45 research outputs found

    Tachyonic open inflationary universes

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    We study one-field open inflationary models in a universe dominated by tachyon matter. In these scenarios, we determine and characterize the existence of the Coleman-De Lucia (CDL) instanton. Also, we study the Lorentzian regime, that is, the period of inflation after tunnelling has occurred.Comment: 13 pages, 7 figures. Accepted by Physics Letters

    Nano-based approved pharmaceuticals for cancer treatment : present and future challenges

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    Altres ajuts: RICORS RD21/0012/0001 (co-funded by the European Regional Development Fund, "A way to make Europe"); Fundación Mutua Madrileña (FMMA) through the project "Targeted therapy for selective elimination of metastatic stem cells CXCR4+ in endometrial cancer" (AP1666942017); Asociación Española contra el cancer (AECC) through the project "Development of an antitumor protein delivery system into ovarian cancer cells using the subcellular vault" (IDEAS18038BENI)Cancer is one of the main causes of death worldwide. To date, and despite the advances in conventional treatment options, therapy in cancer is still far from optimal due to the non-specific systemic biodistribution of antitumor agents. The inadequate drug concentrations at the tumor site led to an increased incidence of multiple drug resistance and the appearance of many severe unde-sirable side effects. Nanotechnology, through the development of nanoscale-based pharmaceuticals, has emerged to provide new and innovative drugs to overcome these limitations. In this review, we provide an overview of the approved nanomedicine for cancer treatment and the rationale behind their designs and applications. We also highlight the new approaches that are currently under investigation and the perspectives and challenges for nanopharmaceuticals, focusing on the tumor microenvironment and tumor disseminate cells as the most attractive and effective strategies for cancer treatments

    Thermal and mechanical characterization of epoxy resins (ELO and ESO) cured with anhydrides

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    In this work we have developed polymeric materials from epoxidized vegetable oils in order to obtain materials with excellent mechanical properties for use as green matrix composites. Epoxidized soybean oil (ESO), epoxidized linseed oil (ELO) and different mixtures of the two oils were used to produce the polymers. Phthalic anhydride (17 mol%) and maleic anhydride (83 mol%) which has a eutectic reaction temperature of 48 °C were used as crosslinking agents while benzyl dimethyl amine (BDMA) and ethylene glycol were used as the catalyst and initiator, respectively. The results showed that samples 100ELO and 80ELO20ESO could be used as a matrix in green composites because they demonstrated good mechanical properties. © 2012 AOCS (outside the USA).This work is part of the project IPT-310000-2010-037,''ECOTEXCOMP: Research and development of textile structures useful as reinforcement of composite materials with marked ecological character'' funded by the "Ministerio de Ciencia e Innovacion", with financial aid of 189,540.20 EUR, within the "Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica 2008-2011" and funded by the European Union through FEDER funds, Technology Fund 2007-2013, Operational Programme on R + D + i for and on behalf of the companies.Samper Madrigal, MD.; Fombuena Borrás, V.; Boronat Vitoria, T.; García Sanoguera, D.; Balart Gimeno, RA. (2012). Thermal and mechanical characterization of epoxy resins (ELO and ESO) cured with anhydrides. Journal of the American Oil Chemists' Society. 89(8):1521-1528. https://doi.org/10.1007/s11746-012-2041-yS15211528898Averous L (2004) Biodegradable multiphase systems based on plasticized starch: a review. J Macromol Sci Polym Rev C44:231–274Bledzki AK, Jaszkiewicz A (2010) Mechanical performance of biocomposites based on PLA and PHBV reinforced with natural fibres—a comparative study to PP. Compos Sci Technol 70:1687–1696Raquez JM, Deleglise M, Lacrampe MF, Krawczak P (2010) Thermosetting (bio)materials derived from renewable resources: a critical review. Prog Polym Sci 35:487–509Charlet K, Jernot JP, Gomina M, Bizet L, Breard J (2010) Mechanical properties of flax fibers and of the derived unidirectional composites. J Compos Mater 44:2887–2896Barreto ACH, Esmeraldo MA, Rosa DS, Fechine PBA, Mazzetto SE (2010) Cardanol biocomposites reinforced with jute fiber: microstructure, biodegradability, and mechanical properties. Polym Compos 31:1928–1937Thakur VK, Singha AS (2010) Physico-chemical and mechanical characterization of natural fibre reinforced polymer composites. Iran Polym J 19:3–16Schmitz WR, Wallace JG (1954) Epoxidation of methyl oleate with hydrogen peroxide. J Am Oil Chem Soc 31:363–365La Scala J, Wool RP (2002) Effect of FA composition on epoxidation kinetics of TAG. J Am Oil Chem Soc 79:373–378de Espinosa LM, Ronda JC, Galia M, Cadiz V (2008) A new enone-containing triglyceride derivative as precursor of thermosets from renewable resources. J Polym Sci Pol Chem 46:6843–6850Gerbase AE, Petzhold CL, Costa APO (2002) Dynamic mechanical and thermal behavior of epoxy resins based on soybean oil. J Am Oil Chem Soc 79:797–802Boquillon N, Fringant C (2000) Polymer networks derived from curing of epoxidised linseed oil: influence of different catalysts and anhydride hardeners. Polymer 41:8603–8613Montserrat S, Flaque C, Calafell M, Andreu G, Malek J (1995) Influence of the accelerator concentration on the curing reaction of an epoxy-anhydride system. Thermochim Acta 269:213–229Zacharuk M, Becker D, Coelho LAF, Pezzin SH (2011) Study of the reaction between polyethylene glycol and epoxy resins using N,N-dimethylbenzylamine as catalyst. Polimeros 21:73–77Lozada Z, Suppes GJ, Tu YC, Hsieh FH (2009) Soy-based polyols from oxirane ring opening by alcoholysis reaction. J Appl Polym Sci 113:2552–256

    Effect of different compatibilizers on injection-molded green composite pieces based on polylactide filled with almond shell flour

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    [EN] Green composites made of polylactide (PLA) filled with almond shell flour (ASF) at a constant weight content of 25Âżwt.-% were manufactured by injection molding. In order to increase the interfacial adhesion between the biopolymer and the lignocellulosic fillers, three different compatibilizers were tested, namely multi-functional epoxy-based styrene-acrylic oligomer (ESAO), aromatic carbodiimide (AC), and maleinized linseed oil (MLO). The effect of each compatibilizer on the thermal, mechanical, and thermomechanical properties and water uptake of the injection-molded PLA/ASF pieces was analyzed. The obtained results indicated that all the here-studied compatibilizers had a positive influence on both the thermal stability and the mechanical and thermomechanical performance of the green composite pieces but low impact on their water uptake profile. In addition, the morphological analysis performed at the fracture surfaces of the green composite pieces revealed that the fillerÂżmatrix gap was substantially reduced. Among the tested compatibilizers, ESAO and MLO yielded the highest performance in terms of mechanical strength and ductility, respectively. In the case of MLO, it also offers the advantage of being a plant-derived additive so that its application in green composites positively contributes to the development of sustainable polymer technologies.This research was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) program number MAT2014-59242-C2-1-R and AGL2015-63855-C2-1-R and Generalitat Valenciana (GV) program number GV/2014/008. A. Carbonell-Verdu wants to thank Universitat Politecnica de Valencia (UPV) for his FPI grant. D. Garcia-Garcia wants to thank the Spanish Ministry of Education, Culture and Sports (MECD) for his FPU grant (FPU13/06011). L. Quiles-Carrillo also wants to thank GV for his FPI grant (ACT/2016/182) and the MECD for his FPU grant (FPU15/03812).Quiles-Carrillo, L.; Montanes, N.; Garcia-Garcia, D.; Carbonell-Verdu, A.; Balart, R.; Torres-Giner, S. (2018). Effect of different compatibilizers on injection-molded green composite pieces based on polylactide filled with almond shell flour. Composites Part B Engineering. 147:76-85. https://doi.org/10.1016/j.compositesb.2018.04.017S768514

    The use of caspase inhibitors in pulsed-field gel electrophoresis may improve the estimation of radiation-induced DNA repair and apoptosis

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    <p>Abstract</p> <p>Background</p> <p>Radiation-induced DNA double-strand break (DSB) repair can be tested by using pulsed-field gel electrophoresis (PFGE) in agarose-encapsulated cells. However, previous studies have reported that this assay is impaired by the spontaneous DNA breakage in this medium. We investigated the mechanisms of this fragmentation with the principal aim of eliminating it in order to improve the estimation of radiation-induced DNA repair.</p> <p>Methods</p> <p>Samples from cancer cell cultures or xenografted tumours were encapsulated in agarose plugs. The cell plugs were then irradiated, incubated to allow them to repair, and evaluated by PFGE, caspase-3, and histone H2AX activation (ÎłH2AX). In addition, apoptosis inhibition was evaluated through chemical caspase inhibitors.</p> <p>Results</p> <p>We confirmed that spontaneous DNA fragmentation was associated with the process of encapsulation, regardless of whether cells were irradiated or not. This DNA fragmentation was also correlated to apoptosis activation in a fraction of the cells encapsulated in agarose, while non-apoptotic cell fraction could rejoin DNA fragments as was measured by ÎłH2AX decrease and PFGE data. We were able to eliminate interference of apoptosis by applying specific caspase inhibitors, and improve the estimation of DNA repair, and apoptosis itself.</p> <p>Conclusions</p> <p>The estimation of radiation-induced DNA repair by PFGE may be improved by the use of apoptosis inhibitors. The ability to simultaneously determine DNA repair and apoptosis, which are involved in cell fate, provides new insights for using the PFGE methodology as functional assay.</p

    In Situ Compatibilization of Biopolymer Ternary Blends by Reactive Extrusion with Low-Functionality Epoxy-Based Styrene Acrylic Oligomer

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    [EN] The present study reports on the use of low-functionality epoxy-based styrene¿acrylic oligomer (ESAO) to compatibilize immiscible ternary blends made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polylactide (PLA), and poly(butylene adipate-co-terephthalate) (PBAT). The addition during melt processing of low-functionality ESAO at two parts per hundred resin (phr) of biopolymer successfully changed the soften inclusion phase in the blend system to a thinner morphology, yielding biopolymer ternary blends with higher mechanical ductility and also improved oxygen barrier performance. The compatibilization achieved was ascribed to the in situ formation of a newly block terpolymer, i.e. PHBVb- PLA-b-PBAT, which was produced at the blend interface by the reaction of the multiple epoxy groups present in ESAO with the functional terminal groups of the biopolymers. This chemical reaction was mainly linear due to the inherently low functionality of ESAO and the more favorable reactivity of the epoxy groups with the carboxyl groups of the biopolymers, which avoided the formation of highly branched and/or cross-linked structures and thus facilitated the films processability. Therefore, the reactive blending of biopolymers at different mixing ratios with low-functionality ESAO represents a straightforward methodology to prepare sustainable plastics at industrial scale with different physical properties that can be of interest in, for instance, food packaging applications.This research was funded by the EU H2020 project YPACK (Reference number 773872) and by the Spanish Ministry of Science, Innovation, and Universities (MICIU) with project numbers MAT2017-84909-C2-2-R and AGL2015-63855-C2-1-R. L. Quiles-Carrillo wants to thank the Spanish Ministry of Education, Culture, and Sports (MECD) for financial support through his FPU Grant Number FPU15/03812. Torres-Giner also acknowledges the MICIU for his Juan de la Cierva contract (IJCI-2016-29675).Quiles-Carrillo, L.; Montanes, N.; Lagaron, J.; Balart, R.; Torres-Giner, S. (2019). In Situ Compatibilization of Biopolymer Ternary Blends by Reactive Extrusion with Low-Functionality Epoxy-Based Styrene Acrylic Oligomer. Journal of Polymers and the Environment. 27(1):84-96. https://doi.org/10.1007/s10924-018-1324-2S8496271Babu RP, O’Connor K, Seeram R (2013) Prog Biomater 2:8Torres-Giner S, Torres A, Ferrándiz M, Fombuena V, Balart R (2017) J Food Saf 37:e12348Quiles-Carrillo L, Montanes N, Boronat T, Balart R, Torres-Giner S (2017) Polym Test 61:421Zakharova E, Alla A, Martínez A, De Ilarduya S, Muñoz-Guerra (2015) RSC Adv 5:46395Steinbüchel A, Valentin HE (1995) FEMS Microbiol Lett 128:219McChalicher CWJ, Srienc F (2007) J Biotechnol 132:296Reis KC, Pereira J, Smith AC, Carvalho CWP, Wellner N, Yakimets I (2008) J Food Eng 89:361Vink ETH, Davies S (2015) Ind Biotechnol 11:167John RP, Nampoothiri KM, Pandey A (2006) Process Biochem 41:759Madhavan Nampoothiri K, Nair NR, John RP (2010) Biores Technol 101:8493Garlotta D (2001) J Polym Environ 9:63Lim LT, Auras R, Rubino M (2008) Prog Polym Sci 33:820Quiles-Carrillo L, Montanes N, Sammon C, Balart R, Torres-Giner S (2018) Ind Crops Prod 111:878Quiles-Carrillo L, Blanes-Martínez MM, Montanes N, Fenollar O, Torres-Giner S, Balart R (2018) Eur Polym J 98:402Witt U, Müller R-J, Deckwer W-D (1997) J Environ Polym Degrad 5:81Siegenthaler KO, Künkel A, Skupin G, Yamamoto M (2012) Ecoflex® and Ecovio®: biodegradable, performance-enabling plastics. In: Rieger B, Künkel A, Coates GW, Reichardt R, Dinjus E, Zevaco TA (eds) Synthetic biodegradable polymers. Springer, Berlin Heidelberg, p 91Jiang L, Wolcott MP, Zhang J (2006) Biomacromol 7:199Brandelero RPH, Yamashita F, Grossmann MVE (2010) Carbohyd Polym 82:1102Muthuraj R, Misra M, Mohanty AK (2014) J Polym Environ 22:336Porter RS, Wang L-H (1992) Polymer 33(10): 2019Koning C, Van Duin M, Pagnoulle C, Jerome R (1998) Prog Polym Sci 23:707Muthuraj R, Misra M, Mohanty AK (2017) J Appl Polym Sci 135:45726Ryan AJ (2002) Nat Mater 1:8Wu D, Zhang Y, Yuan L, Zhang M, Zhou W (2010) J Polym Sci Part B 48:756Kim CH, Cho KY, Choi EJ, Park JK (2000) J Appl Polym Sci 77:226Supthanyakul R, Kaabbuathong N, Chirachanchai S (2016) Polymer 105:1Na Y-H, He Y, Shuai X, Kikkawa Y, Doi Y, Inoue Y (2002) Biomacromolecules 3:1179Zeng J-B, Li K-A, Du A-K (2015) RSC Adv 5:32546Xanthos M, Dagli SS (1991) Polym Eng Sci 31:929Sundararaj U, Macosko CW (1995) Macromolecules 28:2647Milner ST, Xi H (1996) J Rheol 40:663Villalobos M, Awojulu A, Greeley T, Turco G, Deeter G (2006) Energy 31:3227Torres-Giner S, Montanes N, Boronat T, Quiles-Carrillo L, Balart R (2016) Eur Polym J 84:693Lehermeier HJ, Dorgan JR (2001) Polym Eng Sci 41:2172Liu B, Xu Q (2013) J Mater Sci Chem Eng 1:9Eslami H, Kamal MR (2013) J Appl Polym Sci 129:2418Loontjens T, Pauwels K, Derks F, Neilen M, Sham CK, Serné M (1997) J Appl Polym Sci 65:1813Ojijo V, Ray SS (2015) Polymer 80:1Frenz V, Scherzer D, Villalobos M, Awojulu AA, Edison M, Van Der Meer R (2008) Multifunctional polymers as chain extenders and compatibilizers for polycondensates and biopolymers. In: Technical papers, regional technical conference—society of plastics engineers, p. 3/1678Utracki LA (2002) Can J Chem Eng 80:1008Al-Itry R, Lamnawar K, Maazouz A (2012) Polym Degrad Stab 97:1898Lin S, Guo W, Chen C, Ma J, Wang B (2012) Mater Des (1980–2015) 36: 604Arruda LC, Magaton M, Bretas RES, Ueki MM (2015) Polym Test 43:27Wang Y, Fu C, Luo Y, Ruan C, Zhang Y, Fu Y (2010) J Wuhan Univ Technol Mater Sci Ed 25:774Wei D, Wang H, Xiao H, Zheng A, Yang Y (2015) Carbohyd Polym 123:275Abdelwahab MA, Taylor S, Misra M, Mohanty AK (2015) Macromol Mater Eng 300:299Sun Q, Mekonnen T, Misra M, Mohanty AK (2016) J Polym Environ 24:23Torres-Giner S, Gimeno-Alcañiz JV, Ocio MJ, Lagaron JM (2011) J Appl Polym Sci 122:914Miyata T, Masuko T (1998) Polymer 39:5515Muthuraj R, Misra M, Mohanty AK (2015) J Appl Polym Sci 132:42189Ren J, Fu H, Ren T, Yuan W (2009) Carbohyd Polym 77:576Torres-Giner S, Montanes N, Fenollar O, García-Sanoguera D, Balart R (2016) Mater Des 108:648Jamshidian M, Tehrany EA, Imran M, Jacquot M, Desobry S (2010) Compr Rev Food Sci Food Saf 9:552Savenkova L, Gercberga Z, Nikolaeva V, Dzene A, Bibers I, Kalnin M (2000) Process Biochem 35:573Costa ARM, Almeida TG, Silva SML, Carvalho LH, Canedo EL (2015) Polym Test 42:115Zhang K, Mohanty AK, Misra M (2012) ACS Appl Mater Interfaces 4:3091Zhang N, Wang Q, Ren J, Wang L (2009) J Mater Sci 44:250Chinsirikul W, Rojsatean J, Hararak B, Kerddonfag N, Aontee A, Jaieau K, Kumsang P, Sripethdee C (2015) Packag Technol Sci 28:741Auras R, Harte B, Selke S (2004) J Appl Polym Sci 92:1790Sanchez-Garcia MD, Gimenez E, Lagaron JM (2008) Carbohyd Polym 71:235Sanchez-Garcia MD, Gimenez E, Lagaron JM (2007) J Plast Film Sheeting 23:133Lagaron JM (2011) Multifunctional and nanoreinforced polymers for food packaging. In: Multifunctional and nanoreinforced polymers for food packaging. Woodhead Publishing, Cambridge, p 

    Deep Impact

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    Entrevista telefónica realizada por el Canal Internacional TELEMUNDO (Miami) en el año 2005 a Alberto Quijano Vodniza: Participación de nuestro Observatorio en el programa "SMALL TELESCOPE SCIENCE PROGRAM" de DEEP IMPACT - NASA

    Autophagy in hepatocellular carcinomas: from pathophysiology to therapeutic response

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    Srikanta Dash,1,2 Srinivas Chava,1 Partha K Chandra,1 Yucel Aydin,2 Luis A Balart,2 Tong Wu1 1Department of Pathology and Laboratory Medicine, 2Department of Gastroenterology and Hepatology, Tulane University School of Medicine, New Orleans, LA, USA Abstract: Autophagy is an intracellular lysosomal degradation process performed by the cells to maintain energy balance. The autophagy response plays an important role in the progression of liver disease due to hepatitis virus infection, alcoholic liver disease, nonalcoholic fatty liver disease, liver cirrhosis, and hepatocellular carcinoma (HCC). An increased autophagy response also contributes to the pathogenesis of liver disease through modulation of innate and adaptive immune responses; a defective cellular autophagy response leads to the development of HCC. Recent progress in the field indicates that autophagy modulation provides a novel targeted therapy for human liver cancer. The purpose of this review is to update our understanding of how the cellular autophagy response impacts the pathophysiology of liver disease and HCC treatment. Keywords: hepatocellular carcinoma, macroautophagy, microautophagy, autophagy inhibitor, chloroquine, hydroxychloroquine, sorafeni
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