9 research outputs found

    Shadows of the colonial past – diverging plant use in Northern Peru and Southern Ecuador

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    This paper examines the traditional use of medicinal plants in Northern Peru and Southern Ecuador, with special focus on the Departments of Piura, Lambayeque, La Libertad, Cajamarca, and San Martin, and in Loja province, with special focus on the development since the early colonial period. Northern Peru represents the locus of the old Central Andean "Health Axis." The roots of traditional healing practices in this region go as far back as the Cupisnique culture early in the first millennium BC

    Self-esteem in adolescents with Angle Class I, II and III malocclusion in a Peruvian sample

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    ABSTRACT Objective: To compare self-esteem scores in 12 to 16-year-old adolescents with different Angle malocclusion types in a Peruvian sample. Material and Methods: A cross-sectional study was conducted in a sample of 276 adolescents (159, 52 and 65 with Angle Class I, II and III malocclusions, respectively) from Trujillo, Peru. Participants were asked to complete the Rosenberg Self-Esteem Scale (RSES) and were also clinically examined, so as to have Angle malocclusion classification determined. Analysis of covariance (ANCOVA) was used to compare RSES scores among adolescents with Class I, II and III malocclusions, with participants' demographic factors being controlled. Results: Mean RSES scores for adolescents with Class I, II and III malocclusions were 20.47 ± 3.96, 21.96 ± 3.27 and 21.26 ± 4.81, respectively. The ANCOVA test showed that adolescents with Class II malocclusion had a significantly higher RSES score than those with Class I malocclusion, but there were no differences between other malocclusion groups. Supplemental analysis suggested that only those with Class II, Division 2 malocclusion might have greater self-esteem when compared to adolescents with Class I malocclusion. Conclusion: This study shows that, in general, self-esteem did not vary according to adolescents' malocclusion in the sample studied. Surprisingly, only adolescents with Class II malocclusion, particularly Class II, Division 2, reported better self-esteem than those with Class I malocclusion. A more detailed analysis assessing the impact of anterior occlusal features should be conducted

    Synthesis of Cyclic Carbonates from CO2 and Epoxide Catalyzed by Co, Ni and Cu Complexes in Ionic Liquids

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    A series of first row metal complexes (Co, Ni and Cu) containing commercial nitrogen ligands were synthetized and used as catalyst in the cycloaddition of CO2 to epoxides. The reaction was carried out in ionic liquids based on 1-n-butyl-3-methylimidazolium as solvents. Best catalytic results were achieved with Co catalysts in 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMIm.BF4). Under optimized reaction conditions cyclic carbonates were selectively obtained with good to excellent yields, presenting a reliable alternative to synthetize the product using low cost and abundant catalytic system containing a common ligand as ethylenediamine. Finally, macrocycle effects where studied in each case comparing the conversion rates obtained by using ethylenediamine and 1,4,8,11-tetraazacyclotetradecane. [GRAPHICS]

    Study of the Hydrogen Evolution Reaction Using Ionic Liquid/Cobalt Porphyrin Systems as Electro and Photoelectrocatalysts

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    In this work, the design and manufacture of graphite paste (Gr) electrodes is carried out, including N-octylpyridinium hexafluorophosphate (OPyPF6) ionic liquid (IL) as binder and modification with Co-octaethylporphyrin (Co), in order to study the hydrogen evolution reaction (HER) in the absence and presence of light. The system is characterized by XRD and FESEM-EDX (Field Emission Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy), confirming the presence of all the components of the system in the electrode surface. The studies carried out in this investigation confirm that a photoelectrocatalytic system towards HER is obtained. The system is stable, efficient and easy to prepare. Through cyclic voltammetry and electrochemical impedance spectroscopy, was determined that these electrodes improve their electrochemical and electrical properties upon the addition of OPyPF6. These effects improve even more when the systems are modified with Co porphyrin. It is also observed that when the systems are irradiated at 395 nm, the redox process is favored in energy terms, as well as in its electrical properties. Through gas chromatography, it was determined that the graphite paste electrode in the presence of ionic liquid and porphyrin (Gr/IL/Co) presents a high turnover number (TON) value (6342 and 6827 in presence of light) in comparison to similar systems reported

    Carbon neutral electrochemical conversion of carbon dioxide mediated by [M: N +(cyclam)Cln] (M = Ni2+ and Co3+) on mercury free electrodes and ionic liquids as reaction media

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    © 2017 The Royal Society of Chemistry. In this work, the electrochemical reduction of carbon dioxide using [Mn+(cyclam)Cln] (M = Ni2+ and Co3+) as electrocatalysts has been studied in 1-butyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMImBF4 and BMImNTf2 respectively) ionic liquids as reaction media. Complexes were characterized electrochemically in these salts and relevant parameters, such as a heterogeneous electron transfer rate was calculated. Results indicate a faster M(ii)/M(i) redox process in BMImBF4 despite its higher viscosity compared to BMImNTF2. Cyclic voltammetry experiments demonstrated that [Ni(cyclam)Cl2] is the most active macrocycle, towards the reaction under survey. For this compound, potential controlled electrolysis was carried out at-1.4 V vs. Ag/AgCl in BMImBF4 as a solvent, yielding only CO as a reaction product, with a turnover frequency (TOF) of 0.73 h-1. NMR spectra for the ionic liquids, afte
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