Effects of hip abductor strengthening on musculoskeletal loading in hip dysplasia patients after total hip replacement

Hip dysplasia patients after total hip replacement show worse functional performance compared to primary osteoarthritis patients, and unfortunately there is no research on muscle and joint loads that would help understand rehabilitation effects, motor dysfunctions and failure events. We tested the hypothesis that a higher functional improvement in hip dysplasia patients who received hip abductor strengthening after hip replacement, would result in different gait function and musculoskeletal loads during walking compared to patients who performed standard rehabilitation only. In vivo gait analysis and musculoskeletal modeling were used to analyze the differences in gait parameters and hip and muscle forces during walking between the two groups of patients. We found that, in a functional scenario of very mild abnormalities, the patients who performed muscle strengthening expressed a more physiological force pattern and a generally greater force in the operated limb, although statistically significant in limited portions of the gait cycle, and likely related to a higher gait speed. We conclude that in a low-demand task, the abductor strengthening program does not have a marked effect on hip loads, and further studies on hip dysplasia patients would help clarify the effect of muscle strengthening on loads

Experimental behaviour of a three-stage metal hydride hydrogen compressor

A three-stage metal hydride hydrogen compressor (MHHC) system based in AB2-type alloys has been set-up. Every stage can be considered as a Sieverts-type apparatus. The MHHC system can work in the pressure and temperature ranges comprised from vacuum to 250 bar and from RT to 200C, respectively. An efficient thermal management system was set up for the operational ranges of temperature designed. It dumps temperature shifts due to hydrogen expansion during stage coupling and hydrogen absorption/desorption in the alloys. Each reactor consists of a single and thin stainless-steel tube to maximize heat transfer. They are filled with similar amount of AB2 alloy. The MHHC system was able to produce a compression ratio (CR) as high as of 84.7 for inlet and outlet hydrogen pressures of 1.44 and 122 bar for a temperature span of 23 to 120C

Massive Pericardial Effusion in a 14-Year-Old Girl with Mild Fatigue and Neck Pain

Pericardial effusion is rare in pediatric patients and is characterized by a variable clinical presentation. Mild symptoms may be present despite severe effusion. We here report the case of a patient with massive pericardial effusion with mild clinical presentation. Our case points out the need not to exclude this diagnosis in patients with mild general impairment. This clinical suspicion can be lifesaving

Simulation and design of a three-stage metal hydride hydrogen compressor based on experimental thermodynamic data

Los investigadores de la UAM pertenecen al MIRE-GroupA semi-empirical method was developed to design a three stage Metal Hydride Hydrogen Compressor (MHHC) through the determination of thermodynamic properties of several hydrides. As a first step, three AB2-type alloys that satisfy operation conditions were selected from published thermodynamic data entailing over 200 single plateau hydrides. These alloys were synthetized by arc melting and characterized by X-Ray Powder Diffraction (XRPD), Scanning Electron Microscopy (SEM) and Energy Dispersion X-ray spectroscopy (EDX). Absorption and desorption Pressure-composition-Isotherms (P-c-I) were determined between 23 and 80 C to characterize their thermodynamic properties. Subsequently, an algorithm that uses these experimental data and a real equation of state for gaseous H2 was implemented to simulate the volume, alloy mass, pressure and temperature of operation for each compressor stage, while optimizing the compression ratio and total number of compressed H2 moles. Optimal desorption temperatures for the three stages were identified within the range of 110e132 C. A system compression ratio (CR) of 92 was achieved. The number of H2 moles compressed, the alloy mass and volume of each stage depend linearly on the volume of the external tank in which the hydrogen is delivere

El hidrógeno como vector energético: Mucho hecho pero casi todo por hacer

Los autores desarrollan, muy brevemente, los aspectos esenciales de lo que globalmente se denomina “Sistema Energético Solar-Hidrógeno” o a veces “Economía del hidrógeno”. El hidrógeno, obtenido por descomposición del agua mediante energías primarias renovables (solar, eólica…) se convierte en transportador de energía (vector energético) y en combustible limpio. Se discute la conveniencia del uso del hidrógeno en el contexto energético actual, así como los tres pilares fundamentales del uso del hidrógeno como vector energético: su producción usando fuentes renovables, su acumulación mediante diferentes métodos y, finalmente, su combustió

Are Induced Pluripotent Stem Cells a Step towards Modeling Pediatric Leukemias?

Despite enormous improvements in pre-clinical and clinical research, acute leukemia still represents an open challenge for pediatric hematologists; both for a significant relapse rate and for long term therapy-related sequelae. In this context, the use of an innovative technology, such as induced pluripotent stem cells (iPSCs), allows to finely reproduce the primary features of the malignancy and can be exploited as a model to study the onset and development of leukemia in vitro. The aim of this review is to explore the recent literature describing iPSCs as a key tool to study different types of hematological malignancies, comprising acute myeloid leukemia, non-down syndrome acute megakaryoblastic leukemia, B cell acute lymphoblastic leukemia, and juvenile myelomonocytic leukemia. This model demonstrates a positive impact on pediatric hematological diseases, especially in those affecting infants whose onsets is found in fetal hematopoiesis. This evidence highlights the importance of achieving an in vitro representation of the human embryonic hematopoietic development and timing-specific modifications, either genetic or epigenetic. Moreover, further insights into clonal evolution studies shed light in the way of a new precision medicine era, where patient-oriented decisions and therapies could further improve the outcome of pediatric cases. Nonetheless, we will also discuss here the difficulties and limitations of this model

Optimizing the dialysate calcium concentration in bicarbonate haemodialysis

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