In vivo imaging of the dynamic interactions of acute leukaemias with the bone marrow microenvironment

Adult haematopoietic stem cells (HSC) reside in the bone marrow (BM) microenvironment, or niche, where they are regulated by several cell types including osteoblasts, endothelial cells and Nestin-expressing perivascular cells, and by niche-derived signals, such as CXCL12. In parallel, leukaemia growth and chemoresistance have been proposed to be dependent on an analogous malignant microenvironment. Using a murine model of MLL-AF9 driven acute myeloid leukaemia (AML), I show that AML outcompetes non-malignant haematopoiesis by gradual elimination of stroma cells, endosteal endothelium and osteoblastic cells. I further demonstrate that blood vessels in AML-burdened mice are more cell-permeable and likely contribute to loss of haematopoietic cells. The rescue of the endosteal vascular microenvironment in AML rescues HSC loss and improves chemotherapy efficacy (Chapter 3). To address the reverse question, i.e. whether the microenvironment influences disease progression, I studied a mouse model of T-cell acute lymphoblastic leukaemia (T-ALL) driven by constitutively active Notch1. Our group had previously shown that T-ALL progression is independent from particular niches. Here, I show that chemoresistant T-ALL cells are also niche-independent and highly motile, maintaining very transient interactions with surrounding microenvironments (Chapter 4). Studying the in vivo behaviour of Notch-1 T-ALL and MLL-AF9 cells in parallel, I observed that chemoresistant AML cells, in contrast with T-ALL, are less migratory than naïve ones. I also show that AMD3100, an antagonist of CXCR4 (the receptor of CXCL12), inhibits the migration of treatment-naïve and chemoresistant T-ALL cell migration. In contrast, AML cell behaviour remains unaltered after CXCR4 inhibition, likely because of disease-specific, more complex interactions with the BM microenvironment (Chapter 5). These results support the importance of cell-intrinsic and overall tissue influence rather than stroma-specific signals supporting chemoresistant T-ALL. Additionally I show that therapies targeting the endosteal vasculature could potentially improve existing AML therapeutic regimes. The different nature of leukaemia-microenvirnment interactions for the two diseases is further demonstrated by the observation that CXCR4 inhibition affects T-ALL but not AML cell migration within the BM space.Open Acces

Handmade series direct-current motor

Using common materials, it is possible to build a variety of very simple - and yet functioning - electric devices. These devices can be used to verify Electromagnetism fundamentals. Electric currents within magnetic fields originate forces and that is the basic principle of operation of electric motors. This paper describes a universal series motor made with iron bars, insulated copper wire, two small brass plates, insulating tape, six screws and a couple of hoops. The motor is fed with a personal computer 12V DC switched power supply. Rotor speed can achieve several rotations per second

Electromagnet and switchboard for slewing crane

This paper presents an electromagnet and a switchboard used on a science fair slewing crane described in a separate paper. The electromagnet can lift 50kg loads. The switchboard includes a transformer that powers the electromagnet. It also contains relays, contactors and inverters that allow the operation of the crane three-phase motors using a single-phase power supply. Crane slewing is limited to an 180º angle, for safety reasons. Pressing an emergency button switches off all command circuits. An 8051 microcontroller-based system determines the vertical position of the electromagnet, which cannot be switched off while being on a high position, not even if the emergency button is pressed

Projecto “Conservação, estudo, valorização e divulgação do complexo mineiro antigo do vale superior do rio Terva, Boticas" : trabalhos arqueológicos PAVT 2011 : levantamentos topográficos, prospecção e sondagens arqueológicas : relatório final

As ações desenvolvidas contaram com a participação de uma equipa permanente, composta por Luís Fontes, Mafalda Alves e Carla Martins, aos quais se juntaram, em colaborações pontuais, os arqueólogos do município de Boticas, Bruno Delfim e Helena Gonçalves. A assessoria científica para os estudos paleoambientais e geomorfológicos foi dada por José Luíz Meireles. Daremos conta, neste relatório, dos resultados obtidos nas várias ações empreendidas no âmbito desta fase de trabalhos

Slewing crane with electromagnet

This paper describes a slewing crane with electromagnet, operated by three three-phase induction motors. A switchboard described in a separate paper, which also depicts the electromagnet construction details, drives the motors and the electromagnet. From its seat – mounted on the crane - an operator can make the crane arm slew left or right. The electromagnet can be moved back, forward, up or down. The crane is made of iron, has a height of 3m and a length of 2,5m. Such proportions make it very suitable for science fair events

Patologia do Ouvido Interno Imunomediada

As doenças do ouvido interno de etiologia imune podem ocorrer como doença específica de órgão - doença autoimune do ouvido interno - ou no contexto de uma doença autoimune sistémica. O ouvido interno tem capacidade de resposta imune local, e como tal o dano vestibulococlear condicionado por estas patologias pode ocorrer por ativação de autoanticorpos, deposição de imunocomplexos ou fenómenos de vasculite. A etiologia da doença autoimune do ouvido interno não está ainda claramente definida, mas presume-se que a sua etiologia assente numa ativação de autoanticorpos dirigidos a proteínas do ouvido interno, sendo os mais estudados os anti-proteína de 68 kDa, anti-Hsp70 e anti-coclina. O desafio no diagnóstico deste tipo de patologia surge não só pela ausência de marcadores analíticos específicos, mas também pela grande variedade de patologias sistémicas que podem manifestar-se com sintomas audiovestibulares. A implementação de tratamento precoce é preponderante, uma vez que a perda auditiva pode ser reversível

Model predictive current control of a slow battery charger for electric mobility applications

This paper presents a model predictive current control applied to a slow electric vehicle (EV) battery charger. Taking into account the similarities between the power converters inside the EV, it is possible to combine the battery charger and the motor driver in a single integrated converter, thus reducing the weight and volume of the proposed solution, and also contributing to reduce the final price of the EV. Due to the bidirectional power flow capability of the integrated power converter, when working as a slow EV battery charger it can operate in grid-to-vehicle (G2V) mode and in vehicle-to-grid (V2G) mode, contributing to make EVs an important assets in the future smart grids. The integrated power converter working as battery charger operates with sinusoidal current and unitary power factor, contributing to improve the power quality of the electrical grid. This paper provides simulation and experimental results that validate the model predictive control algorithm applied to the proposed integrated power converter working as slow EV battery charger.(undefined)info:eu-repo/semantics/publishedVersio

Real-life comparison between diesel and electric car energy consumption

Vehicle electrification is one of the strategies with higher potential for increasing the efficiency of vehicle powertrains, reducing the dependency on dwindling fossil fuel sources and meeting stringent emissions targets set by policy makers. Despite all the theoretical assessments and manufacturer’s claimed efficiency and emissions records of current vehicles, there is a lack of data concerning real life comparisons of Electric Vehicles (EV) against Internal Combustion Engine (ICE) cars. A test program comparing the energy consumption of an EV and a diesel powered (ICE) car was carried out. Both short (at levelled ground and 6% up hill) and long distance tests were performed for several fixed vehicle speeds. Measurements enabling the assessment of average energy consumption, required power and energy suplied were performed for both vehicles. Results indicate that in terms of vehicle use (Tank to Wheel perspective) the electric powertrain is significantly more energy efficient than the Diesel powertrain, although the difference between the two is less pronounced for higher power events.Fundação para a Ciência e a Tecnologia (FCT) - Project MOBI-MPP (MIT-Pt/EDAM-SMS/0030/2008), SFRH/BPD/51048/2010, SFRH/BPD/89553/2012MIT Portugal Program (EDAM), MOBI-MPP ProjectFEDER - Programa Operacional Factores de Competitividade COMPET

A case study on the conversion of an internal combustion engine vehicle into an electric vehicle

This paper presents the conversion process of a traditional Internal Combustion Engine vehicle into an Electric Vehicle. The main constitutive elements of the Electric Vehicle are presented. The developed powertrain uses a three-phase inverter with Field Oriented Control and space vector modulation. The developed on-board batteries charging system can operate in Grid-to-Vehicle and Vehicle-to-Grid modes. The implemented prototypes were tested, and experimental results are presented. The assembly of these prototypes in the vehicle was made in accordance with the Portuguese legislation about vehicles conversion, and the main adopted solutions are presented.FCT – Fundação para a Ciência e Tecnologia in the scope of the project: PEst - OE/EEI/UI0319/201

Smart charging system of the electric vehicle CEPIUM

In this paper is presented the development of a smart batteries charging system for the Electric Vehicle (EV) CEPIUM, aiming the integration of EVs in the future Smart Grids. The main features of the developed charging system are the mitigation of the power quality degradation and the bidirectional operation, as Grid-to-Vehicle (G2V) and as Vehicle-to-Grid (V2G). The batteries charging process is controlled by an appropriate control algorithm, aiming to preserve the batteries lifespan. During the charging process (G2V), the consumed current is sinusoidal and the power factor is unitary. Along the discharging process (V2G), when the equipment allows delivering back to the electrical power grid part of the energy stored in the batteries, the current is also sinusoidal.FEDER Funds - Operational Programme for Competitiveness Factors (COMPETE)Fundação para a Ciência e a Tecnologia (FCT) - PTDC/EEA-EEL/104569/2008, MITPT/ EDAM-SMS/0030/2008