Recursos de colección

Repositorio Hipermedial UNR - Repositorio Hipermedial de la Universidad Nacional de Rosario (6.314 recursos)

El Repositorio Hipermedial UNR es un repositorio académico abierto creado para archivar, preservar y distribuir digitalmente en variados formatos tanto materiales de enseñanza y aprendizaje (objetos de aprendizaje) como la producción científica de Investigación y Desarrollo (I+D) de los profesores, profesional es e investigadores de la UNR.

Facultad de Ciencias Bioquímicas y Farmacéuticas

Mostrando recursos 1 - 20 de 230

  1. Multivariate calibration-assisted high-performance liquid chromatography with dual UV and fluorimetric detection for the analysis of natural and synthetic sex hormones in environmental waters and sediments

    Pérez, Rocío Laura; Escandar, Graciela Mónica
    A green method is reported based on non-sophisticated instrumental for the quantification of seven natural and synthetic estrogens, three progestagens and one androgen in the presence of real interferences. The method takes advantage of: (1) chromatography, allowing total or partial resolution of a large number of compounds, (2) dual detection, permitting selection of the most appropriate signal for each analyte and, (3) second-order calibration, enabling mathematical resolution of incompletely resolved chromatographic bands and analyte determination in the presence of interferents. Consumption of organic solvents for cleaning, extraction and separation are markedly decreased because of the coupling with MCR-ALS (multivariate curve...

  2. Liquid chromatography with diode array detection and multivariate curve resolution for the selective and sensitive quantification of estrogens in natural waters.

    Pérez, Rocío Laura; Escandar, Graciela Mónica
    Following the green analytical chemistry principles, an efficient strategy involving second-order data provided by liquid chromatography (LC) with diode array detection (DAD) was applied for the simultaneous determination of estriol, 17β-estradiol, 17α-ethinylestradiol and estrone in natural water samples. After a simple pre-concentration step, LC-DAD matrix data were rapidly obtained (in less than 5 min) with a chromatographic system operating isocratically. Applying a second-order calibration algorithm based on multivariate curve resolution with alternating least-squares (MCR-ALS), successful resolution was achieved in the presence of sample constituents that strongly coelute with the analytes. The flexibility of this multivariate model allowed the quantification of...

  3. Desarrollo de un minibiosensor para la determinación de lactato en muestras biológicas

    Marchetti Acosta, Noelia Soledad
    Los biosensores han sido desarrollados como métodos analíticos, cuantitativos o semicuantitativos para detectar determinados analitos o compuestos específicos. Estos dispositivos utilizan un elemento de reconocimiento biológico que se mantiene en contacto espacial directo con un elemento de transducción. La extensa posibilidad de combinaciones de ambos elementos, ha dado lugar a una gran variedad de alternativas para resolver numerosos problemas analíticos en diversos campos como: salud, industria alimentaria y control ambiental. En el presente trabajo nos propusimos desarrollar un minibiosensor que permita la determinación de lactato en muestras biologías, utilizando la enzima L-lactato oxidasa (LOx), inmovilizada sobre una biomembrana de huevo aviar...

  4. Detección de células circulantes tumorales en pacientes con cáncer de mama mediante el uso de dos biomarcadores : mamaglobina A y TWIST-1 : evaluación del daño genotóxico

    Gallucci, Georgina Florencia
    El cáncer de mama se caracteriza por la diseminación temprana de células tumorales a órganos distantes, las cuales se denominan células tumorales circulantes (CTCs) y no son detectadas por métodos de diagnóstico tradicionales. En este estudio se analizó la expresión de los genes TWIST-1 y de MGA en sangre periférica de pacientes con cáncer de mama para detectar las CTCs. Los resultados indicaron que el análisis combinado de la expresión de TWIST-1 y MGA aumentó la sensibilidad de la detección de las CTCs respecto del análisis de cada gen individual. La detección de CTCs podría brindar información pronóstica adicional y...

  5. Criopreservación de células madre neurales embrionarias (CMNEs) mediante la metodología de enfriamiento lento

    Berca, Catalina
    Debido al gran auge en el uso de células madre neurales para terapias regenerativas, es de fundamental importancia contar con métodos de preservación y almacenamiento seguro de las mismas. Uno de los métodos comúnmente usados es la criopreservación mediante enfriamiento lento; sin embargo, no existe al presente un protocolo definido para el mismo. A partir de esto se propone como objetivo del presente trabajo el desarrollo de un protocolo de criopreservación de CMNEs. Para ello, se requiere controlar e investigar las variables asociadas al daño celular durante el proceso de enfriamiento lento de las células en suspensión, de manera de sentar...

  6. Spectrofluorimetric study of phenolic endocrine disruptors in cyclodextrin media

    Pellegrino Vidal, Rocío Laura; Ibañez, Gabriela Alejandra; Escandar, Graciela Mónica
    This study focuses on the spectrofluorimetric behavior of bisphenol A (BPA), 4-octylphenol (OP) and 4-nonylphenol (NP) in the presence of native and derivative cyclodextrins (CDs). The weak fluorescence emission bands of these endocrine disrupting compounds in aqueous media are significantly enhanced by β-CD and its hydroxyethyl-, hydropropyl, methyl-, and heptakis(2,6-di-o-methyl)-derivatives. A 1 : 1 guest : host stoichiometry for most complexes is established, although the additional presence of weak 1 : 2 complexes is suggested in both BPA–hydroxyethyl–β-CD and BPA–heptakis(2,6-di-o-methyl)–β-CD systems. The association constants are calculated by applying a non-linear regression method to the changes brought about by the presence...

  7. Cambios en el tiempo de floración mediados por microARNs en plantas de Arabidopsis thaliana expuestas a radiación UV-B

    Soto, María Soledad
    Las plantas están inevitablemente expuestas a la radiación UV-B debido a que son organismos sésiles y además necesitan absorber fotones de la luz solar para realizar fotosíntesis. Si bien el porcentaje de incidencia de la radiación UV-B sobre la superficie terrestre es pequeño, es el componente de mayor energía de la luz solar no retenida en la atmósfera y con el potencial de causar severos daños en todos los seres vivos. Se ha demostrado además, que en las plantas también puede inducir numerosos cambios en el crecimiento y en el desarrollo, como por ejemplo en el tiempo de floración. El...

  8. Identificación de biomarcadores seminales de utilidad pronóstica en tratamientos de reproducción asistida

    Zoff, Luciana
    Comprender las causas subyacentes de la infertilidad masculina continúa siendo un importante desafío para los andrólogos. Esto es especialmente relevante en pacientes infértiles que muestran parámetros seminales normales y sin anormalidades urogenitales o genéticas. En estos casos de infertilidad idiopática o inexplicada la identificación de nuevos biomarcadores podría ser de gran interés. Los ARNs pequeños son reguladores claves tanto de procesos fisiológicos como patológicos con un gran impacto en la función reproductiva. Estas moléculas se encuentran en diversos fluidos biológicos, incluido el plasma seminal, donde posiblemente actúan como mensajeros paracrinos o endocrinos. Con la finalidad de evaluar su utilidad como nuevos...

  9. Determination of tributyltin at parts-per-trillion levels in natural waters by second-order multivariate calibration and fluorescence spectroscopy

    Olivieri, Alejandro César; Escandar, Graciela Mónica; Bravo, Manuel; Aguilar, Luis Felipe; Quiroz, Waldo
    This work presents a non-sophisticated approach for the trace determination of tributyltin, the most toxic organotin species, in very interfering environments, combining fluorescence measurements of its morin complex and the selectivity of second-order chemometric algorithms. The power of MCR–ALS (multivariate curve resolution/alternating least-squares) to quantify tributyltin through fluorescence excitation–emission matrices in the presence of its main degradation products and of a pool of additional twenty-three metal ions is demonstrated. The applied algorithm successfully faces the challenge of solving the strong overlapping among the spectra of the several sample components. The proposed methodology was applied to tap, river, lagoon and seawater...

  10. Excitation-emission matrices applied to the study of urban effluent discharges in the Chubut River (Patagonia, Argentina)

    Chiarandini Fiore, Jessica Paola; Scapini, María del Carmen; Olivieri, Alejandro César
    Natural and contaminated waters of the final reaches of the Chubut River (Patagonia, Argentina) were studied to obtain information about river organic matter and effects of domestic and industrial discharges (fishery effluents and sewages). Fluorescence Excitation–Emission Matrices (EEMs) were obtained from samples only filtered (0.45 μm) and diluted, if necessary, to avoid the inner filter effect. In addition, physicochemical parameters were measured to know the quality of the water and the effluents. Results show that EEMs allow a rapid and simple control of the effluents from fisheries and domestic sewage in Chubut River estuary, necessary to take management decisions.

  11. Optimization of the hydrolysis of lignocellulosic residues by using radial basis functions modeling and particle swarm optimization

    Olivieri, Alejandro César; Goicoechea, Héctor Casimiro; Beccaria, Alejandro José; Giordano, Pablo César
    The concentrations of glucose and total reducing sugars obtained by chemical hydrolysis of three different lignocellulosic feedstocks were maximized. Two response surface methodologies were applied to model the amount of sugars produced: (1) classical quadratic least-squares fit (QLS), and (2) artificial neural networks based on radial basis functions (RBF). The results obtained by applying RBF were more reliable and better statistical parameters were obtained. Depending on the type of biomass, different results were obtained. Improvements in fit between 35% and 55% were obtained when comparing the coefficients of determination (R²) computed for both QLS and RBF methods. Coupling the obtained...

  12. A convenient and eco-friendly cerium(III) chloride-catalysed synthesis of methoxime derivatives of aromatic aldehydes and ketones

    Cortés, Iván; Kaufman, Teodoro Saúl; Bracca, Andrea Beatriz Juana
    The use of CeCl3·7H2O as an efficient and eco-friendly promoter for the convenient synthesis of methoximes derived from aromatic aldehydes and ketones, is reported. The transformations entail the use of equimolar amounts of MeONH2·HCl and NaOAc in EtOH at 50°C, and no special precautions are needed with regard to the presence of oxygen. The scope and limitations of the transformation were studied and a reaction mechanism was proposed.

  13. Estabilización de antioxidantes naturales por encapsulación

    Acciarri, Giuliana; Guercetti, Julián; Risso, Patricia Hilda; Hidalgo, María Eugenia
    Los arándanos contienen antocianinas (AC), principales responsables de su capacidad antioxidante. En general, se utilizan métodos extractivos de AC que emplean solventes orgánicos tales como etanol, metanol y acetona. Sin embargo, algunos de estos solventes pueden ser tóxicos para la salud humana. Por lo tanto, es de interés eliminarlos del proceso de extracción y reemplazarlos por solventes acuosos, pero manteniendo la concentración de las AC ([AC]) y un elevado poder antioxidante (PA). Una forma de mejorar la estabilidad de las AC extraídas es a través de su encapsulación en matrices poliméricas. El objetivo del trabajo fue estabilizar a las AC...

  14. Efecto de galactomananos sobre la microestructura de geles ácidos de aislados proteicos de soja (SPI)

    Wendeler, Luciano; Palazolo, Gonzalo; Wagner, Jorge Ricardo; Risso, Patricia Hilda; Ingrassia, Romina
    La goma espina corona (GEC), extraída de la leguminosa Gleditsia amorphoides, tiene una relación manosa/galactosa igual a 2,5, similar a la de la goma guar (GG) y la goma garrofin (LBG). El objetivo fue comparar el efecto de estos galactomananos (GM) sobre la microestructura de geles ácidos de SPI inducidos por glucono--lactona (GDL). Previamente se evaluó la compatibilidad termodinámica de SPI y cada uno de los GM, encontrándose que las mezclas SPI/GEC presentaron separación de fases a concentraciones más altas que las mezclas SPI/GG y SPI/LBG. Los geles de SPI 3% y de su mezcla con los tres GM, en...

  15. Desarrollo de quesos frescos funcionales y saludables a partir de leche bovina

    Pavón, Yanina; Galante, Micaela; Boeris, Valeria; Risso, Patricia Hilda; Lazzaroni, Sandra; Rozycki, Sergio
    La industria alimentaria enfrenta el desafío de desarrollar nuevos alimentos funcionales que mejoren el estado nutricional general de la población, con la finalidad de impedir la incidencia de enfermedades surgidas como consecuencia de deficiencias nutricionales y de la ingesta excesiva de con la dieta de compuestos tales como el colesterol. El objetivo de este trabajo fue elaborar un queso fresco tipo Cuartirolo, fortificado con zincy con contenido de colesterol reducido, y comprarlo con un queso tradicional. Adicionalmente, se elaboraron quesos testigos.

  16. Transcriptional and translational mechanisms contribute to regulate the expression of Disc Large 1 protein during different biological processes

    Marziali, Federico; Cavatorta, Ana Laura; Bugnon Valdano, Marina; Facciuto, Florencia; Gardiol, Daniela
    Human discs large (DLG1) has been demonstrated to be involved in cell polarity and maintenance of tissue architecture. However, the mechanisms controlling DLG1 expression are not fully understood. This is relevant as DLG1 is lost during the later stages of malignant progression. We initiated a series of studies to analyse the mechanisms regulating DLG1 expression. We have previously reported the identification of an alternative splicing event in the 5′ untranslated region (5′ -UTR) of DLG1 mRNA that generates transcripts with two different 5′ -UTR (short and large 5′ -UTR variants). In this study, we further examined the impact of the DLG1 transcription and the role of the differential expression of...

  17. Structural characterization of protein isolates obtained from chia (Salvia hispanica L.) seeds

    López, Débora Natalia; Ingrassia, Romina; Busti, Pablo; Bonino, Julia; Delgado, Juan Francisco; Wagner, Jorge; Boeris, Valeria; Spelzini, Darío
    Chia protein isolates (CPI) were obtained through isoelectric precipitation under two different conditions in order to compare their structural properties. Extraction was carried out at pH 10 or 12, whereas precipitation pH was fixed at 4.5. Samples were named as CPI10 or CPI12, according to their extraction pH (10 or 12, respectively). The recovery of chia proteins was higher when the extraction was carried out at pH 12 (17% for CPI12 and 13% for CPI10); however, CPI12 protein content (775g/kg) was slightly lower than CPI10 protein content (782g/kg). Both samples showed similar SDS-PAGE pattern. Protein dispersions of both isolates led...

  18. Amaranth, quinoa and chia protein isolates: physicochemical and structural properties

    López, Débora Natalia; Galante, Micaela; Robson, María; Boeris, Valeria; Spelzini, Darío
    An increasing use of vegetable protein is required to support the production of protein-rich foods which can replace animal proteins in the human diet. Amaranth, chia and quinoa seeds contain proteins which have biological and functional properties that provide nutritional benefits due to their reasonably well-balanced aminoacid content. This review analyses these vegetable proteins and focuses on recent research on protein classification and isolation as well as structural characterization by means of fluorescence spectroscopy, surface hydrophobicity and differential scanning calorimetry. Isolation procedures have a profound influence on the structural properties of the proteins and, therefore, on their in vitro digestibility....

  19. A combined experimental and molecular simulation study of factors influencing interaction of quinoa proteins–carrageenan

    Montellano Durán, Natalia; Spelzini, Darío; Wayllace, Natanel; Boeris, Valeria; Baroso da Silva, Fernando
    The interaction between quinoa proteins isolate (QP isolate) and the negatively charged polysaccharide ι-Carragennan (Carr) as a function of pH was studied. Experimental measurements as turbidity, hydrophobic surface, ζ-potential, and hydrodynamic size were carried out. Associative interaction between QP and Carr was found in the pH range between 1 and 2.9. When both molecules are negatively charged (pH > 5,5), a pure Coulombic repulsion regime is observed and the self-association of QP due to the Carr exclusion is proposed. In the intermediate pH range, the experimental data suggests that the charge regulation mechanism can overcome the electrostatic repulsion that may...

  20. Are Changes in the Wnt/β-Catenin Pathway Involved in Cocaine and Stress-Induced Long-Term Neuroadaptations?

    Cuesta, Santiago; Pacchioni, Alejandra Maria
    Drug addiction has been defined as a chronic relapsing brain disease, characterized by compulsive drug seeking and use, despite harmful consequences. This phenomenon has been extensively studied and the use of animal models has contributed to elucidate neurobiological bases of the different stages in the addiction process. For the past years, we have been studying the role of the Wnt (Wingless-related integration site) pathways in cocaine-induce neuroadaptations by using the behavioral sensitization paradigm to model addiction-like behaviors. The Wnt pathways are critical during the development of both the central and peripheral nervous systems. In particular, we centered our attention on the Wnt/β-catenin or canonical pathway. This pathway mediates the stabilization and...

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