A Versatile Open-Source Printhead for Low-Cost 3D Microextrusion-Based Bioprinting

Three-dimensional (3D) bioprinting promises to be essential in tissue engineering for solving the rising demand for organs and tissues. Some bioprinters are commercially available, but their impact on the field of Tissue engineering (TE) is still limited due to their cost or difficulty to tune. Herein, we present a low-cost easy-to-build printhead for microextrusion-based bioprinting (MEBB) that can be installed in many desktop 3D printers to transform them into 3D bioprinters. We can extrude bioinks with precise control of print temperature between 2–60 °C. We validated the versatility of the printhead, by assembling it in three low-cost open-source desktop 3D printers. Multiple units of the printhead can also be easily put together in a single printer carriage for building a multi-material 3D bioprinter. Print resolution was evaluated by creating representative calibration models at different temperatures using natural hydrogels such as gelatin and alginate, and synthetic ones like poloxamer. Using one of the three modified low-cost 3D printers, we successfully printed cell-laden lattice constructs with cell viabilities higher than 90% after 24-h post printing. Controlling temperature and pressure according to the rheological properties of the bioinks was essential in achieving optimal printability and great cell viability. The cost per unit of our device, which can be used with syringes of different volume, is less expensive than any other commercially available product. These data demonstrate an affordable open-source printhead with the potential to become a reliable alternative to commercial bioprinters for any laboratory

A Versatile Open-Source Printhead for Low-Cost 3D Microextrusion-Based Bioprinting

Three-dimensional (3D) bioprinting promises to be essential in tissue engineering for solving the rising demand for organs and tissues. Some bioprinters are commercially available, but their impact on the field of Tissue engineering (TE) is still limited due to their cost or difficulty to tune. Herein, we present a low-cost easy-to-build printhead for microextrusion-based bioprinting (MEBB) that can be installed in many desktop 3D printers to transform them into 3D bioprinters. We can extrude bioinks with precise control of print temperature between 2–60 °C. We validated the versatility of the printhead, by assembling it in three low-cost open-source desktop 3D printers. Multiple units of the printhead can also be easily put together in a single printer carriage for building a multi-material 3D bioprinter. Print resolution was evaluated by creating representative calibration models at different temperatures using natural hydrogels such as gelatin and alginate, and synthetic ones like poloxamer. Using one of the three modified low-cost 3D printers, we successfully printed cell-laden lattice constructs with cell viabilities higher than 90% after 24-h post printing. Controlling temperature and pressure according to the rheological properties of the bioinks was essential in achieving optimal printability and great cell viability. The cost per unit of our device, which can be used with syringes of different volume, is less expensive than any other commercially available product. These data demonstrate an affordable open-source printhead with the potential to become a reliable alternative to commercial bioprinters for any laboratory

Makerspaces in Higher Education : the UR-Maker experience at the University of La Rioja

Nowadays, in addition to the expected technical knowledge, labor markets demand engineers with personal, interpersonal and system building skills, according to the CDIO (Conceive-Design-Implement-Operate) syllabus. But the current higher education systems are mostly teaching theoretical concepts rather than practical or applied cases. Makerspaces could become a bridge between universities and industry, particularly in STEM (Science, Technology, Engineering, and Math) careers. Makerspaces, also known as hackerspaces, hack labs, and fab labs, are open-access spaces where tools, machines and knowledge are shared with the purpose of implementing an idea. This communication evaluates the current status of the makerspaces at the world's top 10 universities in engineering and three of the most well-known Spanish ones, as well as the new campus makerspace created at the University of La Rioja. All the information was collected from universities' websites. Most of these reviewed universities have created outstanding makerspaces generally for the entire academic community. The Spanish 'Maker UPV' has been exceptionally successful promoting activities and projects in spite of the lack of resources reported. Lastly, the implementation of a new makerspace at the University of La Rioja (UR-Maker) is described with information about its organization, funding sources and activities already performed. This experience can represent an attractive guide for the academic community as other universities can explore the creation of new makerspaces on their own campus.Peer reviewe

Evaluación combinada de los impactos ambientales, económicos y sociales de soluciones estructurales para la construcción de viviendas

Sustainable development in construction is based on three fundamental pillars: economic, environmental and social. This type of approach aims to identify the best possible solutions for sustainably developing structures by conducting a joint evaluation of the impact on those three pillars. The proposed methodology incorporates metadata on the Spanish construction sector. First, a discrete database is generated with 360 alternatives covering a range of common solutions in residential building. A Pareto algorithm is utilized to select the optimal choices and the wide range of solutions is reduced to the 5 % of the initial group. The project manager is therefore provided with an objective assessment of suitable structural alternatives including the overall joint economic, social, and environmental impact. The results obtained demonstrate the importance and utility of the proposed methodology for sustainable construction.El desarrollo sostenible aplicado a la construcción se basa en tres pilares fundamentales: económico, medioambiental y social. El objetivo principal es identificar las mejores soluciones en términos de desarrollo sostenible de alternativas estructurales a partir de la evaluación conjunta de los impactos en dichos pilares. La metodología propuesta incorpora metadatos con información del sector de la construcción en España. Primero se genera una base de datos discreta de 360 alternativas estructurales que cubren el rango de soluciones habituales en edificación residencial. La selección de alternativas óptimas se realiza mediante el algoritmo de Pareto. El abanico de soluciones se reduce al 5 % de las iniciales. Se aporta una valoración objetiva que orienta al proyectista en la selección de alternativas estructurales idóneas, visualizando de forma conjunta el impacto económico, social y ambiental. Los resultados obtenidos muestran la importancia y utilidad de la metodología propuesta en el campo de la construcción sostenible

Evaluation of crumb rubber as aggregate for automated manufacturing of rubberized long hollow blocks and bricks

Waste tire rubber is a promising lightweight aggregate for building products that enhances their thermal and acoustic properties. Even the environmental benefits of its use are evident, higher cost and significant changes in compressive strength and workability hinder its widespread adoption. This article examines the use of crumb rubber (CR) as aggregate in dry-mix mortars to produce rubberized long hollow blocks and bricks using automated brick machines. CR was incorporated over a range of 10-40% with water/ cement ratio varying from 0.7 to 0.9. The production of rubberized bricks exhibited better performance than long hollow blocks in factory trials. Tests showed important deformations and drastic reduction in compressive strength, especially for crumb rubber percentages greater than 20%. Due to this and the high cost of CR, caution must be taken with the design of new rubberized building products to make sure they are profitable. (C) 2015 Elsevier Ltd. All rights reserved.Peer reviewe

In vitro invasion efficiency and intracellular proliferation rate comprise virulence-related phenotypic traits of Neospora caninum

In this study, we examined the in vitro invasion and proliferation capacities of the Nc-Liv and ten Spanish Neospora caninum isolates (Nc-Spain 1 H - Nc-Spain 10). The invasion rate was determined as the number of tachyzoites that completed their internalisation into MARC-145 cells at 2, 4, and 6 h post-inoculation (pi). The proliferation rate was evaluated by determining the doubling time during the exponential proliferation period. Significant differences in the invasion rates of these isolates were detected at 2 and 4 h pi (P < 0.0001, Kruskal-Wallis test). At 4 h pi, the Nc-Spain 4 H and Nc-Liv isolates displayed the highest, while the Nc-Spain 3 H and Nc-Spain 1 H isolates had the lowest invasion rates (by Dunn's test). Variations in the proliferation kinetics of these isolates were also observed. Between different isolates, the lag phase, which occurs before the exponential growth phase, ranged from 8 to 44 h, and the doubling time ranged from 9.8 to 14.1 h (P = 0.0016, ANOVA test). Tachyzoite yield, which combines invasion and proliferation data, was also assessed and confirmed marked differences between the highly and less prolific isolates. Interestingly, a direct correlation between the invasion rates and tachyzoite yields, and the severity of the disease that was exhibited by infected pregnant mice in previous works could be established for the isolates in this study (Spearman's coefficient > 0.62, P < 0.05). The results of this study may help us to explain the differences in the pathogenicity that are displayed by different isolates

Assessment of microproject-based teaching/learning (MicroPBL) experience in industrial engineering degrees

An assessment program to evaluate microproject-based teaching/ learning (MicroPBL) methodology on the technical subject Manufacturing Technology was implemented for four consecutive academic years. Students from three engineering degrees were involved providing feedback through various surveys that allowed us to perform a proper evaluation. More specifically, students' surveys were anonymous after each academic year, except the last one, which included both non-anonymous pre and postsurveys. The polls were mainly meant to evaluate the acquisition of specific competences (using technical questions about the subject) as well as generic ones (using questions concerning soft-skills). Students' satisfaction with the methodology and with the signature, in general, were also checked. Nonanonymous surveys enabled us to study the correlation between polls results and students' final scores. Note that students' self-assessment concerning their knowledge about technical aspects drastically changed after the course. The average final score of this subject from student's perception was slightly higher than the real value. Moreover, student's self-perception on soft-skills increased at the end of the course. In general, the proposed MicroPBL methodology demonstrated a beneficial impact on students of Manufacturing Technology keeping high-motivation levels in students as well as high success rates and scores.Peer reviewe

Data mining teaching throughout cards game competition

[EN] Data-mining techniques and statistical metrics learning can be complicated because of the complexity and overwhelming nature of this field. In this paper a class competition to improve learning of designing Decision Support Systems (DSS) by playing a classic cards game named "Copo" is proposed. The fact that this game is based on a probabilistic problem and that different solutions can be obtained represents a very typical kind of problem in the field of engineering and computer science. During the last four years in which this methodology has been applied to students of Computer Engineering Grade at University of La Rioja, both professors and students h satisfied with the results achieved. The programing of this project was performed in WEKA free software, a data mining suite widely spread in universities and companies. Therefore, not only students learn how to solve stochastic and probabilistic problems, but also the software tools and functions to develop DSS solutions.Antoñanzas-Torres, J.; Urraca, R.; Sodupe-Ortega, E.; Martínez-De-Pison, F.; Pernía-Espinoza, A. (2015). Data mining teaching throughout cards game competition. En 1ST INTERNATIONAL CONFERENCE ON HIGHER EDUCATION ADVANCES (HEAD' 15). Editorial Universitat Politècnica de València. 570-575. https://doi.org/10.4995/HEAd15.2015.333OCS57057

Methodology based on micro-projects in DIY desktop machines for educational purposes in engineering degrees

[EN] The 21st century university has the big educational challenge of how to encourage “a will to learn” in students living in a world saturated with a huge amount of information and distractions. A needed step to keep students motivated is to update their learning environments. Herein we present a proposal with a methodology based on microprojects in DIY desktop machines (MicroP-DIY-DkM). The main idea is to consolidate students’ theoretical background using motivating microprojects in which foreign entities act as petitioners. The students will also receive a broad view of current state of manufacturing technologies. At the same time, English language and Information and Communication Technologies skills can be promoted by our methodology. We provide information about the implementation of several examples of these microprojects, which were applied in the technical subject ‘Manufacturing Technology’. The use of open source DIY-DkM offers students the possibility to understand essential principles of industrial technologies and processes. According to our surveys, students’ scores and success rate results, the methodology proposed demonstrated its convenience to be applied in technical subjects. Students showed greater motivation level and success rate than previous years using conventional methods. Limitation of the proposal and possible means of improvement are also included.Pernia-Espinoza, A.; Sanz-García, A.; Sodupe-Ortega, E.; Antoñanzas-Torres, J.; Antoñanzas-Torres, F.; Urraca-Valle, R. (2016). Methodology based on micro-projects in DIY desktop machines for educational purposes in engineering degrees. En 2nd. International conference on higher education advances (HEAD'16). Editorial Universitat Politècnica de València. 317-325. https://doi.org/10.4995/HEAD16.2015.2731OCS31732