Polytechnic University of Valencia

About: Polytechnic University of Valencia is a education organization based out in Valencia, Spain. It is known for research contribution in the topics: Catalysis & Population. The organization has 16282 authors who have published 40162 publications receiving 850234 citations.

Interactive Effects of Albumin and Phosphate Ions on the Corrosion of CoCrMo Implant Alloy

Abstract: The corrosion behavior of CoCrMo alloy in simulated body fluids has been analyzed by electrochemical techniques and surface analysis. Interaction of albumin and phosphates present in the body fluids on the passive film of the alloy was also investigated. Electrochemical techniques such as potentiodynamic and potentiostatic polarization and electrochemical impedance spectroscopy were employed. Further, ex situ X-ray photoelectron spectroscopy and Auger electron spectroscopy analysis of the passive films were carried out. The study reveals that phosphates and proteins present in simulated body fluid play a significant role in the electrochemical properties of the metal/oxide/electrolyte interface. Surface analysis showed that both species competitively adsorb on the alloy surface. For a given passive potential, the impedance behavior of passive CoCrMo was found to depend on the way passive conditions were established. A simple model has been developed assuming a multilayer structure of the surface including an outer layer where albumin and phosphate ions adsorb, the passive film (inner layer), and the metal. This model is consistent with the obtained electrochemical and surface analysis results.

The results of the pantograph catenary interaction benchmark

Abstract: This paper describes the results of a voluntary benchmark initiative concerning the simulation of pantograph-catenary interaction, which was proposed and coordinated by Politecnico di Milano and pa ...

The SWI2/SNF2 Chromatin Remodeling ATPase BRAHMA Represses Abscisic Acid Responses in the Absence of the Stress Stimulus in Arabidopsis

Abstract: The survival of plants as sessile organisms depends on their ability to cope with environmental challenges. Of key importance in this regard is the phytohormone abscisic acid (ABA). ABA not only promotes seed dormancy but also triggers growth arrest in postgermination embryos that encounter water stress. This is accompanied by increased desiccation tolerance. Postgermination ABA responses in Arabidopsis thaliana are mediated in large part by the ABA-induced basic domain/leucine zipper transcription factor ABA INSENSITIVE5 (ABI5). Here, we show that loss of function of the SWI2/SNF2 chromatin remodeling ATPase BRAHMA (BRM) causes ABA hypersensitivity during postgermination growth arrest. ABI5 expression was derepressed in brm mutants in the absence of exogenous ABA and accumulated to high levels upon ABA sensing. This effect was likely direct; chromatin immunoprecipitation revealed BRM binding to the ABI5 locus. Moreover, loss of BRM activity led to destabilization of a nucleosome likely to repress ABI5 transcription. Finally, the abi5 null mutant was epistatic to BRM in postgermination growth arrest. In addition, vegetative growth defects typical of brm mutants in the absence of ABA treatment could be partially overcome by reduction of ABA responses, and brm mutants displayed increased drought tolerance. We propose a role for BRM in the balance between growth or stress responses.

Patent overlay mapping: Visualizing technological distance

Abstract: We thank Kevin Boyack, Loet Leydesdorff, and Antoine Schoen for open and fruitful discussions about this paper. This research was undertaken largely at Georgia Tech drawing on support from the U.S. National Science Foundation (NSF) through the Center for Nanotechnology in Society (Arizona State University; Award No. 0531194); and NSF Award No. 1064146 ("Revealing Innovation Pathways: Hybrid Science Maps for Technology Assessment and Foresight"). Part of this research was also undertaken in collaboration with the Center for Nanotechnology in Society, University of California Santa Barbara (NSF Awards No. 0938099 and No. 0531184). The findings and observations contained in this paper are those of the authors and do not necessarily reflect the views of the US National Science Foundation.