Improving signal stability in a multi-electrode array (MEA) system for cardiac biopsies

This work evaluates the performance of a microelectrode array (MEA) to be used in a specific platform dedicated for measuring field potentials of small human cardiac samples. A test bench has been developed to characterize the electrodes by measuring their impedance as well as to modify their characteristic curve using a replatinization process, where black platinum is deposited on the indicated areas of the MEA flex-pcb. This set-up consists of the array of microelectrodes made of gold, together with its corresponding electronic adapter board, a potentiostat and an electrochemical interface. Phosphate buffered saline (PBS), which is commonly considered for this type of analysis, has been used for impedance characterization. Initially, the impedance presents a highly variable behavior at different frequencies as well as between the different channels of the array. Once the platinization process has been carried out, the impedance in all the recording channels is very similar and has decreased over a large part of the frequency range under study. A complete electrical model of the electrodes has been proposed and analyzed, achieving better results by including the mathematical constant phase element (CPE) associated with capacitive behavior (model fitting error < 2%). Finally, the characterization of the different noise contributions has been carried out. Based on the obtained results, it can be concluded that the evaluated system allows the recording of field potential signals from small human cardiac tissues

Positive attitudes towards racquet sport of primary school teachers

The aim of this study was to know the attitudes towards racquet sports in Spanish primary school teachers. Eighty one teachers from Zaragoza participated in this study, filling out the scale Positive attitudes towards racquet sport of the validated Table Tennis Attitudes Questionnaire. The internal consistency of this scale was measured with the Cronbach alpha coefficient. The results indicate Md=2.19 (SD=0.38) in this scale. The 27.2% of the teachers have never done one training course of this kind of sports, being the badminton the most studied sport. However, the teachers have mainly badminton teaching material. This study shows which is the prevalence of the racquet sports in the teacher programs. Statistically significant relationships were found between the studies of the teachers or the kind of the school, and the attitudes towards racquet sport. The results of this study suggest us that there have to be more educative programs to implementation racquet sports

Reduced-order models of series resonant inverters in induction heating applications

From the controller design framework, a simple analytical model that captures the dominant behavior in the range of interest is the optimal. When modeling resonant circuits, complex mathematical models are obtained. These high-order models are not the most suitable for controller design. Although some assumptions can be made for simplifying these models, variable frequency operation or load uncertainty can make these premises no longer valid. In this work, a systematic modeling order reduction technique, Slowly Varying Amplitude and Phase (SVAP), is considered for obtaining simpler analytical models of resonant inverters. SVAP gives identical results as the classical model-order residualization technique from automatic control theory. A slight modification of SVAP, Slowly Varying Amplitude Derivative and Phase (SVADP) is applied in this paper to obtain a better validity range. SVADP is validated for a half-bridge series resonant inverter (HBSRI) and for a high- order plant, a dual-half bridge series resonant inverter (DHBSRI) giving analytical second-order transfer functions for both topologies. Simulation and experimental results are provided to show the validity range of the reduced-order models

Expression of collagenase-3 in the rat ovary during the ovulatory process.

We have examined the expression of the murine counterpart of human collagenase-3, a matrix metalloproteinase produced by breast carcinomas, in the course of processes which involve extensive tissue remodeling. By using Northern blot analysis, we have found that collagenase-3 is expressed in the rat ovary, but not in the remaining analyzed tissues including brain, kidney, liver, lung, mammary gland, uterus, bladder, heart, intestine, prostate, spleen, testis and thymus. Collagenase-3 mRNA was detected at high levels in rat ovaries at proestrus and estrus, was at a minimum at metestrus and started to increase during diestrus through to proestrus. In addition, collagenase-3 was also detected on day 21 of pregnancy, which is approximately one day before parturition. However, no significative expression was detected in RNA from ovaries taken immediately after parturition, or on days 1, 5 or 30 postpartum. Northern blot analysis also revealed that collagenase-3 was not expressed at significant levels, compared with ovarian expression, in the uterus or in the mammary gland during pregnancy or after parturition. When follicular granulosa cells were separated from Northern blot, it was seen that collagenase-3 was not expressed by the granulosa cells but was present in the residual tissue containing interstitial and thecal tissues, growing follicles and corpora lutea. Immunohistochemical studies also confirmed, at the protein level, the localization of collagenase-3 in rat ovary. Gonadotropic stimulation of ovulation in immature rats by priming with pregnant mare's serum gonadotropin and stimulation with human chorionic gonadotropin failed to induce the expression of collagenase-3, suggesting that additional factors which are not present in the immature stimulated rats are needed for completely effective induction of the expression of this matrix metalloproteinase. On the basis of these results, together with the comparative analysis of expression of different matrix metalloproteinases in the rat ovary, we propose that collagenase-3 is a major ovarian metalloproteinase potentially involved in ovarian function during the reproductive cycle.Comisión Interministerial de Ciencia y Tecnología (SAF94-0892

Performance outcome measures in padel: a scoping review

Padel is a modern doubles racket sport which has become popular around the world in the last decades. There has been an increase in the quantity of scientific research about this sport in the last years. Therefore, the main objective of this scoping review is to provide an updated contextualization of research regarding padel. PRISMA ScR was used in order to search for articles fulfilling the inclusion criteria in five fields of interest: the anthropometric profile, physiology and physical performance, biomechanics, the epidemiology of injuries, and match analyses Seventy-seven records were included in the study. Padel is an emerging sport both in sport and research terms. This scoping review provides coaches and researchers with all the knowledge available in the five fields of interest. Furthermore, this study enables them to make a map of the current state of the research about padel, and it opens up doors to future investigations. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Anthropometric characteristics of elite paddle players: Pilot study

El objetivo de este estudio fue describir las características antropométricas, la composición corporal y el somatotipo de una muestra internacional de jugadores de pádel de alto nivel de ambos sexos. En el estudio participaron 29 jugadores (15 varones y 14 mujeres) de categoría absoluta. Un total de 16 variables antropométricas fueron evaluadas. Se encontraron diferencias entre sexos en las variables masa, talla e IMC (p<0,001); en los pliegues tricipital, muslo, pierna (p<0,001) y en el sumatorio de 6 pliegues; en los perímetros brazo, muslo (p<0,001) y pierna (p<0,03); y en todos los diámetros analizados (p<0,001). Asimismo se encontraron diferencias en los componentes endomórfico (p<0,01), mesomórfico (p<0,001) y ectomórfico (p<0,05) del somatotipo. Los jugadores presentan un somatotipo mesomórfico-endomórfico y las jugadoras endo-mesomórfico. Esta investigación aporta datos biotipológicos actualizados de referencia para el pádel de élitePaddle is one of the racket sports that has grown the most in recent years. However, there are few or very limited studies that address the biotype of this discipline, especially in the elite paddle. The aim was to describe the anthropometric characteristics, body composition and somatotype of an international sample of high level paddle players. 29 subjects national top level (15 male and 14 female) participated in this study. 16 anthropometric variables were evaluated. Differences were found between sexes in the variables weight, height and BMI (p <0.001); in triceps, thigh and leg folds (p <0.001); in the arm, thigh (p <0.001) and leg (p <0.03) perimeters; and in all diameters analysed (p <0.001). Differences were also found between men and women in the endomorphic (p <0.01), mesomorphic (p <0.001) and ectomorphic (p <0.05) components of the somatotype. Male players present a mesomorphic-endomorphic somatotype while female players are preferably endo-mesomorphic. This research provides up-to-date reference data for somatotype in elite paddle playersInstituto de Estudios Altoaragoneses por el proyecto “Análisis de las demandas fisiológicas del pádel de competición: estudio de marcadores asociados al rendimiento físico-deportivo.

Multifunctional heterometallic Iriii-Aui probes as promising anticancer and antiangiogenic agents

A new class of emissive cyclometallated IrIII-AuI complexes with a bis(diphenylphosphino) methanide bridging ligand was successfully synthesised from the diphosphino complex [Ir(N^C)2(dppm)]+ (1). The different gold ancillary ligand, a triphenylphosphine (2), a chloride (3) or a thiocytosine (4) did not reveal any significant effect on the photophysical properties, which are mainly due to metal-to-ligand charge-transfer (3MLCT) transitions based on IrIII. However, the AuI fragment, along with the ancillary ligand, seemed crucial for the bioactivity in A549 lung carcinoma cells versus endothelial cells. Both cell types display variable sensitivities to the complexes (IC50=0.6–3.5 µM). The apoptotic pathway is activated in all cases, and paraptotic cell death seems to take place at initial stages in A549 cells. Species 2–4 showed at least dual lysosomal and mitochondrial biodistribution in A549 cells, with an initial lysosomal localisation and a possible trafficking process between both organelles with time. The bimetallic IrIII-AuI complexes disrupted the mitochondrial transmembrane potential in A549 cells and increased reactive oxygen species (ROS) generation and thioredoxin reductase (TrxR) inhibition in comparison with that displayed by the monometallic complex 1. Angiogenic activity assays performed in endothelial cells revealed the promising antimetastatic potential of 1, 2 and 4. © 2021 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH

Cardiac electrical defects in progeroid mice and Hutchinson-Gilford progeria syndrome patients with nuclear lamina alterations

Hutchinson–Gilford progeria syndrome (HGPS) is a rare genetic disease caused by defective prelamin A processing, leading to nuclear lamina alterations, severe cardiovascular pathology, and premature death. Prelamin A alterations also occur in physiological aging. It remains unknown how defective prelamin A processing affects the cardiac rhythm. We show age-dependent cardiac repolarization abnormalities in HGPS patients that are also present in the Zmpste24-/- mouse model of HGPS. Challenge of Zmpste24-/- mice with the ß-adrenergic agonist isoproterenol did not trigger ventricular arrhythmia but caused bradycardia-related premature ventricular complexes and slow-rate polymorphic ventricular rhythms during recovery. Patch-clamping in Zmpste24-/- cardiomyocytes revealed prolonged calcium-transient duration and reduced sarcoplasmic reticulum calcium loading and release, consistent with the absence of isoproterenol-induced ventricular arrhythmia. Zmpste24-/- progeroid mice also developed severe fibrosis-unrelated bradycardia and PQ interval and QRS complex prolongation. These conduction defects were accompanied by overt mislocalization of the gap junction protein connexin43 (Cx43). Remarkably, Cx43 mislocalization was also evident in autopsied left ventricle tissue from HGPS patients, suggesting intercellular connectivity alterations at late stages of the disease. The similarities between HGPS patients and progeroid mice reported here strongly suggest that defective cardiac repolarization and cardiomyocyte connectivity are important abnormalities in the HGPS pathogenesis that increase the risk of arrhythmia and premature death.Peer ReviewedPostprint (published version