A novel microfluidic cell co-culture platform for the study of the molecular mechanisms of Parkinson's Disease and other synucleinopathies

Copyright © 2016 Fernandes, Chutna, Chu, Conde and Outeiro. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Although, the precise molecular mechanisms underlying Parkinson's disease (PD) are still elusive, it is now known that spreading of alpha-synuclein (aSyn) pathology and neuroinflammation are important players in disease progression. Here, we developed a novel microfluidic cell-culture platform for studying the communication between two different cell populations, a process of critical importance not only in PD but also in many biological processes. The integration of micro-valves in the device enabled us to control fluid routing, cellular microenvironments, and to simulate paracrine signaling. As proof of concept, two sets of experiments were designed to show how this platform can be used to investigate specific molecular mechanisms associated with PD. In one experiment, naïve H4 neuroglioma cells were co-cultured with cells expressing aSyn tagged with GFP (aSyn-GFP), to study the release and spreading of the protein. In our experimental set up, we induced the release of the contents of aSyn-GFP producing cells to the medium and monitored the protein's diffusion. In another experiment, H4 cells were co-cultured with N9 microglial cells to assess the interplay between two cell lines in response to environmental stimuli. Here, we observed an increase in the levels of reactive oxygen species in H4 cells cultured in the presence of activated N9 cells, confirming the cross talk between different cell populations. In summary, the platform developed in this study affords novel opportunities for the study of the molecular mechanisms involved in PD and other neurodegenerative diseases.JF was supported by FCT (SFRH/BD/73908/2010). TO is supported by the DFG Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB). The work was also supported by FCT through the Associated Laboratory IN—Institute of Nanoscience and Nanotechnology and the research project EXCL/CTM-NAN/0441/2012.info:eu-repo/semantics/publishedVersio

Integration of Single Cell Traps, Chemical Gradient Generator and Photosensors in a Microfluidic Platform for the Study of Alpha-Synuclein Toxicity in Yeast

AbstractAlpha-synuclein (aSyn) is a key player in Parkinson's disease. Genetically engineered yeast cells producing aSyn fused with GFP (aSyn-GFP) have been used to study this protein. In this work, we present a microfluidic platform with integrated photosensors that captures single yeast cells in arrays of hydrodynamic traps and exposes them to a chemical gradient of precise composition. This platform enables the study of the effects of aSyn expression level and aggregation in genetically modified yeast cells by chemical stimulation. The photosensors allow the detection of cells in the traps by measuring the variations in light transmission or of the fluorescence produced by aSyn-GFP for real-time signal acquisition

Unified power converters for battery charging and traction drive systems for electric vehicles: cost and performance analysis

Electric vehicles (EVs) are a promising solution to mitigate the emission of greenhouse gases and atmospheric pollution. Although EVs existence spans from more than one century, only in the recent years there has been a considerable development in the electric mobility paradigm. This development is also verified in the operation modes for the EV, giving it an important role in smart grids. Moreover, the implementation of unified power converters for battery charging and traction drive systems is also a key topic about EVs, allowing at the same time a hardware reduction and an increasing in its functionalities. However, no economic studies about the practical feasibility of these unified systems for EVs have been reported in the literature. In this context, this paper presents a cost assessment of unified battery charging and traction drive systems for EVs focusing on practical aspects. An economic comparison is performed between a traditional EV and a unified system in order to attain a cost/performance analysis for the unified power converters that can be used in EVs.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work has been supported by FCT within the Project Scope DAIPESEV – Development of Advanced Integrated Power Electronic Systems for Electric Vehicles: PTDC/EEI-EEE/30382/2017. This work is part of the FCT project 0302836 NORTE-01-0145-FEDER-030283. Mr. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency

A novel control strategy based on predictive control for a bidirectional interleaved three-phase converter

An experimental confirmation of predictive control applied to a bidirectional interleaved three-phase (BIT) converter is presented. The BIT converter is a powerful solution for numerous applications, mainly, renewables interface, motor drivers, active rectifiers, and active power filters. However, a precise and robust digital control strategy is required, maintaining a low computational effort. In this paper, a predictive control based on continuous control set is proposed as a new control scheme for the BIT converter, permitting the control of the ac side current with fixed switching frequency and with a faster response. The predictive control scheme applied to the BIT converter is defined along the paper, evidencing in detail the digital employment aspects according to the discrete-time model of the BIT converter. An explicit experimental validation under realistic operating conditions is presented using a developed laboratorial prototype, highlighting the convenience of the control applied to the BIT converter.This work has been supported by FCT – Fundação para a Ciência e Tecnologia in the scope of the project: PEstUID/CEC/00319/2013. This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2013. This work is financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation < COMPETE 2020 Programme, and by National Funds through the Portuguese funding agency, FCT < Fundação para a Ciência e a Tecnologia, within project SAICTPAC/0004/2015< POCI< 01<0145<FEDER<016434. Mr. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency.info:eu-repo/semantics/publishedVersio

Development of sandwich panels for multi-functional strengthening of RC buildings: characterization of constituent materials and shear interaction of panel assemblies

This paper presents an experimental and numerical study aiming at the development of a sustainable and multifunctional composite sandwich panel for the rehabilitation of reinforced concrete (RC) buildings from the 1960s to the mid-1980s. The sandwich panel, which was designed for the structural, thermal and acoustic refurbishment of building facades, comprises three main components: (i) thin outer layers of Recycled Steel Fibre Reinforced micro–Concrete (RSFRC) that fulfil the strength, ductility and durability requirements of the panel; (ii) a lightweight core made of polystyrene that provides thermal insulation; and (iii) internally distributed glass fibre reinforced polymer (GFRP) connectors that join the different layers of the panel, providing an adequate structural behaviour to the composite system. The mechanical characterization tests highlighted the viability of using RSFRC for the production of structural sandwich facade panels, as relatively high post-cracking tensile capacity was obtained for thin RSFRC layers. Pushout and pullout tests were carried out on intermediate-scale specimens representative of the sandwich panel solution for assessing the overall composite behaviour of the sandwich panels and analysing the influence of the type of core insulation layer (expanded/extruded polystyrene cores, with different surface finishing), of the anchoring conditions (25 and 35 mm of embedment depth) and diameter of the GFRP connectors (8 and 12 mm). These tests showed that the structural GFRP connectors with diameters of 8 and 12 mm are able to ensure shear load transfer between RSFRC layers, exhibiting better composite behaviour when combined with anchorage depths of 25 and 35 mm, respectively. The numerical part of this study aimed at modelling the failure mechanisms observed at the interface between RSFRC and polystyrene, showing good agreement between experimental and numerical results, with important conclusions being drawn regarding cohesion and friction angle between these materials.The first author wishes to acknowledge the financial support provided by the Portuguese Foundation for Science and Technology (FCT) and the Eco-Construction and Rehabilitation (EcoCoRe) Doctoral Program through the research grant PD/BD/52657/2014. The second author acknowledges the support provided by the project ICoSyTec, POCI-01-0145-FEDER-027990, financed by the FCT (Portuguese Foundation for Science and Technology) and co-funded by FEDER through Operational Competitiveness and Internationalization Programme (POCI)

Performance evaluation of a proportional integral with proportional derivative feedforward voltage control for UPSs

This paper presents a performance evaluation of a proportional-integral (PI) with proportional-derivative (PD) feedforward control for the output voltage of a single-phase off-line uninterruptible power supply (UPS) without using additional sensors. The control system is explained and simulation results are presented to analyze the steady state and transient response of the implemented voltage control. A laboratorial prototype was developed, and acquired experimental results considering linear and nonlinear loads are presented and discussed, corroborating the obtained simulation results.SFRH/BD/134353/2017info:eu-repo/semantics/publishedVersio

An off-board multi-functional electric vehicle charging station for smart homes: analysis and experimental validation

This paper presents the analysis and experimental validation of a single-phase off-board multi-functional electric vehicle (EV) charging station (MF-EVCS), which has a single ac interface and two dc interfaces. As innovative aspects, the proposed MF-EVCS handles the interface of the ac power grid, the dc interface of a renewable energy source (RES), as well as the dc interface of an EV to perform dc charging or discharging of the batteries (in off-board grid-to-vehicle (G2V) or vehicle-to-grid (V2G) modes). Considering the power grid, the individual operation modes of the RES and the EV interfaces can be considered. Moreover, a combination of these modes is also possible. Besides, the MF-EVCS has as key innovative aspect the possibility of operating as an active power filter (APF), supporting the operation with reactive power and/or selected current harmonics. This possibility can be associated with any of the previous mentioned modes. These new features are framed in two distinct scenarios: in a smart home, where the ac-side current can be determined as a function of the other electrical appliances; in a smart grid, where the ac-side current can be determined as a requisite of the power grid. The proposed power theory, as well as the current control strategies for both ac-side and dc-side of the MF-EVCS, are presented in the paper for all the possible operation scenarios. A laboratory prototype was developed to validate the proposed MF-EVCS and the experimental results confirm its suitability for smart homes.INCT-EN -Instituto Nacional de Ciência e Tecnologia para Excitotoxicidade e Neuroproteção(DAIPESEV PTDC/EEI-EEE/30382/2017

Vehicle-to-anything: a power transfer perspective for vehicle electrification

The concept of vehicle-to-anything (V2X) is mainly focused on the bidirectional communication between any technology of vehicle and any external system that can contribute for its operation. However, prospecting the vehicle electrification, this concept can also be associated with the power transfer between an electric vehicle (EV) and any external system, where bidirectional communication is absolutely fundamental. Within the power transfer, the possibility of exchanging active power between an EV and the power grid is considered as a promising operation mode, especially considering the possibility of selling demand response services for the electrical power grid. Contemplating the vehicle electrification context, in addition to the latent possibility of interaction between EVs and the power grid for active power exchange, other possibilities of interaction can also be considered, providing advantageous services for the power grid. Thus, this article approaches the V2X concept for off-board systems in the power transfer perspective for vehicle electrification, aggregating new contributions related with the interaction between an EV and any external electrical system (operating as source or load), and both from on-grid or off-grid point of view. Contributions are meticulously presented, recognizing their advantages and disadvantages in a real-scenario of operation. A comparison in terms of cost of implementation and in terms of efficiency is presented considering the various solutions of the vehicle electrification in a smart grid perspective.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work is financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation ‐ COMPETE 2020 Programme, and by National Funds through the Portuguese funding agency, FCT‐Fundação para a Ciência e a Tecnologia, within project SAICTPAC/0004/2015‐ POCI‐01‐0145‐FEDER‐016434. Mr. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency. This work is part of the FCT project POCI-01-0145-FEDER-030283

Chemical strategies for dendritic magneto-plasmonic nanostructures applied to surface-enhanced Raman spectroscopy

Chemical analyses in the field using surface-enhanced Raman scattering (SERS) protocols are expected to be part of several analytical procedures applied to water quality monitoring. To date, these endeavors have been supported by developments in SERS substrate nanofabrication, instrumentation portability, and the internet of things. Here, we report distinct chemical strategies for preparing magneto-plasmonic (Fe3 O4  : Au) colloids, which are relevant in the context of trace-level detection of water contaminants due to their inherent multifunctionality. The main objective of this research is to investigate the role of poly(amidoamine) dendrimers (PAMAMs) in the preparation of SERS substrates integrating both functionalities into single nanostructures. Three chemical routes were investigated to design magneto-plasmonic nanostructures that translate into different ways for assessing SERS detection by using distinct interfaces. Hence, a series of magneto-plasmonic colloids have been characterized and then assessed for their SERS activity by using a model pesticide (thiram) dissolved in aqueous samples.publishe