Parasporal proteins as an approach to control diseases:genetic modifications, and characterization

Parasporal proteins from Bacillus thuringiensis (Bt) are well studied in various fields of environmental biotechnology and recently in medical biology. Correspondingly, this dissertation presents the use of site-directed mutagenesis technologies to obtain mutant cry and parasporin proteins with different effects against vector-borne diseases and human cancer cell lines. The use of in silico modeling offers a possible explanation of how the altered residues are involved in changing their structure and interacting with cell membrane receptors. The proteins from this work can be used as targets for new studies that will provide more information about the mechanism of action of Bt proteins, and open the door to the employment of these biomolecules in combating diseases

Estudio de dinámicas económicas y potencial de desarrollo de MIPYMES de los sectores priorizados de agroindustria, industria manufacturera y servicios y sus posibles vínculos con las grandes empresas de la región de los Nonualcos : La oferta territorial

El estudio comienza haciendo un recuento de los hitos que han marcado el proceso Los Nonualcos desde el año 2002, con la conformación de la Asociación de Municipios Los Nonualcos. Seguidamente se desarrolla un breve marco conceptual que tiene por objeto tipificar el territorio bajo un enfoque de Desarrollo Territorial. Se ha creído muy pertinente la aplicación de este enfoque que tipifica un territorio, a partir de su dimensión productiva e institucional. A continuación se caracteriza el territorio y sus principales dinámicas. Se toma para ello el insumo base aportado por el Plan de Desarrollo Territorial finalizado en el año 2007. La caracterización y priorización de subsectores se hace mediante la identificación de plataformas socio productivas dentro de cada subsector. Antes que priorizar Micro, Pequeñas y Medianas Empresas (MIPYMES) con potencial de encadenamiento dentro de cada subsector, se han identificado plataformas socio productivas con potencial de encadenarse no solo a las grandes empresas de la región sino también a redes de iguales que pudieran identificarse al interior del territorio. Finalmente se hace un análisis de los posibles eslabonamientos y las necesidades de fortalecimiento a estas plataformas, para que efectivamente puedan articularse de forma ventajosa y permanente

Marcadores de envejecimiento en riñón de ratones sometidos a intervención genética y nutricional

Aging should be considered as a multifactorial phenomenon and, consequently, its study should be addressed through different experimental designs. This includes nutritional and genetic interventions. In addition, it is essential to know the possible synergies or antagonisms that may occur between these conditions and if the extension of their benefits is universally translational to all tissues, genotypes or sexes. Therefore, the main objective of this Doctoral Thesis is the study of aging markers in renal cells and tissue of mice submitted to diverse genetic and nutritional interventions: caloric restriction, diet composition and CYB5R3 overexpression.El envejecimiento es un proceso multifactorial y su estudio requiere de diseños experimentales que contribuyan de forma significativa a la disección de estas múltiples interacciones. Ello puede conseguirse a través de intervenciones que hayan probado su impacto en la salud y longevidad de los modelos experimentales, entre las que destacan las nutricionales y genéticas. Además, resulta vital conocer las posibles sinergias o antagonismos que puedan presentarse entre las mismas y si la extensión de sus beneficios es trasladable de forma general a todos los tejidos, genotipos o sexos. Por todo ello, la presente Tesis Doctoral tiene como objetivo principal el estudio de marcadores de envejecimiento en células y tejido renal de ratones sometidos a diversas intervenciones genéticas y nutricionales como son la restricción calórica, la composición de la dieta y la sobreexpresión de CYB5R3

Communication in M&A: understanding the process and the outcomes

Mergers and Acquisitions have attracted scholars’ attention for several decades, yet the reasons that justify their high rate of failure are not yet entirely understood. Nonetheless, an excessive focus in the financial component of the process, and the lack of studies connecting the several variables of this phenomenon have been cited by authors as two of the main flaws in literature. This paper proposes to address these flaws, conducting an extensive review of papers that have approached Communication in the context of M&A. Based on the findings, a framework linking Communication with several Variables and Outcomes of the M&A process is proposed, in an attempt to provide direction for future researchers

A polarization-consistent model for alcohols to predict solvation free energies

Classical nonpolarizable models, normally based on a combination of Lennard-Jones sites and point charges, are extensively used to model thermodynamic properties of fluids, including solvation. An important shortcoming of these models is that they do not explicitly account for polarization effects, i.e., a description of how the electron density responds to changes in the molecular environment. Instead, polarization is implicitly included, in a mean-field sense, into the parameters of the model, usually by fitting to pure liquid properties (e.g., density). This causes problems when trying to describe thermodynamic properties that involve a change of phase (e.g., enthalpy of vaporization), that directly depend on the electronic response of the medium (e.g., dielectric constant), and that require mixing or solvation in different media (e.g., solvation free energies). Fully polarizable models present a natural route for addressing these limitations but at the price of a much higher computational cost. In this work, we combine the best of those two approaches by running fast simulations using nonpolarizable models and applying post facto corrections to the computed properties in order to account for the effects of polarization. By applying this new paradigm, a new united-atom force field for alcohols is developed that is able to predict both pure liquid properties, including dielectric constant, and solvation free energies in different solvents with a high degree of accuracy. This paves the way for the development of a generic classical nonpolarizable force field that can predict solvation of drug-like molecules in a variety of solvents

Materiales provenientes del reciclamiento de envases de Tetra Pak y su uso en concreto

Son escasos los estudios que involucran el uso de los materiales de reciclo de envases de Tetra Pak. No obstante, se ha estudiado la viabilidad del uso de polietleno de baja densidad (LDPE) y el aluminio reciclados de envases Tetra Pak para la fabricación de tableros rígidos utlizando una prensa caliente. En este capítulo se evaluó el efecto de las partículas de Tetra Pak en concretos poliméricos. Se realizaron ensayos de compresión y fexión, así como el cálculo del módulo de Young; con la finalidad de conocer el efecto de las partículas en la deformación

Unveiling the origin of oxygen atomic impurities in Au nanowires

The appearance of unusually large Au-Au bond distances in linear atomic chains (LACs) of Au nanowires is commonly attributed to the presence of atomic impurities. However, the origin of those contaminants is unknown. We present a study based on density functional theory calculations using quasistatic (T=0) and finite-temperature ab initio molecular-dynamics simulations of a possible route for the formation of atomic impurities in Au nanowires. This process starts with the adsorption of an O2 molecule followed by a CO molecule on Au LACs, leading to the formation of an intermediate O2CO complex. Upon thermal activation at finite temperatures, the complex is able to proceed to oxidation forming a CO2 molecule and leaving an atomic O impurity in the Au LAC

Molecular modification of coumarin dyes for more efficient dye sensitized solar cells

solo para uso personalIn this work, new coumarin based dyes for dye sensitized solar cells (DSSC) have been designed by introducing several substituent groups in different positions of the NKX-2311 structure. Two types of substitutions have been considered: the introduction of three electron-donating groups (–OH, –NH2, and –OCH3) and two different substituents with steric effect: –CH2–CH2–CH2– and –CH2–HC=CH–. The electronic absorption spectra (position and width of the first band and absorption threshold) and the position of the LUMO level related to the conduction band have been used as theoretical criteria to evaluate the efficiency of the new dyes. The introduction of a –NH2 group produces a redshift of the absorption maximum position and the absorption threshold, which could improve the cell efficiency. In contrast, the introduction of –CH2–CH2–CH2– does not modify significantly the electronic structure of NKX-2311, but it might prevent aggregation. Finally, –CH2– HC=CH– produces important changes both in the electronic spectrum and in the electronic structure of the dye, and it would be expected as an improvement of cell efficiency for these dyes.Ministerio de Ciencia e Innovación de España-MAT2008-4918 y CSD2008-002

Influence of temperature on the interaction between Pd clusters and the TiO2 (110) surface

The behavior of a Pd nanocluster on the rutile TiO2 (110) surface has been analyzed by extensive first principles molecular dynamics simulations between 100 K and 1073 K. Calculations predict a steep change in the morphological and electronic cluster structure around 800 K in excellent agreement with previous experimental evidence. At low temperature, the cluster geometry is mainly controlled by the substrate structure; however, upon the transition temperature, the cluster-substrate interaction decreases appreciably, and the cluster adopts a geometry more stable in vacuum and becomes metallic. These results illustrate at an atomistic level the influence of temperature on the geometrical and electronic properties of oxide-supported clusters.Ministerio de Educación y Ciencia MAT2005-0187

Oxygen vacancies on TiO2 (110) from first principles calculations

We have carried out a systematic study of oxygen vacancy formation on the TiO2 ~110! surface by means of plane-wave pseudopotential density-functional theory calculations. We have used models with the mean number of vacancies per surface unit cell being u50.25 and u50.5. The study comprises several kind of vacancies within the outermost layers of the surface. The use of a suitable set of technical parameter is often essential in order to get accurate results. We find that the presence of bridging vacancies is energetically favored in accordance to experimental data, although the formation of sub-bridging vacancies might be possible at moderate temperatures. Surprisingly, the spin state of the vacancy has little influence on the results. Atomic displacements are also analyzed and found to be strongly dependent on the particular arrangement of vacancies.Dirección General de Enseñanza Superior e Investigación Científica. España (DGESIC) MAT2002-57