A Prosthetic Limb Managed by Sensors-Based Electronic System: Experimental Results on Amputees

Taking the advantages offered by smart high-performance electronic devices, transradial prosthesis for upper-limb amputees was developed and tested. It is equipped with sensing devices and actuators allowing hand movements; myoelectric signals are detected by Myo armband with 8 ElectroMyoGraphic (EMG) electrodes, a 9-axis Inertial Measurement Unit (IMU) and Bluetooth Low Energy (BLE) module. All data are received through HM-11 BLE transceiver by Arduino board which processes them and drives actuators. Raspberry Pi board controls a touchscreen display, providing user a feedback related to prosthesis functioning and sends EMG and IMU data, gathered via the armband, to cloud platform thus allowing orthopedic during rehabilitation period, to monitor users’ improvements in real time. A GUI software integrating a machine learning algorithm was implemented for recognizing flexion/extension/rest gestures of user fingers. The algorithm performances were tested on 9 male subjects (8 able-bodied and 1 subject affected by upper-limb amelia), demonstrating high accuracy and fast responses

Estimating the carbon content of the deep mantle with Icelandic melt inclusions

Earth’s carbon budget is central to our understanding of the long-term co-evolution of life and the planet. Direct observations of surface reservoirs allow for the detailed quantification of their carbon content. However, the carbon content of Earth’s deep interior remains poorly constrained. Here we study olivine-hosted melt inclusions from two Icelandic eruptions, with those from the Miðfell eruption allowing us to investigate the carbon content of the deep mantle. Comparison with the previously studied Borgarhraun eruption highlights the presence of deep, plume-sourced mantle material within the Miðfell source region. Miðfell contains trace element-depleted melt inclusions undersaturated in CO2, which have high CO2/Ba (= 396 ± 48) and CO2/Nb (= 1832 ± 316), though some inclusions preserve even greater relative carbon enrichment. These observations allow us to reconstruct the CO2 content of the bulk Miðfell source as being > 690 ppm. By identifying that Miðfell is a mixture of depleted and deep mantle components, we can estimate a CO2 content for the deep mantle component of 1350 ± 350 ppm; a concentration that is over ten times higher than depleted MORB mantle estimates. Assuming that the deep mantle component identified in Miðfell is representative of a global reservoir, then with our new CO2 estimate and by considering a range of representative mantle fractions for this reservoir, we calculate that it contains up to 14 times more carbon than that of the atmosphere, oceans, and crust combined. Our result of elevated CO2/Ba and CO2/Nb ratios, and carbon enrichment support geochemical bulk Earth carbon models that call for the presence of carbon-rich deep mantle domains to balance Earth’s relatively carbon-poor upper mantle and surface environment

HMI design for a self-driving car. Integrated communication between the urban environment and a vehicle.

Tendenze sociali e tecnologiche stanno influenzando la mobilità urbana contribuendo alla trasformazione radicale del modo in cui le persone interagiscono con le città, introducendo un nuovo dinamismo urbano. L’analisi di queste tendenze ha portato alla definizione del progetto BASE5G (Broadband interfAces and services for Smart Environments enabled by 5G technologies) che mira a sfruttare il potenziale della connettività 5G per progettare ambienti urbani adattivi in cui le auto fanno parte di sistemi complessi e sono integrate nell’infrastruttura. Il paper analizza il processo di ricerca che unisce competenze multidisciplinari e collaborazione tra il settore accademico e industriale rappresentato dal Politecnico di Milano e da aziende del settore automobilistico e tecnologico. Il processo di ricerca ha definito un nuovo scenario di design per la mobilità urbana in cui l’auto è al centro del sistema urbano iper-connesso. Obiettivo l’obiettivo della ricerca è il riprogettare gli interni e il cruscotto di un’auto elettrica a guida autonoma, e lo sviluppare un’interfaccia uomo-macchina (HMI) in base alle esigenze di un servizio di mobilità condivisa sfruttando il potenziale delle tecnologie disponibili. Con la diffusione della guida autonoma e il conseguente spostamento dell’attenzione del conducente dalla strada, l’esperienza in auto cambierà completamente. Pertanto, il progetto esplora nuove interazioni ripensando l’HMI dell’auto per fornire un’esperienza utente (UX) integrata. Il paper presenta il processo progettuale e i risultati dalla ricerca in un contesto d’ibridazione delle competenze che funge da catalizzatore per nuovi scenari progettuali.Social and technological trends influence urban mobility and can radically transform the way people interact with mobility, introducing a new urban dynamism. The analysis of these trends led to the BASE5G project (Broadband interfAces and services for Smart Environments enabled by 5G technologies), which aims to exploit the potential of 5G connectivity to design adaptive urban environments where cars are part of complex systems and integrated into the infrastructure. The paper aims to analyse the research process that combines multidisciplinary competencies through a collaboration between the academic and industrial sectors represented by Politecnico di Milano and companies in the automotive and technological fields. The research process has defined a new design scenario for urban mobility in which the car is the main touchpoint. Therefore, the project result was to redesign the interior and dashboard of an electric and self-driving car, develop a human-machine interface (HMI) designed according to the needs of a shared mobility service and exploit the potential of available technologies. Under fully autonomous driving and by shifting the driver’s attention away from the road, the in-car experience will change completely. Therefore, the project explores new interactions by rethinking the car’s HMI to provide a seamless user experience. The paper presents the limitations and opportunities of the design process and highlights how research pushes the drivers of innovation and exploits a context in which the hybridisation of competencies acts as a catalyst for defining new design scenarios

Aging Reveals a Role for Nigral Tyrosine Hydroxylase ser31 Phosphorylation in Locomotor Activity Generation

BACKGROUND:Tyrosine hydroxylase (TH) regulates dopamine (DA) bioavailability. Its product, L-DOPA, is an established treatment for Parkinson's disease (PD), suggesting that TH regulation influences locomotion. Site-specific phosphorylation of TH at ser31 and ser40 regulates activity. No direct evidence shows that ser40 phosphorylation is the dominating mechanism of regulating TH activity in vivo, and physiologically-relevant stimuli increase L-DOPA biosynthesis independent of ser40 phosphorylation. Significant loss of locomotor activity occurs in aging as in PD, despite less loss of striatal DA or TH in aging compared to the loss associated with symptomatic PD. However, in the substantia nigra (SN), there is equivalent loss of DA or TH in aging and at the onset of PD symptoms. Growth factors increase locomotor activity in both PD and aging models and increase DA bioavailability and ser31 TH phosphorylation in SN, suggesting that ser31 TH phosphorylation status in the SN, not striatum, regulates DA bioavailability necessary for locomotor activity. METHODOLOGY AND PRINCIPAL FINDINGS:We longitudinally characterized locomotor activity in young and older Brown-Norway Fischer 344 F(1) hybrid rats (18 months apart in age) at two time periods, eight months apart. The aged group served as an intact and pharmacologically-naïve source of deficient locomotor activity. Following locomotor testing, we analyzed DA tissue content, TH protein, and TH phosphorylation in striatum, SN, nucleus accumbens, and VTA. Levels of TH protein combined with ser31 phosphorylation alone reflected inherent differences in DA levels among the four regions. Measures strictly pertaining to locomotor activity initiation significantly correlated to DA content only in the SN. Nigral TH protein and ser31 phosphorylation together significantly correlated to test subject's maximum movement number, horizontal activity, and duration. CONCLUSIONS/SIGNIFICANCE:Together, these results show ser31 TH phosphorylation regulates DA bioavailability in intact neuropil, its status in the SN may regulate locomotor activity generation, and it may represent an accurate target for treating locomotor deficiency. They also show that neurotransmitter regulation in cell body regions can mediate behavioral outcomes and that ser31 TH phosphorylation plays a role in behaviors dependent upon catecholamines, such as dopamine

Experimental and Numerical Performance Survey of a MW-Scale Supercritical CO2 Compressor Operating in Near-Critical Conditions

Closed power cycles based on carbon dioxide in supercritical conditions (sCO2 in the following) are experiencing a growing scientific, technical and industrial interest, due to the high energy conversion efficiency and components compactness. Despite these advantages, the use of a working fluid operating in proximity to the critical point, especially for the compressor, entails multidisciplinary challenges related to the severe non-ideality of the supercritical fluid, which includes the potential onset of phase change at the impeller intake. On the technical and industrial grounds, the phase-transition might dramatically affect the aerodynamics, the performance and the rangeability of the compressor. On the scientific ground, the modelling of two-phase flows in transonic/supersonic conditions still remains an open issue that demands a thorough experimental assessment. This work illustrates the results of a wide experimental campaign focused on the evaluation of the operative map of a MW-scale high-load sCO2 compressor operating in plant-representative conditions, i.e. in proximity to the critical point (P = 79.8 bar, T = 33°C), designed in the frame of the sCO2Flex project, EU Horizon 2020 funded program (grant agreement #764690). In the design process, the machine had been object of a thorough computational investigation, performed by using a homogeneous equilibrium model equipped with a barotropic equation of state, which revealed a significant impact of the phase change on the compressor aerodynamics and on its rangeability for flow rates higher than the design one. Such phenomena are connected to the sudden drop of the speed of sound, originated when the fluid thermodynamic condition crosses the saturation line, and they weaken as the compressor loading reduces. Experiments carried out on a first of a kind 5 MW sCO2 prototype compressor manufactured and tested by Baker Hughes in 2021 remarkably well matched the predicted compressor performance and, especially, the anticipated and sudden choking of the compressor at nominal peripheral Mach number. Results demonstrates experimentally, for the first time ever, the effects of the phase-change on the operation of a realistic sCO2 compressor, also providing significant insights on the predictive capabilities of the physical models employed for the calculation of two-phase flows in this class of machines

Bone marrow-derived cells can acquire cardiac stem cells properties in damaged heart

Experimental data suggest that cell-based therapies may be useful for cardiac regeneration following ischaemic heart disease. Bone marrow (BM) cells have been reported to contribute to tissue repair after myocardial infarction (MI) by a variety of humoural and cellular mechanisms. However, there is no direct evidence, so far, that BM cells can generate cardiac stem cells (CSCs). To investigate whether BM cells contribute to repopulate the Kit+ CSCs pool, we transplanted BM cells from transgenic mice, expressing green fluorescent protein under the control of Kit regulatory elements, into wild-type irradiated recipients. Following haematological reconstitution and MI, CSCs were cultured from cardiac explants to generate 'cardiospheres', a microtissue normally originating in vitro from CSCs. These were all green fluorescent (i.e. BM derived) and contained cells capable of initiating differentiation into cells expressing the cardiac marker Nkx2.5. These findings indicate that, at least in conditions of local acute cardiac damage, BM cells can home into the heart and give rise to cells that share properties of resident Kit+ CSCs

Experimental observation of non-ideal expanding flows of Siloxane MDM vapor for ORC applications

Abstract Extensive experimental results characterizing the supersonic expansion of an organic vapor in non-ideal conditions are reported in this paper for the first time. The collected data also allowed the assessment of the accuracy of Computational Fluid Dynamic (CFD) tools employed to predict the non-ideal behavior of such flows, including the consistency of thermodynamic models adopted. The investigation has been carried out on the converging-diverging nozzle test section of the Test Rig for Organic VApors (TROVA), at the Laboratory of Compressible fluid-dynamics for Renewable Energy Application (CREA) of Politecnico di Milano. Supersonic nozzle flow was chosen as the simplest one of significance for organic Rankine cycle (ORC) turbine channels. The working fluid under scrutiny is Siloxane MDM, a widely employed compound for high temperature ORCs. MDM vapor expands through the TROVA nozzle at moderate non-ideal conditions in the close proximity of the vapor saturation curve. This is the region where ORC expanders typically operate, thus proving the relevance of the investigation for the ORC community. Indeed, detailed experimental data representative of typical ORC expansions were lacking in the open literature up to date. Two different nozzle geometries, featuring exit Mach number of 2.0 and 1.5 respectively, were tested, exploring a wide range of thermodynamic inlet conditions and diverse levels of non-ideality, from moderate non-ideal state, indicated by a compressibility factor Z = Pv/RT ≃ 0.80, to dilute gas conditions, Z ≥ 0.97. Maximum operating total pressure and temperature are Pt ≃ 5 bar and T T ≃ 250 °C. The nozzle flow is characterized in terms of total pressure, total temperature, static pressure at discrete locations along the nozzle axis, and schlieren imaging. In contrast to the well known case of polytropic ideal gas, the vapor expansion through the nozzle is found to be dependent on the inlet conditions, thus proving the non-ideal character of the flow. This influence is found to be consistent with the one predicted by the quasi-1D theory coupled with simple non-ideal gas models. Experimental data at the nozzle centerline are compared with those resulting from a two-dimensional viscous CFD calculation carried out using the SU2 software suite and the improved Peng Robinson Stryjek Vera (iPRSV) thermodynamic model. A very good accordance is found, demonstrating the high accuracy of the applied tools

A case report: Brugada syndrome in the setting of hypothermia.

Hypothermia is a common diagnosis in the Emergency Department. It can cause a multitude of symptoms and complications if not treated promptly. The following case report discusses Brugada pattern on an electrocardiogram in a patient with hypothermia and diabetic ketoacidosis. There was resolution of the Brugada pattern on the electrocardiogram after the patient was warmed to 35.3 °C