Quick and Accurate Strategy for Calculating the Solutions of the Photovoltaic Single-Diode Model Equation

The photovoltaic (PV) single-diode model is the most widely used to characterize the behavior of a PV panel because it combines high precision with moderate difficulty. Lots of methods to obtain the model parameters use optimization techniques that require the resolution of the characteristic equation thousands of times; therefore, it is essential to calculate its solutions accurately but also in the shortest possible time. The objective of this article is to describe a new numerical strategy to solve the characteristic equation in a simple, fast and precise way. The main idea is based on a reparameterization of the Lambert equation which is closely related with the infinite power tower, and some well-known bounds of this tower will be used as seeds of numerical methods. This strategy is powerful for certain “small” values of the Lambert W function argument, but it is combined with another re-expression of the Lambert equation for the remaining “large” values. The proposed numerical strategy is so precise in very few iterations that it can be suitably transformed into an explicit formula. The results obtained have been compared with some of the best options in the literature and expexperimental results prove the power of the proposed methodolog

Perineuronal Net Formation and the Critical Period for Neuronal Maturation in the Hypothalamic Arcuate Nucleus

In leptin-deficient ob/ob mice, obesity and diabetes are associated with abnormal development of neurocircuits in the hypothalamic arcuate nucleus (ARC)1, a critical brain area for energy and glucose homoeostasis2,3. Because this developmental defect can be remedied by systemic leptin administration, but only if given before postnatal day 28, a critical period for leptin-dependent development of ARC neurocircuits has been proposed4. In other brain areas, critical-period closure coincides with the appearance of perineuronal nets (PNNs), extracellular matrix specializations that restrict the plasticity of neurons that they enmesh5. Here we report that in humans and rodents, subsets of neurons in the mediobasal aspect of the ARC are enmeshed in PNN-like structures. In mice, these neurons are densely packed into a continuous ring that encircles the junction of the ARC and median eminence, which facilitates exposure of ARC neurons to the circulation. Most of the enmeshed neurons are both γ-aminobutyric acid-ergic and leptin-receptor positive, including a majority of Agouti-related-peptide neurons. Postnatal formation of the PNN-like structures coincides precisely with closure of the critical period for maturation of Agouti-related-peptide neurons and is dependent on input from circulating leptin, because postnatal ob/ob mice have reduced ARC PNN-like material that is restored by leptin administration during the critical period. We conclude that neurons crucial to metabolic homoeostasis are enmeshed in PNN-like structures and organized into a densely packed cluster situated circumferentially at the ARC–median eminence junction, where metabolically relevant humoral signals are sensed

Metabolic clustering analysis as a strategy for compound selection in the drug discovery pipeline for leishmaniasis

A lack of viable hits, increasing resistance, and limited knowledge on mode of action is hindering drug discovery for many diseases. To optimize prioritization and accelerate the discovery process, a strategy to cluster compounds based on more than chemical structure is required. We show the power of metabolomics in comparing effects on metabolism of 28 different candidate treatments for Leishmaniasis (25 from the GSK Leishmania box, two analogues of Leishmania box series, and amphotericin B as a gold standard treatment), tested in the axenic amastigote form of Leishmania donovani. Capillary electrophoresis–mass spectrometry was applied to identify the metabolic profile of Leishmania donovani, and principal components analysis was used to cluster compounds on potential mode of action, offering a medium throughput screening approach in drug selection/prioritization. The comprehensive and sensitive nature of the data has also made detailed effects of each compound obtainable, providing a resource to assist in further mechanistic studies and prioritization of these compounds for the development of new antileishmanial drugs

Sex Differences in COVID-19 Hospitalization and Hospital Mortality among Patients with COPD in Spain: A Retrospective Cohort Study

We aimed to assess the effect of COPD in the incidence of hospital admissions for COVID-19 and on the in-hospital mortality (IHM) according to sex. (2) Methods: We used national hospital discharge data to select persons aged ≥40 years admitted to a hospital with a diagnosis of COVID-19 in 2020 in Spain. (3) Results: The study population included 218,301 patients. Age-adjusted incidence rates of COVID-19 hospitalizations for men with and without COPD were 10.66 and 9.27 per 1000 persons, respectively (IRR 1.14; 95% CI 1.08–1.20; p < 0.001). The IHM was higher in men than in women regardless of the history of COPD. The COPD was associated with higher IHM among women (OR 1.09; 95% CI 1.01–1.22) but not among men. The COPD men had a 25% higher risk of dying in the hospital with COVID-19 than women with COPD (OR 1.25, 95% CI 1.1–1.42). (4) Conclusions: Sex differences seem to exist in the effect of COPD among patients suffering COVID-19. The history of COPD increased the risk of hospitalization among men but not among women, and COPD was only identified as a risk factor for IHM among women. In any case, we observed that COPD men had a higher mortality than COPD women. Understanding the mechanisms underlying these sex differences could help predict the patient outcomes and inform clinical decision making to facilitate early treatment and disposition decisions.Fac. de Enfermería, Fisioterapia y PodologíaTRUEComunidad de MadridUniversidad Complutense de Madridpu

Potent Induction of Envelope-Specific Antibody Responses by Virus-Like Particle Immunogens Based on HIV-1 Envelopes from Patients with Early Broadly Neutralizing Responses

Longitudinal studies in HIV-1 infected individuals have indicated that 2-3 years of infection are required to develop broadly neutralizing antibodies. However, we have previously identified individuals with broadly neutralizing activity (bNA) in early HIV-1 infection, indicating that a vaccine may be capable of bNA induction after short periods of antigen exposure. Here, we describe 5 HIV-1 envelope sequences from individuals who have developed bNA within the first 100 days of infection (early neutralizers) and selected two of them to design immunogens based on HIV-1-Gag virus like particles (VLPs). These VLPs were homogeneous and incorporated the corresponding envelopes (7 to 9μg of gp120 in 1010 VLPs). Both envelopes bound to well-characterized bNAbs, including trimer-specific antibodies (PGT145, VRC01 and 35022). For immunogenicity testing, we immunized rabbits with the Env-VLPs or with the corresponding stabilized soluble Envelope trimers. A short immunization protocol (105 days) was used to recapitulate the early nAb induction observed after HIV-1 infection in these two individuals. All VLP and trimeric Envelope immunogens induced a comparably strong anti-gp120 response, despite having immunized rabbits with 30 times less gp120 in the case of the Env-VLPs. In addition, animals immunized with VLP-formulated Envs induced antibodies that cross-recognized the corresponding soluble stabilized trimer and vice versa, even though no neutralizing activity was observed. Nevertheless, our data may provide a new platform of immunogens, based on HIV-1 envelopes from patients with early broadly neutralizing responses, with the potential to generate protective immune responses using vaccination protocols similar to those used in classical preventive vaccines. Importance: It is generally accepted that an effective HIV-1 vaccine should be able to induce broad-spectrum neutralizing antibodies. Since most of these antibodies require long periods of somatic maturation in vivo, several groups are developing immunogens, based on the HIV envelope protein, that require complex and lengthy immunization protocols that would be difficult to implement to the general population. Here, we show that rabbits immunized with new envelopes (VLP-formulated) from two individuals who demonstrated broadly neutralizing activity very early after infection, induced specific HIV-1 antibodies after a short immunization protocol. This evidence provides the basis for generating protective immune responses with classic vaccination protocols with vaccine prototypes based on HIV envelope sequences from individuals who have developed early broadly neutralizing responses.This project received funding from the European Union's Horizon 2020 research and innovation program under grant agreement no. 681137 to I.B., N.G., A.O., C.B., J.A., R.W.S., and E.Y. It was also partially supported by the Spanish AIDS Research Network (RIS), funded by the Instituto de Salud Carlos III and co-funded by the European Regional Development Fund (ERDF) “A way to build Europe” (projects RD16CIII/0002/0001, RD16CIII/0002/0005, and RD16CIII/0025/0041), Plan Estatal de I1D1I 2013-2016 to N.G., A.M.M., J.A., V.S.M., E.Y., M.P., A.O., and C.B.; by IDIBAPS to J.M.M. (80:20 Research grant); by the Fondation Dormeur, Vaduz to C.B.; by the Ministerio de Economía, Industria y Competitividad to N.G., V.S.M., and E.Y. (PI17CIII/00049); by the Ministerio de Ciencia e Innovación to N.G., V.S.M., and E.Y. (PI20CIII/00039); by the Consejo Nacional de Innovación, Ciencia y Tecnología to C.B.P.; and by the HHS/ National Institutes of Health (NIH) to C.B. (P01-AI131568).S

El proceso enseñanza-aprendizaje de la física para la ingeniería/arquitectura

Cuando finalice el curso 2013-14 se producirá la salida de la primera promoción de graduados en la Escuela Politécnica Superior (EPS). Teniendo en cuenta que antes de que transcurran seis años se debe renovar la acreditación de los títulos oficiales de Grado, consideramos adecuado efectuar un análisis crítico del proceso de enseñanza-aprendizaje. En este trabajo presentamos los resultados del seguimiento realizado en el contexto educativo de los fundamentos físicos en los títulos de grado de la EPS. Estos resultados muestran la necesidad de abordar los cambios necesarios para corregir las deficiencias detectadas y mejorar la calidad del aprendizaje. Conviene recordar que el cambio que se pretendía realizar en la enseñanza universitaria era para centrarse en el aprendizaje del alumnado. Además incluimos un estudio de la evolución del aprendizaje de la física analizando las calificaciones de acceso en física y matemáticas y comparándolas con las obtenidas en los fundamentos físicos de los diferentes grados impartidos en la EPS. También presentaremos buena parte de las actividades realizadas para facilitar el aprendizaje continuo de nuestro alumnado mediante el uso de nuevas herramientas informáticas, como blogs, OpenCourseWare, materiales audiovisuales (pUAs), etc

Materiales para el autoaprendizaje y análisis de resultados académicos en dos grupos de física

La preparación previa del alumnado que cursa la asignatura de Fundamentos Físicos en primer curso de grado implantado en la Escuela Politécnica Superior de la Universidad de Alicante, es muy heterogénea. Además, se da la circunstancia que en los últimos cursos alrededor de un 50% del alumnado no ha cursado nunca una asignatura de física anteriormente, aunque esta situación depende del grado concreto. En este trabajo presentamos un análisis de los resultados obtenidos en el curso 14-15 en dos grupos teóricos de Fundamentos Físicos de la Informática a lo largo del curso. Nuestro objetivo es mejorar la metodología de la asignatura en actividades como cursos de iniciación, distribución homogénea del alumnado en los grupos teóricos, o adaptación de la guía docente al contexto particular de cada grupo. Otro aspecto que trabaja la red es el desarrollo de materiales para el autoaprendizaje de la física. Nuestro objetivo es facilitar que el alumnado pueda prepararse la asignatura de Fundamentos Físicos utilizando estos materiales. Entre ellos destacamos la elaboración de libros de resolución de problemas y la elaboración de blogs educativos

Effect of COPD on the Hospital Outcomes and Mortality among Hemorrhagic Stroke Patients. Sex Differences in a Population-Based Study

(1) Background: It is not well known whether there is an association between COPD and hemorrhagic stroke (HS). We aim to analyze the incidence, clinical characteristics, procedures, and outcomes of HS in patients with and without COPD and to assess sex differences. Secondly, to identify factors associated with in-hospital mortality (IHM). (2) Methods: Patients aged ≥40 years hospitalized with HS included in the Spanish National Hospital Discharge Database (2016–2018) were analyzed. Propensity score matching (PSM) was used to compare patients according to sex and COPD status. (3) Results: We included 55,615 patients (44.29% women). Among men with COPD the HS adjusted incidence was higher (IRR 1.31; 95% CI 1.24–1.57) than among non-COPD men. COPD men had higher adjusted incidence of HS than COPD women (IRR 1.87; 95% CI 1.85–1.89). After matching, COPD men had a higher IHM (29.96% vs. 27.46%; p = 0.032) than non-COPD men. Decompressive craniectomy was more frequently conducted among COPD men than COPD women (6.74% vs. 4.54%; p = 0.014). IHM increased with age and atrial fibrillation, while decompressive craniectomy reduced IHM. (4) Conclusions: COPD men had higher incidence and IHM of HS than men without COPD. COPD men had higher incidence of HS than COPD women. Decompressive craniectomy was more frequently conducted in COPD men than COPD women and this procedure was associated to better survival