The laminA/NF-Y protein complex reveals an unknown transcriptional mechanism on cell proliferation

Lamin A is a component of the nuclear matrix that also controls proliferation by largely unknown mechanisms. NF-Y is a ubiquitous protein involved in cell proliferation composed of three subunits (-YA -YB -YC) all required for the DNA binding and transactivation activity. To get clues on new NF-Y partner(s) we performed a mass spectrometry screening of proteins that co-precipitate with the regulatory subunit of the complex, NF-YA. By this screening we identified lamin A as a novel putative NF-Y interactor. Co-immunoprecipitation experiments and confocal analysis confirmed the interaction between the two endogenous proteins. Interestingly, this association occurs on euchromatin regions, too. ChIP experiments demonstrate lamin A enrichment in several promoter regions of cell cycle related genes in a NF-Y dependent manner. Gain and loss of function experiments reveal that lamin A counteracts NF-Y transcriptional activity. Taking advantage of a recently generated transgenic reporter mouse, called MITO-Luc, in which an NF-Y–dependent promoter controls luciferase expression, we demonstrate that lamin A counteracts NF-Y transcriptional activity not only in culture cells but also in living animals. Altogether, our data demonstrate the occurrence of lamin A/NF-Y interaction and suggest a possible role of this protein complex in regulation of NF-Y function in cell proliferatio

Virtual reality telerehabilitation for postural instability in Parkinson's Disease: a multicenter, single-blind, randomized, controlled trial

Introduction: Telerehabilitation enables patients to access remote rehabilitation services for patient-physiotherapist videoconferencing in their own homes. Home-based virtual reality (VR) balance training has been shown to reduce postural instability in patients with Parkinson's disease (PD). The primary aim was to compare improvements in postural stability after remotely supervised in-home VR balance training and in-clinic sensory integration balance training (SIBT). Methods: In this multicenter study, 76 PD patients (modified Hoehn and Yahr stages 2.5-3) were randomly assigned to receive either in-home VR telerehabilitation (n = 38) or in-clinic SIBT (n = 38) in 21 sessions of 50 minutes each, 3 days/week for 7 consecutive weeks. VR telerehabilitation consisted of graded exergames using the Nintendo Wii Fit system; SIBT included exercises to improve postural stability. Patients were evaluated before treatment, after treatment, and at 1-month follow-up. Results: Analysis revealed significant between-group differences in improvement on the Berg Balance Scale for the VR telerehabilitation group (p = 0.04) and significant Time 7 Group interactions in the Dynamic Gait Index (p = 0.04) for the in-clinic group. Both groups showed differences in all outcome measures over time, except for fall frequency. Cost comparison yielded between-group differences in treatment and equipment costs. Conclusions: VR is a feasible alternative to in-clinic SIBT for reducing postural instability in PD patients having a caregiver

Active vibration control systems based on magneto-rheological fluids for sheet metal forming processes

Forming operations are among the most frequently used processes in sheet metal working. Dynamic phenomena occurring represent critical aspects for geometrical accuracy of products and service life of machines parts in high-tech forming machine sector. Stiff presses allow high repeatability and dimensional accuracies but, at the same time, determine rapid and excessive deterioration of tools by stresses and wear. On the other hand, softer ones improve the efficiency and the service life of tools, but with higher energy dissipation and bigger scatter in product dimensions that make processes unreliable with respect to precision. The right trade-off is often the main prerequisite for the technical and economic success of the whole process and must therefore be found, especially with complex non-symmetric geometry and if vibrations take place during the process. Since the interaction of different elements determines the dynamic efficiency of forming machines, controls systems for the compensation of elastic deformations result fundamental for the component accuracy and the required tolerances. Conventional actuators devices present strong limitations in both performances and reliability, with restricted possibilities of closed-loop controls. The best solution is represented by new technologies, able to enhance the control of phenomena process. Magneto-rheological (MR) fluids represent one of the most versatile and promising solutions for the development of high efficiency damping systems, capable to grant high versatility of configuration and effective closed-loop control capabilities. The main objective of this work is to study magneto-rheological fluids technology, used up-to-now especially in anti-seismic and automotive fields, in order to extend to the industrial material forming processes. Due to the complexity of the physics fields involved, the majority of models are based on analytical descriptions that, though easy and fast to implement, present strong limitations for the accurate design of the functional devices. A new approach is introduced, focused on a multi-physics coupled numerical model of the vibration dampers, based on calibrations by physical-simulation. Different damper prototypes are realized for the laboratory tests, in order to experimentally analyse fluid and device behaviours. On these bases, the application of these innovative damping systems and the evaluation of their performances are extended in the industrial context. The experimental tests, conducted on an hydraulic press using both commercially available hydraulic dampers and MR dampers, are analysed with particular focus on the excited frequencies, the vibrations and the powers to quantify the impact of dynamic phenomena on the quality of final parts. The developed prototypes are able to elevated damping performances without complex adjustment calibration when setting up a new process, making flexible its design.Le operazioni di formatura sono tra i processi più diffusi nell’ambito della lavorazione della lamiera metallica. La presenza di fenomeni dinamici è critica per l’accuratezza geometrica dei manufatti e per la vita di servizio delle attrezzature, in particolare per le aziende ad elevata tecnologia nel settore della produzione di macchine utensili. Ottime ripetibilità ed accuratezze dimensionali sono ottenute grazie a presse ad elevata rigidezza strutturale a discapito, tuttavia, della vita degli utensili, esposti a rapidi ed eccessivi fenomeni di usura. Dall’altro lato, l’uso di architetture poco rigide permette di aumentare la durata degli utensili, ma con limiti di efficienza energetica e degli standard di precisione dimensionale. Pertanto il corretto bilanciamento dei differenti fattori rappresenta il prerequisito fondamentale per il successo tecnologico ed economico dell’intero processo. In particolare, nella produzione di geometrie complesse e non simmetriche, oppure quando fenomeni vibratori si manifestano durante il processo di lavorazione. Poiché l’efficienza dinamica di una macchina per formatura è il risultato dell’interazione di diversi fattori, risulta fondamentale un sistema di controllo avanzato per la compensazione delle deformazioni elastiche, soprattutto in relazione alle specifiche richieste dei prodotti. Gli attuatori tradizionali presentano grossi limiti sia nelle prestazioni sia in affidabilità, con poche possibilità di realizzare una catena chiusa nel controllo. La migliore soluzione è rappresentata dall’introduzione di nuove tecnologie, capaci di aumentare il controllo dei processi. I fluidi Magneto–Reologici (MR) rappresentano una delle più versatili e promettenti soluzioni per lo sviluppo di sistemi di smorzamento ad elevata efficienza, capaci di ottima versatilità e controllo continuo dei fenomeni dinamici. Il principale obbiettivo di questo lavoro consiste nello studio della innovativa tecnologia basata sui fluidi magneto–reologici, prevalentemente diffusa nell’ambito automotive e nei sistemi civili antisismici, in modo da estenderla anche ai processi di formatura dei materiali metallici. In seguito alla complessità dei molteplici campi fisici interagenti, la maggior parte dei modelli si basano su descrizioni analitiche che, sebbene relativamente semplici e veloci da implementare, presentano grossi limiti per un’accurata progettazione di dispositivi. Pertanto viene introdotto un nuovo approccio, basato su una modellazione multi-fisica accoppiata dei sistemi di smorzamento e una calibrazione mediante simulazione agli elementi finiti. Sono stati realizzati più prototipi di smorzatori magneto-reologici, in modo da analizzare le prestazioni sia dei fluidi che dei dispositivi stessi, attraverso test di laboratorio. Successivamente, l’applicazione di questi innovativi sistemi di smorzamento è estesa al contesto industriale e valutata mediante prove su una pressa idraulica per tranciatura. Attraverso test sperimentali che comprendono anche il confronto con dispositivi commerciali idraulici, le prestazioni degli smorzatori magneto-reologici vengono analizzate con particolare riferimento allo studio delle frequenze eccitate, alla tipologia di vibrazione e alle potenze in gioco, in modo da quantificare l’impatto dei fenomeni dinamici intervenenti sulla qualità dei prodotti finiti. I prototipi sviluppati sono in grado di elevare le performance di smorzamento senza complessi aggiustaggi durante il settaggio delle nuove sequenze di processo, rendendo flessibile la progettazione del processo stesso

Vibrations reduction in blanking by magneto-rheological shock dampers

Machine vibrations in sheet metal blanking represent a critical problem for geometrical accuracy of products as well as for service life of machines. Conventional mechanical and hydraulic dampers require additional machine power and higher loads, which make critical their use in many applications. This paper presents an innovative system, based on magneto-rheological fluids, for the vibrations damping in sheet metalworking operations. The developed prototypes prove to decrease the vibrations generated in sheet metal blanking with significant reduction of the energy dissipated during the process

Development of innovative systems based on SMART fluids technology for the improvement of the dimensional accuracy in sheet metal forming operations

The dynamic behaviour and the stiffness are critical requirements in high-tech forming machine sector. High performances, in terms of repeatability and dimensional accuracy, are obtained by increasing the structural stiffness and the mass of machines, though this can determine rapid and excessive deterioration of tools due to wear. Furthermore, in sheet metal blanking processes, the machines are subjected to severe vibrations that can significantly reduce their service life. On these bases the use of SMART devices applied to metal forming machines can represent the ideal solution for the closed-loop control of dynamic phenomena. The paper presents an innovative concept for the vibration control occurring in blanking operations, based on the implementation of magneto-rheological (MR) fluids. A new approach based on a multi-physics optimization analysis is presented which proves to be suitable to investigate the mutual metal-MR fluid interactions and to provide a reliable tool for the design and optimization when different physic fields are involved

Improvement of the dimensional accuracy and machines service life in sheet metal forming by control systems based on MR fluids

Dynamic phenomena in metal forming operations represent a critical aspects for geometrical accuracy of products and service life of parts in high-tech forming machine sector. Stiff presses allow high repeatability and dimensional accuracies, but determine excessive deterioration of tools by stresses and wear; softer ones improve the efficiency and the service life of tools, with higher energy dissipation and bigger scatter in product dimensions. On these bases, the use of SMART devices in forming machines can represent the right trade-off solution for the closed-loop control of dynamic effects. The paper presents an innovative concept for the vibration control in blanking operations, based on the implementation of magneto-rheological (MR) fluids. A new approach focused on a multi-physics optimization analysis is presented which proves to be suitable to investigate the mutual metal-MR fluid interactions and to provide a reliable tool for the design and optimization when different physic fields are involved

Reduction of vibrations in blanking by MR dampers

The break through shock during sheet metal blanking operations generates uncontrolled high reverse loads, mechanical vibrations and loud noise that may cause problems such as fatigue cracks in the press components, premature wear in tooling and great discomfort for press operators. In this paper, the application of magneto-rheological (MR) dampers to reduce the shock response of press systems is considered with the aim of evaluating, through full-scale experiments, feasibility and practicability of their implementation and understanding the potential benefits in comparison with conventional dampers