Parametric analysis of an L-band deployable offset reflector for CubeSats

Thanks to the advances in the miniaturization and improved power consumption efficiency of electronics, computers, cell phone technologies, etc., today’s spacecrafts and payloads are reducing their size and increasing their performance. However, not all systems can be reduced, as their dimensions are determined by the laws of physics. This study is focused on the design of an L-band reflector antenna for a CubeSat-based Earth observation mission devoted to measure the surface soil moisture. Two configurations of deployable parabolic reflector antennas and meshes are presented from the mechanical point of view. The electromagnetic analyses including the antenna feeder are also presented. It is found that the regular circular mesh performs slightly better than the irregular one, although requires a more careful manufacturing process.This work was supported in part by the Project “Sensing With Pioneering Opportunistic Techniques-SPOT,” Spanish Agencia Estatal de Investigación under Grant RTI2018-099008-B-C21 and EU ERDF funds, and in part by UPC-CommSensLab María de Maeztu Unit under Grant MDM-2016-0600.Peer ReviewedPostprint (author's final draft

Transcatheter aortic valve replacement in obese patients: procedural vascular complications with the trans-femoral and trans-carotid access routes

Obesity; Transcarotid; TransfemoralObesidad; Transcarotídea; TransfemoralObesitat; Transcaròtida; TransfemoralOBJECTIVES Obesity may increase the risk of vascular complications in transfemoral (TF) transcatheter aortic valve replacement (TAVR) procedures. The transcarotid (TC) approach has recently emerged as an alternative access in TAVR. We sought to compare vascular complications and early clinical outcomes in obese patients undergoing TAVR either by TF or TC vascular access. METHODS Multicentre registry including obese patients undergoing TF- or TC-TAVR in 15 tertiary centres. All patients received newer-generation transcatheter heart valves. For patients exhibiting unfavourable ileo-femoral anatomic characteristics, the TC approach was favoured in 3 centres with experience with it. A propensity score analysis was performed for overcoming unbalanced baseline covariates. The primary end point was the occurrence of in-hospital vascular complications (Valve Academic Research Consortium-2 criteria). RESULTS A total of 539 patients were included, 454 (84.2%) and 85 (15.8%) had a TF and TC access, respectively. In the propensity-adjusted cohort (TF: 442 patients; TC: 85 patients), both baseline and procedural valve-related characteristics were well-balanced between groups. A significant decrease in vascular complications was observed in the TC group (3.5% vs 12% in the TF group, odds ratio: 0.26, 95% CI: 0.07–0.95, P = 0.037). There were no statistically significant differences between groups regarding in-hospital mortality (TC: 2.8%, TF: 1.5%), stroke (TC: 1.2%, TF: 0.4%) and life-threatening/major bleeding events (TC: 2.8%, TF: 3.8%). CONCLUSIONS In patients with obesity undergoing TAVR with newer-generation devices, the TC access was associated with a lower rate of vascular complications. Larger randomized studies are warranted to further assess the better approach for TAVR in obese patients

La angioplastia con balón liberador de fármaco mejora el flujo distal en la revascularización de oclusiones crónicas por vía retrógrada

Sr. Editor: Se presenta el caso de un varón de 72 años con angina de esfuerzo e isquemia grave de la pared inferior confirmada tras exploración mediante tomografía computarizada por emisión de fotón único con Tc-99. Tras obtener el consentimiento informado y por escrito del paciente, se realizó una coronariografía que confirmó la presencia de oclusión coronaria total crónica (OTC) en la coronaria derecha (CD) proximal (figura 1A) con una puntuación en la escala J-CTO de 3 (punto de entrada romo, lesión > 20 mm y calcificación) y presencia de ramas colaterales septales desde la descendente anterior (DA) (figura 1B, vídeo 1 del material adicional). Inicialmente se usó el abordaje anterógrado, que hubo que cambiar rápidamente por el retrógrado debido a las características desfavorables de la lesión. Figura 1. A: oclusión total de CD proximal. B: ramas colaterales septales desde la descendente anterior. C: guía externalizada mediante abordaje retrograde desde las ramas colaterales septales franqueando la oclusión de la coronaria derecha. D: inserción de guía mediante abordaje retrógrado con ayuda de microcatéter colocado en coronaria derecha distal. E: resultado angiográfico tras predilatación de la oclusión e implante de stent con grado de flujo TIMI 1. F: tras el uso del balón farmacoativo,..

Drug-eluting balloon angioplasty improves the distal run-off in retrograde chronic total occlusion revascularization

To the Editor, This is the case of a 72-year-old male examined due to exertional angina, and severe inferior wall ischemia through a single-photon emission computed tomography with Tc-99. After obtaining the patient’s written informed consent he was referred for a coronary angiography that confirmed the chronic total coronary occlusion (CTO) of the proximal right coronary artery (RCA) (figure 1A) with a J-CTO score of 3 (blunt entry shape, lesion > 20 mm, and calcification), and the presence of septal collaterals from the left anterior descending coronary artery (figure 1B, video 1 of the supplementary data). Initial antegrade approach was planned that quickly had to be changed for the retrograde approach due to the unfavorable characteristics of the lesion. Figure 1. A: total occlusion of proximal RCA. B: septal collaterals from the left anterior descending coronary artery. C: externalized retrograde wire from the septal collateral crossing the right coronary artery occlusion. D: antegrade wiring with the help of a microcatheter placed in the distal right coronary artery. E: angiographic result after occlusion predilatation and stenting with TIMI grade-1 flow. F: after drug-eluting balloon, TIMI grade-3 flow is achieved with a diseased distal vessel. After surfing across the septal collateral channels, the distal cap..

Estratificación de la estenosis aórtica: en la integración juiciosa de datos está el éxito

La estenosis aórtica es la valvulopatía más frecuente en nuestro medio. El envejecimiento de la población y la mayor esperanza de vida la convierten en un problema de salud pública relevante. Aunque los criterios diagnósticos de severidad están claramente establecidos, en ocasiones, la cuantificación de la estenosis no es tan sencilla, existiendo diferentes escenarios clínicos y ecocardiográficos llenos de matices en los que otras técnicas diagnósticas de imagen pueden desempeñar un papel fundamental. En este manuscrito de revisión se evalúan estos escenarios y, de acuerdo con trabajos previos, se propone un algoritmo diagnóstico que facilite la toma de decisiones

Leaving obstacles aside: Antegrade paravalvular leakage closure after transcatheter aortic valve replacement

Abstract Paravalvular leakage (PVL) is yet a potential and serious complication after transcatheter aortic valve replacement. Percutaneous PVL closure may be the treatment of choice upon failure of balloon postdilation in patients with excessive surgical risk. If the retrograde approach fails, an antegrade strategy might provide the solution