Effects of the Addition of Ortho

The synthetic tetrapyrrole macrocycles, such as porphyrins (H2P) and phthalocyanines (H2Pc), exhibit interesting physicochemical properties suitable to be used in modern technology. For many applications, those species should be trapped or fixed inside graphite, hydrotalcites, silica, TiO2, or polymers. Methodologies for the optimization of the properties of porphyrins, trapped or fixed inside polymers, have been barely developed. Our research works in the development of methodologies for the optimization of incorporation and display of properties of tetrapyrrole macrocycles inside inorganic, polymeric, or hybrid networks. This paper shows some results about the effect of the spatial disposition of the amine (–NH2) groups attached on the periphery of substituted tetraphenylporphyrins, on the Nylon 66 structure and on the display of the physicochemical properties of the trapped macrocycles. Nylon 66 was synthesized from adipoyl chloride and hexamethylenediamine in presence of tetraphenylporphyrins substituted with –NH2 groups localized at the ortho- or para-positions of the phenyls. Cobalt complexes formation was used to quantify the amount of porphyrins in the polymer fibers. Characterization results show that the spatial position of amine groups of the porphyrins has important structural and textural effect on the Nylon 66 fibers and on the fluorescence of the porphyrins integrated into the fibers

Comparative Study of the Optical and Textural Properties of Tetrapyrrole Macrocycles Trapped Within ZrO2, TiO2, and SiO2 Translucent Xerogels

The entrapping of physicochemical active molecules inside mesoporous networks is an appealing field of research due to the myriad of potential applications in optics, photocatalysis, chemical sensing, and medicine. One of the most important reasons for this success is the possibility of optimizing the properties that a free active species displays in solution but now trapped inside a solid substrate. Additionally it is possible to modulate the textural characteristics of substrates, such as pore size, specific surface area, polarity and chemical affinity of the surface, toward the physical or chemical adhesion of a variety of adsorbates. In the present document, two kinds of non-silicon metal alkoxides, Zr and Ti, are employed to prepare xerogels containing entrapped tetrapyrrolic species that could be inserted beforehand in analogue silica systems. The main goal is to develop efficient methods for trapping or binding tetrapyrrole macrocycles inside TiO2 and ZrO2 xerogels, while comparing the properties of these systems against those of the SiO2 analogues. Once the optimal synthesis conditions for obtaining translucent monolithic xerogels of ZrO2 and TiO2 networks were determined, it was confirmed that these substrates allowed the entrapment, in monomeric form, of macrocycles that commonly appear as aggregates within the SiO2 network. From these experiments, it could be determined that the average pore diameters, specific surface areas, and water sorption capacities depicted by each one of these substrates, are a consequence of their own nature combined with the particular structure of the entrapped tetrapyrrole macrocycle. Furthermore, the establishment of covalent bonds between the intruding species and the pore walls leads to the obtainment of very similar pore sizes in the three different metal oxide (Ti, Zr, and Si) substrates as a consequence of the templating effect of the encapsulated species

On the Selective Isolation of Actinobacteria from Different Mexican Ecosystems

Actinobacteria isolated from less studied sites on our planet represent a huge opportunity for the discovery of novel microorganisms that may produce unique compounds with biological activity. The class actinobacteria encompasses 80% of the microbes that produce the antibacterial compounds used in medicine today. However, the resistance acquired/showed by pathogenic microorganisms opens the opportunity to explore Mexican ecosystems as a source of novel actinobacteria. Air samples have shown to be an excellent site of study, marine ecosystems which include sediments and marine organisms are important sources of novel actinobacteria and soil samples are still a promising source to isolate this microbial group. The isolation of novel actinobacteria is a dynamic strategy that depends on the expertise, patience, and talent of the techniques applied and needs to be fully explored to untap the unknown actinobacterial diversity with potential in biology

Cien días vistos por CINEP (no. 66 abr 2009)

En la edición virtual número 66 de la revista Cien Días vistos por CINEP, presentamos una serie de artículos que nos permiten hacer un balance coyuntural sobre cómo va la construcción de la paz en Colombia, desde distintas dinámicas políticas, sociales y económicas vividas en el país durante los tres primeros meses del año y cómo se conectan con dinámicas estructurales de larga duración. Las cifras del conflicto colombiano, la situación de las víctimas con relación a la ley que cursa en el Congreso de la República, la situación de los indígenas en el país, el tema de las carreteras, las marchas y su relación con los movimientos sociales, el rearme paramilitar, la crisis económica con relación a el ahorro en el país, la concentración de poder en el ejecutivo y algunas voces desde la región, son los temas que usted podrá encontrar y que busca elaborar un análisis crítico sobre la política de seguridad democrática y su aporte real en la construcción de una paz integral y sostenible para los ciudadanos del país.I. Editorial De "Ganar la guerra" a "Construir la Paz" Paz Por Luis Guillermo Guerrero ¿En qué está la Paz? : Cifras del conflicto armado Por Alejandro Angulo S.J, Valentina Zarama, William Rozo, Alejandro Burgos II. Conflicto Rearme paramilitar: Sin novedad en el Frente Teófilo Vásquez III. Movimientos Sociales ¿Hacia dónde marcha el País? Por Mauricio Archila y Martha Cecilia García Tras las cifras del secuestro Por Vladimir Caraballo IV. Política Del Liberalismo por accidente a la concentración del poder Por Maria Clara Torres Superando la crisis con infraestructura ¿Promesas nuevas o promesas viejas? Por Silvia Otero Las víctimas en la arena democrática Por Fernando Sarmiento ¿Es inevitable la nueva reeleción de Uribe? Por Alejandro Vargas V. Derechos Humanos Defender a los defensores Por Camilo Borrero VI. Economía Ahorro financiero y crisis de la economía Por Jorge Iván González VII. Región Pueblos indígenas, control territorial y desarrollo. El caso de la Sierra Nevada de Santa Marta Por Liliana Múnera Piezas del rompecabezas Por Sergio Coronado La Masacre del 16 de mayo de 1998 en Barrancabermeja. Una historia de resistencia, persistencia y búsqueda de justicia Por John J. Montoya Rivera S

ESICM LIVES 2016: part two : Milan, Italy. 1-5 October 2016.

Meeting abstrac