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Reactividad de la Plata con Moléculas Biológicas

LINDA LUCILA LUCERO LANDEROS MARTINEZ (2012)

Los iones de plata se han establecido con anterioridad por ser un buen

agente antimicrobiano. Una manera de determinar el mecanismo de

acción de la plata en las moléculas biológicas aminoácidos, lípidos,

azúcares, bases púricas y pirimídicas, se obtiene a través las estructuras

moleculares y propiedades de las moléculas con la teoría de funcionales

de la densidad B3LYP/6-31G(d), que permite ver la transferencia de

electrones entre la molécula biológica y el ion plata, los cuales se

midieron con los parámetros de reactividad, potencial de ionización (I),

afinidad electrónica (AE), electronegatividad (X), dureza (),

electrofilicidad (),potencial electrodonador (ω

), sitios de reactividad

química utilizando las funciones de Fukui, seguido de la formación de los

complejos plata-molécula, finalmente obteniendo la medición de la

energía de reacción. En base al estudio se obtuvo que las bases púricas

y pirimídicas son las que reaccionan con mayor facilidad con el ion plata,

seguido de los aminoácidos, azúcares y finalizando con los lípidos. Lo

anterior es una herramienta para determinar dónde empieza la plata a

inhibir el metabolismo desde el punto de vista de química

computacional.

Silver ions have been previously established to be a good antimicrobial

agent. One way to determine the mechanism of action of silver in

biological molecules amino acids, lipids, sugars, purine and pyrimidine

bases, is obtained through molecular structures and properties of

molecules with the theory of density functional B3LYP/6- 31G (d), which

allows to see the transfer of electrons between the biological molecule

and the silver ions, which were measured with the parameters of

reactivity, ionization potential (I), electron affinity (EA),

electronegativity (X), hardness (), electrophilicity () electrodonador

potential (ω-) , chemical reactivity sites using Fukui functions, followed

by formation of the complex silver-molecule, finally obtaining the

measurement of reaction energy. Based on the study was obtained that

the purine and pyrimidine bases are those which react more readily with

the silver ion, followed by amino acids, sugars and ending with the

lipids. This is a tool to determine where to start the silver to inhibit the

metabolism from the point of view of computational chemistry.

Master thesis

Estructura-Molecular, reactividad química, energía de reacción Molecular structure, chemical reactivity, reaction energy INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS INGENIERÍA Y TECNOLOGÍA DEL MEDIO AMBIENTE

Computational Molecular Nanoscience Study of the Properties of Copper Complexes for Dye-Sensitized Solar Cells

MARIO DANIEL GLOSSMAN MITNIK NORMA ROSARIO FLORES HOLGUIN JOSE DE JESUS BALDENEBRO LOREDO (2012)

In this work, we studied a copper complex-based dye, which is proposed for

potential photovoltaic applications and is named Cu (I) biquinoline dye. Results of electron

affinities and ionization potentials have been used for the correlation between different

levels of calculation used in this study, which are based on The Density Functional Theory

(DFT) and time-dependent (TD) DFT. Further, the maximum absorption wavelengths of

our theoretical calculations were compared with the experimental data. It was found that

the M06/LANL2DZ + DZVP level of calculation provides the best approximation. This

level of calculation was used to find the optimized molecular structure and to predict the

main molecular vibrations, the molecular orbitals energies, dipole moment, isotropic

polarizability and the chemical reactivity parameters that arise from Conceptual DFT.

Article

molecular structure; absorption spectra; polarizability; chemical reactivity; dipole moment; copper complex; dye-sensitized BIOLOGÍA Y QUÍMICA QUÍMICA

ESTUDIO TEÓRICO DE NANOTUBOS DE CARBONO FUNCIONALIZADOS

KATHY ALEJANDRA RAMIREZ BALDERRAMA (2012)

Los nanotubos de carbono son considerados acarreadores biológicos es por

ello que son funcionalizados para transportar moléculas de interés biológico,

incluyendo, proteínas y antibióticos, entre otras. En el presente estudio se

analizaron dos vías de funcionalización: a través de enlaces directos y por

medio de moléculas intermedias o “puente”, utilizando la teoría de funcionales

de la densidad y con una metodología B3LYP/ 6-31G. Se analizaron las

moléculas intermedias: N-BOC-2,2 dioxietileno dietilamina, N-BOC-2,

2´iminodietilamina, BOC-β-Homolgn-OH, (N-BOC-β-amino)-Ala-OH, N-boc-

1,2-fenilenediamina, N-BOC-1,6-hexanediamina,(BOC-D-Gln-ONp,BOCGln,OSu),

nanotubos de carbono y una secuencia de aminoácidos específicas

de la lectina. Por medio de cálculos de energía se determinaron sitios reactivos

utilizando funciones de Fukui condensadas, además propiedades de

reactividad química para las diferentes moléculas intermedias o “puentes”,

encontrándose que el puente BOC-D-Gln-ONp es el único con una afinidad

electrónica positiva, menor dureza química y mayor electrofilicidad. Además se

calcularon energías de formación dando como resultado que en ambos tipos de

funcionalización ya sea por medio de enlaces directos o por moléculas

intermedias o puentes, se requiere administrarles energía para que se lleven a

cabo las reacciones y por ello se podría prescindir del uso de moléculas

intermedias.

Carbon nanotubes are considered biological carriers, is why we are

functionalized to transport biological molecules, including proteins and

antibiotics, among others. This study considered two ways of functionalization:

through direct links and through intermediate molecules or “linkers”, using the

theory of density functional and methodology B3LYP/6-31G. Intermediate

molecules were analyzed: N-BOC-2, 2 dioxyethylene diethylamine, N-BOC-2,

2'iminodiethylamine, BOC-β-Homolgn-OH, (N-BOC-β-amino)-Ala-OH, N-boc-1

,2-phenylenediamine, N-BOC-1 ,6-hexanediamine, BOC-D-Gln-ONp, (BOC-Gln,

OSu), carbon nanotubes and specific amino acid sequence of the lectin.

Through energy calculations reactive sites were determined using condensed

Fukui functions, in addition to chemical reactivity properties of the different

intermediate molecules or “linkers” finding that the bridge BOC-D-Gln_ONp is

the only one with a positive electron affinity, lower hardness and greater

electrophilicity chemistry. Moreover formation energies were calculated with

the result that in both types of functionalization either through direct lionks or

intermediate molecules or linkers, administering energy required for the

carrying out reactions and therefore could dispense with the use of

intermediate molecules.

Master thesis

Nanotubos de carbono, Sitios reactivos, Reactividad química, Energía de formación. carbon nanotube, reactive sites, chemical reactivity, energy of formation BIOLOGÍA Y QUÍMICA QUÍMICA

Absence of evidence is not evidence of absence: Multiple steady states in ammonia synthesis

JOSE MARTIN MENDEZ GONZALEZ MANUEL DIAZ DE LEON CABRERO (2016)

"Using a chemical reaction network (CRN) Theory approach, three well-accepted mechanisms of ammonia synthesis over iron catalyst taking place within an isothermal Continuous Flow Stirred Tank Reactor (CFSTR) are analyzed. Together with its deficiency analysis, the CRN Theory provides a suitable framework to assert whether a particular reaction network has the capacity to support multiple steady states using the reaction mechanism structure alone. Through deficiency analysis, we argued that the presence of two surface catalytic sites during absorption-desorption of nitrogen (microscale) is causative of bistability (macroscale) in two of the three ammonia synthesis mechanisms here considered."

Article

Ammonia synthesis Chemical reaction network theory Bistability Deficiency analysis Mathematical modelling Reactor engineering INGENIERÍA Y TECNOLOGÍA INGENIERÍA Y TECNOLOGÍA

On Brusselator and Oregonator as chemical reaction networks: a graph approach

JOSE MARTIN MENDEZ GONZALEZ ALEJANDRO RICARDO FEMAT FLORES (2009)

"This paper shows graph similarities between Brusselator and Oregonator reaction mechanisms, using the jacobian matrix in convex coordinates as an adjacency matrix which defines a weighted directed pseudograph. A linear transformation is defined for the task of mapping the weights of the three dimensional system onto a two dimensional one where the Oregonator’s pseudograph is isomorphic to Brusselator’s."

Conference paper

Brusselator Oregonator Chemical reaction networks Graph theory CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA MATEMÁTICAS

Application of density functional theory concepts to the study of the chemical reactivity of isomeric thiadiazolines

MARIO DANIEL GLOSSMAN MITNIK Alfredo Márquez Lucero (2001)

Several useful concepts derived from density functional theory have been applied to the study of the chemical reactivity of the more stable forms of the isomeric thiadiazolines. Dipole moments, total hardness of the molecules in terms of the calculated ionization potentials and electron affinities as a measure of aromaticity and the condensed Fukui functions related to the variation of the net charges of the atoms resulting from a Mulliken population analysis were calculated in order to determine the reactivity of different sites within the molecules studied. The net charges have been obtained from calculations made in the context of the Hartree-Fock and of local (SVWN) and nonlocal (BLYP, B3LYP) density functional approximations. The results were compared with the existing experimental evidence on thiadiazolines and related compounds. Electronic properties calculated using the hybrid B3LYP proved to be the most accurate. It is concluded that the 1, 2, 3-thiadiazoline molecule would be the best starting monomer of the four isomers to be considered for a polymerization reaction.

Article

Density Functional Theory, Chemical Reactivity, Isomeric Thiadiazolines INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE MATERIALES PROPIEDADES DE LOS MATERIALES PROPIEDADES DE LOS MATERIALES

Modifications in the rhombohedral degree of distortion and magnetic properties of Ba-doped BiFeO3 as a function of synthesis methodology

LUIS EDMUNDO FUENTES COBAS ARMANDO REYES ROJAS GABRIEL ROJAS GEORGE (2014)

We present an analysis of crystallographic symmetry and the origin of the pseudo-cubic character of doped BiFeO3. Specifically, barium-doped bismuth ferrite, Bi1−xBaxFeO3 (x = 0.05, 0.075, 0.1, 0.125), perovskite-type nanoparticles have been synthesized by implementing five modifications to the sol–gel technique (citric acid-assisted sol–gel method, ethylene glycol method, tartaric acid-assisted sol–gel method, polyvinyl alcohol–ethylene glycol method, and EDTA complexing sol–gel method) and their final pseudo-cubic character is discussed. The effect of the carboxylic groups and hydroxyl groups during synthesis is critical to obtain single phase BBFO. Fourier transform infrared spectroscopy and thermogravimetric analysis is used to study the decomposition and thermal behavior of the precursors and their relation to the final nanoparticle characteristics. X-ray diffraction analysis shows a single phase with symmetry changes for four of the five synthesis methodologies employed. Only the EDTA complexing sol–gel method, where EDTA is used as dissolver and chelating agent, is not satisfactory in all concentration ranges. Rietveld results suggest that the degree of distortion of the rhombohedral symmetry in the crystallized BiFeO3 powders decreases 12% as a result of progressive substitution of Bi3+ by Ba2+ and that there is no shift from rhombohedral to tetragonal symmetry. Magnetization properties of samples with a low-distortion rhombohedral structure show higher magnetic saturation and remanent magnetization than samples with high-distortion rhombohedral structure.

Article

Chemical synthesis; Magnetic materials; Crystal structure; Nanostructures BIOLOGÍA Y QUÍMICA QUÍMICA

El protocolo familiar: Herramienta para la transferencia generacional de las empresas familiares

LIBNAZARET BETANCOURT RODRIGUEZ ANNISEL DIAZ MONTES THANAIRI DE FATIMA MEZO UC ANDRES MIGUEL PEREYRA CHAN RAYMA IRERI MALDONADO ASTUDILLO (2020)

En México, más del 90 % de las empresas son de tipo familiar. A pesar de su relevancia en la economía nacional, diversos autores concuerdan que son quienes más sufren las altas tasas de mortalidad, primordialmente a raíz del traspaso de una generación a otra. Esta problemática de continuidad, entre otras causas, está asociada a la falta de un protocolo familiar a razón de la inadecuada planeación de la sucesión.

In Mexico, more than 90 % of the companies are family owned. Despite its relevance in the national economy, several authors agree that they suffer the most from high mortality rates, primarily as a result of the transfer from one generation to another. This problem of continuity, among other causes, is associated with the lack of a family protocol due to the inadequate planning of succession.

Article

Empresa familiar Protocolo familiar Continuidad Sucesión Estructura Contenido Family Business Family protocol Succession Continuity Structure Content CIENCIAS SOCIALES SOCIOLOGÍA COMUNICACIONES SOCIALES

MS-1-P-3446 Structure and Morphology Study of Pure and Mixed ZnO and ZnO2 Nanoparticles

FRANCISCO PARAGUAY DELGADO WILBER ANTUNEZ FLORES (2015)

Synthesis of ZnO2 nanoparticles was performed via a sol–gel technique assisted with UV

irradiation. One gram of zinc acetate dehydrate, Zn(CH3COO)2.2H2O, was dissolved under

vigorous stirring in a mixture of 50 ml distilled water and 5 ml of 30% H2O2. The resulting

solution was then irradiated with a 300W Ultra-Vitalux lamp (Osram), positioned 10 cm above

the solution, for 30 min at ambient temperature. This procedure resulted in the formation of a

white zinc peroxide colloidal suspension. The ZnO2 nanoparticles were precipitated by

centrifugation. The precipitate was then washed using distilled water until a pH of 8 was

reached. Finally the resultant white solid was dried at 80 °C for 12 h, similar to follow in the

reference [1]. The resultant powder was annealed between 100 and 220°C for 1 h in an oven

with air atmosphere. The morphology, structure and domain size of the nanoparticles were

determined by X-ray diffraction, and scanning transmission electron microscopy. By X-ray

diffraction, all patterns can be indexed to the zinc peroxide phase for samples prepared up to

120°C. For a sample prepared at 160°C we had a mixture of ZnO2 and ZnO, while for particles

treated at 220°C all the material was pure ZnO.

Conference proceedings

Structure BIOLOGÍA Y QUÍMICA QUÍMICA OTRAS ESPECIALIDADES QUÍMICAS OTRAS