Patterns of Academic Scientific Collaboration at a Distance: Evidence from Southern European Countries

The main objective of this chapter is to examine the trends of academic scientific collaboration (SC) at a distance among public universities located in peripheral countries: Spain, Italy, Greece, and Portugal. The data to capture scientific collaboration consists of a set of co-authored articles published between 2001 and 2010 by universities located in the mentioned Southern countries, indexed by the Science Citation Index expanded (SCI Expanded) of the Information Sciences Institute (ISI) Web of Science (WoS) database. We link this data to institution-level information provided by the EUMIDA dataset. In addition, we retrieved regional data on economic variables from Eurostat. The methodology relies on a descriptive analysis of the evolution of co-publications at different notions of proximity. Our results show a trend toward collaboration over longer distances, although we find heterogeneity by countries and disciplines. Building on our results, we provide some policy implications

Regional scientific production and specialization in Europe. The role of HERD

This paper analyses the effects of R&D expenditure in the higher education sector (HERD) on the scientific production across regions in Europe 15. Our research questions relates to the regional production of science and the role of academic R&D expenditures on regional scientific output. The results show that money affects the production of scientific results in regions. On average, we found different impacts and lags of R&D expenditure according to the level of regional development. Our findings also suggest that scientific specialization is a significant factor affecting scientific outputs, although its effects differ across disciplines and regions.Support for this research was provided in part from the Junta de Andalucía (Grant P08-SEJ-03981)

Thermal expansivity and degradation properties of PLA/HA and PLA/ bTCP in vitro conditioned composites

[EN] The objective of this study was to investigate the thermal expansivities and degradation properties for several in vitro conditioned biodegradable poly(lactic acid)/hydroxyapatite (PLA/HA) and poly(lactic acid)/b-tricalcium phosphate (PLA/ bTCP) composites with different mass% of the particle reinforcements (i.e. 10, 20 and 30). The samples were prepared by extrusion followed by injection moulding and incubated in a customized simulated body fluid at 37 C over 60, 90, 120, 150 and 180 days, respectively. Thermal expansion and degradation properties of in vitro conditioned samples, along with dynamic mechanical properties of unconditioned ones, were systematically investigated through coefficients of linear thermal expansion and thermal strain changes, decomposition temperatures, mass changes and per cent residues. The results indicated that PLA/bTCP composites performed better than PLA/HA composites, irrespective of their filler mass%, revealing high values of glass transition temperatures, around a mean value of 65 C, both on dynamic mechanical analysis and on dilatation measurements but lower values on their degradation temperatures, such as 360 C. The results suggest the feasibility of tailoring high-loaded osteoconductive fillers-reinforced PLA composites for various medical and engineering applications.Ferri, JM.; Motoc, DL.; Ferrándiz Bou, S.; Balart, R. (2019). Thermal expansivity and degradation properties of PLA/HA and PLA/ bTCP in vitro conditioned composites. Journal of Thermal Analysis and Calorimetry (Online). 138(4):2691-2702. https://doi.org/10.1007/s10973-019-08799-0S269127021384Auras R, Lim LT, Selke S, Tsuji H. Poly(lactic acid): structures, production, synthesis, and applications. New York: Wiley; 2010.Murariu M, Dubois P. PLA composites: from production to properties. Adv Drug Deliv Rev. 2016;107:17–46.Haaparanta A-M, Haimi S, Ellä V, Hopper N, Miettinen S, Suuronen R, et al. Porous polylactide/β-tricalcium phosphate composite scaffolds for tissue engineering applications. J Tissue Eng Regen Med. 2010;4(5):366–73.Ahmed J, Varshney SK. Polylactides—chemistry, properties and green packaging technology: a review. Int J Food Prop. 2011;14(1):37–58.Garlotta D. A literature review of poly(lactic acid). J Polym Environ. 2001;9(2):63–84.Slomkowski S, Penczek S, Duda A. Polylactides—an overview. Polym Adv Technol. 2014;25(5):436–47.Avinc O, Khoddami A. Overview of poly(lactic acid) (PLA) fibre. Fibre Chem. 2009;41(6):391–401.Akindoyo JO, Beg MDH, Ghazali S, Heim HP, Feldmann M. Impact modified PLA-hydroxyapatite composites—thermo-mechanical properties. Compos A Appl Sci Manuf. 2018;107:326–33.Nazhat SN, Kellomäki M, Törmälä P, Tanner KE, Bonfield W. Dynamic mechanical characterization of biodegradable composites of hydroxyapatite and polylactides. J Biomed Mater Res. 2001;58(4):335–43.Ignjatovic N, Uskokovic D. Synthesis and application of hydroxyapatite/polylactide composite biomaterial. Appl Surf Sci. 2004;238(1):314–9.Li J, Zheng W, Li L, Zheng Y, Lou X. Thermal degradation kinetics of g-HA/PLA composite. Thermochim Acta. 2009;493(1):90–5.Zhang SM, Liu J, Zhou W, Cheng L, Guo XD. Interfacial fabrication and property of hydroxyapatite/polylactide resorbable bone fixation composites. Curr Appl Phys. 2005;5(5):516–8.Akindoyo JO, Beg MDH, Ghazali S, Heim HP, Feldmann M. Effects of surface modification on dispersion, mechanical, thermal and dynamic mechanical properties of injection molded PLA-hydroxyapatite composites. Compos A Appl Sci Manuf. 2017;103:96–105.Kang Y, Yao Y, Yin G, Huang Z, Liao X, Xu X, et al. A study on the in vitro degradation properties of poly(l-lactic acid)/β-tricalcuim phosphate(PLLA/β-TCP) scaffold under dynamic loading. Med Eng Phys. 2009;31(5):589–94.Huang J, Ten E, Liu G, Finzen M, Yu W, Lee JS, et al. Biocomposites of pHEMA with HA/β-TCP (60/40) for bone tissue engineering: swelling, hydrolytic degradation, and in vitro behavior. Polymer. 2013;54(3):1197–207.Bleach NC, Nazhat SN, Tanner KE, Kellomäki M, Törmälä P. Effect of filler content on mechanical and dynamic mechanical properties of particulate biphasic calcium phosphate—polylactide composites. Biomaterials. 2002;23(7):1579–85.Ferri J, Gisbert I, García-Sanoguera D, Reig M, Balart R. The effect of beta-tricalcium phosphate on mechanical and thermal performances of poly(lactic acid). J Compos Mater. 2016;50(30):4189–98.Li X, Qi C, Han L, Chu C, Bai J, Guo C, et al. Influence of dynamic compressive loading on the in vitro degradation behavior of pure PLA and Mg/PLA composite. Acta Biomater. 2017;64:269–78.Agrawal CM, McKinney JS, Lanctot D, Athanasiou KA. Effects of fluid flow on the in vitro degradation kinetics of biodegradable scaffolds for tissue engineering. Biomaterials. 2000;21(23):2443–52.Kikuchi M, Koyama Y, Takakuda K, Miyairi H, Shirahama N, Tanaka J. In vitro change in mechanical strength of β-tricalcium phosphate/copolymerized poly-L-lactide composites and their application for guided bone regeneration. J Biomed Mater Res. 2002;62(2):265–72.Lim LT, Auras R, Rubino M. Processing technologies for poly(lactic acid). Prog Polym Sci. 2008;33(8):820–52.Ignjatovic N, Suljovrujic E, Budinski-Simendic J, Krakovsky I, Uskokovic D. Evaluation of hot-pressed hydroxyapatite/poly-L-lactide composite biomaterial characteristics. J Biomed Mater Res B Appl Biomater. 2004;71B(2):284–94.Martin C. Twin screw extrusion for pharmaceutical processes. In: Repka MA, Langley N, DiNunzio J, editors. Melt extrusion: materials, technology and drug product design. New York: Springer; 2013. p. 47–79.Cox SC, Thornby JA, Gibbons GJ, Williams MA, Mallick KK. 3D printing of porous hydroxyapatite scaffolds intended for use in bone tissue engineering applications. Mater Sci Eng C. 2015;47:237–47.Corcione C, Scalera F, Gervaso F, Montagna F, Sannino A, Maffezzoli A. One-step solvent-free process for the fabrication of high loaded PLA/HA composite filament for 3D printing. J Therm Anal Calorim. 2018;134:1–8.Siqueira L, Passador FR, Costa MM, Lobo AO, Sousa E. Influence of the addition of β-TCP on the morphology, thermal properties and cell viability of poly (lactic acid) fibers obtained by electrospinning. Mater Sci Eng C. 2015;52:135–43.Drummer D, Cifuentes-Cuéllar S, Rietzel D. Suitability of PLA/TCP for fused deposition modeling. Rapid Prototyp J. 2012;18(6):500–7.Ferri J, Jordá J, Montanes N, Fenollar O, Balart R. Manufacturing and characterization of poly(lactic acid) composites with hydroxyapatite. J Thermoplast Compos Mater. 2018;31(7):865–81.Menczel JD, Prime RB. Thermal analysis of polymers: fundamentals and applications. New York: Wiley; 2014.Aboudi J, Arnold SM, Bednarcyk BA. Chapter 3—fundamentals of the mechanics of multiphase materials. In: Aboudi J, Arnold SM, Bednarcyk BA, editors. Micromechanics of composite materials. Oxford: Butterworth-Heinemann; 2013. p. 87–145.Esposito Corcione C, Gervaso F, Scalera F, Padmanabhan SK, Madaghiele M, Montagna F, et al. Highly loaded hydroxyapatite microsphere/PLA porous scaffolds obtained by fused deposition modelling. Ceram Int. 2018;45:2803–10.Zou H, Yi C, Wang L, Liu H, Xu W. Thermal degradation of poly(lactic acid) measured by thermogravimetry coupled to Fourier transform infrared spectroscopy. J Therm Anal Calorim. 2009;97(3):929.Schindler A, Doedt M, Gezgin Ş, Menzel J, Schmölzer S. Identification of polymers by means of DSC, TG, STA and computer-assisted database search. J Therm Anal Calorim. 2017;129(2):833–42.Lee WA, Knight GJ. Ratio of the glass transition temperature to the melting point in polymers. Br Polym J. 1970;2(1):73–80

Validation of the Use of SEBS Blends as a Substitute for Liquid Silicone Rubber in Injection Processes

Liquid silicone rubber is an interesting material at an industrial level, but there are great difficulties in the design and machining of molds, and in addition, it cannot be processed using conventional equipment. Therefore, new lines of research have focused on the search for new materials capable of providing final properties similar to liquid silicone rubber, that can also be engineered using simple, conventional processes and machinery. In this investigation, a range of compatible blends, based on two commercial grades of styrene-b-ethyleneco- butylene-b-styrene (SEBS) thermoplastic elastomer, was studied in order to obtain a range of different Shore A hardness blends for industrial applications where liquid silicone rubber (different hardness) is currently used. The two blended elastomers used had widely differing Shore A hardness values (5 and 90). Once the blended materials had been characterized, the Cross and Williams et al. [20] (Cross-WLF) mathematical model was applied in order to obtain theoretical performance curves for the viscosity of each of the blends. After this, a model was developed using the Computer Aided Engineering (CAE) software package Autodesk Moldflow 2012TM. This computer modeling validated the results obtained from the mathematical models, thus making available to process engineers the full range of hardnesses necessary for industrial products (where liquid silicone rubber is used), while still providing the advantages of thermoplastic injection molding.The authors wish to thank "Ministerio de Ciencia e Innovacion" IPT-310000-2010-37 and Universidad Politecnica de Valencia PAID 10012 for their financial support.Juárez Varón, D.; R. Balart; T. Boronat; Reig Pérez, MJ.; Ferrándiz Bou, S. (2013). Validation of the Use of SEBS Blends as a Substitute for Liquid Silicone Rubber in Injection Processes. Materials and Manufacturing Processes. 28(11):1215-1221. doi:10.1080/10426914.2013.811732S121512212811Zhang, B., Wong, J. S.-P., Shi, D., Yam, R. C.-M., & Li, R. K.-Y. (2010). Investigation on the mechanical performances of ternary nylon 6/SEBS elastomer/nano-SiO2hybrid composites with controlled morphology. Journal of Applied Polymer Science, 115(1), 469-479. doi:10.1002/app.30185Su, F.-H., & Huang, H.-X. (2009). Mechanical and rheological properties of PP/SEBS/OMMT ternary composites. Journal of Applied Polymer Science, 112(5), 3016-3023. doi:10.1002/app.29875Sugimoto, M., Sakai, K., Aoki, Y., Taniguchi, T., Koyama, K., & Ueda, T. (2009). Rheology and morphology change with temperature of SEBS/hydrocarbon oil blends. Journal of Polymer Science Part B: Polymer Physics, 47(10), 955-965. doi:10.1002/polb.21699Jose, A. J., Alagar, M., & P. Thomas, S. (2012). Preparation and Characterization of Organoclay Filled Polysulfone Nanocomposites. Materials and Manufacturing Processes, 27(3), 247-254. doi:10.1080/10426914.2011.585490Ivanović, N., Marjanović, N., Grbović Novaković, J., Manasijević, M., Rakočević, Z., Andrić, V., & Hadžić, B. (2009). Experimental and Theoretical Investigations of Cured and Uncured Disiloxane Bisbenzocyclobutene Thin Films. Materials and Manufacturing Processes, 24(10-11), 1180-1184. doi:10.1080/10426910902978811Perisić, M., Radojević, V., Uskoković, P. S., Stojanović, D., Jokić, B., & Aleksić, R. (2009). Wood–Thermoplastic Composites Based on Industrial Waste and Virgin High-Density Polyethylene (HDPE). Materials and Manufacturing Processes, 24(10-11), 1207-1213. doi:10.1080/10426910903032212Iqbal, H., Sheikh, A. K., Al-Yousef, A., & Younas, M. (2012). Mold Design Optimization for Sand Casting of Complex Geometries Using Advance Simulation Tools. Materials and Manufacturing Processes, 27(7), 775-785. doi:10.1080/10426914.2011.648250Özek, C., & Çelık, Y. H. (2011). Calculating Molding Parameters in Plastic Injection Molds with ANN and Developing Software. Materials and Manufacturing Processes, 27(2), 160-168. doi:10.1080/10426914.2011.560224Hirschmanner, M., Mörwald, K., & Fröhlich, C. (2011). Next Generation Mold Level Control: Development of LevCon 2.0. Materials and Manufacturing Processes, 26(1), 169-174. doi:10.1080/10426910903206691Selvakumar, P., & Bhatnagar, N. (2009). Studies on Polypropylene/Carbon Fiber Composite Foams by Nozzle-Based Microcellular Injection Molding System. Materials and Manufacturing Processes, 24(5), 533-540. doi:10.1080/10426910902742738Gramegna, N., Corte, E. D., & Poles, S. (2011). Manufacturing Process Simulation for Product Design Chain Optimization. Materials and Manufacturing Processes, 26(3), 527-533. doi:10.1080/10426914.2011.564248Marković, G., Radovanović, B., Marinović-Cincović, M., & Budinski-Simendić, J. (2009). The Effect of Accelerators on Curing Characteristics and Properties of Natural Rubber/Chlorosulphonated Polyethylene Rubber Blend. Materials and Manufacturing Processes, 24(10-11), 1224-1228. doi:10.1080/10426910902967087Mehat, N. M., & Kamaruddin, S. (2011). Investigating the Effects of Injection Molding Parameters on the Mechanical Properties of Recycled Plastic Parts Using the Taguchi Method. Materials and Manufacturing Processes, 26(2), 202-209. doi:10.1080/10426914.2010.529587Chen, C.-C., Su, P.-L., Chiou, C.-B., & Chiang, K.-T. (2011). Experimental Investigation of Designed Parameters on Dimension Shrinkage of Injection Molded Thin-Wall Part by Integrated Response Surface Methodology and Genetic Algorithm: A Case Study. Materials and Manufacturing Processes, 26(3), 534-540. doi:10.1080/10426914.2010.530331Martinez, A., Castany, J., & Aisa, J. (2011). Characterization of In-Mold Decoration Process and Influence of the Fabric Characteristics in This Process. Materials and Manufacturing Processes, 26(9), 1164-1172. doi:10.1080/10426914.2010.536934Primo Benitez-Rangel, J., Trejo-Hernández, M., Alberto Morales-Hernández, L., & Domínguez-González, A. (2010). Improvement of the Injection Mold Process by Using Vibration Through a Mold Accessory. Materials and Manufacturing Processes, 25(7), 577-580. doi:10.1080/10426910903124902Chen, C.-C. (2011). Design of Effective Parameters on the Wick-Debinding Process for Powder Injection Molded Green Compact. Materials and Manufacturing Processes, 26(10), 1261-1268. doi:10.1080/10426914.2010.544826Boronat, T., Segui, V. J., Peydro, M. A., & Reig, M. J. (2009). Influence of temperature and shear rate on the rheology and processability of reprocessed ABS in injection molding process. Journal of Materials Processing Technology, 209(5), 2735-2745. doi:10.1016/j.jmatprotec.2008.06.013Cross, M. M. (1965). Rheology of non-Newtonian fluids: A new flow equation for pseudoplastic systems. Journal of Colloid Science, 20(5), 417-437. doi:10.1016/0095-8522(65)90022-xReig, M. J., Segui, V. J., & Zamanillo, J. D. (2005). Rheological Behavior Modeling of Recycled ABS/PC Blends Applied to Injection Molding Process. Journal of Polymer Engineering, 25(5). doi:10.1515/polyeng.2005.25.5.43

HCT116 cells deficient in p21Waf1 are hypersensitive to tyrosine kinase inhibitors and adriamycin through a mechanism unrelated to p21 and dependent on p53

El pdf del artículo es la versión de autor.-- et al.p21Waf1 (p21) was described as a cyclin-dependent kinase inhibitor, but other p21 activities have subsequently been described, including its ability to inhibit apoptosis in some models. Comparative work on the human colon cancer isogenic cell lines HCT116 and HCT116p21-/- led to the proposal that p21 protects colon cancer cells against apoptosis by genotoxic drugs. We asked whether p21 also protected from cell death induced by non-genotoxic drugs, such as tyrosine kinase inhibitors. We found that p21-deficient cells were dramatically more sensitive towards imatinib and gefitinib than parental cells. Interestingly, HCT116p21-/- also showed higher basal activity of protein kinases as c-Abl, c-Src, and Akt. We generated HCT116p21-/- sublines with inducible p21 expression and found that p21 did not rescue the hypersensitivity to imatinib. Moreover, down-regulation of p21 by enforced c-Myc expression or by p21 siRNA did not sensitize parental HCT116 cells. We found that, in HCT116p21-/- cells, p53 showed higher stability, higher transcriptional activity and phosphorylation in serines associated with p53 activity. Furthermore, silencing of p53 with siRNA and inactivation of p53 with a dominant negative mutant rescued the hypersensitive response to kinases inhibitors, 5-fluorouracil and adriamycin in HCT116p21-/- cells. Consistently, HCT116p53-/- cells are more resistant to imatinib than parental cells, suggesting that imatinib activity is partly dependent on p53 in colon cancer cells. We conclude that high p53 activity, rather than p21 deficiency, is the mechanism responsible for hypersensitivity to drugs of HCT116p21-/- cells. Therefore the role of p21 on apoptosis of HCT116 colon cancer cells should be re-evaluated. © 2008 Elsevier B.V. All rights reserved.N.F. is funded by a predoctoral fellowship from the Spanish Ministry of Education and Science (MEC) and from the University of Cantabria. Work at the laboratory of J.L. is funded by MEC grants SAF2005-00461 and Spanish Ministry of Health and Consume (MSC) grant ISCIII-RETIC-RD06/0020. M.D.D. is funded by MSC grant FIS04-1083, and J.M.P. is funded by grants from Fundación de Investigación Médica Mutua Madrileña and MEC grant SAF2006-00371.Peer Reviewe

Macroeconomics in practice: using WIKIS for collaborative learning

This project is based on the creation of collaborative wikis for students of Macroeconomics to elaborate a final work in which they apply the theoretical knowledge learnt in the subject to the real world. The initiative was implemented during the course 2015-2016 and aimed at 140 students enrolled in the subject at the Degree of Finance and Accountancy of the University of Cadiz. To emphasize the link between the theories explained in class and the real world, in previous courses we have already used news and other resources. With this project, we now introduce the use of wikis, which consist on the creation of a website to allow collaborative creation and modification of contents and structure from the web browser. Students were organized in 44 teams, of about 3 members, to examine data on a certain macroeconomic variable (i.e. inflation or GDP), in a particular geographical context (i.e. G20 or EU countries). The objectives of the project include: i) to enhance learning and comprehension of theoretical knowledge and ii) to contribute to the development of skills related to the subject, such as the skill to apply the acquired knowledge, the skill to analyze and search information and teamwork. Students’ opinions gathered from a survey at the end of the course suggest that these objectives have been achieved

Antiapoptotic proteins Bcl2 and BclX do not protect chronic myeloid leukemia cells from imatinib-mediated growth arrest

Imatinib (Glivec, Gleevec, STI571), a Bcr-Abl kinase inhibitor, is the most used drug in chronic myeloid leukemia. Imatinib induces apoptosis in a number of CML-derived cell lines, including K562. However, in order to achieve hematological remissions it is required chronic treatment with the drug, a fact inconsistent with a cytotoxic mechanism of imatinib in vivo. In this work we have analysed the effects of imatinib on the proliferation and apoptosis of K562-derived cell lines with constitutive expression of the anti-apoptotic genes Bcl2 and BclX. We found that imatinib-mediated apoptosis was completely abrogated in both Bcl2- and BclX-cell lines. However, imatinib inhibited proliferation, although growth rate was higher than in parental K562. We conclude that, besides its apoptotic effect, imatinib acts through an apoptosis-independent mechanism to arrest cell growth.The work was supported by grant PM98-0109 and SAF2002-04193 from Spanish Ministry of Science and Technology to J.L.Peer Reviewe

Failure analysis of a plastic modular belt in-service

[EN] In this study, an analysis of the possible causes of the failure in-service of a section of a plastic modular belt was conducted. The study begins with a reproduction of the service conditions in a traction gear. An analysis of the fracture surfaces revealed the existence of defects in the interior of the parts. With the aim of determining the origin of the imperfections and their influence on the failure, an exhaustive mechanical and rheological characterization of the material was carried out. The development of an FE Analysis established that the reduction of the tensile strength of the part due to internal defects was around 70%. Tests also showed that the most stressed area was the area where the most defects appeared. A simulation of the injection process showed that the defects are caused by the geometry of the part, leading to the conclusion that its failure was caused by bad dimensioning of thicknesses.Sanchez-Caballero, S.; Sellés Cantó, MÁ.; Ferrándiz Bou, S.; Peydro, MA.; Oliver, B. (2018). Failure analysis of a plastic modular belt in-service. Engineering Failure Analysis. 93:13-25. https://doi.org/10.1016/j.engfailanal.2018.06.019S13259