Browsing by Author "Vergara, Elizabeth"

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    Multiple sclerosis and related disorders: Short report peripheral vascular events in a real-world cohort of multiple sclerosis patients using Fingolimod
    (2020) Pelayo, Carolina; Ciampi Díaz, Ethel Leslie; Uribe San Martín, Reinaldo; Soler León, Bernardita María; Reyes, Ana; Vergara, Elizabeth; Cárcamo Rodríguez, Claudia Andrea
    Background: Fingolimod is a high-efficacy disease-modifying therapy for multiple sclerosis (MS) and was the first oral treatment approved for the disease. Adverse events include bradyarrhythmia, hypertension, macular oedema and increased risk of infections, mainly due to its main mechanism of action, the non-selective modulation of sphingosine-1-phosphate receptor.", "Methods and Results: We report the baseline characteristics, effectiveness outcomes and adverse events of a prospective cohort of 177 patients with a median treatment duration of 24 months, in which four patients (2.3%) presented with otherwise non-provoked peripheral vascular events (PVE).", "Conclusions: Further studies are still needed to evaluate the frequency and severity of PVE in fingolimod patients.
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    Role of β-CD Macromolecule Anchored to α-Fe2O3/TiO2 on the Selectivity and Partial Oxidation of Guaiacol to Add-Value Products
    (2021) Espinoza-Villalobos, Nicole ; Rojas, Susana ; Salazar, Ricardo Andrés ; Contreras, David ; Escalona, Nestor ; Vergara, Elizabeth ; Laguna-Bercero, Miguel Angel ; Mendizabal, Fernando ; Barrientos, Lorena
    Biomass is a naturally abundant, sustainable, and clean resource, which has the potential to replace fossil feedstock for sustainable production of high add-value chemicals. However, an efficient conversion process is still difficult to achieve due to the difficult reaction conditions. In this study as a novel and versatile concept, we introduced the use of beta-cyclodextrin (beta-CD) macromolecule to enhance the photocatalytic behavior of a alpha-Fe2O3/TiO2 heterojunction. The selective conversion of guaiacol was evaluated using 0.2, 1.0, and 2.0 molar ratios of beta-CD anchored on 0.7 wt % alpha-Fe2O3/TiO2 under mild reaction conditions. 1.0 molar ratio of beta-CD promoted photo-oxidation of guaiacol to mainly produce p-benzoquinone with similar to 68% selectivity at similar to 10% conversion. To understand this effect, Electron Paramagnetic Resonance Spectroscopy (EPR) in operando mode and Diffuse Reflectance Spectroscopy (DRS) experiments were performed. The results showed that the 1.0 molar ratio of beta-CD decreases the bandgap from 3.06 to 2.76 eV and controls the center dot OH radical concentration due to the formation of a covalent bond between beta-CD and semiconductors. The improved guaiacol adsorption capacity on the photocatalyst resulted in the enhancement of the photochemical activity and selectivity. Additionally, a possible pathway of guaiacol transformation was proposed through the oxidation intermediates. Furthermore, the photocatalyst beta-CD/alpha-Fe2O3/TiO2 can be recycled efficiently and reused three times, without loss in reactivity.