analysis of the dimers further substantiates the notion that no radical oxyl-coupling pathways are accessible. We thus conclude that the alternative path, nucleophilic attack of water on high-valent Ir-oxo species, may be the preferred mechanistic pathway of water oxidation with these catalysts, and bimolecular oxo-coupling is not a valid mechanistic alternative as in the related ruthenium chemistry, at least in the present system

Active packaging films based on polyolefins modified by organic and inorganic nanoparticles

Nowadays, the use of polymer films for flexible packaging has gained a widespread importance because of their easy processing, good final properties, light weight and low relative cost. In order to fulfill the needs of increasingly demanding consumers respect to the quality of packaged products, additional capabilities must be incorporated into packaging. In this sense, academic and industrial efforts have focused on new technologies that provide a complementary functionality to the packaging performance. These emerging developments involve active and intelligent packaging, which can attract to consumers, improve product quality and/or balance any detrimental effect. In this context, the use of nanoparticle (NP) modified polyolefins, either in bulk (nanocomposites) or on the surface, allows the inclusion of specific functionalities. These new capabilities enable obtaining active packaging according to the requirements of the product. The aim of this chapter is to analyze the aforementioned approaches for the development of active films by incorporating antibacterial, antifungal and/or repellent functionalities. Currently, several sustainable developments of this type of active films are based on commodity thermoplastics such as poly(ethylene) and poly(propylene). These materials, modified by the incorporation of organic and inorganic NPs, are promising candidates since their final properties can be tailored for packaging application.Fil: Alonso, Yanela Natalin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Grafia, Ana Luisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Castillo, Luciana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Barbosa, Silvia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; Argentin