26 research outputs found

    Iron profile and hepcidin associated with oxidative stress and metabolic disturbances in pregnancy

    Get PDF
    Background: A common problem during pregnancy is anemia and to reduce its prevalence the WHO and national guidelines recommend a prescription of 30 to 60 mg of iron/day. The aim of this study was to evaluate the association of iron profile, hepcidin and oxidative stress in pregnant women prescribed with iron as a probable cause of metabolic disorders. Method: In this cohort study two groups were followed: A) women with low-risk pregnancy (WLRP), B) women with high-risk pregnancy (WHRP): women with metabolic disorders (dyslipidemias, GDM and high blood pressure). Oxidative stress enzymes, iron profile and hepcidin were measured in the second and third trimesters. Results: There were significant differences in hepcidin levels between WLRP and WHRP in 2nd (3.6 ± 4.2 vs 4.69 ± 3.23 P=0.005) and 3rd trimester (3.65 ± 3.44 vs 6.84 ± 5.14 P=0.02). The serum iron concentration had a negative relationship with catalase (-0.599; P=0.04) and a positive relationship with glutathione peroxidase (0.729; P=0.007). Conclusion: The iron serum levels increase could induce oxidative damage in pregnancy. Increased hepcidin is a useful biomarker for determining iron availability in pregnancy and its association with antioxidant systems

    knOWLearn: a reuse-based approach for building ontologies in a semi-automatic way

    Get PDF
    Abstract. In this poster paper we present an overview of knOWLearn, a novel approach for building domain ontologies in a semi-automatic fashion. Keywords: Domain ontology building, ontology learning, ontology reuse 1 Introduction Ontologies are useful mechanism for representing knowledge, containing concepts and relationships about the domain of interest. Developing ontologies in a manual fashion is a complex and time consuming process, which implies the participation of domain experts and ontology engineers. For this reason, the definition of approaches to semi-automatically build domain ontologies, what is called ontology learning, is one of the main research topics in Ontology Engineering. However, current ontology learning approaches from textual documents have results not completely satisfactory The knOWLearn Approach Our approach to build domain ontologies consists of five main phases (see (1) Term Extraction, this phase performs the extraction of relevant domain terms from text documents. FTC algorithm [2], to cluster documents, has been extended to obtain simple domain terms (of a single word). When the terms have been obtained, the most frequent n-grams (n={2,3}) containing such terms are searched in the input documents. These n-grams are the most relevant multi-words for the domain

    Mono- and Dinuclear Complexes of Tricarbonylrhenium(I) with 4-Methyl-2,2'-bipyridine-4'-carbonitrile

    Get PDF
    Novel mono- and dinuclear tricarbonylrhenium(I) complexes of formula [Re(Mebpy-CN)(CO)3Cl] (1), [Re(Mebpy-CN)-(CO)3(CH3CN)](PF6) (2), and [(CH3CN)(CO)3Re(Mebpy-CN)Ru(NH3)5](PF6)3 (3), in which Mebpy-CN = 4-methyl-2,2-bipyridine-4-carbonitrile, were prepared and characterized by spectroscopic, photophysical, and computational techniques. The complete structure of complex 2 was determined by X-ray diffraction. The increased conjugation in the bipyridyl ring owing to the nitrile substituent increases the emission quantum yields of the 3MLCT (metal-to-ligand charge-transfer) lowest-lying excited states of 1 and 2 with respect to the corresponding bpy complexes (bpy = 2,2-bipyridine). The mixed-valent species of formula [(CH3CN)(CO)3Re(Mebpy-CN)Ru(NH3)5]4+ (4) was prepared in situ and as a mixed salt; the charge recombination from its metal-to-metal charge-transfer(MMCT) excited state is predicted to lie in the Marcus inverted region. The electronic structures and optical properties of all the reported complexes calculated by DFT and TD-DFT methods agree reasonably well with experimental results.Fil: Mecchia Ortiz, Juan Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Quimica del Noroeste; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Moran Vieyra, Faustino Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santiago del Estero; Argentina. Universidad Nacional de Santiago del Estero; ArgentinaFil: Borsarelli, Claudio Darío. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santiago del Estero; Argentina. Universidad Nacional de Santiago del Estero; ArgentinaFil: Romero, Isabel. Universidad de Girona; EspañaFil: Fontrodona, Xavier. Universidad de Girona; EspañaFil: Parella, Teodor. Universitat Autonoma de Barcelona; EspañaFil: Lis de Katz, Noemí D.. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Quimica del Noroeste; ArgentinaFil: Fagalde, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Quimica del Noroeste; Argentina. Universidad Nacional de Tucumán; ArgentinaFil: Katz, Néstor Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Quimica del Noroeste; Argentina. Universidad Nacional de Tucumán; Argentin

    Mitochondrial physiology

    Get PDF
    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Mitochondrial physiology

    Get PDF
    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Resistivity and thermal conductivity measurements on heavy-fermion superconductors in rotating magnetic fields

    No full text
    CeCu_2Si_2 was the first heavy-fermion compound showing signatures of bulk superconductivity (T_c = 0.5 K). Further observations have put in evidence the correlations between superconductivity, magnetic order, Kondo physics, and quantum critical phenomena. In spite of the interest generated, a systematic study of such correlations was hampered by strong sample dependences. Fortunately, the inherent complexity associated to the stoichiometric composition has been recently understood. The availability of single-crystals with well-defined properties has thus reignited the interest in CeCu_2Si_2 as a window to novel phenomena, such as unconventional superconductivity. The present work summarizes the results of my doctoral research. It exemplifies the importance not only of high-quality materials, but also of suitable experimental techniques. A first step in this project involved the design of angle-dependent techniques in the milli-kelvin range, namely: electrical resistivity and thermal conductivity. It comprised the development of a rotational stage, the construction of sample holders, and the implementation of controlling and measuring components. In the second part of the project, electrical- and thermal-transport measurements on CeCu_2Si_2 were performed. Power-law behavior below T_c in the thermal conductivity suggests the presence of lines of nodes in the gap function. Also, the non-vanishing extrapolated residual terms (k_00/T ) support the presence of a residual density of states. The nodes are broadened by potential scattering, which appears to be significant in CeCu_2Si_2. The scattering hinders the determination of the symmetry of the order parameter and might be responsible for the observed isotropic angle dependence of the thermal conductivity. In contrast, angle-dependent measurements of the upper critical field exhibit a four-folded behavior, which also points towards the presence of nodes. By comparing with a weak-coupling model including the effects of Pauli limiting and anisotropic Fermi velocity, the results point towards a d_xy-wave symmetry of the order parameter. Such results represent the first angle-dependent measurements supporting a d-wave symmetry in CeCu_2Si_2

    Determination of the concentration of the essential amino acid tryptophan in model systems

    No full text
    El Triptófano (Trp) es un aminoácido esencial, constituyente de las proteínas que ha de seraportado necesariamente a través de la alimentación, encontrándose en carnes blancas y rojas,leche, queso, huevos, soja, semillas de calabaza, nueces, maní, etc. Es conocido por su efectotranquilizante y calmante del sistema nervioso, debido a que ayuda al cerebro a producirserotonina (la hormona de la felicidad), la cual está directamente relacionada con la concentraciónde Trp. Por otro lado, las propiedades fotofísicas y fotoquímicas de este aminoácidoson de gran interés biológico, debido a que se utiliza como sonda fluorescente de proteínas,y sirve para caracterizar el micro entorno proteico. El estudio de sus propiedades espectroscópicastales como rendimiento cuántico de fluorescencia, posición de la banda de emisión,etc., es útil para determinar su distribución en sistemas modelo como las micelas inversas dedocusato de sodio (AOT). Este sistema modelo se usa con el fin de imitar, en un sistema experimentalrelativamente simple, algunas de las características del entorno que simulan suubicación en proteínas funcionales y de esta forma inferir la concentración de este aminoácidoesencial en alimentos. Los resultados muestran que cuando el Trp se encuentra dentro de unamicela inversa de AOT de baja relación molar agua/surfactante (W = [H2O]/[AOT] ≤ 5), laspropiedades espectroscópicas difieren a los de una solución acuosa. Sin embargo a medidaque el W aumenta, dichas propiedades se aproximan a las de una solución homogénea. Estecomportamiento se debe por la presencia de dos poblaciones fluorescentes. Para dilucidar lacompartamentalización del aminoácido, se determinó la constante de partición en el sistemaagua/surfactante, estimando las concentraciones de equilibrio en función del tamaño micelar,mediante absorción UV-vis y fluorescencia estacionaria y resuelta en el tiempo.Fil: Perez, Hugo A.. Universidad Nacional de Santiago del Estero. Instituto de Bionanotecnología del Noa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Bionanotecnología del Noa; ArgentinaFil: Moran Vieyra, Faustino Eduardo. Universidad Nacional de Santiago del Estero. Instituto de Bionanotecnología del Noa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Bionanotecnología del Noa; ArgentinaFil: Borsarelli, Claudio Darío. Universidad Nacional de Santiago del Estero. Instituto de Bionanotecnología del Noa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Bionanotecnología del Noa; Argentin
    corecore