Current sensorless power factor correction based on digital current rebuilding

A new digital control technique for power factor correction is presented. The main novelty of the method is that there is no current sensor. Instead, the input current is digitally rebuilt, using the estimated input current for the current loop. Apart from that, the ADCs used for the acquisition of the input and output voltages have been designed ad-hoc. Taking advantage of the slow dynamic behavior of these voltages, almost completely digital ADCs have been designed, leaving only a comparator and an RC filter in the analog part. The final objective is obtaining a low cost digital controller which can be easily integrated in an ASIC along with the controller of paralleled and subsequent power section

Factores explicativos de la eficiencia en relación con el tamaño empresarial en el sector manufacturero español

Este trabajo analiza la eficiencia técnica y sus factores explicativos en función del tamaño empresarial, en un panel de datos durante el periodo 2000-2010 en 26 sectores industriales españoles, a tres dígitos de la cnae (Clasificación Nacional de Actividades Económicas). Los resultados alcanzados por medio del modelo de frontera estocástica revelan la existencia de dos fronteras de producción para empresas pequeñas y medianas (epm) y empresas grandes (eg). Los factores explicativos de la eficiencia influyen en ambas fronteras de forma parcialmente diferente. Por un lado, la cualificación de los trabajadores se asocia con una relación positiva de la eficiencia independientemente del tamaño de la empresa y el sector de actividad. Por otro lado, la edad de la compañía tiene una influencia positiva/negativa o no significativa tanto en epm como eg en función del sector de actividad. La intensidad de capital, en general, tiene una relación inversa con la eficiencia en las epm o no significativa en las eg, principalmente. Finalmente, los niveles de eficiencia y sus patrones de omportamiento en el periodo de análisis presentan heterogeneidad intra e intersectorial.

Universal Approximation of a Class of Interval Type-2 Fuzzy Neural Networks in Nonlinear Identification

Neural networks (NNs), type-1 fuzzy logic systems (T1FLSs), and interval type-2 fuzzy logic systems (IT2FLSs) have been shown to be universal approximators, which means that they can approximate any nonlinear continuous function. Recent research shows that embedding an IT2FLS on an NN can be very effective for a wide number of nonlinear complex systems, especially when handling imperfect or incomplete information. In this paper we show, based on the Stone-Weierstrass theorem, that an interval type-2 fuzzy neural network (IT2FNN) is a universal approximator, which uses a set of rules and interval type-2 membership functions (IT2MFs) for this purpose. Simulation results of nonlinear function identification using the IT2FNN for one and three variables and for the Mackey-Glass chaotic time series prediction are presented to illustrate the concept of universal approximation

EGF-Coupled Gold Nanoparticles Increase the Expression of CNPase and the Myelin-Associated Proteins MAG, MOG, and MBP in the Septal Nucleus Demyelinated by Cuprizone

ARTICULO DE ACCESO ABIERTOCurrent pharmacological therapies against demyelinating diseases are not quite satisfactory to promote remyelination. Epidermal growth factor (EGF) can expand the population of oligodendrocyte precursor cells (OPCs) that may help with the remyelination process, but its delivery into the injured tissue is still a biomedical challenge. Gold nanoparticles (GNPs) may be a useful tool for drug delivery into the brain. To evaluate remyelination in the septal nucleus, we administered intracerebral GNPs coupled with EGF (EGF–GNPs). C57BL6/J mice were demyelinated with 0.4% cuprizone (CPZ) and divided into several groups: Sham, Ctrl, GNPs, EGF, and EGF–GNPs. We evaluated the remyelination process at two time-points: 2 weeks and 3 weeks post-injection (WPI) of each treatment. We used the rotarod for evaluating motor coordination. Then, we did a Western blot analysis myelin-associated proteins: CNPase, MAG, MOG, and MBP. EGF–GNPs increase the expression of CNPase, MAG, and MOG at 2 WPI. At 3 WPI, we found that the EGF–GNPs treatment improves motor coordination and increases MAG, MOG, and MBP. EGF–GNPs enhance the expression of myelin-associated proteins and improve the motor coordination in mice. Thus, EGF-associated GNPs may be a promising pharmacological vehicle for delivering long-lasting drugs into the brain.S/

Caracterización de la logística en la cadena de suministro de cosméticos y productos de aseo

The sector of cosmetics and toiletries is a world class sector, consolidated in Colombia with 690 companies of which 420 are in Bogotá D.C. Taking into account that logistics management generates competitive advantage in organizations as factor of success in a global economy, this paper proposes a logistics analysis applied to the case of cosmetics and toiletries supply chain. The results include the diagnosis of logistics processes and resources, which they were studied with an own methodology proposal. The methodology allowed study the logistics factors and variables, elements that recognized the logistical behaviour in the different links of the supply chain.El sector de cosméticos y productos de aseo de talla mundial, consolidado en Colombia con 690 empresas de las cuales 420 se encuentran en Bogotá, D.C. Al considerar que la gestión logística genera ventaja competitiva en las organizaciones como factor de éxito en una economía globalizada, este artículo presenta una propuesta metodológica, que permite estudiar factores y variables logísticas, elementos que identifican el comportamiento de la cadena de suministro en los diferentes eslabones, la cual es aplicada al caso de la cadena de suministro de cosméticos y productos de aseo. El resultado incluye el diagnóstico de los procesos logísticos y recursos.

Generalidades de la farmacovigilancia en colombia

Cuando hablamos acerca de la farmacovigilancia, se describe de una gestión en las acciones, utilizada para la prevención de riesgos de los medicamentos en los seres humanos y para evitar los costes económicos relacionados a los efectos adversos no esperados, así mismo mencionamos las características de las reacciones adversas, que se presentan en el día a día, esto quiere decir que la farmacovigilancia es aquella que se encarga de identificar, contar y evaluar la prevención de los riesgos en el uso de los medicamentos, por tal razón la evaluación que se les hace a los medicamentos es para garantizar su seguridad. Estos objetivos que se ocupan de estudiar, prevenir y de detectar los posibles efectos contrarios de los medicamentos, también se encarga de generar señales de alerta de estos posibles efectos opuestos de los medicamentos. Por consiguiente, los implicados son las autoridades sanitarias (comunitarias, estatales y autonómicas), los encargados de la autorización comercial y el personal sanitario (médicos, farmacéuticos, enfermeros y odontólogos). El INVIMA es la organización que se encarga de la recolección de datos. Gracias a ella los errores encontrados en la comercialización y en la dispensación de los mismos ha tenido una disminución favorable, retroalimentado para las prevenciones futuras.When we talk about pharmacovigilance, we describe a management in the actions, we detect the prevention of drug risks in humans and we avoid the economic costs related to the unexpected adverse effects, we also mention the characteristics of the adverse reactions, which They are presented on a day-to-day basis, this means that pharmacovigilance is the one that is in charge of identifying, counting and evaluating the prevention of risks in the use of medications, for this reason the evaluation that is made of medications is to protect your safety. These objectives, which are concerned with studying, preventing and detecting the possible opposite effects of medications, are also responsible for generating warning signs of these possible opposite effects of medications. In general, those involved are health authorities (community, state and regional), those in charge of commercial authorization and health personnel (doctors, pharmacists, nurses and dentists). INVIMA is the organization in charge of data collection. Thanks to it, the errors found in the search and in the dispensing of the same have suffered a favorable decrease, fed back for future preventions. Key words: pharmacovigilance, adverse reactions, pharmacoepidemiology, medication, patient

Risk factors for one-year mortality in hospitalized adults with severe covid-19 comment

As the body''s immunity declines with age, elderly-hospitalized patients due to COVID-19 might be at higher mortality risk. Therefore, the aim of this prospective study was to examine the possible risk factors (demographic, social or comorbidities) most associated with mortality one-year after diagnosis of COVID-19. Routine data were collected from a cohort of hospitalized adults with severe COVID-19. The primary endpoint was mortality at one-year after diagnosis of COVID-19. We used a Cox proportional hazard model to estimate the hazard ratios (HRs) for both all-cause and specific cardiorespiratory mortality. A fully adjusted model included sex, socioeconomic status, institutionalization status, disability, smoking habit, and comorbidities as confounders. A total of 368 severe cases hospitalized on average 67.3 +/- 15.9 years old were included. Participants aged >= 71 years had significantly higher HRs for all-cause mortality (adjusted HRs = 2.86, 95%CI: 2.01-4.07) and cardiorespiratory mortality (adjusted HRs = 2.86, 95%CI: 1.99-4.12). The association between age and mortality after diagnosis of COVID-19 due to both all-causes and cardiorespiratory mortality showed a consistent dose-response fashion. Institutionalization, disability, and socioeconomic status also showed a significant association with mortality. In conclusion, aging itself was the most important risk factor associated with mortality one year after diagnosis of COVID-19. People with disabilities, institutionalized or low socioeconomic status are significantly more likely to die after COVID-19

Displasia broncopulmonar en pacientes de un programa madre canguro en Popayán-Colombia. Estudio de cohorte retrospectivo

Kangaroo-Mother Care (KMC) is a follow-up program for premature infants with comorbidities such as bronchopulmonary dysplasia (BPD). The objective was to characterize patients with BPD and describe their nutritional, neurological, and respiratory outcomes in a KMC. A retrospective cohort study of the KMC in a University Hospital between 2015-2018. Included patients with BPD and excluded major malformations. Nutritional, neurological, and respiratory outcomes were evaluated at 40 weeks, 6, and 12 months of corrected-age using scales recommended in Colombia. A descriptive analysis was carried out, the variables were compared according to the severity of BPD. The changes in the outcomes in patients with complete follow-up were evaluated. 490 patients were admitted in four years, 50 with BPD (10,2%); 58% with moderate-BPD, none with severe BPD. 46% were born at <29 weeks of gestational-age, 96% had low socioeconomic status and 90% and 90% of these submitted  to mechanical ventilation. In the follow-up, height-for-age remained at risk at 6 and 12 months. 98% had abnormal Amiel-Tisson test. Around 75% had respiratory symptoms between 6 and 12 months and 33% had at least one hospital readmission. Patients with BPD in KMC have alterations in height-for-age, neurodevelopment, and respiratory system when complete the follow-up. El Programa Madre Canguro (PMC) permite un seguimiento a prematuros con comorbilidades como displasia broncopulmonar (DBP). El objetivo fue caracterizar los pacientes con DBP, describir su compromiso nutricional, neurológico, respiratorio en un PMC. Se realizó un estudio de cohorte retrospectivo en el PMC de un Hospital Universitario con aprobación del comité de ética. Incluyó pacientes con DBP entre 2015-2018, sin malformaciones mayores. Evaluamos el estado nutricional, neurológico y respiratorio a las 40 semanas, 6 y 12 meses de edad corregida mediante escalas recomendadas en Colombia. Realizamos análisis descriptivo y comparación según severidad de la DBP. Describimos la evolución en pacientes con seguimiento completo. Ingresaron 490 pacientes en cuatro años, 50 con DBP (10,2%); 58% con DBP-moderada, ninguno con DBP-severa. 96% de estrato socioeconómico bajo, 46% <29 semanas de edad gestacional y el 90% sometidos a ventilación mecánica. Encontramos compromiso del promedio de Talla/Edad a 6 y 12 meses. Prueba Amiel Tisson anormal en 98%. Cerca del 75% presentaron síntomas respiratorios entre 6 y 12 meses y 33% tuvo al menos un reingreso hospitalario. Los pacientes con DBP del PMC tienen compromiso en la Talla/Edad, neurodesarrollo y alteraciones respiratorias al completar el seguimiento