Estudio sobre el rendimiento académico de los alumnos de la Escuela Universitaria de Informática de la Universidad Politécnica de Valencia

Los controles para limitar el acceso a la Universidad, como las pruebas de Selectividad y posterior aplicación de numerus clausus en algunas Facultades y Escuelas Técnicas han conseguido dejar fuera de la Universidad a algunos potenciales alumnos que intentaban cursar una carrera universitaria con unas posibilidades de éxito presuntamente bajas, aunque en algunos casos con una muy alta motivación. En cambio, lo que estos controles no han conseguido es eliminar los altos índices de fracaso académico que aquejan a muchas Facultades y Escuelas Técnicas, ni tampoco impedir que muchos de los alumnos que superaron los límites de acceso iniciales eternicen sus estudios bien porque sólo consiguen superar un número de créditos muy bajo cada año, bien porque ni siquiera se presentan a una elevada proporción de los créditos de los que se matricularon, creando unas “bolsas” de alumnos que sólo lo son en términos administrativos. Ante esta situación, se propone que se incida más en la vía del control del rendimiento y de la permanencia de los alumnos en la Escuela, y menos en la limitación en el número de alumnos de nuevo ingreso

Coherence of the assessment in the subject Physics Foundations on Computer Science

The creation of the European Higher Education Area (EHEA) and the introduction of new university degrees have promoted a new conceptualization and adaptation of the teaching methodology and the consequent and inevitable diversification of the assessment methods. Especially due to the introduction of continuous evaluation, many activities that had no direct influence on the final grade before, contribute now, to a greater or lesser extent, to the final grade. This set of information obtained during the course offers often great differences between them and other qualifications. Some differences are fully justified and other less justifiable. The main aim of this paper is comparing and analyzing results of different evaluation acts obtained by students in the subject Physics Foundations on Computer Science. Our sample includes 170 of 512 enrolled students (37%). Linear fitting of academic data (tests, midterm and laboratory exams) have been compared with admission mark and previous studies at high school, traditionally identified as determinants for later academic performance. Two ad hoc parameters have been defined: the Results Deviation Parameter (RDP) and the Previous Studies Parameter (PSP). The analysis, even though it confirms a significant deviation from the expected ideal/linear result, offers results fairly coherent as well as the pattern of these results and previous academic studies of students.Olmos Sanchis, JJ.; Salandin, A.; Más Estellés, J. (2016). Coherence of the assessment in the subject Physics Foundations on Computer Science. IATED Academy. http://hdl.handle.net/10251/77508

Estudio sobre la heterogeneidad de conocimientos básicos en alumnos de primer curso de universidades politécnicas

El trabajo analiza los resultados de un test relativo a conocimientos básicos de Matemáticas y Física realizado con alumnos de primer curso de la Escuela Universitaria de Informática (EUD y de la Escuela Técnica Superior de Ingenieros de Telecomunicaciones (ETSIT) de la Universidad Politécnica de Valencia, durante los cursos 1996-97 y 1997-98. Los resultados se analizan estableciendo comparaciones según el Centro (EUI y ETSIT) y según procedencia (COU y FP)

Axonal extension from dorsal root ganglia on fibrillar and highly aligned poly(lactic acid)-polypyrrole substrates obtained by two different techniques: Electrospun nanofibres and extruded microfibres

[EN] The biological behaviour of Schwann cells (SCs) and dorsal root ganglia (DRG) on fibrillar, highly aligned and electroconductive substrates obtained by two different techniques is studied. Mats formed by nanometer-sized fibres of poly(lactic acid) (PLA) are obtained by the electrospinning technique, while bundles formed by micrometer-sized extruded PLA fibres are obtained by grouping microfibres together. Both types of substrates are coated with the electrically conductive polymer polypyrrole (PPy) and their morphological, physical and electrical characterization is carried out. SCs on micrometer-sized substrates show a higher motility and cell-cell interaction, while a higher cell-material interaction with a lower cell motility is observed for nanometer-sized substrates. This higher motility and cell-cell interaction of SCs on the micrometer-sized substrates entails a higher axonal growth from DRG, since the migration of SCs from the DRG body is accelerated and, therefore, the SCs tapestry needed for the axonal growth is formed earlier on the substrate. A higher length and area of the axons is observed for these micrometer-sized substrates, as well as a higher level of axonal sprouting when compared with the nanometer-sized ones. These substrates offer the possibility of being electrically stimulated in different tissue engineering applications of the nervous system.The authors acknowledge financing from the Spanish Government's State Research Agency (AEI) through projects DPI2015-72863-EXP and RTI2018-095872-B-C22/ERDF. FGR acknowledges scholarship FPU16/01833 of the Spanish Ministry of Universities. We thank the Electron Microscopy Service at the UPV, where the FESEM images were obtainedGisbert-Roca, F.; Más Estellés, J.; Monleón Pradas, M.; Martínez-Ramos, C. (2020). Axonal extension from dorsal root ganglia on fibrillar and highly aligned poly(lactic acid)-polypyrrole substrates obtained by two different techniques: Electrospun nanofibres and extruded microfibres. International Journal of Biological Macromolecules. 163:1959-1969. https://doi.org/10.1016/j.ijbiomac.2020.09.181S19591969163Houschyar, K. S., Momeni, A., Pyles, M. N., Cha, J. Y., Maan, Z. N., Duscher, D., … Schoonhoven, J. van. (2016). The Role of Current Techniques and Concepts in Peripheral Nerve Repair. Plastic Surgery International, 2016, 1-8. doi:10.1155/2016/4175293Daly, W., Yao, L., Zeugolis, D., Windebank, A., & Pandit, A. (2011). A biomaterials approach to peripheral nerve regeneration: bridging the peripheral nerve gap and enhancing functional recovery. 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Positioning of the cross-stitch on the modified Kessler core tendon suture

[EN] Cryopreserved human tendons were sutured with different variations of a modified Kessler-type grasping suture in a series of different designs in order to assess the influence of the distance between the cross-stitch on the core suture (5 and 10 mm from the cut tendon edge) on the peripheral suture. An original mathematical model was employed to explain the mechanical behavior (strength, deformation, and distribution of load) of the different suture designs. The effect of the peripheral epitendinous suture, combined with the distance of the core suture, was evaluated. The variation of core suture distance had no relevant consequences on the overall resilience of the design. However, increasing the distance between the cross-stitches of the core suture reduces the deformation that is absorbed not only by the core suture itself but also by the peripheral suture. Adding a peripheral epitendinous suture to a 10-mm design almost doubles the breaking load in absolute values. The mathematical model predicts that the peripheral suture will support a greater load when the distance of the core suture cross-stitches is increased. The evidence level is II.Gil Santos, L.; Monleón Pradas, M.; Gomar-Sancho, F.; Más Estellés, J. (2018). Positioning of the cross-stitch on the modified Kessler core tendon suture. Journal of the Mechanical Behavior of Biomedical Materials. 80:27-32. https://doi.org/10.1016/j.jmbbm.2018.01.018S27328

New bioreactor for mechanical stimulation of cultured tendon-like constructs: design and validation.

[EN] Objective: Although several different types of bioreactors are currently available with mechanical stimulation of constructs or prostheses for tendon regeneration, they are in many cases expensive and difficult to operate. This paper proposes a simple bioreactor to mechanically stimulate up to three constructs for tendon and ligament repair, composed of a stainless-steel frame and an electric motor. Methods: The deformation is produced by a cam wheel, whose eccentricity defines the maximum deformation. The test samples, braids of PLA seeded in surface with mouse fibroblasts, are immersed in the culture medium during mechanical stimulation. Results: Its advantages over existing similar bioreactor designs include: easy renewal of the culture medium and an external electric motor to avoid heating and contamination issues. After 14 days of stretching, the culture samples showed enhanced cellular proliferation and cell fiber alignment in addition to higher production of type I collagen. The cells initially seeded on the braid surface migrated to the inside of the braid. Conclusion: Although the results obtained have a poor statistical basis, they do suggest that the bioreactor could be usefully applied to stimulate constructs for tendon and ligament repair. Anyway, further experiments should be conducted in the future.This paper was funded through a researching contract with the Researching Association of the Textil Industries (AITEX, Alcoi, Spain).Araque Monrós, MC.; Gil-Santos, L.; Monleón Pradas, M.; Más Estellés, J. (2020). New bioreactor for mechanical stimulation of cultured tendon-like constructs: design and validation. Expert Review of Medical Devices. 17(10):1115-1121. https://doi.org/10.1080/17434440.2020.1825072111511211710Murray, G. A. W., & Semple, J. C. (1979). 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Tissue Engineering Part B: Reviews, 23(1), 44-58. doi:10.1089/ten.teb.2016.0181Araque Monrós C, Gil Santos L, Gironés Bernabé S, et al. Universitat Politècnica de València. Procedimiento de obtención de una prótesis biodegradable. Patent of invention nº P201130919. 2011.Freeman, J. W., Woods, M. D., & Laurencin, C. T. (2007). Tissue engineering of the anterior cruciate ligament using a braid–twist scaffold design. Journal of Biomechanics, 40(9), 2029-2036. doi:10.1016/j.jbiomech.2006.09.025Laurencin, C. T., & Freeman, J. W. (2005). Ligament tissue engineering: An evolutionary materials science approach. Biomaterials, 26(36), 7530-7536. doi:10.1016/j.biomaterials.2005.05.073Merolli, A., & Joyce, T. J. (Eds.). (2009). Biomaterials in Hand Surgery. doi:10.1007/978-88-470-1195-3Moreau, J. E., Bramono, D. S., Horan, R. L., Kaplan, D. L., & Altman, G. H. (2008). Sequential Biochemical and Mechanical Stimulation in the Development of Tissue-Engineered Ligaments. Tissue Engineering Part A, 14(7), 1161-1172. doi:10.1089/ten.tea.2007.0147Nirmalanandhan, V. S., Rao, M., Shearn, J. T., Juncosa-Melvin, N., Gooch, C., & Butler, D. L. (2008). Effect of scaffold material, construct length and mechanical stimulation on the in vitro stiffness of the engineered tendon construct. Journal of Biomechanics, 41(4), 822-828. doi:10.1016/j.jbiomech.2007.11.009Sumanasinghe, R. D., Osborne, J. A., & Loboa, E. G. (2008). Mesenchymal stem cell‐seeded collagen matrices for bone repair: Effects of cyclic tensile strain, cell density, and media conditions on matrix contraction in vitro. Journal of Biomedical Materials Research Part A, 88A(3), 778-786. doi:10.1002/jbm.a.31913Saber, S., Zhang, A. Y., Ki, S. H., Lindsey, D. P., Smith, R. L., Riboh, J., … Chang, J. (2010). Flexor Tendon Tissue Engineering: Bioreactor Cyclic Strain Increases Construct Strength. Tissue Engineering Part A, 16(6), 2085-2090. doi:10.1089/ten.tea.2010.0032Tohyama, H., & Yasuda, K. (2000). The effects of stress enhancement on the extracellular matrix and fibroblasts in the patellar tendon. Journal of Biomechanics, 33(5), 559-565. doi:10.1016/s0021-9290(99)00217-1Wang, T., Lin, Z., Day, R. E., Gardiner, B., Landao-Bassonga, E., Rubenson, J., … Zheng, M. H. (2013). Programmable mechanical stimulation influences tendon homeostasis in a bioreactor system. Biotechnology and Bioengineering, 110(5), 1495-1507. doi:10.1002/bit.24809Wang, T., Gardiner, B. S., Lin, Z., Rubenson, J., Kirk, T. B., Wang, A., … Zheng, M. H. (2013). Bioreactor Design for Tendon/Ligament Engineering. Tissue Engineering Part B: Reviews, 19(2), 133-146. doi:10.1089/ten.teb.2012.0295Abousleiman, R. I., Reyes, Y., McFetridge, P., & Sikavitsas, V. (2009). Tendon Tissue Engineering Using Cell-Seeded Umbilical Veins Cultured in a Mechanical Stimulator. Tissue Engineering Part A, 15(4), 787-795. doi:10.1089/ten.tea.2008.0102Masuda, T., Takahashi, I., Anada, T., Arai, F., Fukuda, T., Takano-Yamamoto, T., & Suzuki, O. (2008). Development of a cell culture system loading cyclic mechanical strain to chondrogenic cells. Journal of Biotechnology, 133(2), 231-238. doi:10.1016/j.jbiotec.2007.08.007Xu, Z. C., Zhang, W. J., Li, H., Cui, L., Cen, L., Zhou, G. D., … Cao, Y. (2008). Engineering of an elastic large muscular vessel wall with pulsatile stimulation in bioreactor. Biomaterials, 29(10), 1464-1472. doi:10.1016/j.biomaterials.2007.11.037TC-3F Ebers Medical Technology, S.L. [cited 2019 May 15]. Available from: https://ebersmedical.com/tissue-engineering/bioreactors/load-culture/tc-3f-bioreactor.CellScale biomaterials testing. [cited 2020 Mar 16]. Available from: https://cellscale.com/https://www.cellscale.com/products/mct6Lim, W. L., Liau, L. L., Ng, M. H., Chowdhury, S. R., & Law, J. X. (2019). 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Oportunidades de la industria textil en el campo de los biomateriales

Un campo que proporciona nuevas oportunidades a la industria textil es el de la biotecnología en su sentido más amplio; la consecución de prendas con aplicaciones sanitarias para aplicaciones muy específicas es, ya, un campo de investigación abierto. Y dentro de las aplicaciones biotecnológicas, la investigación de materiales biológicamente utilizables es un área que abre múltiples oportunidades a la industria textil.Más Estellés, J.; Rodríguez Hernández, JC.; Gómez Ribelles, JL. (2008). Oportunidades de la industria textil en el campo de los biomateriales. AITEX Review. 27:20-22. http://hdl.handle.net/10251/52664S20222

Tenocytic induction of stem cells from bone marrow on polymeric microparticles for a new concept of tendon regenerative prosthesis

A new concept of a regenerative and resorbable prosthesis for tendon and ligament has been developed. The prosthesis consists of a poly-lactide acid (PLA) braid, microparticles in its interior serving as cell carriers, and a surface non-adherent coating. The aim of this study is to select the most suitable support, microparticles of poly-L-lactide (PLLA) or chitosan (CHT), for carrying the cells inside the hollow PLA braid. Microparticles of these polymers were manufactured and blended with microparticles of hyaluronic acid (HA). All of them were physically and biologically characterized. Cell viability, morphology and proliferation of human mesenchymal stem cells (hMSCs) on the different supports were evaluated and compared, revealing that PLLA microparticles were the most appropriate to be used as injectable cell-carrier. Finally, hMSCs differentiation into tenocytes was carried out on PLLA microparticles using bone morphogenetic protein-12 (BMP-12) and a mixture of transforming growth factor-β1 (TGF-β1) and insulin-like growth factor1 (IGF-1). Cell morphology was analyzed by electronic and confocal microscopy and cell differentiation was evaluated immunocytochemically for the presence of type I collagen and tenomodulin. Besides, the tenomodulin and decorin gene expression were measured by real-time quantitative polymerase chain reaction (RT-qPCR). Our results showed that the medium supplemented with BMP-12 promoted higher expression of tenomodulin and decorin, both of them differentiation markers of tenocytes. This approach might be relevant to future tissue engineering applications in reconstruction of tendon and ligament defects. Authors acknowledge support of the Spanish Instituto de Salud Carlos III through CIBERbbn and the Spanish Network on Cell Therapy (Red TerCel) initiatives.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Study of degradation of a new PLA braided biomnaterial in buffer phosphate saline, basic and acid media, intended for the regeneration of tendons and ligaments

NOTICE: this is the author’s version of a work that was accepted for publication in Polymer Degradation and Stability. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Polymer Degradation and Stability, [Volume 98, Issue 9, September 2013, Pages 1563–1570] DOI 10.1016/j.polymdegradstab.2013.06.031The purpose of this study was to evaluate the effects of hydrolytic degradation on the properties of a PLA hollow braid designed as a new concept of biodegradable prosthesis for the regeneration of tendons and ligaments. The main function of the braided material is to bear mechanical loads while it is being replaced by the newly-generated tissue. The kinetics of braided material degradation is thus an important factor in determining the success of the product. In order to study this mechanism, PLA braid was subjected to a 12-month degradation process at 37 °C in PBS at pH 7.4 (to simulate the human physiological medium) and to accelerated degradation for one month in pH 12 and pH 3 solutions. Degradation of the braid subjected to hydrolysis was evaluated by weight loss, molecular weight distribution, mechanical properties, and calorimetric and morphologic analyses. The weight loss in a basic medium reached 21%, versus no significant change in the other media. Average molecular weight was reduced by approximately 50% in the three media, with loss of mechanical properties in all cases. The morphological changes were more evident in the PLA degraded in the basic medium. The crystallinity of the material increased at the first stages of degradation, regardless of the medium used.This work has been carried out thanks to the financial support of AITEX (Valencia, Spain).Araque Monrós, MC.; Vidaurre, A.; Gil Santos, L.; Gironés Bernabé, S.; Monleón Pradas, M.; Más Estellés, J. (2013). Study of degradation of a new PLA braided biomnaterial in buffer phosphate saline, basic and acid media, intended for the regeneration of tendons and ligaments. Polymer Degradation and Stability. 98(9):1563-1570. doi:10.1016/j.polymdegradstab.2013.06.031S1563157098

BDNF-Gene Transfected Schwann Cell-Assisted Axonal Extension and Sprouting on New PLA-PPy Microfiber Substrates

[EN] The work here reported analyzes the effect of increased efficiency of brainderived neurotrophic factor (BDNF) production by electroporated Schwann cells (SCs) on the axonal extension in a coculture system on a biomaterial platform that can be of interest for the treatment of injuries of the nervous system, both central and peripheral. Rat SCs are electrotransfected with a plasmid coding for the BDNF protein in order to achieve an increased expression and release of this protein into the culture medium of the cells, performing the best balance between the level of transfection and the number of living cells. Gene-transfected SCs show an about 100-fold increase in the release of BDNF into the culture medium, compared to nonelectroporated SCs. Cocultivation of electroporated SCs with rat dorsal root ganglia (DRG) is performed on highly aligned substrates of polylactic acid (PLA) microfibers coated with the electroconductive polymer polypyrrol (PPy). The coculture of DRG with electrotransfected SCs increase both the axonal extension and the axonal sprouting from DRG neurons compared to the coculture of DRG with nonelectroporated SCs. Therefore, the use of PLA¿PPy highly aligned microfiber substrates preseeded with electrotransfected SCs with an increased BDNF secretion is capable of both guiding and accelerating axonal growth.The authors acknowledge financial support from the Spanish Government's State Research Agency (AEI) through projects DPI2015-72863-EXP and RTI2018-095872-B-C22/ERDF. F.G.R. acknowledges the scholarship FPU16/01833 and the short stay mobility aid EST18/00524 of the Spanish Ministry of Universities. F.G.R. also acknowledges the hosting at the Vectorology and Anti-cancer Therapies Centre (UMR 8203 CNRS). The authors thank the Electron Microscopy Service at the UPV, where the FESEM images were obtained.Gisbert-Roca, F.; André, FM.; Más Estellés, J.; Monleón Pradas, M.; Mir, LM.; Martínez-Ramos, C. (2021). BDNF-Gene Transfected Schwann Cell-Assisted Axonal Extension and Sprouting on New PLA-PPy Microfiber Substrates. Macromolecular Bioscience (Online). 21(5):1-13. https://doi.org/10.1002/mabi.202000391S11321