78 research outputs found
Preliminary structural analysis of an active exoskeleton for robotic neuro-rehabilitation
In this paper the exoskeleton P.I.G.R.O. (Pneumatic Interactive Gait Rehabilitation
Orthosis), developed in the Department of Mechanical and Aerospace Engineering (DIMEAS)
Politecnico di Torino with the important co-operation with doctors, is presented. It was preliminary
designed for a completely unloaded walking gait cycle in order to treat the first steps of the neurorehabilitation trainings. An initial FEM evaluation of P.I.G.R.O. structure is here presented. It
underlines a lot of important aspects and techniques to analyse the structural characteristics of
P.I.G.R.O. legs rigid parts using a commercial software but analysing both the actions of the
pneumatic actuators and of the patients muscles and/or movements. The results obtained are good
and allow to verify the P.I.G.R.O. legs structure and to establish a procedure to study its
characteristics also with the presence of the patien
Environmental evolution and archaeological record of Barrancas river basin, Jujuy province, Argentina
Since 2012 our research team started the “Barrancas Archaeological Project” which main goal is to study the history of the people that dwelled this locality and neighbouring areas during the last 10000 years and yo put in value the cultural heritage of these societies. This paper have two aims: 1) to characterize the general environmental evolution of the Barrancas river basin since the end of Pleistocene and to discuss its impact on the human groups that used it: and 2) to briefly describe the archaeological record recovered in the upper and mid-section of the Barrancas river, mainly the chronology and general characteristics of the archaeological sites under study and the relative chronology and placement of the currently documented rock art. Barrancas archaeological evidence conjoined with the paleoenvironmental data obtained in this basin shows that substantial changes in local habitats have had a relevant role in the way in what human groups used this spaces through time, allowing to characterize them alternatively as a nodal or inter-nodal area through Holocene.Introducción El área de estudio - Antecedentes paleoambientales suprarregionales y regionales Evolución ambiental de Barrancas - Los registros paleoambientales de Barrancas - Tendencias paleoambientales - Evolución de la capacidad de carga en la cuenca desde los 7300 cal AP Síntesis de los sitios arqueológicos y ocupaciones humanas en Barrancas - Ocupaciones humanas del Holoceno Temprano y Medio (10.000-3750 años cal. AP) - Ocupaciones humanas entre 3500-1550 años cal. AP - Ocupaciones humanas ente 1200 y 200 cal AP - Manifestaciones rupestres Discusión y Conclusió
In Vivo Evaluation of the Biocompatibility of Surface Modified Hemodialysis Polysulfone Hollow Fibers in Rat
Polysulfone (Psf) hollow fiber membranes (HFMs) have been widely used in blood purification but their biocompatibility remains a concern. To enhance their biocompatibility, Psf/TPGS (d-α-tocopheryl polyethylene glycol 1000 succinate) composite HFMs and 2-methacryloyloxyethyl phosphorylcholine (MPC) coated Psf HFMs have been prepared. They have been evaluated for in vivo biocompatibility and graft acceptance and compared with sham and commercial membranes by intra-peritoneal implantation in rats at day 7 and 21. Normal body weights, tissue formation and angiogenesis indicate acceptance of implants by the animals. Hematological observations show presence of post-surgical stress which subsides over time. Serum biochemistry results reveal normal organ function and elevated liver ALP levels at day 21. Histological studies exhibit fibroblast recruitment cells, angiogenesis and collagen deposition at the implant surface indicating new tissue formation. Immuno-histochemistry studies show non-activation of MHC molecules signifying biocompatibilty. Additionally, Psf/TPGS exhibit most favorable tissue response as compared with other HFMs making them the material of choice for HFM preparation for hemodialysis applications
Green Urbanism and its Application to Singapore
Green urbanism has been applied to cities but not in Asia. Seven characteristics of green urbanism are outlined and then applied to Singapore. The Renewable City is not yet a concept for Singapore. The Carbon Neutral City is being developed for an island Palau Ubin and by some firms but not to significant sectors or parts of urban Singapore. The Distributed City is being developed around Singapore’s polycentric model but needs specific infrastructure plans similar to ones developed by Singapore for Tianjin Eco-City. The Biophillic City is being developed as a world first through its Skyrise Greenery initiative and urban landscaping. The Eco-Efficient City is also being demonstrated through Singapore closing the loop on their water and solid waste systems. The Place Based City is very evident in all its 22 sub centres. And the Sustainable Transport City is an Asian leader in integrated transport planning though there are signs of this becoming harder to achieve
Nitric oxide synthetic pathway and cGMP levels are altered in red blood cells from end-stage renal disease patients
Red blood cells (RBCs) enzymatically produce nitric oxide (NO) by a functional RBC-nitric oxide synthase (RBC-NOS). NO is a vascular key regulatory molecule. In RBCs its generation is complex and influenced by several factors, including insulin, acetylcholine, and calcium. NO availability is reduced in end-stage renal disease (ESRD) and associated with endothelial dysfunction. We previously demonstrated that, through increased phosphatidylserine membrane exposure, ESRD-RBCs augmented their adhesion to human cultured endothelium, in which NO bioavailability decreased. Since RBC-NOS-dependent NO production in ESRD is unknown, this study aimed to investigate RBC-NOS levels/activation, NO production/bioavailability in RBCs from healthy control subjects (C, N = 18) and ESRD patients (N = 27). Although RBC-NOS expression was lower in ESRD-RBCs, NO, cyclic guanosine monophosphate (cGMP), RBC-NOS Serine1177 phosphorylation level and eNOS/Calmodulin (CaM)/Heat Shock Protein-90 (HSP90) interaction levels were higher in ESRD-RBCs, indicating increased enzyme activation. Conversely, following RBCs stimulation with insulin or ionomycin, NO and cGMP levels were significantly lower in ESRD- than in C-RBCs, suggesting that uremia might reduce the RBC-NOS response to further stimuli. Additionally, the activity of multidrug-resistance-associated protein-4 (MRP4; cGMP-membrane transporter) was significantly lower in ESRD-RBCs, suggesting a possible compromised efflux of cGMP across the ESRD-RBCs membrane. This study for the first time showed highest basal RBC-NOS activation in ESRD-RBCs, possibly to reduce the negative impact of decreased NOS expression. It is further conceivable that high NO production only partially affects cell function of ESRD-RBCs maybe because in vivo they are unable to respond to physiologic stimuli, such as calcium and/or insulin
Highly controlled ultrasound-mediated drug delivery experiments: an in vitro set-up
This work reports the design, development and characterization of a low-intensity pulsed ultrasound (LIPUS) stimulation system to be used for highly controlled ultrasound-triggered drug delivery in vitro experiments. The use of a versatile signal generator and different types of transducers allows the fine tuning of the stimulation parameters over a broad range. Such transducers were carefully characterized in terms of pressure field shape and intensity, guaranteeing a precise estimation and control of the ultrasound dose delivered to the target. Such a system will be used for controlled drug release tests from ultrasound-responsive systems, such as nano and micro carriers, scaffolds and patches, in the context of the REBORN project
Analisi CFD nel progetto di sistemi pneumatici per il trasporto su rotaia
Vengono presentati alcuni esempi di analisi CFD per il progetto di componenti e sistemi elettropneumatici utilizzati in veicoli per il trasporto su rotaia
Dispositivi pressoterapici per arto superiore
PRESENTIAMO LO STUDIO E LA COSTRUZIONE DI ALCUNI PROTOTIPI DI DISPOSITIVI APPLICABILI IN AMBITO BIOMEDICO PER TRATTAMENTI PRESSOTERAPIC
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