Electrochemical characterization of hybrid flexible and bioresorbable hydrogels

Actualment, el món de l'enginyeria biomèdica aposta molt per la branca de l'enginyeria de teixits, no tant perquè ha estat poc estudiada sinó també per l'ampli ventall de possibilitats que ens pot oferir. En un esforç per desenvolupar aquesta branca, el grup de recerca IMEM (Innovació en Materials i Enginyeria Molecular) de la Universitat Politècnica de Catalunya pretén aplicar aquests coneixements al desenvolupament de polímers conductors biodegradables i flexibles per obtenir sensors flexibles, biocompatibles i bioresorbibles. Els elèctrodes dels sensors de corrent estan fets majoritàriament de materials metàl·lics que, tot i que són adequats per les seves propietats conductores, els metalls no tenen propietats físiques semblants a les dels teixits vius d'un organisme. Aquesta és una de les raons per les quals aquest projecte se centra en el desenvolupament d'un elèctrode basat en hidrogel per utilitzar-lo en un sensor implantable. Aquest treball de fi de grau es centra en dues parts fonamentals: La primera part se centrarà a desenvolupar i fabricar els diferents hidrogels que es volen estudiar com a possibles candidats per utilitzar-los com a elèctrodes per a sensors implantables. La segona part estarà destinada a caracteritzar aquests hidrogels desenvolupats. Aquesta part, que forma la majoria d'aquest projecte, pretén determinar la funcionalitat a llarg termini d'aquests hidrogels en un entorn in vitro. En aquesta caracterització es realitzaran assaigs per determinar les seves propietats de conductivitat i degradabilitat, així com l'estudi de les seves diferències d'estructura.Actualmente, el mundo de la ingeniería biomédica está apostando fuerte por la rama de la ingeniería de tejidos, no tanto porque haya sido poco estudiada sino también por el amplio abanico de posibilidades que nos puede ofrecer. En un esfuerzo por desarrollar esta rama, el grupo de investigación IMEM (Innovación en Materiales e Ingeniería Molecular) de la Universitat Politècnica de Catalunya pretende aplicar este conocimiento al desarrollo de polímeros conductores biodegradables y flexibles para obtener sensores flexibles, biocompatibles y biorreabsorbibles. Los electrodos de los sensores de corriente están hechos en su mayoría de materiales metálicos que, aunque adecuados por sus propiedades conductoras, los metales no tienen propiedades físicas muy similares a las de los tejidos vivos de un organismo. Esta es una de las razones por las que este proyecto se centra en el desarrollo de un electrodo a base de hidrogel para su uso en un sensor implantable. Este trabajo de fin de grado se centra en dos partes fundamentales: La primera parte se centrará en el desarrollo y la fabricación de varios hidrogeles destinados a ser estudiados como posibles candidatos para su uso como electrodos para sensores implantables. La segunda parte estará encaminada a caracterizar estos hidrogeles desarrollados. Esta parte, que constituye la mayor parte de este proyecto, tiene como objetivo determinar la funcionalidad a largo plazo de estos hidrogeles en un entorno in vitro. En esta caracterización se realizarán ensayos para determinar sus propiedades conductivas y degradables, así como un estudio de sus diferencias estructurales.Currently, the world of biomedical engineering is betting heavily on the branch of tissue engineering, not so much because it has been little studied but also because of the wide range of possibilities it can offer us. In an effort to develop this branch, the IMEM (Innovation in Materials and Molecular Engineering) research group of the Universitat Politècnica de Catalunya aims to apply this knowledge to the development of biodegradable and flexible conductive polymers to obtain flexible, biocompatible and bioresorbable sensors. The electrodes of current sensors are mostly made of metallic materials which, although suitable for their conductive properties, metals do not have physical properties quite similar to those of the living tissues of an organism. This is one of the reasons why this project focuses on the development of an electrode based on hydrogel for use in an implantable sensor. This final degree thesis project focuses on two fundamental parts: The first part will focus on developing and fabricating the various hydrogels intended to be studied as possible candidates for use as electrodes for implantable sensors. The second part will be aimed at characterizing these developed hydrogels. This part, which forms the majority of this project, aims to determine the long-term functionality of these hydrogels in an in vitro environment. In this characterization, tests will be carried out to determine its conductive and degradability properties as well as a study of their structure differences

On the Use of Gallic Acid as a Potential Natural Antioxidant and Ultraviolet Light Stabilizer in Cast-Extruded Bio-Based High-Density Polyethylene Films

This study originally explores the use of gallic acid (GA) as a natural additive in bio-based high-density polyethylene (bio-HDPE) formulations. Thus, bio-HDPE was first melt-compounded with two different loadings of GA, namely 0.3 and 0.8 parts per hundred resin (phr) of biopolymer, by twin-screw extrusion and thereafter shaped into films using a cast-roll machine. The resultant bio-HDPE films containing GA were characterized in terms of their mechanical, morphological, and thermal performance as well as ultraviolet (UV) light stability to evaluate their potential application in food packaging. The incorporation of 0.3 and 0.8 phr of GA reduced the mechanical ductility and crystallinity of bio-HDPE, but it positively contributed to delaying the onset oxidation temperature (OOT) by 36.5 °C and nearly 44 °C, respectively. Moreover, the oxidation induction time (OIT) of bio-HDPE, measured at 210 °C, was delayed for up to approximately 56 and 240 min, respectively. Furthermore, the UV light stability of the bio-HDPE films was remarkably improved, remaining stable for an exposure time of 10 h even at the lowest GA content. The addition of the natural antioxidant slightly induced a yellow color in the bio-HDPE films and it also reduced their transparency, although a high contact transparency level was maintained. This property can be desirable in some packaging materials for light protection, especially UV radiation, which causes lipid oxidation in food products. Therefore, GA can successfully improve the thermal resistance and UV light stability of green polyolefins and will potentially promote the use of natural additives for sustainable food packaging applications

Millora del hardware dels UAVs utilitzats per combatre les plagues de llagosta al desert

El present document i projecte té l’objectiu de continuar amb el desenvolupament d’un sistema basat amb l’actual tecnologia UAV (Unnamed aerial vehicle) amb la qual oferir una eina actualitzada per la lluita contra les plagues de llagosta. Les plagues de llagosta amenacen els recursos agrícoles els quals són la base de la subsistència humana i animal, estem parlant dels cultius, camps de pastura, muntanyes, entre altres. És una de les plagues més crítiques i nocives, ja que tenen la capacitat de desplaçar-se per aire fins a 150 km per dia a part de poder travessar oceans com l’Atlàntic. La metodologia emprada és l’ús de plataformes UAVs. Aquesta tecnologia està demostrant ser una de les puntes de llança en l’àmbit tecnològic en moltes àrees, disciplines i indústries gràcies a la seva versatilitat i accessibilitat. El plantejament d’aquest projecte és la continuació dels anteriors treballs per a obtenir una solució més eficaç i avantguardista en els UAVs utilitzats actualment per a combatre les plagues de llagosta. Tots els recursos emprats que engloben el desenvolupament de les plataformes en l’àmbit tècnic i operacional han estat prestades per l’empresa HEMAV, l’operadora número 1 d’UAV a Espanya. Finalment es pot observar que entre els mètodes utilitzats en un principi i els utilitzats en les últimes operacions, hi ha un salt considerable tant en l’àmbit tecnològic com en l’àmbit de recursos humans en els mètodes emprats i les solucions que s’estan començant a dur a terme. On l’objectiu d’aquest TFG és poder seguir contribuint en aquests avenços per combatre aquesta causa

A novel sigma factor reveals a unique regulon controlling cell-specific recombination in Mycoplasma genitalium

The Mycoplasma genitalium MG428 protein shows homology to members of the sigma-70 family of sigma factors. Herein, we found that MG428 activates transcription of recA, ruvA and ruvB as well as several genes with unknown function. Deletion of MG_428 or some of the up-regulated unknown genes led to severe recombination defects. Single cell analyses revealed that activation of the MG428-regulon is a rare event under laboratory growth conditions. A conserved sequence with sigma-70 promoter architecture (TTGTCA-N-ATTWAT) was identified in the upstream region of all of the MG428-regulated genes or operons. Primer extension analyses demonstrated that transcription initiates immediately downstream of this sigma70-type promoter in a MG428-dependent manner. Furthermore, mutagenesis of the conserved −10 and −35 elements corroborated the requirement of these regions for promoter function. Therefore, a new mycoplasma promoter directs transcription of a unique recombination regulon. Additionally, MG428 was found to interact with the RNAP core enzyme, reinforcing the predicted role of this protein as an alternative sigma factor. Finally, our results indicate that MG428 contributes to the generation of genetic diversity in this model organism. Since recombination is an important mechanism to generate antigenic variation, MG428 emerges as a novel factor contributing to M. genitalium virulence

Spark deployment and performance evaluation on the MareNostrum supercomputer

In this paper we present a framework to enable data-intensive Spark workloads on MareNostrum, a petascale supercomputer designed mainly for compute-intensive applications. As far as we know, this is the first attempt to investigate optimized deployment configurations of Spark on a petascale HPC setup. We detail the design of the framework and present some benchmark data to provide insights into the scalability of the system. We examine the impact of different configurations including parallelism, storage and networking alternatives, and we discuss several aspects in executing Big Data workloads on a computing system that is based on the compute-centric paradigm. Further, we derive conclusions aiming to pave the way towards systematic and optimized methodologies for fine-tuning data-intensive application on large clusters emphasizing on parallelism configurations.Peer ReviewedPostprint (author's final draft

Avaluació de la presència d'organismes entomopatògens (nematodes i fongs) a sòls d'avellaners amb diferents tipus de producció

El present estudi pertinent a una fase inicial d'un projecte d'investigació del Ministeri d'Educació i Ciència que es porta a terme al Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia (BABVE) de la Universitat Autònoma de Barcelona amb col·laboració del Departament d'Agricultura, Alimentació i Acció Rural de la Generalitat de Catalunya anomenat "Control biològic del diabló de l'avellaner, Curculio nucum L. (Coleoptera, Curculionidae) mitjançant organismes entomopatògens (nematodes i fongs)", es basa en la recerca d'organismes autòctons en els camps d'avellaners que un cop aïllats i caracteritzats puguin ser utilitzats com a insecticides biològics pel control de la plaga clau que afecta els avellaners de Catalunya, el diabló de l'avellaner (Curculio nucum L.). Aquest insecte, pertanyent a la família dels coleòpters presenta una àmplia distribució a l'Europa temperada i septentrional, essent especialment abundant a Espanya, Itàlia i Turquia

Urban data and urban design: A data mining approach to architecture education

The configuration of urban projects using Information and Communication Technologies is an essential aspect in the education of future architects. Students must know the technologies that will facilitate their academic and professional development, as well as anticipating the needs of the citizens and the requirements of their designs. In this paper, a data mining approach was used to outline the strategic requirements for an urban design project in an architecture course using a Project-Based Learning strategy. Informal data related to an award-winning public space (Gillett Square in London, UK) was retrieved from two social networks (Flickr and Twitter), and from its official website. The analysis focused on semantic, temporal and spatial patterns, aspects generally overlooked in traditional approaches. Text-mining techniques were used to relate semantic and temporal data, focusing on seasonal and weekly (work-leisure) cycles, and the geographic patterns were extracted both from geotagged pictures and by geocoding user locations. The results showed that it is possible to obtain and extract valuable data and information in order to determine the different uses and architectural requirements of an urban space, but such data and information can be challenging to retrieve, structure, analyze and visualize. The main goal of the paper is to outline a strategy and present a visualization of the results, in a way designed to be attractive and informative for both students and professionals - even without a technical background - so the conducted analysis may be reproducible in other urban data contexts.Postprint (author's final draft

Development of Sustainable and Cost-Competitive Injection-Molded Pieces of Partially Bio-Based Polyethylene Terephthalate through the Valorization of Cotton Textile Waste

[EN] This study presents the valorization of cotton waste from the textile industry for the development of sustainable and cost-competitive biopolymer composites. The as-received linter of recycled cotton was first chopped to obtain short fibers, called recycled cotton fibers (RCFs), which were thereafter melt-compounded in a twin-screw extruder with partially bio-based polyethylene terephthalate (bio-PET) and shaped into pieces by injection molding. It was observed that the incorporation of RCF, in the 1¿10 wt% range, successfully increased rigidity and hardness of bio-PET. However, particularly at the highest fiber contents, the ductility and toughness of the pieces were considerably impaired due to the poor interfacial adhesion of the fibers to the biopolyester matrix. Interestingly, RCF acted as an effective nucleating agent for the bio-PET crystallization and it also increased thermal resistance. In addition, the overall dimensional stability of the pieces was improved as a function of the fiber loading. Therefore, bio-PET pieces containing 3¿5 wt% RCF presented very balanced properties in terms of mechanical strength, toughness, and thermal resistance. The resultant biopolymer composite pieces can be of interest in rigid food packaging and related applications, contributing positively to the optimization of the integrated biorefinery system design and also to the valorization of textile wastes.This research was supported by the Ministry of Science, Innovation, and Universities (MICIU) through the AGL2015-63855-C2-1-R and MAT2017-84909-C2-2-R program numbers. L.Q.-C. wants to thank the Generalitat Valenciana (GVA) for his FPI grant (ACIF/2016/182) and the Spanish Ministry of Education, Culture, and Sports (MECD) for his FPU grant (FPU15/03812). S.T.-G. is a recipient of a Juan de la Cierva Incorporación contract (IJCI-2016-29675) from MICIU.Montava-Jordà, S.; Torres-Giner, S.; Ferrándiz Bou, S.; Quiles-Carrillo, L.; Montanes, N. (2019). Development of Sustainable and Cost-Competitive Injection-Molded Pieces of Partially Bio-Based Polyethylene Terephthalate through the Valorization of Cotton Textile Waste. International Journal of Molecular Sciences. 20(6):1-19. https://doi.org/10.3390/ijms20061378S119206Tharanathan, R. . (2003). Biodegradable films and composite coatings: past, present and future. Trends in Food Science & Technology, 14(3), 71-78. doi:10.1016/s0924-2244(02)00280-7Plastics in a circular economyhttp://www.europarl.europa.eu/RegData/etudes/ATAG/2018/625163/EPRS_ATA(2018)625163_EN.pdfBabu, R. P., O’Connor, K., & Seeram, R. (2013). Current progress on bio-based polymers and their future trends. 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Is elective surgery during the COVID-19 pandemic safe? A multi-center prospective study in a high incidence area

Elective surgery; COVID-19 pandemicCirugía electiva; Pandemia de COVID-19Cirurgia electiva; Pandèmia de COVID-19Objective: The aim of this study was to describe the evolution of patients admitted for elective orthopaedic surgery during the immediate post-COVID-19 peak of the pandemic. Methods: This is a multi-center, observational study conducted in 8 high complexity hospitals of Catalonia, one of the highest COVID-19 incidence areas in Spain. We included patients ≥18 years of age undergoing elective surgery (total knee or hip arthroplasty, knee or hip revision arthroplasty, shoulder or knee arthroscopy, hand or wrist surgery, forefoot surgery, or hardware removal) after the COVID-19 peak (between May 5th and June 30th, 2020). The main exclusion criterion was a positive result for SARS-CoV-2 PCR within the 7 days before the surgery. The primary outcomes were postoperative complications within 60 days (+/-30) or hospital readmission due to a COVID-19 infection. Following the recommendations of the International Consensus Group (ICM), elective surgeries were re-started when the nationwide lockdown was lifted. Before the surgery, patients were contacted by phone to rule out any exposure to confirmed COVID-19 cases, a reverse transcription-polymerase chain reaction (PCR) assay was performed in all patients 48-72 hours before hospital admission, and they were asked to maintain home confinement until the day of the surgery. Results: 675 patients were included: 189 patients in the arthroplasty group (28%) and 486 in the ambulatory surgery group (72%). Mean [SD] age was 57.6 [15.3] years. The mean Charlson Comorbidity Index score was 2.21 (SD = 2.01, Min = 0, Max = 13). A total of 84 patients (12.75%) obtained an American Society of Anesthesiologists (ASA) score ≥ 3, showing no association between the ASA score and the risk of developing COVID-19 symptoms at follow-up (χ 2 (4) = 0.77, P = 0.94). The mean occupation rate of hospital beds for COVID-19 patients was 13% and the mean occupation rate of critical care beds for COVID-19 patients was 27% at the time of re-introducing elective surgeries. These were important rates to consider to decide when to reintroduce elective surgeries after lockdown. Surgical time, time of ischemia and intra-operative bleeding were not related with a higher risk of developing COVID-19 post-operatively (χ 2 (1) = 0.00, P = 0.98); (χ 2 (2) = 2.05, P = 0.36); (χ 2 (2) = 0.37, P = 0.83). Only 2 patients (0.3 %) presented with a suspected COVID-19 infection at follow-up. None of them presented with pneumonia or required confirmation by a reverse transcription PCR assay. Hospital re-admission was not needed for these patients. Conclusion: The risk of developing COVID-19 during the immediate post-COVID-19 peak in a region with a high incidence of COVID-19 has not been proved. These data suggest that elective orthopaedic surgeries can be resumed when assertive and strict protocols are followed