795 research outputs found
Complexation of adamantyl derivatives by a .beta.-cyclodextrin dimer
No full textThe binding constants, standard molar enthalpy, Gibbs free energy, and entropy changes were determined for the formation of complexes between adamantyl derivatives and a β-cyclodextrin dimer. It is concluded that, within experimental error, the two cyclodextrin residues in the dimer behave independent to each other when complexing the adamantyl derivatives
OBREGON, Alvaro. ARTICULOS (3 of 4)
No full text"
A note which says: “Collect these with discretion”. Article with no author or date titled “The dots on the I’s”, regarding the conferences between the representatives of Presidents Obregón and Harding. Article with no author or date indicating that Gen. Alvaro Obregón is having problems with reconstructing Mexico within the limits of the budget.
/ Minuta con la anotación ""Coleccionar éstos con discreción"". Artículo sin autor ni fecha titulado ""Los puntos sobre las íes"", que trata sobre las conferencias entre los representantes de los presidentes Obregón y Harding. Artículo sin autor ni fecha que aborda el problema del Gral. Alvaro Obregón para lograr la reconstrucción de México sobre el presupuesto de ingresos.
OBREGON, Alvaro. ARTICULOS (3 of 4)
No full text"
A note which says: “Collect these with discretion”. Article with no author or date titled “The dots on the I’s”, regarding the conferences between the representatives of Presidents Obregón and Harding. Article with no author or date indicating that Gen. Alvaro Obregón is having problems with reconstructing Mexico within the limits of the budget.
/ Minuta con la anotación ""Coleccionar éstos con discreción"". Artículo sin autor ni fecha titulado ""Los puntos sobre las íes"", que trata sobre las conferencias entre los representantes de los presidentes Obregón y Harding. Artículo sin autor ni fecha que aborda el problema del Gral. Alvaro Obregón para lograr la reconstrucción de México sobre el presupuesto de ingresos.
Supramolecular Structures Generated by a p-tert-Butylphenylamide Derivative of Deoxycholic Acid. From Planar Sheets to Tubular Structures through Helical Ribbons
No full textThe formation of supramolecular structures initiated by a p-tert-butylphenylamide derivative of deoxycholic acid (Na-t-butPhDC) is investigated. At 1.18 mM concentration of Na-t-butPhDC and 37 degrees C, initial flat ribbons are observed which sell-transform into helical ribbons (with a mean pitch angle of 47 +/- 6) which finally originate molecular tubes with an external diameter of 241 +/- 28 inn. Most of the molecular tubes show helical markings with a pitch angle value of 45 +/- 4 degrees, in full agreement with predictions of simple models based on chiral elastic properties of the membrane. A lateral association mechanism is proposed to account or the growth of the external diameter (from 225 +/- 32 to 546 +/- 59 nm) of tubes with time at 3.99 mM
Ice-like encapsulated water by two cholic acid moieties
No full textStarting from the structure of ice (in which each water molecule is surrounded by other four water molecules forming a tetrahedron with a value of 4.51 A for the edge O-O distance), and the knowledge that this value also corresponds to the O7-O12 distance of the skeleton of cholic acid, it is hypothesized that two steroid cholic acid moieties, with an appropriate steroid-steroid distance and a belly-to-belly orientation, could encapsulate a single water molecule between them. To check this hypothesis two succinyl derivatives of cholic acid (a monomer and the related head-head dimer in which the succinyl group is the linking bridge) were designed. The expected "ice-like" structure is found in the crystal of the dimer. There is a hydrogen bond synergy between those participating in the "ice-like" structure, and those in which the bridge is involved with the O7-H hydroxy group and the side chain of the steroid. (c) 2012 Elsevier Inc. All rights reserved
Métricas de autor Alvaro Hernan Moreno Durán
No full textInforme de las métricas de autor del Dr. Alvaro Hernan Moreno Durán de las publicaciones indexadas en Google Académico cuyo objetivo es entregar un insumo para el fortalecimiento de las capacidades y potencialidades de los autores de la Universidad Santo Tomás en el posicionamiento y visibilidad de sus publicaciones.Report of the author metrics Alvaro Hernan Moreno Durán of the publications indexed in Google Scholar whose objective is to provide an input for the strengthening of the capacities and potentialities of the authors of the Santo Tomás University in the positioning and visibility of their publications.http://unidadinvestigacion.usta.edu.c
Aggregation Behavior of Tetracarboxylic Surfactants Derived from Cholic and Deoxycholic Acids and Ethylenediaminetetraacetic Acid
No full textThe reaction of 3 beta-aminoderivatives of cholic and deoxycholic acids (steroid residues) with dimethyl ester of ethylenediaminetetraacetic acid (bridge) leads to the formation of dimers carrying four carboxylic organic function,, two of them located on the side chain of each steroid residue and the other two on the bridge. As tetrasodium stilts. these new compounds behave as surfactants and have been characterized by surface tension. fluorescence intensity of pyrene (as a probe), and static and dynamic light scattering measurements. Thermodynamic parameters for micellization were obtained from the dependence of the critical micelle concentration (cmc) with temperature. For both surfactants. the fraction of bound counterions is close to 0.5. The aggregation behavior is similar to one of their bile salt residues [i.e., sodium cholate (NaC) and sodium deoxycholate (NaDC)] and can be Summarized its follows: (i) molecular areas at the interface for the new surfactants are fairly close to twice the value for a single molecule in a monolayer of natural bile salts; (ii) the environment where pyrene is solubilized is very apolar, as in natural bile salt aggregates; (iii) Gibbs free energies (per steroid residue) for micellization are not far from published values for NaC and NaDC, and the differences can e understood on the basis of less hydrophobicity of the new surfactants due to the charges in the bridge: and (iv) as for NaC and NaDC. aggregates have rather low aggregation numbers (which depend oil the amount of added inert salt, NaCl). A structure based oil the disklike model accepted for small bile salt aggregates is proposed
Complexation of 3.alpha.,7.alpha.,12.alpha.-trihydroxy-5.beta.-cholan-24-amine by .beta.- and .gamma.-cyclodextrins
No full textThe binding constants, standard molar enthalpy, Gibbs free energy, and entropy changes were determined for the formation of inclusion complexes between 3α,7α,12α-
trihydroxy-5β-cholan-24-amine, C24NH2, and β-cyclodextrin and γ-cyclodextrin. The stoichiometry of both complexes is 1:1 in agreement with previously reported results for other trihydroxy bile salts. The equilibrium constant values for the formation of the inclusion complex are similar as well. The structure of the C24NH2/γ-cyclodextrin complex was studied by ROESY experiments. These results suggest that B, C and D-rings of the steroid skeleton, as well as the side chain, interact with the cyclodextrin cavity, while the A ring of the steroid nucleus remains outside the cavity
OBREGON, Alvaro (Gral.); CABRERA, Luis (Lic.)
No full textFile originally titled “Gen. Alvaro Obregón. File number 5. Subject: B.A. Luis Cabrera. Letter signed by Clemente Reynoso on April 29-919”. Clemente Reynoso is a pseudonym of Gen. Alvaro Obregón, used when answering a letter written by B.A. Luis Cabrera, Secretary of Finance and Public Credit. In said letter, Cabrera addresses three issues: How friends are made using an elevated position. How those friends are “political dead weight” and why the author himself did not make friends by using his position as Secretary of Finance and Public Credit. Clemente Reynoso analyzes the three points, harshly criticizing Cabrera. (This letter can also be found in series 11020700, file C-20, “CABRERA, Luis”, in the Alvaro Obregón database and in series 13010201 “Documents in a Lock Box. CABRERA, Luis; Clemente REYNOSO”, file 10/7 from this same Database). / Cédula titulada originalmente "Señor General Alvaro Obregón. Expediente número 5. Asunto: Lic. Luis Cabrera. Carta firmada por Clemente Reynoso al. Abril 29-919". Clemente Reynoso es un seudónimo del Gral. Alvaro Obregón, quien contesta una carta del Lic. Luis Cabrera, Secretario de Hacienda y Crédito Público, en la que Cabrera aborda tres asuntos: Cómo se fabrican amigos estando en un puesto elevado. Cómo esos amigos son el "lastre político" y por qué no fabricó amigos usando el puesto de Secretario de Hacienda y Crédito Público. Clemente Reynoso analiza los tres puntos criticando duramente a Cabrera. (Esta carta se encuentra también en la serie 11020700, expediente C-20, "CABRERA, Luis" del Fondo Alvaro Obregón y en la serie 13010201 "Documentos en Caja. CABRERA, Luis; Clemente REYNOSO", expediente 10/7 de este mismo Fondo)
OBREGON, Alvaro (Gral.); CABRERA, Luis (Lic.)
No full textFile originally titled “Gen. Alvaro Obregón. File number 5. Subject: B.A. Luis Cabrera. Letter signed by Clemente Reynoso on April 29-919”. Clemente Reynoso is a pseudonym of Gen. Alvaro Obregón, used when answering a letter written by B.A. Luis Cabrera, Secretary of Finance and Public Credit. In said letter, Cabrera addresses three issues: How friends are made using an elevated position. How those friends are “political dead weight” and why the author himself did not make friends by using his position as Secretary of Finance and Public Credit. Clemente Reynoso analyzes the three points, harshly criticizing Cabrera. (This letter can also be found in series 11020700, file C-20, “CABRERA, Luis”, in the Alvaro Obregón database and in series 13010201 “Documents in a Lock Box. CABRERA, Luis; Clemente REYNOSO”, file 10/7 from this same Database). / Cédula titulada originalmente "Señor General Alvaro Obregón. Expediente número 5. Asunto: Lic. Luis Cabrera. Carta firmada por Clemente Reynoso al. Abril 29-919". Clemente Reynoso es un seudónimo del Gral. Alvaro Obregón, quien contesta una carta del Lic. Luis Cabrera, Secretario de Hacienda y Crédito Público, en la que Cabrera aborda tres asuntos: Cómo se fabrican amigos estando en un puesto elevado. Cómo esos amigos son el "lastre político" y por qué no fabricó amigos usando el puesto de Secretario de Hacienda y Crédito Público. Clemente Reynoso analiza los tres puntos criticando duramente a Cabrera. (Esta carta se encuentra también en la serie 11020700, expediente C-20, "CABRERA, Luis" del Fondo Alvaro Obregón y en la serie 13010201 "Documentos en Caja. CABRERA, Luis; Clemente REYNOSO", expediente 10/7 de este mismo Fondo)
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