264 research outputs found

    Real-time predictive maintenance for wind turbines using Big Data frameworks

    Full text link
    This work presents the evolution of a solution for predictive maintenance to a Big Data environment. The proposed adaptation aims for predicting failures on wind turbines using a data-driven solution deployed in the cloud and which is composed by three main modules. (i) A predictive model generator which generates predictive models for each monitored wind turbine by means of Random Forest algorithm. (ii) A monitoring agent that makes predictions every 10 minutes about failures in wind turbines during the next hour. Finally, (iii) a dashboard where given predictions can be visualized. To implement the solution Apache Spark, Apache Kafka, Apache Mesos and HDFS have been used. Therefore, we have improved the previous work in terms of data process speed, scalability and automation. In addition, we have provided fault-tolerant functionality with a centralized access point from where the status of all the wind turbines of a company localized all over the world can be monitored, reducing O&M costs

    Phase Transitions in a Kinetic Flocking Model of Cucker-Smale Type

    Get PDF
    We consider a collective behavior model in which individuals try to imitate each others' velocity and have a preferred speed. We show that a phase change phenomenon takes place as diffusion decreases, bringing the system from a “disordered” to an “ordered” state. This effect is related to recently noticed phenomena for the diffusive Vicsek model. We also carry out numerical simulations of the system and give further details on the phase transition

    Intra-regional classification of grape seeds produced in Mendoza province (Argentina) by multi-elemental analysis and chemometrics tools

    Get PDF
    The feasibility of the application of chemometric techniques associated with multi-element analysis for the classification of grape seeds according to their provenance vineyard soil was investigated. Grape seed samples from different localities of Mendoza province (Argentina) were evaluated. Inductively coupled plasma mass spectrometry (ICP-MS) was used for the determination of twenty-nine elements (Ag, As, Ce, Co, Cs, Cu, Eu, Fe, Ga, Gd, La, Lu, Mn, Mo, Nb, Nd, Ni, Pr, Rb, Sm, Te, Ti, Tl, Tm, U, V, Y, Zn and Zr). Once the analytical data were collected, supervised pattern recognition techniques such as linear discriminant analysis (LDA), partial least square discriminant analysis (PLS-DA), k-nearest neighbors (k-NN), support vector machine (SVM) and Random Forest (RF) were applied to construct classification/discrimination rules. The results indicated that nonlinear methods, RF and SVM, perform best with up to 98% and 93% accuracy rate, respectively, and therefore are excellent tools for classification of grapes.Fil: Canizo, Brenda Vanina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Laboratorio de Química Analítica para Investigación y Desarrollo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Escudero, Leticia Belén. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Laboratorio de Química Analítica para Investigación y Desarrollo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Pérez, María Belén. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales. Laboratorio de Química Analítica para Investigación y Desarrollo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Pellerano, Roberto Gerardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Wuilloud, Rodolfo German. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentin

    Revisiting performance persistence in real estate funds

    Get PDF
    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2005.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (leaves 46-47).In this thesis, real estate opportunity fund returns were analyzed for evidence of persistence in subsequent funds from the same manager; it is designed to update and enhance a prior thesis performed by Cathy C. Hahn (2003), using both parametric and non-parametric tests. Tests were performed on gross and net returns covering the period from 1991-2004. These tests confirm the prior finding that past fund performance is a significant indicator of future fund performance within the same firm. Our study also found the strongest evidence of persistence to exist in the extreme performers ranking in the top and bottom quartile amongst their vintage year peers. Additional tests for persistence, as well as effects of fund characteristics on performance, were employed using a methodology similar to that performed on private equity funds by Kaplan and Schoar (2003). Our tests yielded similar results to those found by Kaplan and Schoar(2003), but were not substantiated with statistical significance.by Robert A. LaFever and Luis Canizo.S.M

    Modulation of bovine pluripotency genes: a platform development for obtaining and culturing pluripotent stem cells

    Get PDF
    Las células madre embrionarias (ESC) se han utilizado exitosamente desde hace más de 30 años en la transgénesis de ratón y más recientemente en rata para llevar a cabo investigaciones en genética, biología del desarrollo y posibles futuras aplicaciones en medicina regenerativa. Estas células derivadas del macizo celular interno (ICM) del embrión de ratón tiene cuatro propiedades fundamentales que han facilitado su utilización para la modificación genética: 1- pluripotencia, 2- clonogenicidad, 3- capacidad de auto renovación a largo plazo y 4- capacidad de formar quimeras y contribuir a la línea germinal (“quimeras germinales”). Esta última característica permite obtener quimeras de forma muy eficiente: 60 % de animales nacidos vivos en el caso de inyección en blastocistos de ratón y 80 % mediante la agregación de ESC a embriones de 8 células. Las células con estas propiedades se definen como células pluripotentes naïve y se diferencian de otro tipo de célula embrionaria pluripotente derivadas del epiblasto, denominadas células primed (EpiSC). En los últimos años, se han llevado a cabo numerosos estudios para establecer los mecanismos que determinan la pluripotencia naïve durante el desarrollo embrionario temprano y durante la generación de células madre pluripotentes inducidas (iPSC), aunque en su mayoría se han realizado en ratón y en menor medida en humano. La generación de células naïve bovinas y su utilización para generar bovinos transgénicos requiere entonces trasladar este tipo de estudios. El objetivo general de esta tesis fue estudiar los mecanismos involucrados en la emergencia de la pluripotencia durante el desarrollo embrionario temprano en bovinos y aplicar estos conocimientos al desarrollo de una plataforma biotecnológica para la producción de bovinos transgénicos con fines productivos (molecular pharming) basados en la derivación de células pluripotentes embrionarias y en la reprogramación de células somáticas. Para ello en el primer capítulo se estudió dos condiciones alternativas al medio clásico SOF/BSA para cultivo in vitro de embriones sin suero. El medio N2B27 se estableció como la mejor opción libre de suero para obtener blastocistos bovinos de alta calidad necesarios para estudiar el impacto de la modulación de las vías de señalización y su efecto en la segregación embrionaria. Posteriormente se estudiaron los marcadores de epiblasto e hipoblasto (PE) bovino resultando NANOG y SOX17 los escogidos para evaluar los efectos en la especificación de estos linajes. Adicionalmente se documentó la dinámica de expresión de estos genes durante el desarrollo temprano en embriones de 4 células a blastocitos. La co-expresión comienza al estadio de 8 células, se intensifica en el estadio de mórula y se restringe mutuamente en el de blastocisto. Mediante la detección por inmunofluorescencia se determinó el número de células positivas de cada marcador y con ello se evaluó el efecto de diferentes medios de cultivo sobre la evolución de embriones bovinos producidos in vitro. Se comparó el medio N2B27 t2iGo LIF, utilizado para establecer líneas de células madre embrionarias naïve de ratón y humano, con el control (DMSO), y con el medio al que solo se le agregó h-LIF o t2iGö. Este último es una combinación de PD0325901 y CHIR, inhibidores de MAPK7ERK y GSK3 respectivamente, con la adición de PKC (Gö6983). Del análisis de los resultados se concluyó que el medio N2B27 h-LIF aumentó el número de células NANOG y SOX17 positivas y por tanto del ICM en detrimento del trofoectodermo (TE), lo que indica un efecto en el primer evento de diferenciación embrionaria. A su vez este medio aumentó el número de células que co-expresan NANOG y SOX17. Por otro lado, en el medio N2B27 t2iGö h-LIF se detectaron diferencias en la segregación del epiblasto e hipoblasto de día 8 con un efecto parcial, generando un mayor número de células NANOG positivas en el ICM en detrimento de las SOX17 positivas sin lograr bloquear completamente la formación del hipoblasto. De acuerdo a estos resultados, se cree que existe algún otro mecanismo que junto a la vía MAPK/ERK participa en el embrión bovino para el establecimiento del segundo evento de diferenciación. Para evaluar esta nueva hipótesis, se estudió el efecto de N2B27 suplementado con PD0325901 en una concentración de 10 μM (PD032+), solo y en conjunto con IWP2 el inhibidor de Wnt. Se compararon estos grupos con el control (DMSO) y el medio con solo IWP2. Se ha reportado previamente que la inhibición conjunta de MARPK/ERK y Wnt inhiben el desarrollo del PE en embriones de monos. Inesperadamente nuestros resultados demuestran que PD032+ bloquea la expresión de SOX17 y probablemente la formación del PE, aunque sin el aumento del número de células que expresan NANOG. Este efecto también se observa en la combinación IWP2 + PD032+. Posteriormente, con el fin de establecer si la disminución de las células NANOG positivas se debió a la alta concentración del inhibidor, se llevó a cabo un análisis de la curva dosis respuesta en la que se varió la concentración de PD032 de 2.5, 5 y 10 μM. En todas las concentraciones, se observó la ausencia de células SOX17, en cuanto que NANOG respondió de forma parabólica en la que el número de células positivas es mayor a 5 μM que a 2.5 y 10 y semejante a la del control (DMSO). Al contrario de lo que se esperaba, este resultado en el que no hay un aumento del marcador de un linaje en detrimento del otro nos lleva a pensar que el efecto del bloqueo de SOX17 no se debe a un cambio en la decisión del destino celular. Se necesita profundizar el análisis para determinar la causa de dicho efecto. En el segundo capítulo se evaluaron diferentes metodologías para la generación de iPSC bovinas, tanto aquellas en la que los factores de reprogramación OCT4, KLF4, SOX2 y C-MYC (OKSM) se introdujeron en la célula de forma transitoria mediante episomas, como las que se insertaron en el genoma mediante la transducción de las células con partículas lentivirales. Se realizó en paralelo la reprogramación de células de fibroblastos porcinos (PEF), utilizadas en primera instancia como control del protocolo de reprogramación. Se establecieron las condiciones óptimas en los procesos de transfección de episomas y de generación de partículas lentivirales, previo a la reprogramación. Se trabajó con diferentes medios de reprogramación, el convencional KSR + FGF, el medio E8 de cultivo de células en medio feeder and serum free y el medio SB43 en el que se modulan las vías MAPK/ERK, Wnt y las mediadas por TGF. Se caracterizaron las células obtenidas por inmunofluorescencia de marcadores de pluripotencia nucleares y de membrana, por RT-PCR, actividad de fosfatasa alcalina (AP), detección de la inserción del vector (STEMCCA) en el genoma y expresión de los factores exógenos mediante RT-PCR. Los resultados obtenidos en los experimentos con episomas ponen en evidencia una vez más la dificultad de reprogramar células somáticas en las especies en estudio (bovino y porcino), en los que aún no se han logrado establecer líneas de iPSC genuinas. Por otro lado, haciendo uso de partículas lentivirales en donde la expresión de los genes es constitutiva y suficiente para iniciar la reprogramación, se obtuvieron con mayor facilidad a partir de células porcinas que bovinas, colonias de morfología semejante a las iPSC. Reprogramar células bovinas requirió de la modificación de las condiciones de reprogramación para ajustar los mismos a la cinética de crecimiento de fibroblastos bovinos y a la baja eficiencia con que estos se transducen a una misma MOI con respecto a otras especies. Para ambas especies sigue siendo un desafío establecer el cultivo en forma estable en el tiempo sin que las células varíen sus características. Determinar las condiciones de cultivo que favorezcan la expresión de genes endógenos de la red de pluripotencia e inactiven los exógenos utilizados en los protocolos de partículas lentivirales sigue siendo el cuello de botella en los procesos de establecimiento de iPSC bovinas y porcinas. Como aún no se lograron las células totalmente reprogramadas en estas especies, es fundamental ganar más conocimiento de los mecanismos moleculares de establecimiento de pluripotencia y diferenciación en animales de granja para superar este obstáculo.Embryonic stem cells (ESC) have been successfully employed in mouse transgenesis during more than 30 years, and more recently in rats, to carry on research about genetics, developmental biology and future regenerative medicine applications. These cells are derived from the inner cells mass (ICM) of mouse embryos and have two properties that make able their use as a vector in genetic modified animals generation: 1) pluripotency, 2) clonogenicity, 3) self-renewal, 4) capacity for making chimeras and contributing to the germ line. This last feature allows them to produce chimeras in an efficiently manner: 60% of lived born animals when blastocyst injection is used and 80% by 8 cells aggregation of ESC. These kind of cells are defined as “naive” pluripotent stem cells and they differ from that derived from the epiblast: the primed state of pluripotent stem cells (EpiSC). Over the last few years many studies have been carried on to establish the molecular mechanism that define naive pluripotency during early embryonic development and during the generation of induced pluripotent stem cells (iPSC). These studies were mainly focused on mouse and then in human pluripotency. The generation of naive bovine cells and their use for generating bovine transgenic animals require to study this as well. The main objective of this research was to study the mechanism of pluripotency emergency during bovine embryonic development and the use of this new knowledge for developing a biotechnological platform to produce transgenic bovines with productive purposes (molecular pharming) based on derivation of ESC and reprogramming of somatic cells. In the first chapter, two serum free conditions for culturing bovine embryos were studied. The N2B27 medium was the best option for producing bovine blastocysts of high quality to study the impact of molecular pathways and their effect in lineage segregation. Then, molecular markers for epiblast and hypoblast were chosen resulting NANOG and SOX17 as the better options for studying the specification of these two lineages. Moreover, their dynamic expression was studied during early embryonic development starting with 4 cell stage to blastocyst stage. Co expression of NANOG/SOX17 was detected at 8 cell stage, their expression was intensified at morula stage and become mutually restricted at blastocyst stage. Then, the number of positive cells of each marker was determined by immunofluorescence analysis and therefore the effect of different medium formulations was evaluated in the in vitro bovine embryos. N2B27 t2iGö h-LIF used in the establishment of mouse and human naive ESC was compared with control (N2B27 with DMSO) and N2B27 with h-LIF or t2iGö. t2iGö is a combination of PD0325901 and CHIR, MAPK/ERK and GSK3 inhibitors respectively known as 2i, with PKC inhibitor (Gö6983). Results shows that N2B27 h-LIF increased the number of NANOG and SOX17 positive cells and therefore the size of ICM in detriment of trophectoderm (TE). Therefore, h-LIF influenced the first event of lineage segregation when ICM and TE are specified. At the same time, this medium increased the number of NANOG and SOX17 co expressed cells. On the other hand, N2B27 t2iGö h-LIF was the only medium able to impact on the second event of embryo lineage segregation, having more NANOG positive cells in day 8 embryos treated with it and partially blocking PE specification. In conclusion, we expected that other pathway with MAPK/ERK specifies primitive endoderm in bovine embryos. For elucidating this new hypothesis, we studied the effect of N2B27 with PD0325901 at 10 μM (PD032+), alone and with IWP2, a Wnt inhibitor. This groups were compared with control (DMSO) and N2B27 with IWP2. Previously was reported that dual inhibition of MARPK/ERK and Wnt blocks the development of PE in marmoset embryos. Unexpectedly, our results show that PD032+ blocked SOX17 expression and probably the PE specification although without NANOG positive cells increase (actually a decrease regard of the control). This effect was also seen in the combination IWP2 + PD032+. Then, with the aim of establishing if NANOG positive cells decrease was due to a high concentration of PD032, we made and analysis of dose response curve with 2.5, 5 and 10 μM of the inhibitor. In all the conditions, we saw the ablation of SOX17 expression, meanwhile the NANOG number of cells respond in a parabolic manner where the highest number was at a concentration of 5 μM and at this concentration the positive cells number was like the control (DMSO). Contrary to we expected, this result in which there is no an increase of one lineage in detriment of the other suggests us that the effect on the PE is not due to a change in the decision fate of the cell. More studies are needed to understand what happened at high concentration of PD032 inhibitor. In the second chapter, different strategies were evaluated for bovine iPSC generation. Episomes and lentivirus were used for introducing reprogramming factors OCT4, KLF4, SOX2, C-MYC (OKSM). At the same time, porcine fibroblast (PEF) were reprogramming as control of the method employed. Episomes transfection and generation of lentivirus were previously optimized. Cells were cultured in different media: KSR + FGF, E8 medium for feeder and serum free conditions and finally SB43 medium in which MAPK/ERK, Wnt and TGF pathways are modulated. Cells with changed morphology were characterized by immunofluorescence of pluripotency markers, RT-PCR, alkaline phosphatase and detection of STEMCCA in the genome of reprogramming cells. Finally, detection of exogenously factors were analysed during long term culture by RT-PCR. Results obtained with episomes demonstrate once again that bovine and porcine cells are recalcitrant for reprogramming. Culturing of bonafide iPSC cells in these species are still difficult and pluripotency is not maintained by endogenous factors but exogenous. On the other hand, protocols based on lentiviruses produce porcine iPSC-like cells more easily then bovine. That means that protocols used in other species are useful for obtaining porcine colonies but working with bovine cells need the adjustment of conditions. Despite of the fact of getting colonies, long term culture of iPSC is still difficult for both species; they maintained the stem cells features only by the expression of exogenous factors. Inactivation of the STEMCCA is still a bottleneck for establishing bonafide iPSC, since culture medium did not maintain endogenous OKSM expression. Therefore, it is still crucial getting more knowledge regard on the molecular mechanism for pluripotency and differentiation establishment in farm animals.Fil: Canizo, Jesica Romina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

    Multi-head CNN–RNN for multi-time series anomaly detection: An industrial case study

    Get PDF
    Detecting anomalies in time series data is becoming mainstream in a wide variety of industrial applications in which sensors monitor expensive machinery. The complexity of this task increases when multiple heterogeneous sensors provide information of di_erent nature, scales and frequencies from the same machine. Traditionally, machine learning techniques require a separate data preprocessing before training, which tends to be very time-consuming and often requires domain knowledge. Recent deep learning approaches have shown to perform well on raw time series data, eliminating the need for pre-processing. In this work, we propose a deep learning based approach for supervised multitime series anomaly detection that combines a Convolutional Neural Network (CNN) and a Recurrent Neural Network (RNN) in different ways. Unlike other approaches, we use independent CNNs, so-called convolutional heads, to deal with anomaly detection in multi-sensor systems. We address each sensor individually avoiding the need for data pre-processing and allowing for a more tailored architecture for each type of sensor. We refer to this architecture as Multi-head CNN-RNN. The proposed architecture is assessed against a real industrial case study, provided by an industrial partner, where a service elevator is monitored. Within this case study, three type of anomalies are considered: point, context-specific, and collective. The experimental results show that the proposed architecture is suitable for multi-time series anomaly detection as it obtained promising results on the real industrial scenario

    Conversion of High Biomass/Bagasse from Sorghum and Bermuda Grass into Second-Generation Bioethanol

    Get PDF
    Sorghum (Sorghum bicolor) and Bermuda (Cynodon dactylon) grass are examples of annual and perennial forage crops produced throughout the globe. These crops should be harvested at the peak of biomass production when the levels of lignin are relatively low. The high biomass sorghum, sweet sorghum bagasse (2 cuts or crops year−1) or Bermuda grass capable of yielding up to 50, 60 and 27 tons of dry forage ha−1 year−1 rich in cellulose and hemicellulose can be efficiently transformed into bioethanol using second-generation technologies consisting of milling, pretreatment (chemical and/or enzymatic) and fermentation with microorganisms capable of transforming C5/C6 sugars to obtain ethanol. An alternative process contemplates the extrusion aimed toward the physical disruption of cell walls minimizing the use of considerable amounts of water and chemicals commonly used during pretreatment. Extruded feedstocks treated with fiber-degrading enzyme cocktails had conversion efficiencies between 60 and 78% of the hemicellulose and cellulose similar to the ones achieved after acid/enzyme hydrolyses. The chief advantages of this continuous process are that hydrolysates are practically free of enzymes and yeast inhibitors. These feedstocks can produce up to 310 L anhydrous bioethanol dry t−1 and have a great potential for widespread use

    Perfil ambiental de la generación termoeléctrica en la Argentina en el cuatrienio 1997-2000

    Get PDF
    La realización de estudios de Análisis de Ciclo de Vida (ACV) de productos y sistemas es una práctica cada vez más frecuente, sobre todo en países desarrollados, pero con un incipiente desarrollo también en países menos desarrollados. Para llevar a cabo un ACV de un determinado producto, es necesario conocer gran cantidad de datos acerca de los impactos ambientales asociados con los insumos necesarios para su constitución. Uno de los insumos más utilizados en la sociedad moderna es la energía eléctrica, que tiene asociado un importante impacto sobre el ambiente. Es por lo tanto de suma importancia conocer cuál es el impacto que tiene cada unidad de energía eléctrica generada en el país, en términos de recursos consumidos y emisiones liberadas, con sus impactos potenciales asociados (calentamiento global, acidificación, smog, etc.) En este trabajo se realiza un primer estudio con el objeto de conocer las consecuencias ambientales asociadas con la generación de energía eléctrica en Argentina, restringido al parque generador térmico. La metodología adoptada para la evaluación de las emisiones es la del IPCC (Panel Intergubernamental sobre el Cambio Climático). Se ha analizado el cuatrienio 1997-2000, considerando la participación de los distintos tipos de centrales en el mix energético del país.Life Cycle Assessment (LCA) is a very widespread methodology for the evaluation of the environmental impact associated with a product or system, mainly in developed countries but also growing in developing ones. In order to develop the LCA of a product, many data about the environmental impact of the system-product’s input (energy, raw materials, other products) are required. One of the main inputs for every modern process is electricity. The generation of electrical energy has a heavy environmental impact associated, which must be known if the LCA of almost any other product or service is to be performed. The amount of resources consumed and of emissions generated, as well as their associated potential environmental impacts such as global warming potential, summer smog or acidification potentials should then be calculated for every country. In this work a first insight into the environmental profile of electricity generation in Argentina is performed, restraining the study to the thermal power plants. The IPCC methodology has been followed, taking into consideration from 1997 to 2000 years, considering the share of the different thermal power plants currently operating in the country.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

    Implementation of a Large-Scale Platform for Cyber-Physical System Real-Time Monitoring

    Get PDF
    The emergence of Industry 4.0 and the Internet of Things (IoT) has meant that the manufacturing industry has evolved from embedded systems to cyber-physical systems (CPSs). This transformation has provided manufacturers with the ability to measure the performance of industrial equipment by means of data gathered from on-board sensors. This allows the status of industrial systems to be monitored and can detect anomalies. However, the increased amount of measured data has prompted many companies to investigate innovative ways to manage these volumes of data. In recent years, cloud computing and big data technologies have emerged among the scientific communities as key enabling technologies to address the current needs of CPSs. This paper presents a large-scale platform for CPS real-time monitoring based on big data technologies, which aims to perform real-time analysis that targets the monitoring of industrial machines in a real work environment. This paper is validated by implementing the proposed solution on a real industrial use case that includes several industrial press machines. The formal experiments in a real scenario are conducted to demonstrate the effectiveness of this solution and also its adequacy and scalability for future demand requirements. As a result of the implantation of this solution, the overall equipment effectiveness has been improved.The authors are grateful to Goizper and Fagor Arrasate for providing the industrial case study, and specifically Jon Rodriguez and David Chico (Fagor Arrasate) for their help and support. Any opinions, findings and conclusions expressed in this article are those of the authors and do not necessarily reflect the views of the funding agencies

    Living myocardial slices for the study of nucleic acid-based therapies

    Get PDF
    Gene therapy based on viral vectors offers great potential for the study and the treatment of cardiac diseases. Here we explore the use of Living Myocardial Slices (LMS) as a platform for nucleic acid-based therapies. Rat LMS and Adeno-Associated viruses (AAV) were used to optimise and analyse gene transfer efficiency, viability, tissue functionality, and cell tropism in cardiac tissue. Human cardiac tissue from failing (dilated cardiomyopathy) hearts was also used to validate the model in a more translational setting. LMS were cultured at physiological sarcomere length for 72-h under electrical stimulation. Two recombinant AAV serotypes (AAV6 and AAV9) at different multiplicity of infection (MOI) expressing enhanced green fluorescent protein (eGFP) were added to the surface of rat LMS. AAV6 at 20,000 MOI proved to be the most suitable serotype without affecting LMS contractility or kinetics and showing high transduction and penetrability efficiency in rat LMS. This serotype exhibited 40% of transduction efficiency in cardiomyocytes and stromal cells while 20% of the endothelial cells were transduced. With great translational relevance, this protocol introduces the use of LMS as a model for nucleic acid-based therapies, allowing the acceleration of preclinical studies for cardiac diseases
    corecore