Balancing porosity and mechanical properties of titanium samples to favor cellular growth against bacteria

Two main problems limit the success of titanium implants: bacterial infection, which restricts their osseointegration capacity; and the stiffness mismatch between the implant and the host cortical bone, which promotes bone resorption and risk of fracture. Porosity incorporation may reduce this difference in stiffness but compromise biomechanical behavior. In this work, the relationship between the microstructure (content, size, and shape of pores) and the antibacterial and cellular behavior of samples fabricated by the space-holder technique (50 vol % NH4HCO3 and three ranges of particle sizes) is established. Results are discussed in terms of the best biomechanical properties and biofunctional activity balance (cell biocompatibility and antibacterial behavior). All substrates achieved suitable cell biocompatibility of premioblast and osteoblast in adhesion and proliferation processes. It is worth to highlighting that samples fabricated with the 100–200 μm space-holder present better mechanical behavior—in terms of stiffness, microhardness, and yield strength—which make them a very suitable material to replace cortical bone tissues. Those results exposed the relationship between the surface properties and the race of bacteria and mammalian cells for the surface with the aim to promote cellular growth over bacteria.University of Seville (Spain) VI Plan Propio de Investigación y Transferencia—US 2018, I.3A

The Natural Price Theory: Empirical Evidences of the Purchasing Power Parity and the Long Term Stock Market Function

Natural price theory suggests that the prices of all markets of the nations are interconnected. If this is correct, then the world exchange rate market and the world stock market should reflect the fact that they constitutes an organised system of rational markets with a precise and demonstrable relationship between each other

Raman Identification of Pigments in Wall Paintings of the Colonial Period from Bolivian Churches in the Ruta De La Plata

Micro-Raman spectroscopy was used to analyze and identify pigments and determine the palette of color in wall paintings from four churches of the Colonial Period, in the Bolivian highlands. The ancient churches Santiago de Callapa, Curahuara de Carangas, NuestraSeñora de Copacabana de Andamarca and San José de Soracachi were constructed during the 17th and 18th centuries, around the important colonial Ruta de la Plata, between Potosí city and Arica harbor on the Pacific coast of South America. Most pigments used in the wall paintings correspond to inorganic minerals as well as to organic colorants. Fully chlorinated copper phthalocyanine (green), copper phthalocyanine (blue), β-naphthol (yellow) and benzoimidazolone (red), were identified in the corresponding colored areas suggesting subsequent recent interventions or restorations. Ground layer materials were also characterized. The present results allow for discussion of the pictorial techniques used in the Andean highland during the colonial period and allow conservators and restorers to make important decisions regarding the type of intervention to perform in the case of these important historical and patrimonial monuments

New international financial architecture – vectors & constraints

This paper refers to organisms and international financial relationships, and deals with some recent contribution to the economic literature concerned to the financial crises. It identifies, in the conventional proposals of reordering the international financial architecture, the search for the same principles based on self-regulation, in contrast with the proposals that are based on the recognition of the intrinsic instability of the de-ruled economy. As a conclusion, the text points out some new vectors of a “new international financial architecture”, not before detaching the main constraints imposed by a reality marked by the supremacy of the liberalized and de-regulated finances

Sobre el grado de desviación de comercio en el MERCOSUR

Este artículo examina el proceso de integración en el MERCOSUR, un bloque económico regional en América del sur, formado por Brasil, Argentina, Paraguay y Uruguay. El objetivo del estudio es discutir los efectos de la formación del bloque, en términos de desviación de comercio. Para ello se analiza el comportamiento del comercio a través del análisis de siete categorías CUCI, seleccionadas según su participación en el total exportado por cada uno de los miembros del MERCOSUR. Los resultados obtenidos no confirman la existencia de desviación de comercio en el bloque. Los análisis muestran que aunque la formación del MERCOSUR haya estimulado en gran medida el flujo de comercio intraregional, no hay evidencias de que las condiciones preferenciales generadas al comercio intra-bloque hayan reducido de manera significativa el comercio con terceros países