SYNTHESIS OF CYCLIC AZOBENZENE ANALOGUES FOR INCORPORATION INTO OLIGONUCLEOTIDES, PEPTIDES AND POLYMERS

(A) In recent years, considerable amount of effort has contributed towards enhancing our understanding of the new photoswitch, cyclic azobenzene, particularly from the theoretical point of view. However, the challenging part with this system was poor efficiency of its synthesis from 2,2’- dinitrodibenzyl and lack of effective methods for further modification which would be useful to incorporate this system into biomolecules as a photoswitch. We report the synthesis of cyclic azobenzene and analogues from 2,2’-dinitrodibenzyl, which would allow for further incorporation of this cyclic azobenzene into biomolecules. Reaction of 2,2’-dinitrodibenzyl with zinc metal powder in the presence of triethylammonium formate buffer (pH-9.5) gave a cyclic azoxybenzene, 11,12-dihydrodibenzo[c,g][1,2]diazocine-5-oxide. The latter compound was converted into cyclic azobenzene analogues (bromo-, chloro-, cyano-, and carboxyl) through subsequent transformations. The carboxylic acid analogue was reacted with D-threoninol to give the corresponding amide, which readily undergoes photo-isomerization upon illumination with light. Upon illumination with light at 400 nm, approximately 70% of cis- isomer of amide was isomerized to trans- isomer. It was observed that cis- to trans- isomerization reached the maximum steady state of light transmission after approximately 40 min, whereas the trans- to cis- isomerization approximately acquired in 2 h to regain full recovery of light transmission. Cyclic azobenzene phosphoramidite was synthesized from DMT-protected D-threoninol linked cyclic azobenzene. (B) In recent years, there has been considerable interest invested towards the synthesis of azobenzene analogues for incorporation into proteins. Among the many azobenzene analogues, the synthesis of bi-functional cyclic azobenzene analogues for the incorporation into proteins is relatively new. In this thesis, we report the synthesis of a cyclic azobenzene biscarboxylic acid from 4-(bromomethyl)benzonitrile. (C) Azobenzene has been widely used in the field of polymer science to study the surface morphology and surface properties of polymers. In this thesis, we report the incorporation of cyclic azobenzene into a commercial polymer 2- (hydroxyethyl)methacrylate. Samples collected after 24 h from the reaction solution showed approximately 9% of incorporation of cyclic azobenzene into polymer compared to samples collected after 10 h, which showed approximately 6% incorporation.

Lipase-Mediated Enzymatic Catalysis For The Synthesis of New Chiral Polymers

Immobilized lipase B from Candida antarctica (N435) was investigated as a potential biocatalyst to generate silicone-based chiral polymers from monomers derived from the enzymatic dihydroxylation of bromobenzene. Several conditions and parameters have been investigated for this purpose and lipase transesterification preference to each of the free secondary alcohols in the chiral monomers was documented. The N435 was challenged with a series of substrates where the free alcohol moieties were systematically protected in order to study the substrate preference(s) for the transesterification reactions.

Exploring Capacity Building of Ontario Dental Hygiene Educators During National Curriculum Reform

In times of educational change, educators are given the task of implementing new initiatives that meet the needs of a changing environment; yet, they are often dismissed from developmental phases of the reform. This top-down structure deters educators’ personal capacity building as their knowledge, values, assumptions, and beliefs are not acknowledged or explicitly developed as part of the initiative. This study explored Ontario dental hygiene educators’ perspectives of how they may build personal capacity during an externally mandated national curriculum reform, the Entry-to-Practice Competencies and Standards for Canadian Dental Hygienists (National Competencies). Narratives were collected from 5 dental hygiene educators of diverse educational training and teaching organizations. Three themes emerged that included perceptions of structural influence, perceptions of learning access, and perceptions of identity. Each theme was linked to tasks that were required to build personal capacity for sustainable school change. The theoretical framework and the required tasks demonstrated the interconnectedness between educators, leaders, and the organization for building educators’ personal capacity.

Prevalencia de caries dental y parodontopatías según estratificación socioeconómica de la población escolar del Municipio de Cienega de Flores, N. L. \f 1982.

Tesis (Maestría en Salud Pública, Especialidad en Odontología Social) UANL

Contenido de fluoruros en el agua de consumo y sus efectos en el tejido dental : San Luis Potosí, México, 1988

Tesis (Maestría en Salud Pública con Especialidad en Odontología Social) UANL

Caries dental y diabetes mellitus no insulino dependiente

Tesis (Maestría en Salud Pública con Especialidad en Odontología Social) UANL.

La participación de los factores externos en el efecto preventivo de la fluoruración o el agua de consumo domestico en la caries dental

Tesis (Maestría en Salud Pública con Esp. en Odontología Social) U.A.N.L.

Diseño de un monitoreo de la dispersión de rayos X en radiografía dental

Tesis (Maestro en Ciencias con especialidad en Metrología de la Radiación) U.A.N.L.

Análisis de la dispersión de rayos-X en el aire en radiografía dental [por] Guillermo Escobedo Valle

Tesis (Maestría en Ciencias con Especialidad en Metrología de la Radiación) U.A.N.L.

Eficacia de las medidas preventivas para caries dental

Tesis (Maestría en Salud Pública con Especialidad en Odontología Social) U.A.N.L.

Prevalencia de caries dental en niños de edad preescolar. Estudio comparativo realizado en las ciudades de Monterrey y Apodaca, N.L.

Tesis ( Maestría en Ciencias Odontológicas con Especialidad en Odontología Infantil) U.A.N.L.

Medición de la longitud de arco dental y su relación con el género y edad en niños de 3 a 6 años que acuden al Posgrado de Odontopediatría de la UANL.

Tesis (Maestría en Ciencias Odontológicas con Especialidad en Odontopediatría) UANL, 2010.

Prevalencia de caries dental en preescolares de tres estratos socioeconómicos.

Tesis (Maestría en Ciencias con Especialidad en Odontología Infantil) UANL, 2010.

Separación padre-hijo : elección de los padres durante la atención dental en la Clínica de Posgrado de Odontopediatría de la UANL.

Tesis (Maestría en Ciencias Odontológicas con Especialidad en Odontopediatría) UANL, 2011.

Conocimiento de los padres de niños preescolares acerca de la primera visita dental de sus hijos.

Tesis (Maestría en Ciencias Odontológicas con Orientación en Odontopediatría) UANL, 2012.