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Introducción: El comercio electrónico se ha convertido en una herramienta fundamental que mueve una gran parte de la economía mundial, estando presente en gestión de todo tipo de empresas. Objetivos: El objetivo de la investigación fue determinar el efecto del comercio electrónico en la rentabilidad de la Pymes en el Ecuador. Metodología: Se utilizó el método deductivo con un enfoque cuantitativo y un nivel de investigación descriptivo. Se aplicó como instrumento de recogida de información el cuestionario e información documental de los estados financieros de una población de 81 Pymes ubicadas en la provincia de Tungurahua cantón Ambato. Resultados: Los resultados muestran que las empresas utilizan siempre el comercio electrónico; las empresas obtuvieron un incremento en las ventas al utilizar el comercio electrónico; las Pymes del sector de alimentos y bebidas incrementaron sus ventas durante la pandemia Covid-19. Conclusiones: Se concluye que el comercio electrónico incide en la rentabilidad de las empresas de alimentos y bebidas de las Pymes en épocas de pandemia y que la probabilidad de mantener esta situación es alta. Área de estudio: Gestión Socioeconómica, Contable, Tributaria y Laboral.

Resumen Introducción. El incremento en la producción de piña (Ananas comosus (L.) Merr.) exige al mercado frutas de buena calidad, con menor impacto ambiental y mínimo uso de productos químicos. Objetivo. Determinar la dosis efectiva del hongo Bauveria bassiana y la formulación adecuada como bioinsecticida para el control de tecla (Strymon megarus Godart) en el cultivo de piña. Materiales y métodos. La investigación se realizó de febrero a abril de 2019 en una finca en Río Jiménez, Guácimo, Limón, Costa Rica. Se estableció un diseño de parcelas irrestricto al azar con medias repetidas en el tiempo con siete tratamientos y cinco réplicas por tratamiento. Para cada réplica se tomaron semanalmente datos de veinticinco frutos de piña, desde los 50 hasta los 92 días después de la inducción floral (ddf). Los tratamientos fueron: B. bassiana WP en dosis de 1,0, 2,0 y 3,0 kg ha-1, dos tratamientos de B. bassiana a 3 kg ha-1, coadyuvante Carrier y formulación miscible en aceite (OL); además, se tuvo un testigo absoluto sin aplicación de insecticida y un insecticida biológico Turex 3,8 WP (Bacillus thuringiensis) a 1,0 kg ha-1. Se realizaron cinco aspersiones por tratamiento, la primera a los 50 ddf y el resto con intervalos de siete días hasta llegar a los 78 días. Resultados. Todos los tratamientos mostraron una menor incidencia de daño viejo (gomosis) comparado con el testigo absoluto. Solo el T7 (testigo comercial B. thurigiensis 1 kg ha-1) y el T2 (B. bassiana a 1 kg ha-1) mostraron una incidencia de daño menor al 5 %, durante todo el periodo de evaluación sin diferencias significativas entre ellos, pero sí con el resto de los tratamientos. Conclusión. Los tratamientos T7 (testigo comercial B. thurigiensis 1 kg ha-1) y T2 (B. bassiana a 1 kg ha-1), fueron los más efectivos para el control de Strymon megarus Godart en el cultivo de piña. Abstract Introduction. The increase in pineapple (Ananas comosus (L.) Merr.) production demands good quality fruits from the market, with less environmental impact and minimal use of chemical products. Objective. To determine the effective dose of the fungus Beauveria bassiana and the appropriate formulation as a bioinsecticide for the control of key (Strymon megarus Godart) in pineapple crop. Materials and methods. This research was developed from February to April 2019 on a farm at Río Jiménez, Guácimo, Limón, Costa Rica. An unrestricted randomized plot design with repeated means over time was established with seven treatments and five replicates per treatment. For each replicate, data from twenty-five pineapple fruits were collected weekly, from 50 to 92 days after floral induction (ddf). The treatments were: B. bassiana WP at doses of 1.0, 2.0, and 3.0 kg ha-1, two treatments of B. bassiana at 3 kg ha-1, Carrier adjuvant, and oil-miscible formulation (OL), there were also an absolute control without insecticide application, and a biological insecticide Turex 3.8 WP (Bacillus thuringiensis) at 1.0 kg ha-1. Five sprays were made per treatment, the first at 50 ddf, and the rest at seven-day intervals until reaching 78 days. Results. All treatments showed a lower incidence of old damage (gummosis) compared to the absolute control. Only the T7 (comercial control B. thurigiensis 1 kg ha-1) and T2 (B. bassiana a 1 kg ha-1) treatments showed a damage incidence lower than 5 % during the whole evaluation period without significant differences between them, but with the rest of the treatments. Conclusion. The T7 (commercial control B. thurigiensis 1 kg ha-1) and T2 (B. bassiana 1 kg ha-1), treatments were the most effective for the control of Strymon megarus Godart in pineapple crops.

We study solutions of the equation$$u_t-\Delta u+\lambda u=f$$ut-Δu+λu=f, for initial data that is ‘large at infinity’ as treated in our previous papers on the unforced heat equation. When$$f=0$$f=0we characterise those$$(u_0,\lambda )$$(u0,λ)for which solutions converge to 0 as$$t\rightarrow \infty $$t→∞, as not every$$\lambda >0$$λ>0is able to achieve that for all initial data. When$$f\ne 0$$f≠0we give conditions to guarantee that the solution is given by the usual ‘variation of constants formula’$$u(t)=\mathrm{e}^{-\lambda t}S(t)u_0+\int _0^t\mathrm{e}^{-\lambda (t-s)}S(t-s)f(s)\,\mathrm{d}s$$u(t)=e-λtS(t)u0+∫0te-λ(t-s)S(t-s)f(s)ds, where$$S(\cdot )$$S(·)is the heat semigroup. We use these results to treat the elliptic problem$$-\Delta u+\lambda u=f$$-Δu+λu=fwhenfis allowed to be ‘large at infinity’, giving conditions under which a solution exists that is given by convolution with the usual Green’s function for the problem. Many of our results are sharp when$$u_0,f\ge 0$$u0,f≥0.

Introduction.The increase in pineapple (Ananas comosus(L.) Merr.) production demands good quality fruits from the market, with less environmental impact and minimal use of chemical products.Objective.To determine the effective dose of the fungusBeauveria bassianaand the appropriate formulation as a bioinsecticide for the control of key (Strymon megarusGodart) in pineapple crop.Materials and methods.This research was developed from February to April 2019 on a farm at Río Jiménez, Guácimo, Limón, Costa Rica. An unrestricted randomized plot design with repeated means over time was established with seven treatments and five replicates per treatment. For each replicate, data from twenty-five pineapple fruits were collected weekly, from 50 to 92 days after floral induction (ddf). The treatments were:B. bassianaWP at doses of 1.0, 2.0, and 3.0 kg ha-1, two treatments ofB. bassianaat 3 kg ha-1, Carrier adjuvant, and oil-miscible formulation (OL), there were also an absolute control without insecticide application, and a biological insecticide Turex 3.8 WP (Bacillus thuringiensis) at 1.0 kg ha-1. Five sprays were made per treatment, the first at 50 ddf, and the rest at seven-day intervals until reaching 78 days.Results.All treatments showed a lower incidence of old damage (gummosis) compared to the absolute control. Only the T7 (comercial controlB. thurigiensis1 kg ha-1) and T2 (B. bassianaa 1 kg ha-1) treatments showed a damage incidence lower than 5 % during the whole evaluation period without significant differences between them, but with the rest of the treatments.Conclusion.The T7 (commercial controlB. thurigiensis1 kg ha-1) and T2 (B. bassiana1 kg ha-1), treatments were the most effective for the control ofStrymon megarusGodart in pineapple crops. Introducción.El incremento en la producción de piña (Ananas comosus(L.) Merr.) exige al mercado frutas de buena calidad, con menor impacto ambiental y mínimo uso de productos químicos.Objetivo.Determinar la dosis efectiva del hongoBauveria bassianay la formulación adecuada como bioinsecticida para el control de tecla (Strymon megarusGodart) en el cultivo de piña.Materiales y métodos.La investigación se realizó de febrero a abril de 2019 en una finca en Río Jiménez, Guácimo, Limón, Costa Rica. Se estableció un diseño de parcelas irrestricto al azar con medias repetidas en el tiempo con siete tratamientos y cinco réplicas por tratamiento. Para cada réplica se tomaron semanalmente datos de veinticinco frutos de piña, desde los 50 hasta los 92 días después de la inducción floral (ddf). Los tratamientos fueron:B. bassianaWP en dosis de 1,0, 2,0 y 3,0 kg ha-1, dos tratamientos deB. bassianaa 3 kg ha-1, coadyuvante Carrier y formulación miscible en aceite (OL); además, se tuvo un testigo absoluto sin aplicación de insecticida y un insecticida biológico Turex 3,8 WP (Bacillus thuringiensis) a 1,0 kg ha-1. Se realizaron cinco aspersiones por tratamiento, la primera a los 50 ddf y el resto con intervalos de siete días hasta llegar a los 78 días.Resultados.Todos los tratamientos mostraron una menor incidencia de daño viejo (gomosis) comparado con el testigo absoluto. Solo el T7 (testigo comercialB. thurigiensis1 kg ha-1) y el T2 (B. bassianaa 1 kg ha-1) mostraron una incidencia de daño menor al 5 %, durante todo el periodo de evaluación sin diferencias significativas entre ellos, pero sí con el resto de los tratamientos.Conclusión.Los tratamientos T7 (testigo comercialB. thurigiensis1 kg ha-1) y T2 (B. bassianaa 1 kg ha-1),fueron los más efectivos para el control deStrymon megarusGodart en el cultivo de piña.

In this paper we show that solutions of the heat equation that are given in terms of the heat kernel define semigroups on the family of Frechet spaces L 0 p ( R d ) , the intersection (over all e > 0 ) of the spaces L e p ( R d ) of functions such that ∫ R d e − e | x | 2 | f ( x ) | p d x ∞ . These spaces consist of functions that are ‘large at infinity’, and L 0 1 ( R d ) is the maximal space in which one can use the heat kernel to obtain globally-defined solutions of the heat equation. We prove suitable estimates from L 0 p ( R d ) into L 0 q ( R d ) , q ≥ p , for these semigroups. We then consider the heat semigroup posed in spaces that are dual to these spaces of functions, namely the spaces L − e p ( R d ) of very-rapidly decreasing functions such that ∫ R d e e | x | 2 | f ( x ) | p d x ∞ . We show that ( L p e p ( R d ) ) ′ = L − q e q ( R d ) (with 1 p ∞ and ( p , q ) conjugate), and that the heat flow on L e p ( R d ) is the adjoint of the flow on L − δ q ( R d ) for an appropriate (time-dependent) choice of δ.

Background Hypertrophic cardiomyopathy (HCM) carries an increased risk of sudden death due to ventricular arrhythmias (VAs). The implantable cardioverter–defibrillator (ICD) is a well-established therapy for treatment of VA. Monomorphic ventricular tachycardias (MVTs) are frequent in HCM patients and suitable for antitachycardia pacing (ATP) termination. Objective The purpose of this study was to describe ventricular tachycardia (VT) characteristics in a population of HCM patients with ICD and to study the effectiveness and safety of ATP for MVT. Methods Data were obtained from the multicenter prospective observational UMBRELLA trial, which included all patients with HCM and ICD followed by the CareLink Monitoring System. All episodes of VA were collected and analyzed. ATP effectiveness and safety were described, and factors related to ATP effectiveness were studied with generalized estimating equation (GEE) models. Results Among 251 patients followed for 47 months, 67 (26.7%) were implanted as secondary prevention. Fifty-six patients presented 326 episodes of VA (286 [87%] MVT). Mean cycle length was 312 ± 64 ms. Among 264 MVTs that received ICD therapy, 202 (76.5%) were ATP terminated. The first ATP burst was effective in 169 episodes (68.4%), and overall effectiveness of the first or second ATP burst was 73.8%. Multivariate GEE-adjusted analysis showed 2 variables related to ATP effectiveness: programming fast VT zone On vs Off (odds ratio [OR] 2.4; 95% confidence interval [CI] 1.5–5.2; P = .03) and programming ≥2 ATP bursts vs 1 burst only (OR 1.6; 95% CI 1.2–3.4; P = .04; and OR 2.9; 95% CI 1.8–6.3; P = .02; respectively). Conclusion MVT is the predominant VA in HCM patients with ICD. ATP is highly effective in terminating the majority of MVTs, and its proved effectiveness should guide device selection and programming in order to avoid unnecessary high-energy shocks.

Background Premature ventricular contractions (PVC) are known to reduce the percentage of biventricular (BiV) pacing in patients with cardiac resynchronization (CRT), decreasing the clinical response. The aim of this study was to evaluate the prevalence of a high PVC burden, as well as therapeutic action (pharmacotherapy, catheter ablation or device programming), in a large CRT implantable-defibrillator (CRT-D) population. Methods Patients with a CRT-D device from the UMBRELLA multicenter prospective remote monitoring registry were included. The PVC count was collected from each remote monitoring transmission. Patients were divided into two high (≥1 transmission ≥200/≥400 PVC/h, respectively) and one low (all transmissions, Highlights • This study shows that in a large CRT-D population (UMBRELLA registry) a significant proportion presented a high PVC burden. • A minority received treatment aimed at reducing PVC, possibly since the high PVC count was missed during the remote transmission follow-up. • In untreated patients with high PVC burden temporal trends varied substantially. • Several consecutive recordings of a high PVC burden should be warranted before considering therapeutic action such as catheter ablation.

Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Medtronic Inc. Introduction Catheter ablation of atrial fibrillation, both cryoablation and radiofrequency pulmonary vein isolation, have demonstrated to be safe and effective techniques for treating symptomatic atrial fibrillation as a first procedure. However, about one in three patients may face a redo procedure due to AF recurrence. The most suitable technique for redo is unknown. Purpose The aim of this study is to assess the efficacy of cryoballoon AF ablation as a redo technique in patients with prior cryoballoon or radiofrequency AF ablation. Methods We analyzed a nation-wide real-world cryoablation registry (RECABA) and compared patients who were referred for a first cryoballoon AF ablation procedure with those who had previously undergone cryoballoon or radiofrequency pulmonary vein isolation. The primary endpoint was AF recurrence during the first year after a 3-month blanking period. We performed survival analysis and built univariate and multivariate cox regression models. Results From 1742 patients, 1625 had a 12-month follow-up visit. 1551 (95.45%) underwent a first cryoballoon ablation, whereas 33 (2.03%) had a previous CB ablation performed and 41 (2.52%) a previous RF ablation. Mean age was 58.6 ±10.4 years and 511 (31.5%) were women. 463 (28.5%) had persistent atrial fibrillation and there were no major clinical differences between groups. Prior-CB group had a higher share of veins without electrogram visualization, with a median of 100% (IQR 75%-100%), compared to prior-RF group (median 67%, IQR 25%-75%) and first procedure group (median 25%, IQR 0%-50%). Kruskal-Wallis test Chi2=54.35, p 12-month Kaplan–Meier estimate of freedom from AF recurrence after the blanking period was 78.5% (95% CI 76.2% - 80.7%) in the first procedure group, 61.0% (95% CI 41.4% - 75.8%) in the prior-CB and 89.2% (95% CI 73.6% - 95.9%) in the prior-RF group. Log-rank test Chi2=17.49, p Multivariate cox regression analysis pointed female sex, persistent AF, and prior-CB ablation as independent predictors of AF recurrence. The adjusted HR for AF recurrence of prior-CB ablation vs first-CB ablation was 3.13 (95% CI 1.82 -5.40) and for prior-RF vs first CB-ablation was 1.01 (95% CI 0.51 – 1.97). Conclusion Repeat cryoballoon AF ablation shows higher rates of AF recurrences compared to first CB procedures or after prior RF ablation. These data suggest that patients with AF recurrence after CB-ablation have worse arrhythmic outcomes and may benefit from other ablation techniques after a recurrence.

In this paper we analyse the asymptotic behaviour of some nonlocal diffusion problems with local reaction term in general metric measure spaces. We find certain classes of nonlinear terms, including logistic type terms, for which solutions are globally defined with initial data in Lebesgue spaces. We prove solutions satisfy maximum and comparison principles and give sign conditions to ensure global asymptotic bounds for large times. We also prove that these problems possess extremal ordered equilibria and solutions, asymptotically, enter in between these equilibria. Finally we give conditions for a unique positive stationary solution that is globally asymptotically stable for nonnegative initial data. A detailed analysis is performed for logistic type nonlinearities. As the model we consider here lack of smoothing effect, important focus is payed along the whole paper on differences in the results with respect to problems with local diffusion, like the Laplacian operator.

BackgroundSARS-CoV-2 viral load and kinetics assessed in serial blood samples from hospitalised COVID-19 patients by RT-PCR are poorly understood.MethodsWe conducted an observational, prospective case series study in hospitalised COVID-19 patients. Clinical outcome data (Intensive Care Unit admission and mortality) were collected from all patients until discharge. Viremia was determined longitudinally during hospitalisation, in plasma and serum samples using two commercial and standardised RT-PCR techniques approved for use in diagnosis of SARS-CoV-2. Viral load (copies/mL and log10) was determined with quantitative TaqPath™COVID-19 test.ResultsSARS-CoV-2 viremia was studied in 57 hospitalised COVID-19 patients. Persistent viremia (PV) was defined as two or more quantifiable viral loads detected in blood samples (plasma/serum) during hospitalisation. PV was detected in 16 (28%) patients. All of them, except for one who rapidly progressed to death, cleared viremia during hospitalisation. Poor clinical outcome occurred in 62.5% of patients with PV, while none of the negative patients or those with sporadic viremia presented this outcome (pConclusionsDetection of persistent SARS-CoV-2 viremia, by real time RT-PCR, expressed as viral load over time, could allow identifying hospitalised COVID-19 patients at risk of poor clinical outcome.HighlightsCommercial RT-PCR techniques could be used to monitor SARS-CoV-2 viremia kinetics.SARS-CoV-2 persistent viremia is related with poor outcome in COVID-19 patient.SARS-Cov-2 viremia kinetics could be used as a biomarker of poor prognosis.Plasma samples are the best choice for analysis of SARS-CoV-2 viremia kinetics.

Resumen Introduccion y objetivos En Espana no se dispone de datos sobre la implantacion de electrodos de desfibrilacion. Registros internacionales han descrito en los ultimos anos un cambio en favor de los electrodos monobobina. El objetivo primario de nuestro estudio fue tratar de inferir como ha sido la implantacion de electrodos de desfibrilacion durante los ultimos anos en nuestro pais. El objetivo secundario busca identificar diferencias entre ambos tipos de electrodos. Metodos Se analizaron datos de 4.131 pacientes espanoles portadores de un desfibrilador automatico implantable, incluidos consecutivamente en el registro UMBRELLA y seguidos remotamente mediante sistema CareLink, entre 2005 y 2016. Resultados Inicialmente la proporcion de electrodos de desfibrilacion monobobina era Conclusiones La practica clinica con desfibriladores ha ido cambiando tanto en la forma de implantar como en la forma de programar los dispositivos. En lo que a electrodos de desfibrilacion se refiere, en nuestro registro se observo un cambio en la eleccion del tipo de electrodo de desfibrilacion, ya que fueron los electrodos monobobina los implantados con mas frecuencia en los ultimos anos.

Atrial electrical remodelling (AER) is a transitional period associated with the progression and long-term maintenance of atrial fibrillation (AF). We aimed to study the progression of AER in individual patients with implantable devices and AF episodes. Observational multicentre study (51 centres) including 4618 patients with implantable cardioverter-defibrillator +/-resynchronization therapy (ICD/CRT-D) and 352 patients (2 centres) with pacemakers (median follow-up: 3.4 years). Atrial activation rate (AAR) was quantified as the frequency of the dominant peak in the signal spectrum of AF episodes with atrial bipolar electrograms. Patients with complete progression of AER, from paroxysmal AF episodes to electrically remodelled persistent AF, were used to depict patient-specific AER slopes. A total of 34 712 AF tracings from 830 patients (87 with pacemakers) were suitable for the study. Complete progression of AER was documented in 216 patients (16 with pacemakers). Patients with persistent AF after completion of AER showed ∼30% faster AAR than patients with paroxysmal AF. The slope of AAR changes during AF progression revealed patient-specific patterns that correlated with the time-to-completion of AER (R2 = 0.85). Pacemaker patients were older than patients with ICD/CRT-Ds (78.3 vs. 67.2 year olds, respectively, P

In this paper we derive the limiting PDES for parabolic problems where localized large diffusion touches the boundary of the domain. Hence the limit problem reflects the interaction of large diffusion and boundary conditions. The limit problem is a PDE coupled with a system of ODEs through some nonlocal terms. We study the well posedness and dissipativity of the (nonstandard) limit problem as well as the continuity of the dynamics as diffusion becomes large.

RESUMEN Se presenta aquí el documento de consenso para la implantación y desarrollo del Código Sepsis en la Comunidad de Madrid, cuya redacción se completó en abril de 2017. Este documento ha sido adoptado por la Consejería de Sanidad madrileña como base de trabajo para la puesta en marcha del Código Sepsis, tanto en el ámbito hospitalario (hospitales de agudos y de media y larga estancia) como en Atención Primaria y los Servicios de Emergencia Extrahospitalaria. Se publica ahora sin modificaciones con respecto a la versión original, añadiendo únicamente las referencias bibliográficas más significativas. El documento se estructura en cuatro partes: introducción, detección y valoración iniciales, tratamiento inicial y organización asistencial. En las partes segunda a cuarta se proponen 25 recomendaciones, consensuadas por los autores después de varias reuniones presenciales y una extensa discusión “online”. Se incluyen nueve tablas que pretenden servir de guía práctica para la activación y aplicación del código sepsis. Tanto el contenido de las recomendaciones como su redacción formal se han realizado teniendo en cuenta su aplicabilidad en todos los ámbitos a los que se dirigen, que cuentan con recursos y características estructurales y funcionales muy dispares, por lo que deliberadamente se ha huido de un mayor grado de concreción: el objetivo no es que el código sepsis se organice y se aplique de forma idéntica en todos ellos, sino que los recursos sanitarios trabajen de forma coordinada alineados en la misma dirección.

Background Large‐scale studies describing modern populations using an implantable cardioverter‐defibrillator (ICD) are lacking. We aimed to analyze the incidence of arrhythmia, device interventions, and mortality in a broad spectrum of real‐world ICD patients with different heart disorders. Methods and Results The UMBRELLA study is a prospective, multicenter, nationwide study of contemporary patients using an ICD followed up by remote monitoring, with a blinded review of arrhythmic episodes. From November 2005 to November 2017, 4296 patients were followed up. After 46.6±27.3 months, 16 067 episodes of sustained ventricular arrhythmia occurred in 1344 patients (31.3%). Appropriate ICD therapy occurred in 27.3% of study population. Patients with ischemic cardiomyopathy (hazard ratio [HR], 1.51; 95% CI, 1.29–1.78), dilated cardiomyopathy (HR, 1.28; 95% CI, 1.07–1.53), and valvular heart disease (HR, 1.94; 95% CI, 1.43–2.62) exhibited a higher risk of appropriate ICD therapies, whereas patients with hypertrophic cardiomyopathy (HR, 0.72; 95% CI, 0.54–0.96) and Brugada syndrome (HR, 0.25; 95% CI, 0.14–0.45) showed a lower risk. All‐cause death was 13.4% at follow‐up. Ischemic cardiomyopathy (HR, 3.09; 95% CI, 2.58–5.90), dilated cardiomyopathy (HR, 3.33; 95% CI, 2.18–5.10), and valvular heart disease (HR, 3.97; 95% CI, 2.25–6.99) had the worst prognoses. Delayed high‐rate detection was enabled in 39.7% of patients, and single‐zone programming occurred in 52.6% of primary prevention patients. Both parameters correlated with lower risk of first appropriate ICD therapy, with no excess risk of mortality. The rate of inappropriate shocks at follow‐up was low (6%) and did not differ among type of ICD but was lower in SmartShock‐capable devices. Conclusions Irrespective of the cause, contemporary ICD patients with heart failure–related disorders had a similar risk of ICD life‐saving interventions and death. Current ICD programming recommendations still need to be implemented. Registration URL: https://www.clinicaltrials.gov ; Unique identifier: NTC01561144.

In this paper, we analyze evolution problems associated to homogenous operators. We show that they have an homogenous associated semigroup of solutions that must satisfy some sharp estimates when acting on homogenous spaces and on the associated fractional power spaces. These sharp estimates are determined by the homogeneity alone. We also consider fractional diffusion problems and Schrödinger type problems as well. We apply these general results to broad classes of PDE problems including heat or higher order parabolic problems and the associated fractional and Schrödinger problems or Stokes equations. These equations are considered in Lebesgue or Morrey spaces.

Introduction The clinical impact of slow ventricular tachycardia (VT), occurring in patients carrying implantable cardiac defibrillators (ICD), is still under debate. Methods and results From the UMBRELLA registry (multicenter, observational, and prospective study on patients with ICD), 659 episodes of slow VT were observed in 97 patients. Untreated slow VT (n = 93) had longer duration (23.7 min, CI95%: 10-39), compared with episodes treated effectively by anti-tachycardia pacing (ATP;n = 527; 0.32 min, IC95%: 0.22-0, 48) or shock (n = 39; 1 min, CI95%: 0.8-1.2). Despite of longer duration, the time to the first contact with the medical services was similar to those episodes treated by ATP (50 days [CI95%: 45-55] vs. 41 days [CI95%: 39-44]). However, both were significantly longer than the time observed in episodes treated with shock (10 days, CI95%: 6-15). This tendency was maintained with successive interrogations of the device (2nd and 3rd). There were no significant differences in mortality during follow-up (48 +/- 16 months), neither other adverse outcomes, between patients who presented untreated slow TV and those who did not (log-rankp = 0.28). In a Cox regression analysis, the variable "presenting untreated episodes of slow VT" was not able to predict mortality. However, being in sinus rhythm (vs. atrial fibrillation, OR: 0.31,p = 0.009), narrower QRS (OR: 1.036,p = 0.037) and diabetes (OR 4.673,p = 0.049) appropriately predict survival. Conclusions Untreated slow VT does not significantly worsen patient prognosis. Our results support the limitation of therapies to ATP only, thus avoiding therapies that have been associated with increased risk of morbidity and mortality.

In this paper we show how solutions of a wave equation with distributed damping near the boundary converge to solutions of a wave equation with boundary feedback damping. Sufficient conditions are given for the convergence of solutions to occur in the natural energy space.

In this paper we study several PDE problems where certain linear or nonlinear termsin the equation concentrate in the domain, typically (but not exclusively) near the boundary. We analyze some linear and nonlinear elliptic models, linear and nonlinear parabolic ones as well as some damped wave equations. We show that in all these singularly perturbed problems, the concentrating terms give rise in the limit to a modification in the original boundary condition of the problem. Hence we describe in each case which is the singular limit problem and analyze the convergence of solutions.

This study aimed to assess the efficacy of ceftazidime/avibactam (C/A) in the treatment of infections due to Gram-negative bacteria (GNB) in critically ill patients. A multicentre, retrospective, observational study was conducted in critically ill patients receiving C/A for GNB infections. We evaluated demographic data, localisation and severity of infection, clinical and microbiological outcomes, and mortality. A total of 68 patients received C/A for serious GNB infections. The main infections were respiratory (33.8%), intra-abdominal (22.1%) and urinary tract infections (10.3%); bacteraemia was found in 22 cases (32.4%). Most infections were complicated by septic shock (58.8%) or sepsis (36.8%) and most of them required life-supporting therapies. Enterobacterales (79.4%) and Pseudomonas aeruginosa (19.1%) were the most frequently isolated bacteria; 84.2% of isolates were carbapenem-resistant. Thirty-four patients (50.0%) received C/A in combination with other antimicrobials. Fifty patients (73.5%) presented a favourable clinical response. Microbiological eradication was documented in 25 cases (36.8%). No significant differences were found in clinical response between patients treated with monotherapy or combined therapy (79.4% vs. 67.6%; P = 0.27). Overall intensive care unit (ICU) mortality was 41.2%. Univariate analysis showed that 30-day all-cause mortality was significantly (P0.05) associated with bacteraemia, previous corticosteroid use and the need of life-supporting therapies. C/A appears to be an effective therapy for severe infections due to GNB, including carbapenem-resistant isolates, in critically ill patients. C/A combination therapy was not associated with a higher clinical response. Mortality correlated significantly with the presence of bacteraemia, previous corticosteroid use and the need for life-supporting therapies.

Resumen Introduccion y objetivos Las taquicardias ventriculares rapidas en zona de fibrilacion ventricular en pacientes con desfibriladores implantables son susceptibles de terminacion mediante estimulacion antitaquicardica (EA). Algunos fabricantes permiten la programacion de 2 rafagas de EA: antes de la carga (AC) y durante la carga (DC). Nuestro objetivo es describir la efectividad y la seguridad de la EA AC y DC en las taquicardias ventriculares rapidas en zona de fibrilacion ventricular en pacientes con desfibriladores implantables en la practica clinica diaria. Metodos Los datos proceden del ensayo multicentrico UMBRELLA, y se incluyo a los pacientes portadores de desfibriladores implantables seguidos por el sistema de monitorizacion a distancia CareLink. Se incluyeron las taquicardias ventriculares rapidas en la zona de fibrilacion ventricular hasta una longitud de ciclo de 200 ms y tratadas con EA AC y/o DC. Resultados Se revisaron 542 episodios en 240 pacientes. Dos rafagas de EA (AC/DC) se programaron en 291 episodios (el 53,7%, 87 pacientes) mientras que 251 (el 46,3%, 153 pacientes) tuvieron 1 sola EA DC. Los episodios terminados por 1 EA DC fueron 139: el 55,4% de eficacia (ajustado por las ecuaciones de estimacion generalizada, el 60,4%). Los episodios terminados por 1 o 2 EA (AC/DC) fueron 256, el 88% de efectividad (ajustado por las ecuaciones de estimacion generalizada, el 79,3%). La OR para la eficacia de la EA AC/DC frente a DC fue 2,5 (IC95%, 1,5-4,1; p Conclusiones La EA DC en la zona de fibrilacion ventricular en taquicardias ventriculares rapidas es moderadamente eficaz. La adicion de una rafaga de EA AC aumenta la efectividad general, reduce la necesidad de descargas y no prolonga el episodio.

We analyse the behaviour of solutions of the linear heat equation in R d for initial data in the classes M e ( R d ) of Radon measures with ∫ R d e − e | x | 2 d | u 0 | ∞ . We show that these classes are optimal for local and global existence of non-negative solutions: in particular M 0 ( R d ) : = ∩ e > 0 M e ( R d ) consists of those initial data for which a solution of the heat equation can be given for all time using the heat kernel representation formula. We prove existence, uniqueness, and regularity results for such initial data, which can grow rapidly at infinity, and then show that they give rise to properties associated more often with nonlinear models. We demonstrate the finite-time blowup of solutions, showing that the set of blowup points is the complement of a convex set, and that given any closed convex set there is an initial condition whose solutions remain bounded precisely on this set at the ‘blowup time’. We also show that wild oscillations are possible from non-negative initial data as t → ∞ and that one can prescribe the behaviour of u ( 0 , t ) to be any real-analytic function γ ( t ) on [ 0 , ∞ ) .

Presence of SARS-CoV-2 RNA in serum (viremia) of COVID-19 patients has been related to poor prognosis and death. The aim of this study was to evaluate both the ability to detect viremia in COVID-19 patients of two commercial reverse real-time-PCR (rRT-PCR) tests, Cobas® and TaqPath™, comparing them with a gold standard method, and their implementation in microbiology laboratories. This retrospective cohort study included 303 adult patients (203 diagnosed with COVID-19 and 100 non-COVID-19 patients) admitted to a tertiary hospital, with at least one serum sample collected within the first 48 hours from admission. A total of 365 serum samples were included: 100 from non-COVID-19 patients (pre-pandemic and pandemic control groups) and 265 from COVID-19 patients. Serum samples were considered positive when at least one target was detected. All patients in control groups showed negative viremia. Cobas® and TaqPath™ tests showed specificity and Positive Predictive Value over 96%. Nevertheless, sensitivity (53.72 and 73.63, respectively) and Negative Predictive Value (64.78 and 75) were lower. Viremia difference between ICU and non-ICU patients was significant (p ≤ 0.001) for both techniques. Consequently, SARS-CoV-2 viremia detection by both rRT-PCR tests should be considered a good tool to stratify COVID-19 patients and could be implemented in microbiology laboratories.

Linear 2m-th order uniformly elliptic operators are shown to generate semigroups of bounded linear operators with suitable smoothing properties in scales of locally uniform Bessel's and Lebesgue's spaces.

Starting form basic principles, we obtain mathematical models that describe the traffic of material objects in a network represented by a graph. We analyze existence, uniqueness, and positivity of solutions for some implicit models. Also, some linear models and their equilibria are analyzed.

We solve second order parabolic equations with nonsmooth coefficients and initial data in suitable uniform spaces. We also show the smoothing effect of the corresponding analytic semigroup depending on the integrability properties of the coefficients. Robustness with respect to perturbations in the coefficients is also obtained.

In this paper we address the well posedness of the linear heat equation under general periodic boundary conditions in several settings depending on the properties of the initial data. We develop an Lq theory not based on separation of variables and use techniques based on uniform spaces. We also allow less directions of periodicity than the dimension of the problem. We obtain smoothing estimates on the solutions. Also, based on symmetry arguments, we handle Dirichlet or Neumann boundary conditions in some faces of the unit cell.

Background: Concerns about the efficacy of prophylactic ICD in non-ischemic cardiomyopathy (NICM) heart failure (HF) patients are still present. We aimed to assess whether survival and arrhythmic risk were different among ischemic cardiomyopathy (ICM) and NICMICD-only patients, along with specific predictors for mortality. Methods: HF patients undergoing ICD-only implant were extracted from the nationwide multicenter UMBRELLA registry. Arrhythmic events were collected by remote monitoring and reviewed by a committee of experts. Results: 782 patients (556 ICM; 226 NICM) were recruited: mean ejection fraction of 26.6%; 83.4% in NYHA class II-III; mean QRS duration of 108.9 ms (only 14.9% with QRS > 130 ms). After 4.35 years of mean follow-up, all-cause mortality rate was 4.2%/year. In propensity-score (PS) analysis no survival differences between ICM and NICM subgroups appeared (mortality rates: 19.4% vs. 20%, p = 0.375). Age (hazard ratio [HR] = 1.02, p = 0.009), diabetes (HR = 2.61, p = 0.001), chronic obstructive pulmonary disease (HR = 2.13, p = 0.002), and previous HF (HR = 2.28, p = 0.027) correlated with increased mortality for the entire population, however atrial fibrillation (AF) (HR = 2.68, p = 0.002) and chronic kidney disease (HR = 3.74, p = 0.001) emerged as specific predictors in NICM patients. At follow-up, 134 patients (17.1%) were delivered a first appropriate ICD therapy (5.1%/year) without significant differences between ICM and NICM patients in the PS analysis (17.6% vs. 15.8%, p = 0.968). ICD shocks were associated with a higher mortality (HR = 2.88, p < 0.001) but longer detection windows (HR = 0.57, p = 0.042) correlated with fewer appropriate therapies. Conclusions: Mortality and arrhythmia free survival is similar among ICM and NICMHF patients undergoing ICD-only implant for primary prevention strategy. (c) 2018 Elsevier B.V. All rights reserved.

Purpose Comparisons of the efficacy of dual- vs. single-chamber implantable cardioverter defibrillators (ICDs) in preventing inappropriate shocks have had contradictory results. We investigated whether dual-chamber devices have a lower risk of inappropriate shocks and the specific role of supraventricular tachycardia (SVT) discriminators. Methods All heart failure (HF) patients without an indication for pacing and implanted with a prophylactic ICD were recruited from the nationwide multicenter UMBRELLA registry. Arrhythmic events were collected by remote monitoring and reviewed by a committee of experts. Results Among 782 patients, single-chamber ICDs were implanted in 537 (68.7%) and dual-chamber devices in 245 (31.3%). During a mean follow-up of 52.224.5months, 109 inappropriate shocks were delivered in 49 patients (6.2%). In the propensity-score-matched analysis, dual-chamber ICDs were related to lower rates of inappropriate shocks as compared to single-chamber devices (0.9% vs. 11.8%, p=200bpm emerged as protective factors.

[EN] The introduction of bilingual programmes in the classrooms has been, and is, one of the biggest challenges of the Spanish educational system. However, it is difficult for teachers to use the correct methodology that integrates content and foreign language in bilingual schools. It must be borne in mind that it is highly benefitial to create didactic units that integrate English language and other subjects, such as Physical Education, Arts and Crafts or Sciences (Alario and Crespo, 2011). Therefore, aiming at providing an innovative didactic approach, we will introduce a proposal about a procedure which will show that Social Science contents can be achieved in a fun way. In order to do so, a variety of materials as well as unusual spaces, such as the ones in which the Physical Education sessions take place, will be used to teach Social Science through English language., [ES] La introducción del bilingüismo en las aulas ha sido y es una de las grandes apuestas del sistema educativo español. Sin embargo, a los docentes nos cuesta usar la metodología adecuada, aunando el contenido y la lengua extranjera en los centros de enseñanza bilingüe. Por este motivo, teniendo en cuenta que resulta muy beneficiosa la creación de unidades didácticas que integran inglés y otras áreas, como Educación Física, Plástica o Ciencias (Alario y Crespo, 2011), y con la finalidad de aportar un enfoque didáctico innovador, vamos a presentar una propuesta de intervención a través de la cual mostraremos que las Ciencias Sociales se pueden trabajar de una manera más lúdica y, a su vez, con unos materiales y en unos espacios poco habituales, como son los que ofrece la asignatura de Educación Física, enseñada en lengua inglesa.

We analyze the asymptotic behavior of positive solutions of parabolic equations with a class of degenerate logistic nonlinearities of the type λ u − n ( x ) u ρ . An important characteristic of this work is that the region where the logistic term n ( ⋅ ) vanishes, that is K 0 = { x : n ( x ) = 0 } , may be non-smooth. We analyze conditions on λ, ρ, n ( ⋅ ) and K 0 guaranteeing that the solution starting at a positive initial condition remains bounded or blows up as time goes to infinity. The asymptotic behavior may not be the same in different parts of K 0 .

Background We sought to assess the efficacy of high-energy shocks to restore rhythm and predictors of success in patients with sustained ventricular arrhythmias and implantable cardioverter defibrillator (ICD). Methods and results Data from 162 patients included in the UMBRELLA study that experienced one or more episodes of ventricular tachycardia (VT) for which ICD shocks of at least 30 Joules were delivered (appropriate high-energy shocks) were analyzed. In total, 456 ventricular arrhythmia episodes were registered. Forty four episodes (9.6%) from 39 patients (24%) had at least one ineffective high-energy shock delivered. Hypertrophic cardiomyopathy was more frequent among patients with unsuccessful shocks (10.3% vs 2.4%). Patients with ineffective shocks had higher proportion of sustained monomorphic ventricular arrhythmias (86.4%; the other 13.6% were sustained polymorphic and ventricular fibrillation [VF]) compared with patients with all their shocks effective (62.9%, P = 0.02). No statistical differences were found between groups in time from detection to the high-energy shock delivery, in tachycardia cycle length, or in antitachycardia pacing, but patients with ineffective high-energy shocks had higher proportion of previously ineffective low-energy shock (9.1% vs 0.5%, P = 0.01). Conclusion We found a substantial rate of ineffective high-energy shocks for the treatment of VT or VF in patients with ICD. High-energy shock efficacy seems to be reduced by hypertrophic cardiomyopathy and by the administration of previous low-energy shocks.

Este síndrome que se ha denominado Nefrosis del Nefrón Distal a Enfermedad Tubular Aguda reconoce en general 3 grandes mecanismos fisiopatológicos en su desarrollo clínico: 1) Destrucción tisular o sanguínea con liberación de elementos nefrotóxicos. 2) Colapso vascular con hipotensión prograsiva y alteraciones arteriales, metabólicas y de los electroitos. 3) Sensibilidad o sensibilización de ciertos parénquimas y de manera preferente del riñón a diversas noxas del metabolismo alterado o a toxinas microbianas o a ciertos compuestos químicos y drogas.