Browsing by Author "Espinoza, Mauricio"

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    Dynamic DC-Link Voltage Control of Back to Back Modular Multilevel Converter for Drive Applications
    (IEEE, 2019) Lillo, Jonathan; Rojas, Félix; Verdugo, Diego; Dí­az, Matias; Pereda Torres, Javier Eduardo; Gatica, Gustavo; Espinoza, Mauricio
    In this work a dynamic control of the dc-link voltage in a hybrid Back-to-Back (BtB) Modular Multilevel Converter for medium-voltage drive applications is presented. The proposed control scheme relates the speed of the machine with the dc-link voltage magnitude to reduce the large circulating currents and common-mode voltage of the converter when the machine operates at low speed. Simulation results, performed in the software PLECS, validate the model of the BtB converter and the proposed control scheme, reducing circulating currents and common mode voltage in almost 70% and 60% respectively, when the machine operates at very low speed.
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    Proteinuria in Hantavirus Cardiopulmonary Syndrome: A Frequent Finding Linked To Mortality
    (2021) Lopez, Rene; Espinoza, Mauricio; Graf, Jeronimo; Mertz, Gregory; Ferres, Marcela; Calvo, Mario; Vial, Cecilia; Vial, Pablo A.
    Objectives: To determine the relative frequency and prognosis value of proteinuria in hantavirus cardiopulmonary syndrome (HCPS) due to Andes virus. Methods: This observational analytical study prospectively obtained data from patients admitted to 12 health centers in nine Chilean cities between 2001 and 2018. Only patients with confirmed Andes virus HCPS and laboratory characterization that included qualitative proteinuria determination at admission were considered. Results: The database involved 175 patients, 95 of them had a measurement of urine protein at the time of hospital admission. They were mainly male (71%) and the median age was 35 [22-47] years. Median duration of the febrile prodromal time was 5 [4-7] days. Hospital length of stay and hospital mortality rate were 10 [7-14] days and 21.1%, respectively. Seventy-three patients (77%) were identified with proteinuria at admission, which was associated with increased mortality rate (26% versus 5%, p = 0.036) and the relative risk was 1.3 [1.1-1.6], p = 0.002. Conclusions: Proteinuria is a frequent finding in patients with HCPS, which is associated with a higher mortality rate. (c) 2021 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )