233 research outputs found

    Hollow Microcrystals of Copper Hexafluoroacetylacetonate-Pyridine Derivative Adducts via Supercritical CO2 Recrystallization

    Get PDF
    An innovative crystallization process, based in the use of the eco-friendly supercritical carbon dioxide (scCO2) solvent, is presented for the production of coordination compounds macrocrystals of general formula [Cu(hfacac)2(dPy)2], with intriguing prismatic hollow structures and single polymorphic forms. On the contrary, conventional solvents yielded compact microstructures. Studied pyridine derivatives (dPy) were 4-phenylpyridine, PhPy; 4-benzylylpyridine, BzPy; and 4-acetylpyridine, AcPy. In the specific case of the [Cu(hfacac)2(AcPy)2] adduct, the use of scCO2 as a solvent allows obtaining a pure polymorph, while the conventional solvent trials yielded a mixture of two polymorphs. Four new crystalline structures have been resolved from single crystal X-ray diffraction. All the structures consist in mononuclear complexes connected through intermolecular interactions, including H···H, H···O, F···F, C-F···Caromatic and/or C-F··· interactions, generating bidimensional networks that determine their crystallization mode in scCO2.This work was partially financed by the Spanish National Plan of Research CTQ2014-56324 and Severo Ochoa SEV-2015-0496, and by the Generalitat de Catalunya 2014SGR377. A. López-Periago acknowledges the RyC-2012-11588 contract. ALBA synchrotron is acknowledged for the provision of beamtime.Peer Reviewe

    Exploring a novel preparation method of 1D metal organic frameworks based on supercritical CO2

    Get PDF
    The preparation of copper(II) one-dimensional MOFs using an eco-efficient method is reported here. This method is based exclusively on using supercritical CO2 as a solvent, without the addition of any other additive or co-solvent. Neutral acetylacetonate copper complexes and two linear linkers, namely, the bidentate 4,4¿-bipyridine and 4,4¿-trimethylenedipyridine molecules, were reacted under compressed CO2 at 60 °C and 20 MPa for periods of 4 or 24 h. The success achieved in the synthesis of the different studied 1D-MOFs was related to the solubility of the reagents in supercritical CO2. The reaction yield of the synthesized coordination polymers via the supercritical route was close to 100% because both the reactants were almost completely depleted in the performed experiments. © The Royal Society of Chemistry 2015.This work was partially financed by EU COST project MP1202 OC-2011-2-10820 and by the Generalitat de Catalunya 2014SGR377. A. López-Periago acknowledges the RyC-2012- 11588 contract. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer Reviewe

    Contenido de aminoácidos libres en frutos de chirimoyo durante la maduración

    Get PDF
    El chirimoyo es un fruto tropical que crece en algunos países de América y en una serie de selectivas áreas del sur de España, siendo una fuente rica de aminoácidos libres. Los efectos de las temperaturas después de la postrecolección de este fruto han sido estudiadas. La firmeza del fruto se ha determinado con un medidor de textura y los aminoácidos libres se determinaron por cromatografía en columna de intercambio iónico, utilizando un autoanalizador de aminoácidos. El chirimoyo se caracterizó por un alto contenido en prolina y citrulina. El ácido glutámico y la glutamina estaban también presentes pero en pequeñas cantidades. La citrulina y la prolina se incrementaron durante la maduración; el aumento dependió de la temperatura de almacenamiento

    The Right Tool for the Job: Detection of Soil-Transmitted Helminths in Areas Co-endemic for Other Helminths

    Get PDF
    Due to the recent increased use of the McMaster (MM) fecal egg counting method for assessing benzimidazole drug efficacy for treating soil-transmitted helminth (STH) infections, the aim of the current study was to determine the operational value of including the MM method alongside the Kato-Katz (KK) fecal thick smear to increase the diagnostic sensitivity when STHs are co-endemic with trematode helminths (e.g., Schistosoma mansoni). Methods A cross-sectional study was conducted in school-aged children aged 4-18 years in the northeastern region of the State of Minas Gerais (Brazil), where Necator americanus, Ascaris lumbricoides, Trichuris trichiura, and S. mansoni are co-endemic. One fecal sample from each participant was collected and transported to the field laboratory for analysis. Coprological diagnosis was performed on each fecal sample by three different methods: Formalin-Ether Sedimentation (FES), KK and the MM technique. The diagnostic sensitivity and negative predictive value (NPV) of each technique was calculated using the combination of all three techniques as the composite standard. In order to determine the agreement between the three techniques Fleiss´ kappa was used. Both the Cure Rate (CR) and the Fecal Egg Count Reduction (FECR) were calculated using the two quantification techniques (i.e., the MM and KK). Results Fecal samples from 1260 children were analyzed. The KK had higher diagnostic sensitivity than the MM for the detection of both A. lumbricoides (KK 97.3%, MM 69.5%) and hookworm (KK 95.1%, MM 80.8%). The CR of a single dose of mebendazole varied significantly between the KK and MM for both A. lumbricoides (p = 0.016) and hookworm (p = 0.000), with lower rates obtained with the KK. On the other hand, the FECR was very similar between both techniques for both A. lumbricoides and hookworm. Conclusion The MM did not add any diagnostic value over the KK in areas where both STHs and trematodes were co-endemic. The lower sensitivity of the MM would have an important impact on the administration of selective school-based treatment in this area since if only the MM were used, 36 (13.9%) children diagnosed with A. lumbricoides would have gone untreated. Author Summary Diagnosis of intestinal helminths and Schistosoma mansoni infections is based on the detection of eggs in feces. There are many techniques available for both detection and quantification of infection. For the quantification of helminth infections, the methods traditionally used are the Kato-Katz (KK) fecal think smear in humans, and the McMaster (MM) counting method in animals. Recently, the MM has been used for assessing the efficacy of benzimidazole drugs for treating soil-transmitted helminth (STH) infections in humans. In most parts of the world, however, STHs occur simultaneously with other helminth species, and the MM does not detect other helminth eggs. Therefore, in this study we sought to determine if the use of the MM in an area of Brazil were both STHs and S. mansoni are co-endemic, added any value to the current standard of diagnosis using the KK

    The Next WHO Director-General’s Highest Priority: a Global Treaty on the Human Right to Health

    Get PDF
    Amidst the many challenges facing the next WHO Director-General, the new WHO head should find WHO’s foremost priority in its most important constitutional pillar: the right to health. The centerpiece of this endeavor should be leadership on the Framework Convention on Global Health (FCGH), the proposed global treaty based in the right to health and aimed at national and global health equity. The treaty would reform global governance for health to enhance accountability, transparency, and civil society participation and protect the right to health in trade, investment, climate change, and other international regimes, while catalyzing governments to institutionalize the right to health at community through to national levels. It would usher in a new era of global health with justice – vast improvements in health outcomes, equitably distributed. With the Framework Convention on Tobacco Control having served as a proof of concept, the FCGH would be an innovative treaty finding solutions to overcome global health failings in accountability, equality, financing, and inter-sectoral coherence. It would include a global health accountability framework, encompassing, civil society engagement, independent monitoring, and plans for redress, while catalyzing national health accountability strategies, accountability mechanisms, disaggregated data, and community participation. National health equity strategies, pro-poor pathways to universal health coverage, and robust non-discrimination provisions could elevate the voices, priorities, and ultimately power of marginalized populations. The FCGH would include a national and global health financing framework, while reaching beyond the health sector with right to health assessments, public health participation in developing international agreements, and responsibility for all sectors for improving health outcomes. The FCGH would reinvigorate WHO’s global health leadership, breathing new life into its founding principles. It could become the platform for reforming WHO as a rights-based 21st century institution, with badly-needed reforms, such as community participation, new priorities favouring social determinants of health, and a culture of transparency and accountability. The next Director-General should launch a historic effort to align national and global governance for with human rights through the FCGH, bringing the world closer to global health with justice

    Prevention, control, and elimination of neglected diseases in the Americas: Pathways to integrated, inter-programmatic, inter-sectoral action for health and development

    Get PDF
    BACKGROUND: In the Latin America and Caribbean region over 210 million people live below the poverty line. These impoverished and marginalized populations are heavily burdened with neglected communicable diseases. These diseases continue to enact a toll, not only on families and communities, but on the economically constrained countries themselves. DISCUSSION: As national public health priorities, neglected communicable diseases typically maintain a low profile and are often left out when public health agendas are formulated. While many of the neglected diseases do not directly cause high rates of mortality, they contribute to an enormous rate of morbidity and a drastic reduction in income for the most poverty-stricken families and communities. The persistence of this "vicious cycle" between poverty and poor health demonstrates the importance of linking the activities of the health sector with those of other sectors such as education, housing, water and sanitation, labor, public works, transportation, agriculture, industry, and economic development. SUMMARY: The purpose of this paper is three fold. First, it focuses on a need for integrated "pro-poor" approaches and policies to be developed in order to more adequately address the multi-faceted nature of neglected diseases. This represents a move away from traditional disease-centered approaches to a holistic approach that looks at the overarching causes and mechanisms that influence the health and well being of communities. The second objective of the paper outlines the need for a specific strategy for addressing these diseases and offers several programmatic entry points in the context of broad public health measures involving multiple sectors. Finally, the paper presents several current Pan American Health Organization and other institutional initiatives that already document the importance of integrated, inter-programmatic, and inter-sectoral approaches. They provide the framework for a renewed effort toward the efficient use of resources and the development of a comprehensive integrated solution to neglected communicable diseases found in the context of poverty, and tailored to the needs of local communities

    Contenido de aminoácidos libres en frutos de chirimoyo durante la maduración

    Get PDF
    Cherimoya, a subtropical fruit growing in sorne American countries and restricted areas of the south of Spain, is one of the richest sources of free amino acids. The effects of post-harvest temperatures on the texture and free amino acid profile of this fruit were studied. Fruit firmness was determined with a pressure tester, and free amino acids were measured by ion-exchange colum chromatography using an automatic amino acid analyzer. Cherimoya was characterized by high contents of proline and citrulline. Glutamic acid and glutamine were also present but at lower levels. Citrulline and proline increased during ripening; the increases depended on the temperature of storage.El chirimoyo es un fruto tropical que crece en algunos países de América y en una serie de selectivas áreas del sur de España, siendo una fuente rica de aminoácidos libres. Los efectos de las temperaturas después de la postrecolección de este fruto han sido estudiadas. La firmeza del fruto se ha determinado con un medidor de textura y los aminoácidos libres se determinaron por cromatografía en columna de intercambio iónico, utilizando un autoanalizador de aminoácidos. El chirimoyo se caracterizó por un alto contenido en prolina y citrulina. El ácido glutámico y la glutamina estaban también presentes pero en pequeñas cantidades. La citrulina y la prolina se incrementaron durante la maduración; el aumento dependió de la temperatura de almacenamiento

    Changes in the content of free amino acids In cherimoya fruits at various ripening temperatures

    Get PDF
    The variations in the content of free amino acids in fruits during ripening is a matter of interest since these compounds are related to their flavour, taste and structure. This study was designed to determine the changes of free amino acids in ripening cherimoya fruits (Annona cherimolia var. Fino de Jete, evaluating the influence of the storage temperature afier harvesting. Methanolic fruit extracts of epicarp and mesocarp were used for quantification of free amino acids which were analyzed by ion-exchange chromatography. Citrulline and proline were detected in relatively high amounts. Glutamate, glutamine, aspartate, asparagine and the non proteinogenic taurine, y-aminobutyric and y-aminoadipic acids were found in concentrations that varied between 2-6% of the total free amino acids content. Ripening increased the contents of amino acids, mainly proline, citrulline and glutamate when cherimoya storage at 20 oC or 80 oC. These increases did not occur when the storage temperature was maintained at 4 oC suggesting that chilling injury markedly affects the synthesis pathway of proline from glutamateLas variaciones en el contenido de aminoácidos libres en frutos durante la maduración es un tema de interés debido a la relación de estos compuestos con su olor, sabor y estructura. Este estudio se ha diseñado para determinar los cambios en aminoácidos libres durante la maduración de los frutos del chirimoyo (Annona cherimolia varo Fino de Jete), evaluando la influencia de la temperatura de almacenamiento después de la recolección. Extractos metanólicos de epicarpio y mesocarpio del fruto se usaron para la cuantificación de los aminoácidos libres, los cuales fueron analizados por cromatografia de intercambio iónico. Citrulina y prolina se detectaron en cantidades relativamente altas. Glutamato, glutamine, aspartato, asparragina y los no proteinogenéticos taurina, ácido y-aminobutírico y ácido Y-aminoadípico fueron encontrados en concentraciones que variaron entre 2-6% del total del contenido de aminoácidos libres. La maduración incrementó el contenido de aminoácidos, sobre todo de prolina, citrulina y glutamato, cuando los chirimoyos se almacenaron a 20 oC o 8 oc. Este incremento no ocurrió cuando la temperatura de almacenamiento se mantuvo a 4 oC, sugiriendo que el daño por frío afecta marcadamente a la vía de síntesis de la prolina a partir de glutamat

    Effect of phosphorus on the attenuation of lead and chromium

    Get PDF
    This study analyses the adsorption of Pb(II) and Cr(III) in soils. These metals are commonly found together in nature in urban wastes or industrial spillages, and the theoretical approach of the work was to evaluate the response of the soil to continuous Cr and Pb spillages to soil in terms of several physicochemical parameters. The influence of an anthropogenic input of phosphorus was evaluated. Continuous flow experiments were run in duplicates in acrylic columns (25 cm × 3.2 cm). The influent Cr(III) and Pb(II) solutions of 10 mg l−1 and 25 mg l−1 at pH 5 were pumped upward through the bottom of the columns to ensure saturation flow conditions. Also, successive experiments were run with the above concentrations of Cr(III) and Pb(II) and NaH2PO4, keeping metal to phosphorus ratio of 1:0, 1:0.1 and 1:1. Modelling parameters included Freundlich and Langmuir equations, together with the Two-site adsorption model using CXTFIT code. Results obtained allowed concluding that Pb(II) adsorption presents a certain degree of irreversibility and the continued spillages over soil increment the fraction which is not easily desorbed. Cr(III) desorption was almost complete, evidencing its high mobility in nature. The presence of an anthropogenic input of phosphorus leads to a marked increase of both Pb(II) and Cr(III) adsorption in soils. Z-potential measurements allow to discard the electrostatic attraction of Cr(III) and Pb(II) with the surface charged soil as the dominant process of metal sorption. Instead, CheaqsPro simulation allows to identify PbH2PO4 +, PbHPO4 (aq) and CrHPO4 + as the dominant species which regulate Cr(III) and Pb(II) transport in soils.Fundação para a Ciência e a Tecnologi
    corecore