ROS production by endogenously generated Protoporphyrin IX in murine leukemia cells Diez, Berenice Andrea; Cordo Russo, Rosalia Ines; Teijo, Maria Julieta; Hajos, Silvia Elvira; Batlle, Alcira María del C.; Fukuda, Haydee Endogenous production of Protoporphyrin IX (Pp1X) is succesfully exploited for photodynamic therapy (PDT) on malignant cells, following 5-aminolevulinic acid (ALA) administration and light irradiation. This treatment kills cancer cells by damaging organelles and impairing metabolic pathways via cellular reactive oxygen species (ROS) generation. We studied the efficiency of Pp1X synthetized from ALA on ROS generation, in the vincristine resistant (LBR-V160), Doxorubicin resistant (LBR-D160) and sensitive (LBR-) murine leukemia cells. Cells were incubated 4hr with 1mM ALA and then irradiated during different times with flourescent light. One hour later, production of ROS was analyzed by flow cytometry using different flourescent probes: Hydroethidine (HE) for superoxide anion, 2,7 Dichlorodihydroflourescein diacetate (DCFH-DA) for hydrogen peroxide; mitochondrial damage was examined with 3,3 Dinexyloxacarbocyanine iodide (DIOC6). We found that superoxide anion production in the three cell lines increased with irradiation time whereas no peroxide hydrogen was detected. Mitochondrial damage also increased in an irradiation time dependent manner, being higher in the Vincristineresistant line. Previous studies have demonstrated that apoptotic cell death increased with irradiation time, which is consistent with these results, indicating that ROS are critical in ALA-PDT efficiency to kill malignant cells.  

A Neural Network Model for Estimating the Particle Size Distribution of Dilute Latex from Multiangle Dynamic Light Scattering Measurements Gugliotta, Luis Marcelino; Stegmayer, Georgina; Clementi, Luis Alberto; González, Verónica Doris Guadalupe; Minari, Roque Javier; Leiza, José; Vega, Jorge Ruben The particle size distribution (PSD) of dilute latex was estimated through a general regression neural network (GRNN) that was supplied with PSD average diameters derived from multiangle dynamic light scattering (MDLS) measurements. The GRNN was trained with a large set of measurements that were simulated from unimodal normal-logarithmic distributions representing the PSDs of polystyrene (PS) latexes. The proposed method was first tested through three simulated examples involving different PSD shapes, widths, and diameter ranges. Then the GRNN was employed to estimate the PSD of two PS samples; a latex standard of narrow PSD and known nominal diameter, and a latex synthesized in our laboratory. Both samples were also characterized through independent techniques (capillary hydrodynamic fractionation, transmission electron microscopy, and disc centrifugation). For comparison, all examples were solved by numerical inversion of MDLS measurements through a Tikhonov regularization technique. The PSDs estimated by the GRNN gave more accurate results than those obtained through other conventional techniques. The proposed method is a simple, effective, and robust tool for characterizing unimodal PSDs.

Reversible Ion Induced Modification of Consequent Secondary Electron Emission in Porous Silicon Ruano Sandoval, Gustavo Daniel; Ferron, Julio; Koropecki, Roberto Roman We report measurements of secondary electron emission (SEE) induced by electron and ion bombardment on porous silicon (PS). We found that electron induced emission is strongly reduced by ion bombardment, and that this reduction is reversible. The reduction effect is large even for ion fluxes much lower compared to that of the electron beam.
We attribute this effect to changes in the charge distribution of the surface dipole originated in the difference between ion and electron charge deposition depths. The nanostructure of PS plays an important role in this effect as well as in the reversibility of the process. We think that this effect could be useful in the dynamic centering and monitoring of ion and electron beams in electron spectroscopy.

Effect of anthelmintics on reproductive performance and first lactation culling rate in heifers Mejía, M. E.; Perri, Adrián Francisco; Miglierina, M. M.; Formía, N.; Becu, Damasia; Lacau, Isabel María Female Holstein calves were treated with ivermectin from birth to first oestrus to study the effect of parasitic burden and anthelmintic treatment on reproductive and productive performance. First oestrus, age at first service and age at calving were advanced by 30, 70 and 110 days, respectively (P<0·05), in ivermectin-treated animals compared with controls. No significant differences were observed in the conception rate, the number of services and the characteristics of the newborn calves and any problems at calving between the two groups. Daily milk yield, fat content in milk during first lactation, and the concentrations of growth hormone, insulin-like growth factor type 1, insulin and prolactin in serum were similar in both groups of cows. Culling during the first lactation was more common in untreated (47 per cent) than in treated (11 per cent) cows (P<0·05).

Essential oils of plants used in home medicine in North of Argentina Dambolena, José Sebastián; Zunino, María Paula; Lucini, Enrique Iván; Zygadlo, Julio Alberto; Rotman, Alicia Dora; Ahumada, Osvaldo Héctor; Biurrum, Fernando Essential oils of the medicinal plants Satureja parvifolia, Satureja boliviana, Hyptis mutabilis, Leonorus sibiricus, Lippia turnerifolia, Xeroaloysia ovatifolia and Acantholippia salsoloides of north Argentina were analyzed by GC and GC/MS. Seventy-five compounds, representing more than 90% of the oils, were identified. The oils of both populations of S. parvifolia studied were characterized by a high content of piperitone (41.9% and 46%) and piperitenone oxide (50.1% and 49.3%). The most abundant constituents identified in S. boliviana oil were iso menthone (33%) and pulegone (25.3%). Hyptis mutabilis oil was characterized by b-phellandrene (27.1%) and b-caryophyllene (59.4%). The main constituents of L. sibiricus oil were the sesquiterpene hydrocarbons b-caryophyllene (35.2%), a-humulene (22.1%) and a-cubebene (18.4%). The oils of L. turnerifolia and X. ovatifolia also had a high content of sesquiterpenes. These were a-humulene (40.1%) and b-bisabolene (22.9%) in the oil of L. turnerifolia and b-caryophyllene (14.4%), (E)-nerolidol (10.5%), spathulenol (21.6%) and epi-a-cadinol (21.9%) in the oil of X. ovatifolia. Acantholippia salsoloides oil from Jujuy accumulated high contents of p-cymene (52.8%) and thymol (46.8%), while the oil from the population of Catamarca accumulated a-thujone (98.8%) as the major compound. 

Macroporous monolithic polymers: preparation and applications Arrua, Ruben Dario; Strumia, Miriam Cristina; Alvarez Igarzabal, Cecilia Ines In the last years, macroporous monolithic materials have been introduced as a new and useful generation of polymers used in different fields. These polymers may be prepared in a simple way from a homogenous mixture into a mold and contain large interconnected pores or channels allowing for high flow rates at moderate pressures. Due to their porous characteristics, they could be used in different processes, such as stationary phases for different types of chromatography, high-throughput bioreactors and in microfluidic chip applications. This review reports the contributions of several groups working in the preparation of different macroporous monoliths and their modification by immobilization of specific ligands on the products for specific purposes.

El voto peronista en Corrientes. Análisis de las elecciones ejecutivas entre 1946 y 1955 Solís Carnicer, María del Mar El surgimiento del peronismo en la política Argentina significó una ruptura con respecto a las formas de entender y hacer política en el país. Estas transformaciones se reprodujeron en cada una de las provincias y se reflejan en los cambios que se dieron en la configuración de los partidos políticos, en la redefinición de los liderazgos y en las prácticas. La provincia de Corrientes no fue ajena a estas transformaciones a pesar de ser una provincia marcada por una larga tradición de gobiernos conservadores y el predominio de partidos provinciales tradicionales. Sin embargo, y a diferencia de lo ocurrido en otras provincias, en Corrientes el cambio se dio paulatinamente. Por ejemplo, en las elecciones de 1946 el peronismo no resulto victorioso, lo que recién ocurrirá en 1948, luego de una intervención federal. En este trabajo se busca analizar ese proceso peculiar a través del estudio de las elecciones provinciales llevadas a cabo entre 1946 y 1955. En particular, el análisis se centra en examinar la evolución y distribución del voto peronista en la provincia, las mudanzas de las preferencias del electorado provincial y la influencia del sistema electoral en el resultado de las elecciones.

Síntesis y caracterización de pinturas selectivas de Co3O4 para superficies selectivas en colectores solares de baja temperatura Gardey Merino, María Celeste; Belda, R.; Lascalea, Gustavo Enrique; Vazquez, Patricia Graciela Para aumentar el rendimiento energético de los calefones solares se recubre al colector con superficies selectivas, donde las pinturas selectivas representan una alternativa económica. El Co3O4 utilizado como pigmento en pinturas selectivas se ha obtenido por diferentes métodos, pero mediante síntesis por combustión se han encontrado pocas referencias respecto a la temática. Se obtuvieron micropartículas de Co3O4 mediante una vía de combustión. Luego, por Difracción de Rayos X se determinó la estructura cúbica del Co3O4, además, por Microscopía Electrónica de Barrido, se observó una morfología compacta y aglomeración y mediante Microscopía Electrónica de Transmisión se apreciaron tamaños de partícula de 1m aprox. La absorbancia espectral en un rango de 500 a 1100 nm de longitud de onda de las películas formadas a partir de los pigmentos de Co3O4 sobre vidrio y aluminio está entre 0.92 y 0.96 menor al obtenido para una pintura comercial que está entre 0.95 y 0.97.

Quantifying the Contribution of Organisms to the Provision of Ecosystem Services Luck, Gary; Harrington, Richard; Harrison, Paula A.; Kremen, Claire; Berry, Pam M.; Bugter, Rob; Dawson, Terence P.; de Bello, Francesco; Diaz, Sandra Myrna; Feld, Christian K.; Haslett, John R.; Hering, Daniel; Kontogianni, Areti; Lavorel, Sandra; Ronsevell, Mark; Samways, Michael J.; Sandin, Leonard; Settele, Josef; Sykes, Martin T.; van den Hove, Sybille; Wandewalle, Marie; Zobel, Martin Research on ecosystem services has grown rapidly over the last decade. Two conceptual frameworks have been published to guide ecological assessments of organisms that deliver services?the concepts of service-providing units (SPUs) and ecosystem service providers (ESPs). Here, we unite these frameworks and present an SPU-ESP continuum that offers a coherent conceptual approach for synthesizing the latest developments in ecosystem service research, and can direct future studies at all levels of organization. In particular, we show how the service-provider concept can be applied at the population, functional group, and community levels. We strongly emphasize the need to identify and quantify the organisms and their characteristics (e.g., functional traits) that provide services, and to assess service provision relative to the demands of human beneficiaries. We use key examples from the literature to illustrate the new approach and to highlight gaps in knowledge, particularly in relation to the impact of species interactions and ecosystem dynamics on service provision.

Recomendaciones para gestantes con diabetes: conclusiones del Consenso reunido por convocatoria del Comité de Diabetes y Embarazo de la SAD Faingold, María Cristina; Lamela, C.; Gheggi, María Soledad; Lapertosa, S.; Di Marco, Ingrid; Basualdo, María Natalia; Rovira, G.; Jawerbaum, Alicia Sandra; Glatstein, Lucia; López, C.; Caamaño, A.; Salcedo, L.; Rodriguez, M. E.; Alvariñas J. La diabetes gestacional es una alteración de la tolerancia a la glucosa con severidad variable que comienza o es reconocida por primera vez durante el embarazo en curso. Esta definición es válida independientemente del tratamiento que requiera, de si se trata de una diabetes previa al embarazo que no fue diagnosticada, o si la alteración del metabolismo hidrocabonado persiste al concluir la gestación. El presente trabajo, realizado por Consenso en el Comité de Diabetes y Embarazo de la Sociedad Argentina de Diabetes, actualiza los criterios diagnósticos de la diabetes gestacional, así como también el tratamiento, seguimiento y control de la patología tanto durante la gestación, como en el parto y el puerperio.

Infinite horizon MPC with non-minimal state space feedback González, Alejandro Hernán; Pérez, José; Odloak, Darci In the MPC literature, stability is usually assured under the assumption that the state is measured. Since the closed-loop system may be nonlinear because of the constraints, it is not possible to apply the separation principle to prove global stability for the output feedback case. It is well known that, a nonlinear closed-loop system with the state estimated via an exponentially converging observer combined with a state feedback controller can be unstable even when the controller is stable. One alternative to overcome the state estimation problem is to adopt a non-minimal state space model, in which the states are represented by measured past inputs and outputs [P.C. Young, M.A. Behzadi, C.L. Wang, A. Chotai, Direct digital and adaptative control by input–output, state variable feedback pole assignment, International Journal of Control 46 (1987) 1867–1881; C. Wang, P.C. Young, Direct digital control by input–output, state variable feedback: theoretical background, International Journal of Control 47 (1988) 97–109]. In this case, no observer is needed since the state variables can be directly measured. However, an important disadvantage of this approach is that the realigned model is not of minimal order, which makes the infinite horizon approach to obtain nominal stability difficult to apply. Here, we propose a method to properly formulate an infinite horizon MPC based on the output-realigned model, which avoids the use of an observer and guarantees the closed loop stability. The simulation results show that, besides providing closed-loop stability for systems with integrating and stable modes, the proposed controller may have a better performance than those MPC controllers that make use of an observer to estimate the current states.

Enlarging the domain of attraction of stable MPC controllers, maintaining the output performance González, Alejandro Hernán; Odloak, Darci This work presents an alternative way to formulate the stable Model Predictive Control (MPC) optimization problem that allows the enlargement of the domain of attraction, while preserving the controller performance. Based on the dual MPC that uses the null local controller, it proposed the inclusion of an appropriate set of slacked terminal constraints into the control problem. As a result, the domain of attraction is unlimited for the stable modes of the system, and the largest possible for the non-stable modes. Although this controller does not achieve local optimality, simulations show that the input and output performances may be comparable to the ones obtained with the dual MPC that uses the LQR as a local controller.

Cone Calorimetry Studies of Benzoxazine-Epoxy Systems Flame Retarded By Chemically Bonded Phosphorus or Silicon Spontón, Marisa Elisabet; Ronda, J.; Galià, M.; Cádiz, V. The combustion behaviour of phosphorus- and silicon-containing benzoxazine-epoxy systems has been studied by LOI and cone calorimetry giving a clear evidence that incorporation of 3.5% P into the benzoxazine-epoxy systems, resulted in flame retardation while the silicon-containing copolymer was found to have no improvement in the LOI and cone calorimeter data, with values similar to the polymers without heteroatom, thus indicating that the 3.9% silicon content has no flame retarding effect. The peak of heat release rate value is reduced significantly for the phosphorus-containing benzoxazine as a result a combination of condensed-phase and gas-phase mechanisms.The incorporation of phosphorus or silicon into the modified benzoxazine-epoxy system increases the smoke hazard and the CO emissions compared to the heteroatom-free system.

Simple and Friendly Sulfones Synthesis Using Aqueous Hydrogen Peroxide with a Reusable Keggin Molybdenum Heteropolyacid, Immobilized on Aminopropyl-Functionalized Silica Palermo, Valeria; Romanelli, Gustavo Pablo; Vazquez, Patricia Graciela Keggin molybdenum heteropolyacid (H3PMo12O40), immobilized on aminopropyl-functionalized silica catalysts, were made using two immobilization methods: incipient wetness and equilibrium adsorption. The material prepared for the equilibrium adsorption technique was found to be a highly efficient, ecofriendly, and recyclable heterogeneous catalyst for the selective oxidation of sulfides to sulfones in excellent yields, under mild reaction condition using 35% w/v aqueous hydrogen peroxide as the oxidant.

Evaluación termo-energético de una vivienda bioclimática en la periferia de la ciudad de Mendoza Mercado, Maria Victoria; Esteves Miramont, Alfredo; Chavez, Carolina El diseño de viviendas bioclimáticas responde a las expectativas de mejoramiento de la calidad de la edificación en un sentido medio-ambiental. El objetivo principal de este trabajo apunta a revisar y evaluar la respuesta de una vivienda y las tecnologías utilizadas como parte de un diseño térmico y energéticamente eficiente. La primer etapa construida de la vivienda presentada aquí se compone de cocina-comedor, dormitorio principal, paso y baño. El sistema constructivo utilizado fue el tradicional para muros ladrillón con revoques, y para techos se utilizó una cubierta liviana. Las estrategias bioclimáticas utilizadas fueron: conservación de energía y ganancia solar directa e indirecta. Se realizó una evaluación térmico-energética con mediciones in-situ y balance energético con el método RCC/FAS. La situación térmica presenta estabilidad dentro del rango de confort, manteniéndose entre los 19-22ºC. Se advierte que la vivienda con la incorporación de estrategias bioclimáticas reduce el consumo de energía hasta un 50%.; Bioclimatic housing design meets the expectations of improving the quality of the building in a environmental sense. The main objective of this study is to review and evaluate the response of housing and the technologies used as part of a thermal design and energy efficient. The first phase of housing built consists of kitchen / dining room, bedroom and bath step. The construction system used was the traditional ladrillón with plaster walls and ceilings are used to cover light. Bioclimatic strategies used were: energy conservation and solar gain directly and indirectly. An assessment was made with thermal-energy in-situ measurements and energy balance method with the RCC / FAS. The situation presents thermal stability within the comfort range, remaining between 19-22 º C. Be warned that the housing with the addition of bioclimatic strategies reduces energy consumption up to 50%.

Sistema de cocción solar integrado a la vivienda bioclimática: Estudios térmico, ergonómico y de impacto socioambiental en el árido San Juan Buigues Nollens, Arturo; Rojas, F. Este trabajo tiene como objetivo, la integración sustentable de sistemas solares para cocción de alimentos en la vivienda bioclimática. La metodología consiste en un estudio ambiental, a través del análisis de modos de vida de sus usuarios, respecto al espacio cocina; la sustitución de materiales convencionales por otros alternativos, con menor impacto ambiental y una evaluación del impacto global de su implementación. Los resultados demuestran la necesidad de incorporar el uso de hornos solares, facilitando su control visual y del ambiente desde el interior. La utilización de materiales alternativos presenta similar comportamiento que en hornos convencionales. Finalmente el estudio de impacto realizado, para zonas aisladas de San Juan, demuestra que éstos son una posible solución tecnológica sustentable de mayor escala, por sus muy bajos costos de implementación, en relación a lo que cuesta eliminar el CO2 del ambiente, evitando una importante tala de especies forestales en esta árida región.; The object of this paper is to achieve a sustained integration of solar systems to cooking in bioclimatic houses. The methodology consists of an environmental analysis, which studies the way of living of its users concerning the cooking space, the substitution of the conventional materials for others of less environmental impact and an evaluation of the global implementation impact. The results show the need to incorporate the use of solar ovens, facilitating the visual control of the oven and of the environment, from inside. The use of alternative materials present a similar behaviour to that of the conventional ovens. Finally the environmental study carried out in isolated areas of San Juan proves that this is a possible sustained technological solution of a higher scale, due to very low costs of implementation, in relation to the cost of eliminating CO2 from the environment, preventing an important logging of tree species in this arid region.

Gonadectomy influences blood pressure through the kallikrein-kinin system Azurmendi, Pablo Javier; Oddo, Elisabet Mónica; Obika, Leonard F.; Corbera, Natalia Leonor; Martin, Rodolfo Santiago; Ibarra, Fernando Raúl; Arrizurieta, Elvira The kallikrein-kinin system (KKS) appears to be involved in blood pressure regulation. We showed that ovariectomy (oVx) stimulates urinary kallikrein activity (UKa). So, we test whether gonadectomy (Gx) would affect blood pressure through an increase in KKS activity and which mechanism(s) were involved. We studied adult Wistar rats of either sex, with and without Gx. At baseline all groups were normotensive although the oVx mean arterial pressure (MAP) was lower than female MAP (p < 0.05). KKS blockade by aprotinin increased MAP (p < 0.05) exclusively in the oVx group. The probably mechanism(s) involved in KKS regulation (synthesis, renal content and UKa) were also studied. Previous Gx, kallikrein content (nkat/g kidney weight) and UKa (nkat/g kidney weight/day) were higher in female than in male rats: 12 ± 1.1 versus 6 ± 0.7 and 40 ± 6.8 versus 26 ± 3.4, respectively. After Gx, kallikrein content increased significantly in both orchiectomized (oRx) and oVx rats, and UKa showed a similar tendency (NS). Kallikrein synthesis did not show gender difference in non-Gx rats, but an increase after oVx was observed. KKS was found to be involved in blood pressure regulation in oVx animals. oVx may trigger the increase in kallikrein synthesis and content and UKa to act upon blood pressure.

Hippocampal-related memory deficits and histological damage induced by neonatal ionizing radiation exposure: Role of oxidative status Cáceres, Lucila Guadalupe; Aon Bertolino, Maria Laura; Saraceno, Gustavo Ezequiel; Zorrilla Zubilete, María Aurelia; Kiessling Duran, Roberto Anibal; Capani, Francisco; Guelman, Laura Ruth Ionizing radiations induce oxidative stress on target tissues, mainly through the generation of reactive oxygen species (ROS). However, there are few data available on the behavioral effects of moderate doses of ionizing radiation. The aim of the present work was to evaluate the performance of adult rats irradiated at birth in different hippocampal-dependent behavioral tasks and to establish a relationship with the oxidative status and histological changes in rat hippocampus (Hip). Male Wistar rats were irradiated with 5 Gy of X rays between 24 and 48 h after birth. Thirty days later, rats were subjected to open field, object recognition and inhibitory avoidance tasks. In addition, oxidative status markers as well as protein kinase C (PKC) activity and histological changes were assessed in control and irradiated Hip. Results show an impairment in recognition and habituation memories in 30-day-old animals exposed to neonatal ionizing radiation, both at short- (ST) and at long-term (LT), whereas an improvement in associative memory was observed at ST. In addition, histological alterations were observed in irradiated Hip. Although an increase in ROS levels and PKC activity were found in irradiated Hip, no changes in the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were observed. Taken together, our results support the hypothesis that an increased PKC activity, induced by neonatal ionizing radiation on rat Hip, could play a role in the generation of an imbalance between ROS levels and antioxidant systems and might underlie radiation-induced hippocampal histological damage as well as the Hip-dependent behavioral changes found in irradiated rats.

5-Nitrofuranes and 5-nitrothiophenes with anti-Trypanosoma cruzi activity and ability to accumulate squalene Gerpe, Alejandra; Alvarez, Guzmán; Benítez, Diego; Boiani, Lucía; Quiroga, Martín; Hernández, Paola; Sortino, Maximiliano Andrés; Zacchino, Susana Alicia Stella; González, Mercedes; Cerecetto, Hugo Chagas disease represents a serious public health problem in South America. The first line of treatment is Nifurtimox and Benznidazole which generate toxic effects in treated patients. We have recently shown that a number of 5-nitrofuranes possess activity against Trypanosoma cruzi through oxidative stress and inhibition of parasite ergosterol biosynthesis, specifically at the level of squalene epoxidase. Here, we identify new 5-nitrofuranes and the thia-analogues with excellent effects on the viability of T. cruzi and adequate parasite/mammal selectivity indexes. Analysis of the free sterols from parasite incubated, during 120 h, with the compounds showed that some of them accumulated squalene suggesting the squalene epoxidase activity inhibition of the parasite. Nifurtimox was able to accumulate squalene only at lower incubation times. Due to this fact some derivatives were also tested as antifungal agents. Quantitative structure-activity relationship studies were also performed showing relevant features for further new derivatives design. Taken together, the results obtained in the present work point to a more general effect of 5-nitrofuranes and 5-nitrothiophenes in trypanosomatids, opening potential therapeutic possibilities of them for these infectious diseases.

Evaluación térmica de bolsas plásticas económicas para la calefacción solar de agua Passamai, Victor Jose; Checura Diaz, Miguel Straty; Passamai, Teresita Maria Se evalúan térmicamente bolsas transparentes usadas para la calefacción solar de agua. Su construcción se realiza con polietileno de 70 micrones de espesor, de pared doble y cierre hermético. El objetivo del estudio fue la obtención de 10 litros de agua a más de 40 - 60 °C, de manera práctica y sencilla para uso sanitario de diferentes usuarios (mochileros, viajeros, viviendas económicas, etc.). Las bolsas fueron colocadas sobre superficie horizontal y expuestas a la radiación solar desde la mañana hasta la tarde, en la ciudad de Salta. Se evaluaron diferentes comportamientos térmicos por la exposición solar: sobre piso, mesa y superficie negra, con y sin aislación térmica. En todos los casos la temperatura del agua aumenta y el pico máximo ocurre posteriormente al de la radiación solar, por inercia térmica. Mediante Simusol se realiza la modelización teórica de uno de los casos experimentados.