This research focused on the synthesis of a functional alginate-based material via chemical modification processes with two steps: oxidation and reductive amination. In previous alginate functionalization with a target molecule such as cysteine, the starting material was purified and characterized by UV-Vis, 1H-NMR and HSQC. Additionally, the application of FT-IR techniques during each step of alginate functionalization was very useful, since new bands and spiked signals around the pyranose ring (1200–1000 cm−1) and anomeric region (1000–750 cm−1) region were identified by a second derivative. Additionally, the presence of C1-H1 of β-D-mannuronic acid residue as well as C1-H1 of α-L-guluronic acid residue was observed in the FT-IR spectra, including a band at 858 cm−1 with characteristics of the N-H moiety from cysteine. The possibility of attaching cysteine molecules to an alginate backbone by oxidation and post-reductive amination processes was confirmed through 13C-NMR in solid state; a new peak at 99.2 ppm was observed, owing to a hemiacetal group formed in oxidation alginate. Further, the peak at 31.2 ppm demonstrates the presence of carbon -CH2-SH in functionalized alginate—clear evidence that cysteine was successfully attached to the alginate backbone, with 185 μmol of thiol groups per gram polymer estimated in alginate-based material by UV-Visible. Finally, it was observed that guluronic acid residue of alginate are preferentially more affected than mannuronic acid residue in the functionalization.

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Theoretical and experimental studies on the energetic, structural and some other relevant physicochemical properties of the antioxidant tyrosol (1), hydroxytyrosol (1OH) molecules and the corresponding radicals 1 rad• and 1O rad • are reported in this work. The experimental values of the gas-phase enthalpy of formation, Δ f H m 0 (g), in kJ•mol −1 , of 1 (−302.4 ± 3.4) and 1OH (−486.3 ± 4.1) have been determined. Quantum chemical calculations, at DFT (M05-2X) and composite ab initio G3 and G4 levels of theory, provided results that served to (i) confirm the excellent consistency of the experimental measurements performed, (ii) establish that the stabilizing effect of H-bond of hydroxyethyl chain and aromatic ring (OH•••π interaction) is smaller in radicals than in parent molecules, (iii) deducecombining experimental data in isodesmic reactionsΔ f H m 0 (g) of radicals 1 rad • (−152.3 ± 4.4 kJ• mol −1 ) and 1O rad • (−370.6 ± 3.8 kJ•mol −1 ), (iv) estimate a reliable O−H bond dissociation enthalpy, BDE of 1 (368.1 ± 5.6 kJ•mol −1 ) and of 1OH (333.7 ± 5.6 kJ• mol −1 ), and (v) corroborateusing "BDE criteria"than 1OH is a more effective antioxidant than 1.

La presente conversación entre Ana Valderrama y Jorge Jáuregui intenta proveer una mirada crítica sobre el proyecto y la gestión de la vivienda social en Latinoamérica. El artículo plantea el desafío de pensar la complejidad física, social y ambiental que implica hacer ciudad en contextos dinámicos, altamente conflictivos, donde el proyecto de la vivienda trasciende la “casa” e incorpora todas las infraestructuras necesarias para propiciar la cohesión social. Así, la arquitectura podría ser pensada como una urbanidad catalizadora de la vida social y colectiva, rearticuladora del territorio y potenciadora de las identidades locales. En el transcurso del diálogo, Jorge Jáuregui recorre críticamente el legado de la modernidad, proponiendo alternativas a la tabla rasa, la segregación por funciones, la repetición infinita de la misma tipología y el concepto de desarrollo. Además, se despliegan una serie de temas prioritarios vinculados al diseño y la gestión de la vivienda de obra pública, que debieran estar en la agenda de las políticas públicas de los gobiernos latinoamericanos. Se espera que este escrito interpele los modos habituales de pensar las ciudades latinoamericanas tendiendo a modelos de justicia ambiental, social y física, en relación con estrategias para dinamizar la economía popular relativas a la generación de trabajo y renta, articuladas al urbanismo social.

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