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A broadband differential-MMIC low-noise amplifier (DLNA) using metamorphic high-electron-mobility transistors of 70 nm in Gallium Arsenide (70 nm GaAs mHEMT technology) is presented. The design and results of the performance measurements of the DLNA in the frequency band from 1 to 16 GHz are shown, with a high dynamic range, and a noise figure (NF) below 1.3 dB is obtained. In this work, two low-noise amplifiers (LNAs) were designed and manufactured in the OMMIC foundry: a dual LNA, which we call balanced, and a differential LNA, which we call DLNA. However, the paper focuses primarily on DLNA because of its differential architecture. Both use a 70 nm GaAs mHEMT space-qualified technology with a cutoff frequency of 300 GHz. With a low power bias Vbias/Ibias (5 V/40.5 mA), NF < 1.07 dB “on wafer” was achieved, from 2 to 16 GHz; while with the measurements made “on jig”, NF = 1.1 dB, from 1 to 10 GHz. Furthermore, it was obtained that NF < 1.5 dB, from 1 to 16 GHz, with a figure of merit equal to 145.5 GHz/mW. Finally, with the proposed topology, several LNAs were designed and manufactured, both in the OMMIC process and in other foundries with other processes, such as UMS. The experimental results showed that the NF of the DLNA MMIC with multioctave bandwidth that was built in the frequency range of the L-, S-, C-, and X-bands was satisfactory.

In this paper, a robust analysis of SO2 concentration measurements taken at the Belisario air quality monitoring station, Quito, Ecuador is carried out. The analyzed data contain 12 years of measurements, from January 2008 to December 2019. In addition, this set of measurements was decomposed into variables that represent each year, month, day of the week, and hour of the day in groups of two hours. For the analysis, classic, nonparametric and robust statistical methods were used, and the data were classified based on criteria established by the Quiteño Air Quality Index, taking confidence intervals into account. The results showed that the level of air pollution at the Belisario station due to the SO2 concentration is acceptable. In addition, the trend in the level of SO2 concentration decreased over the years studied, with a sharp drop from 2008 to 2012, then a small rise in 2013 and another fall until 2019, presenting decreasing oscillations that tend toward a desirable level of pollution. In this paper, it was shown that the air pollution at the Belisario station due to the concentration of SO2 in the last 12 years is not harmful to humans, with the measurement precision provided by robust statistical methods. Therefore, it can be concluded that the measures that have been taken by the Quito city council over the last few years are yielding good results.

In this paper, the precise design of a high-power amplifier (HPA) is shown, along with the problems associated with the stability of “on-wafer” measurements. Here, techniques to predict possible oscillations are discussed to ensure the stability of a monolithic microwave-integrated circuit (MMIC). In addition, a deep reflection is made on the instabilities that occur when measuring both on wafer and using a mounted chip. Stability techniques are used as tools to characterize measurement results. Both a precise design and instabilities are shown through the design of a three-stage X-band HPA in gallium nitride (GaN) from the WIN Semiconductors Corp. foundry. As a result, satisfactory performance was obtained, achieving a maximum output power equal to 42 dBm and power-added efficiency of 32% at a 20 V drain bias. In addition to identifying critical points in the design or measurement of the HPA, this research shows that the stability of the amplifier can be verified through a simple analysis and that instabilities are often linked to errors in the measurement process or in the characterization of the measurement process.

In this paper, a comparative analysis between the PM2.5 concentration in downtown Quito, Ecuador, during the COVID-19 pandemic in 2020 and the previous five years (from 2015 to 2019) was carried out. Here, in order to fill in the missing data and achieve homogeneity, eight datasets were constructed, and 35 different estimates were used together with six interpolation methods to put in the estimated value of the missing data. Additionally, the quality of the estimations was verified by using the sum of squared residuals and the following correlation coefficients: Pearson’s r, Kendall’s τ, and Spearman’s ρ. Next, feature vectors were constructed from the data under study using the wavelet transform, and the differences between feature vectors were studied by using principal component analysis and multidimensional scaling. Finally, a robust method to impute missing data in time series and characterize objects is presented. This method was used to support the hypothesis that there were significant differences between the PM2.5 concentration in downtown Quito in 2020 and 2015–2019.

Resumen: Objetivo: Describir la incidencia de complicaciones en pacientes que iniciaron tratamiento con Acenocumarol, así como analizar los factores asociados, la etiología de las complicaciones y mortalidad de dichos pacientes. Método: Estudio observacional, descriptivo, retrospectivo. Se seleccionó una muestra aleatoria de pacientes de entre aquellos que iniciaron Acenocumarol en 2015. Resultados: 124 pacientes fueron incluidos. El 56,5% eran hombres. No se encontraron diferencias estadísticamente significativas entre la aparición de complicaciones y las comorbilidades estudiadas. Tampoco se encontró relación entre el desajuste de los niveles de INR y la intercurrencia de una complicación. Los pacientes con desajustes de INR presentaron un mayor número de ingresos hospitalarios. Conclusiones: La prevalencia de complicaciones hemorrágicas en el primer año fue del 12%, siendo mayor en los primeros meses tras el comienzo con Acenocumarol Abstract Objective: To describe the incidence of bleeding complications during treatment with Acenocumarol, as well as associated factors, ethiology of this complications and patient´s mortality . Method: Retrospective, observational and descriptive review. A randomly sample of patient was collected from those who started Acenocumarol in 2015. Results: 124 patients were included. 56,5% were men. No statistically significant differences were found between the occurrence of complications and comorbidities. There was also no relation between the mismatch of the INR levels and the intercourse of a complication. There was also no relation between the mismatch of the levels of INR and the presence of complications. Conclusions: Bleeding complications prevalence during first year were 12%, being greater in the first months after starting with Acenocumarol

This paper analyzes 12 years of tropospheric ozone (O3) concentration measurements using robust techniques. The measurements were taken at an air quality monitoring station called Belisario, which is in Quito, Ecuador; the data collection time period was 1 January 2008 to 31 December 2019, and the measurements were carried out using photometric O3 analyzers. Here, the measurement results were used to build variables that represented hours, days, months, and years, and were then classified and categorized. The index of air quality (IAQ) of the city was used to make the classifications, and robust and nonrobust confidence intervals were used to make the categorizations. Furthermore, robust analysis methods were compared with classical methods, nonparametric methods, and bootstrap-based methods. The results showed that the analysis using robust methods is better than the analysis using nonrobust methods, which are not immune to the influence of extreme observations. Using all of the aforementioned methods, confidence intervals were used to both establish and quantify differences between categories of the groups of variables under study. In addition, the central tendency and variability of the O3 concentration at Belisario station were exhaustively analyzed, concluding that said concentration was stable for years, highly variable for months and hours, and slightly changing between the days of the week. Additionally, according to the criteria established by the IAQ, it was shown that in Quito, the O3 concentration levels during the study period were not harmful to human health.

RESUMEN La enfermedad de Castleman(EC) es una enfermedad hematológica rara caracterizada por hiperplasia de nódulos linfoides con dos patrones histológicos y clínicos bien diferenciados: hialino-vascular que suele ser unicéntrico, de comportamiento poco agresivo y cuya exeresis consigue la curación en la mayor parte de los casos. La variante plasmocelular es más agresiva, su presentación clínica remeda los linfomas de alto grado y requiere quimioterapia para su erradicación. Juegan un papel etiopatogenico el HVH-8 y las interleucinas IL-6 e IL-1. Nuevos fármacos basados en el bloqueo de la IL-6 o su receptor han demostrado recientemente su utilidad para el control de la enfermedad. Presentamos cuatro casos clínicos que representan el espectro de la EC. ABSTRACT Castleman 's disease (CD) is a rare hematological disease characterized by hyperplasia of lymphoid nodules with two distinct histological and clinical patterns : hyaline - vascular which is usually single-center , low and aggressive behavior which gets exeresis healing in most of cases . The plasma cell variant is more aggressive clinical presentation mimics high-grade lymphomas and requires chemotherapy to eradicate. Play an etiopathogenic role HHV -8 and IL -6 and IL -1 cytokines. New drugs based on the blockade of IL -6 or its receptors have recently proved useful in the control of the disease. We present four cases representing the spectrum of CD.