Almost thirty years after the discovery of quasicrystals and after the Nobel Prize in Chemistry awarded to their discoverer, this short paper reviews the quasicrystals from a particular point of view. In the present paper the state of the art knowledge of quasicrystals is presented starting from their discovery and finishing with their manipulation at the nanoscopic scale.

Almost thirty years after the discovery of quasicrystals and after the Nobel Prize in Chemistry awarded to their discoverer, this short paper reviews the quasicrystals from a particular point of view. In the present paper the state of the art knowledge of quasicrystals is presented starting from their discovery and finishing with their manipulation at the nanoscopic scale.

Almost thirty years after the discovery of quasicrystals and after the Nobel Prize in Chemistry awarded to their discoverer, this short paper reviews the quasicrystals from a particular point of view. In the present paper the state of the art knowledge of quasicrystals is presented starting from their discovery and finishing with their manipulation at the nanoscopic scale.

The objective of this literature review is to identify the different sources for obtaining hydroxyapatite (HAP) from natural residues in order to use it as dental bone grafts. Hydroxyapatite can be classified according to its sources of origin as synthetic or biological; Among the sources of biological origins we can find of animal origin, aquatic origin, coral origin, egg shell origin and plant origin. The different types of synthesis available in the literature are described for obtaining hydroxyapatite from each natural source and its behavior as a bone filling material. The natural sources for obtaining hydroxyapatite from organic waste reduce the environmental impact (bio-waste) in addition to having multiple properties that are biocompatible with human bone tissue.

In this paper, we report on the bacterial growth inhibitory activity of nanoparticles of cemented and commercial copper. Strains of Staphylococcus aureus ATCC 6538 (Gram positive) and Escherichia coli ATCC 35218 (Gram negative) were used to determine the inhibitory effect by the minimal inhibitory concentration of the nanoparticles diluted in nutrient culture broth and distributed in ELISA plates. The copper cements (obtained from hydrometallurgical processes) and the commercial one were nanostructured employing a mechanical milling equipment. The results indicate that commercial copper nanoparticles (after 2.5 hours of milling) show growth inhibitory action of S. aureus strain. However, in the case of E. coli strains no inhibitory action has been observed. It was also determined that the minimal inhibitory concentration of the commercial copper is 20 μg/mL against S. aureus. On the oth...

En el presente trabajo se reporta la actividad inhibitoria del crecimiento bacteriano por nanopartículas de cobre cementado y de cobre comercial. Se utilizaron las cepas de Staphylococcus aureus ATCC 6538 (Gram positiva) y Escherichia coli ATCC 35218 (Gram negativa) para determinar el efecto inhibitorio mediante la concentración mínima inhibitoria de las nanopartículas diluidas en caldo de cultivo nutritivo y distribuidas en placas de ELISA. Las muestras de cobre cementado (obtenidas por procesos hidrometalúrgicos) y de cobre comercial fueron nanoestructuradas empleando un equipo de molienda mecánica. Los resultados indican que las nanopartículas de cobre comercial (a 2.5 horas de molienda) muestran acción inhibitoria del crecimiento de la cepa S. aureus y no así en la cepa E. coli. Asimismo, se determinó que la concentración mínima inhibitoria de la muestra de cobre comercia...

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: J.C.-V. thanks to Circulo de Investigacion e Innovacion de Materiales Avanzados para la Industria y Biomedicina of FONDECYT (CONCYTEC) under grant No 011-2014-FONDECYT, and to the Brazilian Society of Physics (PLAF program) that financed part of this work. C. V.L., J.Q.-M. and V.P.R. are grateful to FONDECYT (CONCYTEC) for financial support through the Excellence Center Program.