Synthesis, characterization and activity of imidazolate-bridged and Schiff-base dinuclear complexes as models of Cu,Zn-SOD. A comparative study Daier, Veronica Andrea; Rivière, Eric; Mallet Ladeira, Sonia; Moreno, Diego Martin; Hureau, C; Signorella, Sandra Rosanna Two imidazolate-bridged diCuII and CuIIZnII complexes, [CuZn(dien)2(μ-Im)](ClO4)3·MeOH (1) and [Cu2(dien)2(μ-Im)](ClO4)3 (2) (Im = imidazole, dien = diethylenetriamine), and two complexes formed with Schiff base ligands, [CuZn(salpn)Cl2] (3) and [Cu2(salbutO)ClO4] (4) (H2salpn = 1,3-bis(salicylidenamino)propane, H3salbutO = 1,4-bis(salicylidenamino)butan-2-ol) have been prepared and characterized. The reaction of [Cu(dien)(ImH)](ClO4)2 with [Zn(dien)(H2O)](ClO4)2 at pH ≥ 11 yields complex 1; at lower pH, the Cu3Zn tetranuclear complex [{(dien)Cu(μ-Im)}3Zn(OH2)(ClO4)2](ClO4)3 (1a) forms as the main reaction product. X-ray diffraction of 1a reveals that the complex contains a metal centered windmill-shaped cation having three blades with a central Zn ion and three peripheral capping Cu(dien) moieties bound to the central Zn ion through three imidazolate bridges. The four complexes are able to disproportionate O2− in aqueous medium at pH 7.8, with relative rates 4 > 1 > 2 ≫ 3. [Cu2(salbutO)]+ (4) is the most easily reducible of the four complexes and exhibits the highest activity among the SOD models reported so far; a fact related to the ligand flexibility to accommodate the copper ion in both CuI and CuII oxidation states and the lability of the fourth coordination position of copper facilitating stereochemical rearrangements.

A high temperature study on thermodynamic, thermal expansion and electrical properties of BaCe0.4Zr0.4Y0.2O3−δ proton conductor Basbus, Juan Felipe; Arce, Mauricio Damián; Prado, Fernando Daniel; Caneiro, Alberto; Mogni, Liliana Verónica BaCe0.4Zr0.4Y0.2O3−δ (BCZY) was synthesized by solid state reaction, calcined and sintered at 1600 °C for 12 h. Crystal structure was studied by X-ray diffraction (XRD). Morphology and porosity were determined by scanning electron microscopy (SEM). Crystalline structure, oxygen non-stoichiometry, linear expansion and electrical conductivity were characterized under oxidizing and reducing atmosphere by high temperature X-ray diffraction (HT-XRD), thermogravimetry (TG), dilatometry, and electrochemical impedance spectroscopy (EIS), respectively. Chemical stability under CO2-rich atmosphere was evaluated by TG. BCZY electrical conductivity was studied by EIS under O2-containing atmosphere with water vapor (2% H2O) and heavy water vapor (2% D2O) in order to evaluate protonic conductivity. Throughout these techniques, interstitial proton incorporation/loss was observed under oxidizing and reducing atmosphere, between 300 and 500 °C. The conductivity presents two contributions. The bulk conductivity at high frequencies takes the same value regardless wet oxidizing or reducing atmosphere, decreasing its value in presence of D2O vapor supporting H-conductivity. On the other hand, the grain boundary conductivity was strongly dependent on the nature of wet atmosphere.

Micro and nanoparticles of native and modified cassava starches as carriers of the antimicrobial potassium sorbat Alzate Calderón, Paola Carolina; Zalduendo, María Mercedes; Gerschenson, Lia Noemi; Flores, Silvia Karina Cross-linked and/or acetylated cassava starches were synthesized and characterized. The acetylation increased the water retention capacity and the solubility in water while the higher level of cross-linking produced the opposite effect on starch. Native (NCS) and acetylated cassava starches (ACS) were used to generate starch micro- and nanoparticles by the dialysis technique.The nanoparticle fraction was around 1.8 g 100 g1 and 12 g 100 g1 (starch dry basis) for NCS and ACS, respectively. The nanoparticle sizes were around 23?255nm with zeta potential extending from 4 to 44mV, while the microscopic fractions ranged 5?87mm. In addition, the capacity of particles to support potassium sorbate (KS) was tested. NCS and ACS particles supported a similar quantity of KS (1400 ppm) and the presence of antimicrobial decreased the particle size for NCS. The precipitation in ethanol technique was also used to generate microparticles where the particles generated from acetylated starches were smaller (8?58mm) than those from native ones (30?227 mm). The KS content that these particles could incorporate was around 2020 ppm. The applied technique modulated the average dimension of the particles obtained, as well as the antimicrobial retention capacity. These innovative materials could bepotentially helpful for shelf life extension by the contribution to the KS stabilization to be incorporated in the bulk of food products.

Análisis polínico de mieles inmaduras en el sector oeste de las yungas de Jujuy (Argentina) Méndez, Magalí Verónica; Sánchez, Ana Carina; Flores, Fabio Fernando; Lupo, Liliana Concepcion Con el objetivo de conocer los recursos nectaríferos utilizados por Apis mellifera L. en el sector oeste de las Yungas, se examinaron 14 muestras de miel inmadura y dos de miel madura correspondientes a los períodos apícolas 2011?2012 y 2012?2013, pertenecientes a un apiario de la localidad de Tilquiza (Jujuy). Las muestras fueron procesadas de acuerdo a las técnicas melisopalinológicas convencionales con posterior acetólisis. Se identificaron un total de 53 tipos polínicos pertenecientes a 31 familias botánicas, siendo las familias con mayor riqueza polínica Asteraceae y Fabaceae. Se identificaron como recursos dominantes a Crinodendron tucumanum en setiembre de 2011, Blepharocalyx salicifolius en noviembre y diciembre de 2011 y al tipo Scutia/Condalia en octubre de 2012. Como aportes secundarios se registraron a Allophylus edulis, Zanthoxylum, Parapiptadenia excelsa, Baccharis, Gnaphalium, Eucalyptus y tipo Cissus, destacándose la influencia de la flora nativa de las Yungas. A partir de este estudio se pudo conocer la dinámica del ingreso de néctar a la colmena y valorar aquellos recursos que no se encuentran presentes en las mieles maduras y que son de importancia para el desarrollo de la colmena.

Memorias y usos públicos del pasado en torno a la "lucha antisubversiva": Notas sobre Carlos Sacheri y Jordán Bruno Genta; Memories and public uses of the past throughout the “antisubversive struggle”: Notes about Carlos Sacheri and Jordán Bruno Genta Cersósimo, Facundo En 1974 fueron asesinados en la vía pública Jordán Bruno Genta y Carlos Alberto Sacheri. Para la época ambos intelectuales eran referentes de sectores nacionalistas y católicos que en el convulsionado escenario político argentino promovieron la necesidad de la “lucha antisubversiva”. A partir de reconstruir los diversos usos públicos de los que fueron objeto luego de sus asesinatos, el presente artículo estudia el proceso de elaboración de las memorias alternativas que buscaron legitimar la actuación represiva de las Fuerzas Armadas tras el retorno de la democracia en 1983. Al final del artículo también se reflexionará acerca del lugar del historiador al momento abordar aquellos fragmentos del pasado marcados por la violencia política, y que fueron recortados y descontextualizados para ser utilizados en los combates memoriales analizados.; In 1974 where murdered in the public space Jordan Bruno Genta y Carlos Alberto Sacheri. By the time both intelectuals were an important reference of nationalists and catholic groups that, in the agitated political scenario of Argentina, promoted the need of an “antisubversive struggle”. As from the reconstruction of the different public wich they were subject, the present article studies the process of elaboration of alternative memories wich seek to legitimate the repressive action of the Armed Forces after the return of Democracy at 1983. At the closing of the article is also a reflection about the role of the historian at the moment of analyze those fragments of the past signed by the political violence, wich were trimmed and decontextualized to be used in the memorial combats analyzed.

Nuclear Magnetic Resonance Relaxation Studies in Shale Ramia, Maximo Elias; Martín, C. A. The present work involves a comprehensive experimental study of proton (1 H) nuclear magnetic resonance (NMR) transversal relaxation in shale. The sample studied belongs to the “Vaca Muerta” formation of the Neuquén basin, Argentina. The results show that the relaxation process is governed by anomalous diffusion processes in micro-pores. These processes result from the combination of interactions between the liquid molecules and the pore walls, whose structure is characterized by both large tortuosity and abundance of paramagnetic impurities, giving rise to local strong time-dependent magnetic field gradients. In addition, a simultaneous experimental method of data fitting is presented which allows processing all the relaxation profiles within a single time domain. Thus, yielding results univocally related to the complete set of relaxation data.

The UVB1 Vitamin D Analogue Inhibits Colorectal Carcinoma Progression Ferronato, María Julia; Alonso, Eliana Noelia; Gandini, Norberto Ariel; Fermento, María Eugenia; Villegas, María Emilia; Quevedo, Mario Alfredo; Arevalo, Julian; López Romero, Alejandro; Rivadulla, Marcos Lois; Gómez, Generosa; Fall, Yagamare; Facchinetti, Maria Marta; Curino, Alejandro Carlos Vitamin D has been shown to display a wide variety of antitumour effects, but their therapeutic use is limited by its severe side effects. We have designed and synthesized a Gemini vitamin D analogue of calcitriol (UVB1) which has shown to display antineoplastic effects on different cancer cell lines without causing hypercalcemia. The aim of this work has been to investigate, by employing in silico, in vitro, and in vivo assays, whether UVB1 inhibits human colorectal carcinoma progression. We demonstrated that UVB1 induces apoptotic cell death and retards cellular migration and invasion of HCT116 colorectal carcinoma cells. Moreover, the analogue reduced the tumour volume in vivo, and modulated the expression of Bax, E-cadherin and nuclear β-catenin in tumour animal tissues without producing toxic effects. In silico analysis showed that UVB1 exhibits greater affinity for the ligand binding domain of vitamin D receptor than calcitriol, and that several characteristics in the three-dimensional conformation of VDR may influence the biological effects. These results demonstrate that the Gemini vitamin D analogue affects the growth of the colorectal cancer and suggest that UVB1 is a potential chemotherapeutic agent for treatment of this disease.

Fever-range hyperthermia improves the anti-apoptotic effect induced by low pH on human neutrophils promoting a proangiogenic profile Erra Diaz, Fernando Alberto; Dantas, Ezequiel Carlos; Cabrera, Maia Diana Eliana; Arriola Benitez, Paula Constanza; Delpino, María Victoria; Duette, Gabriel; Rubione, Julia; Sanjuan, Norberto Aníbal; Trevani, Analía Silvina; Geffner, Jorge Raúl Neutrophils have the shortest lifespan among leukocytes and usually die via apoptosis, limiting their deleterious potential. However, this tightly regulated cell death program can be modulated by pathogen-associated molecular patterns (PAMPs), danger-associated molecular pattern (DAMPs), and inflammatory cytokines. We have previously reported that low pH, a hallmark of inflammatory processes and solid tumors, moderately delays neutrophil apoptosis. Here we show that fever-range hyperthermia accelerates the rate of neutrophil apoptosis at neutral pH but markedly increases neutrophil survival induced by low pH. Interestingly, an opposite effect was observed in lymphocytes; hyperthermia plus low pH prevents lymphocyte activation and promotes the death of lymphocytes and lymphoid cell lines. Analysis of the mechanisms through which hyperthermia plus low pH increased neutrophil survival revealed that hyperthermia further decreases cytosolic pH induced by extracellular acidosis. The fact that two Na+/H+ exchanger inhibitors, 5-(N-ethyl-N-isopropyl) amiloride (EIPA) and amiloride, reproduced the effects induced by hyperthermia suggested that it prolongs neutrophil survival by inhibiting the Na+/H+ antiporter. The neutrophil anti-apoptotic effect induced by PAMPs, DAMPs, and inflammatory cytokines usually leads to the preservation of the major neutrophil effector functions such as phagocytosis and reactive oxygen species (ROS) production. In contrast, our data revealed that the anti-apoptotic effect induced by low pH and hyperthermia induced a functional profile characterized by a low phagocytic activity, an impairment in ROS production and a high ability to suppress T-cell activation and to produce the angiogenic factors VEGF, IL-8, and the matrix metallopeptidase 9 (MMP-9). These results suggest that acting together fever and local acidosis might drive the differentiation of neutrophils into a profile able to promote both cancer progression and tissue repair during the late phase of inflammation, two processes that are strongly dependent on the local production of angiogenic factors by infiltrating immune cells.

Very fast dissolving acid carboxymethylcellulose-rifampicin matrix: development and solid-state characterization Luciani Giacobbe, Laura Carolina; Ramírez Rigo, María Veronica; Garro Linck, Yamila; Monti, Gustavo Alberto; Manzo, Ruben Hilario; Olivera, Maria Eugenia One of the main obstacles to the successful treatment of tuberculosis is the poor and variable oral bioavailability of rifampicin (RIF), which is mainly due to its low hydrophilicity and dissolution rate. The aim of this work was to obtain a hydrophilic new material that allows a very fast dissolution rate of RIF and therefore is potentially useful in the development of oral solid dosage forms. The acid form of carboxymethylcellulose (CMC) was co-processed with RIF by solvent impregnation to obtain CMC-RIF powder, which was characterized by polarized optical microscopy, powder x-ray diffraction, DSC-TGA, hot stage microscopy, 13C and 15N solid-state NMR and FT-IR spectroscopy. In addition, the CMC-RIF matrices were subjected to water uptake and dissolution studies to assess hydrophilicity and release kinetics. CMC-RIF is a crystalline solid dispersion. Solid-state characterization indicated that no ionic interaction occurred between the components, but RIF crystallized as a zwitterion over the surface of CMC, which drastically increased the hydrophilicity of the solid. The CMC-RIF matrices significantly improved the water uptake of RIF and disintegrated in a very short period immediately releasing RIF. As CMC improves the hydrophilicity and delivery properties of RIF, CMC-RIF is very useful in the design of oral solid dosage forms with very fast dissolution of RIF, either alone or in combination with other antitubercular drugs.

Kinetic of the thermal decomposition of disubstituted tetroxanes Bordón, Alexander Germán; Pila, Andrea Natalia; Jorge, María Cristina; Jorge, Lilian Cristina; Profeta, Mariela Inés; Romero, Jorge Marcelo; Jorge, Nelly Lidia The thermal decomposition of diphenyl diperoxide (DFT) and dibutanal diperoxide (DPG) were investigated over the temperature range 130 to 166°C. They were found to be first order with a high degree of conversion (60%). Arrhenius parameters were calculated: activation energy, 108 kJ mol-1 and pre-exponential factor, 6.5 109 s -1 for DFT and 80.8 kJ mol-1 and pre-exponential factor, 1.8 109 s - 1 for DPG. The principle decomposition products were aldehyde (about 1.9 mole per mole DFT and 2.0 mole per mole DPG) and oxygen molecule. All observations were interpreted in terms of decomposition pathways initiated by O-O homolysis. The corresponding activation parameters for the reaction of DFT in methanol (ΔH0# = 103.8 ± 3.3 kJ mol-1 ; ΔS0# = -69.9 ± 7.5 J mol-1 K -1 ; ΔG0# = 133.1 ± 3.3 kJ mol-1) were compared with values obtained for PDG thermolysis in the same solvents (ΔH0# = 75.4 ± 2.9 kJ mol-1 ; ΔS0# = -189.2 ± 2.5 J mol-1 K -1 ; ΔG0# = 157.4 ± 2.9 kJ mol-1). Furthermore, the pertinent substituent effect on the peroxidic bond strength of those molecules in solution was evaluated.

El Fondo Tecnológico Argentino informa que se ha prorrogado la fecha límite para la presentación de propuestas de la convocatoria ANR P+L 2016 C2.

Un equipo de investigadores del Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas de la Universidad Nacional de La Plata realizó importantes aportes en el estudio de nanomateriales para las áreas de energía y de salud. El trabajo a escala nanométrica permite potenciar las propiedades y mejorar la eficiencia de los materiales.

El Fondo Tecnológico Argentino (FONTAR) anuncia los resultados del proceso de reconsideración para la convocatoria ANR Plan Argentina Innovadora 2020 Temas Estratégicos 2015 mediante Resolución de Directorio N°484/16.

El Fondo Tecnológico Argentino (FONTAR) anuncia los resultados del proceso de evaluación para la convocatoria ANR TEC 2016 C1 mediante Resolución de Directorio N°481/16.

El Fondo Tecnológico Argentino (FONTAR) anuncia los resultados del proceso de reconsideración de la convocatoria FIN SET 2015 mediante Resolución N° 480/16.

El Fondo Tecnológico Argentino (FONTAR) anuncia los resultados del proceso de reconsideración para la convocatoria ANR 2200 2015 C3 mediante Resolución de Directorio N°486/16.

El Fondo Tecnológico Argentino (FONTAR) anuncia los resultados del proceso de evaluación para la convocatoria ANR 3500 2016 C1 mediante Resolución de Directorio N°492/16.

El Fondo Tecnológico Argentino (FONTAR) anuncia los resultados del proceso de reconsideración para la convocatoria ANR P+L 2015 C2 mediante Resolución de Directorio N°482/16.

A través de un taller destinado principalmente a investigadores de instituciones públicas y privadas, la Agencia Nacional de Promoción Científica y Tecnológica presentó los instrumentos de financiamiento destinados a generar nuevas competencias tecnológicas.

El Fondo para la Investigación Científica y Tecnológica (FONCYT) anuncia los resultados del proceso de reconsideración para la convocatoria PICT 2015 mediante Resolución de Presidencia de Agencia N° 498/16 con fecha 27/09/2016.