Fabry Disease and the Heart: A Comprehensive Review

Fabry disease (FD) is an X-linked lysosomal storage disorder caused by mutations of the GLA gene that result in a deficiency of the enzymatic activity of α-galactosidase A and consequent accumulation of glycosphingolipids in body fluids and lysosomes of the cells throughout the body. GB3 accumulation occurs in virtually all cardiac cells (cardiomyocytes, conduction system cells, fibroblasts, and endothelial and smooth muscle vascular cells), ultimately leading to ventricular hypertrophy and fibrosis, heart failure, valve disease, angina, dysrhythmias, cardiac conduction abnormalities, and sudden death. Despite available therapies and supportive treatment, cardiac involvement carries a major prognostic impact, representing the main cause of death in FD. In the last years, knowledge has substantially evolved on the pathophysiological mechanisms leading to cardiac damage, the natural history of cardiac manifestations, the late-onset phenotypes with predominant cardiac involvement, the early markers of cardiac damage, the role of multimodality cardiac imaging on the diagnosis, management and follow-up of Fabry patients, and the cardiac efficacy of available therapies. Herein, we provide a comprehensive and integrated review on the cardiac involvement of FD, at the pathophysiological, anatomopathological, laboratory, imaging, and clinical levels, as well as on the diagnosis and management of cardiac manifestations, their supportive treatment, and the cardiac efficacy of specific therapies, such as enzyme replacement therapy and migalastat.     

Detection of water ingress in composite sandwich structures: a magnetic resonance approach

Water ingress inside honeycomb sandwich panels during service has been linked to in-flight failure in some aircraft. There is an ongoing effort to develop nondestructive testing methods to detect the presence of water within the panels. Magnetic resonance (MR) represents an attractive approach in that it is sensitive to moisture. Using a unilateral MR sensor, testing can be applied directly to the surface of the panel. The viability of MR is demonstrated through laboratory imaging of both water within sandwich panels, as well as the adhesive itself. The detection of water using a one-sided handheld MR sensor is presented. It is shown that simple detection, as well as spatial localization of water within sandwich panels is possible.     

Comparison of a contactor catalytic membrane reactor with a conventional reactor: example of wet air oxidation

A wet air oxidation reaction was carried out in a gas/liquid catalytic membrane reactor of the contactor type. The oxidation of formic acid was used as a model reaction. The mesoporous top-layer of a ceramic tubular membrane was used as catalyst (Pt) support, and was placed at the interface of the gas (air) and liquid (HCOOH solution) phases.

A similar reaction was carried out in a conventional batch reactor, using a steering rate high enough to avoid gas-diffusion limitations, and exactly identical conditions than for the CMR (amount of catalyst, pressure, etc.). At room temperature, the CMR showed an initial activity three to six times higher than the conventional reactor. This activity increase was attributed to an easier oxygen access to the catalytic sites. Nevertheless, the catalytic membrane gradually deactivated after a few hours of operation. Different deactivation mechanisms are presented.     

Twin-image suppression in digital in-line holography based on wave-front filtering

Pattern Analysis and Applications - Digital holography is an imaging process able to recreate three-dimensional representations of objects from recording pattern interference among distinct waves....     

Gripper Design for Radio Base Station Autonomous Maintenance System

For an autonomous system to perform maintenance tasks in a networking device or a radio base station (RBS), it has to deal with a series of technological challenges ranging from identifying hardware-related problems to manipulating connectors. This paper describes the development of a robot maintenance system dedicated to detect and resolve faulty links caused by unplugged or poorly connected cables. Although the maintenance system relies on four subsystems, we significantly focus on our low-cost and efficient custom gripper solution developed to handle RJ45 Ethernet connectors. To examine our gripper, we conducted three experiments. First, a qualitative questionnaire was submitted to 30 users in the case of the teleoperated scenario of the gripper attached to a robotic arm. Similarly, we also tested the automatic operation mode. The results showed that our system is reliable and delivers a highly efficient maintenance tool in both teleoperated and autonomous operation modes. The practical experiment containing the removal or unplugging of connectors demonstrated our gripper’s ability to adequately handle these, whereas the feedback from the questionnaire pointed to a positive user experience. The automatic test assessed the gripper’s robustness against the continuous operation.

     

Upcycling by grafting onto semi-crystalline polymers using supercritical CO2

The creation of graft copolymers by selectively grafting a second polymer to the amorphous fraction of a semi-crystalline polymer in supercritical CO₂ is demonstrated herein. The graft copolymer is synthesized by free radical polymerization of a vinyl monomer within the semi-crystalline polymer below its melt temperature. Such conditions afford selective grafting on the amorphous regions (block “B”) while leaving the crystalline domains (block “A”) unmodified. Accordingly, unique A-B, A-B-A, A-B-A-B-A, and so forth. block structures are formed. In this work, styrene is polymerized within polyamide 6, polyethylene terephthalate, and isotactic polypropylene. Purification of these material is performed to remove the un-grafted homopolymer, allowing for determination of the graft yield, the portion of polymer which covalently bonds to the semi-crystalline matrix. Grafting yields achieved in polyamide 6, polyethylene terephthalate, and isotactic polypropylene were 98%, 59%, and 15%, respectively. Property enhancements were observed upon further characterization of polystyrene-polyamide 6 copolymers, including high glass transition temperatures, the ability to be remelted, and tunable grafting molecular weight. Additionally, hydrophobicity is controlled by varying polystyrene composition. The remarkable range of accessed properties demonstrates this as a potential route to upcycling plastics.     

High temperature oxidation mechanism of dilute copper aluminium alloys

Dilute copper-aluminium alloys were oxidized in air from 700 to 1000 °C. Two distinctive behaviours were observed: alloys with at least 3 wt% aluminium showed excellent oxidation resistance in the whole temperature range. Alloys with 2 wt% or less aluminium exhibited good oxidation resistance up to 800 °C; but as the temperature was further increased, the oxidation rate of these alloys increased and became comparable to that of pure copper. A kinetic model was developed to explain the oxidation behaviour and indirectly determine the amount of dissolved oxygen in the alloys tested. It was found that the oxygen dissolved in alloys with up to 2 wt% Al exceeded its solubility limit in copper, whereas the dissolved oxygen in alloys with higher aluminium contents was below the solubility limit. This difference may account for the significantly different oxidation resistance.     

Stabilised finite element methods for a bending moment formulation of the Reissner-Mindlin plate model

This work presents new stabilised finite element methods for a bending moments formulation of the Reissner-Mindlin plate model. The introduction of the bending moment as an extra unknown leads to a new weak formulation, where the symmetry of this variable is imposed strongly in the space. This weak problem is proved to be well-posed, and stabilised Galerkin schemes for its discretisation are presented and analysed. The finite element methods are such that the bending moment tensor is sought in a finite element space constituted of piecewise linear continuos and symmetric tensors. Optimal error estimates are proved, and these findings are illustrated by representative numerical experiments.