13 research outputs found

    Through the Eyes of VERTa

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    [eng] This paper describes a practical demo of VERTa for Spanish. VERTa is an MT evaluation metric that combines linguistic features at different levels. VERTa has been developed for English and Spanish but can be easily adapted to other languages. VERTa can be used to evaluate adequacy, fluency and ranking of sentences. In this paper, VERTa's modules are described briefly, as well as its graphical interface which provides information on VERTa's performance and possible MT errors. [spa] Este artículo describe la demostración práctica de VERTa para el castellano. VERTa es una métrica de evaluación de traducción automática que combina información lingüística a diferentes niveles. VERTa ha sido desarrollada para el inglés y el castellano pero se puede adaptar fácilmente a otras lenguas. La métrica puede evaluar la adecuación, la fluidez y ranking de frases. En este artículo se describen brevemente los módulos de VERTa y su interficie gráfica, la cual proporciona información sobre el rendimiento de la métrica y posibles errores de traducción

    A Través de los Ojos de VERTa

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    This paper describes a practical demo of VERTa for Spanish. VERTa is an MT evaluation metric that combines linguistic features at different levels. VERTa has been developed for English and Spanish but can be easily adapted to other languages. VERTa can be used to evaluate adequacy, fluency and ranking of sentences. In this paper, VERTa’s modules are described briefly, as well as its graphical interface which provides information on VERTa’s performance and possible MT errors.Este artículo describe la demostración práctica de VERTa para el castellano. VERTa es una métrica de evaluación de traducción automática que combina información lingüística a diferentes niveles. VERTa ha sido desarrollada para el inglés y el castellano pero se puede adaptar fácilmente a otras lenguas. La métrica puede evaluar la adecuación, la fluidez y ranking de frases. En este artículo se describen brevemente los módulos de VERTa y su interficie gráfica, la cual proporciona información sobre el rendimiento de la métrica y posibles errores de traducción.This work has been funded by the Spanish Government (project TUNER, TIN2015-65308-C5-1-R)

    Microfabrication of poly(acrylamide) hydrogels with independently controlled topography and stiffness

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    The stiffness and topography of a cell's extracellular matrix are physical cues that play a key role in regulating processes that determine cellular fate and function. While substrate stiffness can dictate cell differentiation lineage, migration, and self-organization, topographical features can change the cell's differentiation profile or migration ability. Although both physical cues are present and intrinsic to the native tissues in vivo, in vitro studies have been hampered by the lack of technological set-ups that would be compatible with cell culture and characterization. In vitro studies therefore either focused on screening stiffness effects in cells cultured on flat substrates or on determining topography effects in cells cultured onto hard materials. Here, we present a reliable, microfabrication method to obtain well defined topographical structures of micrometer size (5-10 µm) on soft polyacrylamide hydrogels with tunable mechanical stiffness (3-145 kPa) that closely mimic the in vivo situation. Topographically microstructured polyacrylamide hydrogels are polymerized by capillary force lithography using flexible materials as molds. The topographical microstructures are resistant to swelling, can be conformally functionalized by extracellular matrix proteins and sustain the growth of cell lines (fibroblasts and myoblasts) and primary cells (mouse intestinal epithelial cells). Our method can independently control stiffness and topography, which allows to individually assess the contribution of each physical cue to cell response or to explore potential synergistic effects. We anticipate that our fabrication method will be of great utility in tissue engineering and biophysics, especially for applications where the use of complex in vivo-like environments is of paramount importance

    Dynamic photopolymerization produces complex microstructures on hydrogels in a moldless approach to generate a 3D intestinal tissue model

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    Epithelial tissues contain three-dimensional (3D) complex microtopographies that are essential for proper performance. These microstructures provide cells with the physicochemical cues needed to guide their self-organization into functional tissue structures. However, most in vitro models do not implement these 3D architectural features. The main problem is the availability of simple fabrication techniques that can reproduce the complex geometries found in native tissues on the soft polymeric materials required as cell culture substrates. In this study reaction-diffusion mediated photolithography is used to fabricate 3D microstructures with complex geometries on poly(ethylene glycol)-based hydrogels in a single step and moldless approach. By controlling fabrication parameters such as the oxygen diffusion/depletion timescales, the distance to the light source and the exposure dose, the dimensions and geometry of the microstructures can be well-defined. In addition, copolymerization of poly(ethylene glycol) with acrylic acid improves control of the dynamic reaction-diffusion processes that govern the free-radical polymerization of highly-diluted polymeric solutions. Moreover, acrylic acid allows adjusting the density of cell adhesive ligands while preserving the mechanical properties of the hydrogels. The method proposed is a simple, single-step, and cost-effective strategy for producing models of intestinal epithelium that can be easily integrated into standard cell culture platfor

    Cells as active particles in asymmetric potentials: Motility under external gradients

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    Cell migration is a crucial event during development and in disease. Mechanical constraints and chemical gradients can contribute to the establishment of cell direction, but their respective roles remain poorly understood. Using a microfabricated topographical ratchet, we show that the nucleus dictates the direction of cell movement through mechanical guidance by its environment. We demonstrate that this direction can be tuned by combining the topographical ratchet with a biochemical gradient of fibronectin adhesion. We report competition and cooperation between the two external cues. We also quantitatively compare the measurements associated with the trajectory of a model that treats cells as fluctuating particles trapped in a periodic asymmetric potential. We show that the cell nucleus contributes to the strength of the trap, whereas cell protrusions guided by the adhesive gradients add a constant tunable bias to the direction of cell motion

    Bioengineered in vitro 3D model of myotonic dystrophy type 1 human skeletal muscle

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    Myotonic dystrophy type 1 (DM1) is the most common hereditary myopathy in the adult population. The disease is characterized by progressive skeletal muscle degeneration that produces severe disability. At present, there is still no effective treatment for DM1 patients, but the breakthroughs in understanding the molecular pathogenic mechanisms in DM1 have allowed the testing of new therapeutic strategies. Animal models and in vitro two-dimensional cell cultures have been essential for these advances. However, serious concerns exist regarding how faithfully these models reproduce the biological complexity of the disease. Biofabrication tools can be applied to engineer human three-dimensional (3D) culture systems that complement current preclinical research models. Here, we describe the development of the first in vitro 3D model of DM1 human skeletal muscle. Transdifferentiated myoblasts from patient-derived fibroblasts were encapsulated in micromolded gelatin methacryloyl-carboxymethyl cellulose methacrylate hydrogels through photomold patterning on functionalized glass coverslips. These hydrogels present a microstructured topography that promotes myoblasts alignment and differentiation resulting in highly aligned myotubes from both healthy and DM1 cells in a long-lasting cell culture. The DM1 3D microtissues recapitulate the molecular alterations detected in patient biopsies. Importantly, fusion index analyses demonstrate that 3D micropatterning significantly improved DM1 cell differentiation into multinucleated myotubes compared to standard cell cultures. Moreover, the characterization of the 3D cultures of DM1 myotubes detects phenotypes as the reduced thickness of myotubes that can be used for drug testing. Finally, we evaluated the therapeutic effect of antagomiR-23b administration on bioengineered DM1 skeletal muscle microtissues. AntagomiR-23b treatment rescues both molecular DM1 hallmarks and structural phenotype, restoring myotube diameter to healthy control sizes. Overall, these new microtissues represent an improvement over conventional cell culture models and can be used as biomimetic platforms to establish preclinical studies for myotonic dystrophy

    Hydrogel co-networks of gelatine methacrylate and poly(ethylene glycol) diacrylate sustain 3D functional in vitro models of intestinal mucosa

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    Mounting evidence supports the importance of the intestinal epithelial barrier and its permeability both in physiological and pathological conditions. Conventional in vitro models to evaluate intestinal permeability rely on the formation of tightly packed epithelial monolayers grown on hard substrates. These two-dimensional (2D) models lack the cellular and mechanical components of the non-epithelial compartment of the intestinal barrier, the stroma, which are key contributors to the barrier permeability in vivo. Thus, advanced in vitro models approaching the in vivo tissue composition are fundamental to improve precision in drug absorption predictions, to provide a better understanding of the intestinal biology, and to faithfully represent related diseases. Here, we generate photo-crosslinked gelatine methacrylate (GelMA) - poly(ethylene glycol) diacrylate (PEGDA) hydrogel co-networks that provide the required mechanical and biochemical features to mimic both the epithelial and stromal compartments of the intestinal mucosa, i.e., they are soft, cell adhesive and cell-loading friendly, and suitable for long-term culturing. We show that fibroblasts can be embedded in the GelMA-PEGDA hydrogels while epithelial cells can grow on top to form a mature epithelial monolayer that exhibits barrier properties which closely mimic those of the intestinal barrier in vivo, as shown by the physiologically relevant transepithelial electrical resistance (TEER) and permeability values. The presence of fibroblasts in the artificial stroma compartment accelerates the formation of the epithelial monolayer and boosts the recovery of the epithelial integrity upon temporary barrier disruption, demonstrating that our system is capable of successfully reproducing the interaction between different cellular compartments. As such, our hydrogel co-networks offer a technologically simple yet sophisticated approach to produce functional three-dimensional (3D) in vitro models of epithelial barriers with epithelial and stromal cells arranged in a spatially relevant manner and near-physiological functionality

    Notes de recerca

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    Parejas mixtas residentes fuera de España: relaciones de género,dinámicas sociales y conexiones transnacionalesMovilidad y vida cotidiana en Cataluña: etno-geografía de los espacios y tiempos metropolitanosPràctiques locals i discursos globals en la reproducció de les comunitats rurals. Desenvolupament rural, agroecologia i sobirania alimentària“Encounters and Engagements”: el primer congrés mundial d'antropologia mèdica, organitzat a la URV al juny del 2013 De gladiadores y antropó[email protected] reseña sobre XIII Congreso de Antropología “Periferias, fronteras y diálogos”Los congresos de antropología de la FAAEE: una breve reflexió

    Engineered Macroscale Cardiac Constructs Elicit Human Myocardial Tissue-like Functionality

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    In vitro surrogate models of human cardiac tissue hold great promise in disease modeling, cardiotoxicity testing, and future applications in regenerative medicine. However, the generation of engineered human cardiac constructs with tissue-like functionality is currently thwarted by difficulties in achieving efficient maturation at the cellular and/or tissular level. Here, we report on the design and implementation of a platform for the production of engineered cardiac macrotissues from human pluripotent stem cells (PSCs), which we term "CardioSlice." PSC-derived cardiomyocytes, together with human fibroblasts, are seeded into large 3D porous scaffolds and cultured using a parallelized perfusion bioreactor with custom-made culture chambers. Continuous electrical stimulation for 2 weeks promotes cardiomyocyte alignment and synchronization, and the emergence of cardiac tissue-like properties. These include electrocardiogram-like signals that can be readily measured on the surface of CardioSlice constructs, and a response to proarrhythmic drugs that is predictive of their effect in human patients
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