576 research outputs found

    Mn valence instability in La2/3Ca1/3MnO3 thin films

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    A Mn valence instability on La2/3Ca1/3MnO3 thin films, grown on LaAlO3 (001)substrates is observed by x-ray absorption spectroscopy at the Mn L-edge and O K-edge. As-grown samples, in situ annealed at 800 C in oxygen, exhibit a Curie temperature well below that of the bulk material. Upon air exposure a reduction of the saturation magnetization, MS, of the films is detected. Simultaneously a Mn2+ spectral signature develops, in addition to the expected Mn3+ and Mn4+ contributions, which increases with time. The similarity of the spectral results obtained by total electron yield and fluorescence yield spectroscopy indicates that the location of the Mn valence anomalies is not confined to a narrow surface region of the film, but can extend throughout the whole thickness of the sample. High temperature annealing at 1000 C in air, immediately after growth, improves the magnetic and transport properties of such films towards the bulk values and the Mn2+ signature in the spectra does not appear. The Mn valence is then stable even to prolonged air exposure. We propose a mechanism for the Mn2+ ions formation and discuss the importance of these observations with respect to previous findings and production of thin films devices.Comment: Double space, 21 pages, 6 figure

    Molecular Oxygen Lignin Depolymerization: An Insight into the Stability of Phenolic Monomers

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    This is the peer reviewed version of the following article: Y. Mathieu, J. D. Vidal, L. Arribas Martínez, N. Abad Fernández, S. Iborra, A. Corma, ChemSusChem 2020, 13, 4743, which has been published in final form at https://doi.org/10.1002/cssc.202001295. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] During oxidative depolymn. of lignin in aq. alk. medium using mol. oxygen as oxidant, the highly functionalized primary phenolic monomers are not stable products, owing to various not fully identified secondary reaction mechanisms. However, better understanding of the mechanisms responsible for the instability of the main part of the products of interest derived from lignin is of much interest. Evaluation of their individual reactivities under oxidative conditions should significantly help to find a better way to valorize the lignin polymer and to maximize the yields of target value-added products. Consequently, the main objective of this study is to assess the individual stabilities of some selected ligninbased phenolic compds., such as vanillin, vanillic acid, and acetovanillone, together with some other pure chem. compds. such as phenol and anisole to give an insight into the mechanisms responsible for the simultaneous formation and repolymn. of those products and the influence of the oxidn. conditions. Various complementary strategies of stabilization are proposed, discussed, and applied for the oxidative depolymn. reactions of a tech. lignin extd. from pinewood with a high content of b-O-4 interconnecting bonds to try to obtain enhanced yields of value-added products.The authors thank Tecnicas Reunidas for material and financial support. We also acknowledge the Spanish Ministry of Science, Innovation, and Universities for funding through the "Severo Ochoa" Excellence Program (SEV 2016-0683) and the LIGNO-PRIZED project from the Spanish Centre for the Development of Industrial Technology (CDTI) in the framework of the Strategic Program of National Business Research Consortia (CIEN-2016). Special and kindly thanks are also given to Dr. Dalgi Sunith Barbosa Trillos and Dr. Jakob Mottweiler for their priceless help during the elaboration of the present work.Mathieu, Y.; Vidal, JD.; Arribas Martínez, L.; Abad Fernández, N.; Iborra Chornet, S.; Corma Canós, A. (2020). Molecular Oxygen Lignin Depolymerization: An Insight into the Stability of Phenolic Monomers. ChemSusChem. 13(17):4743-4758. https://doi.org/10.1002/cssc.202001295S474347581317BP. energy outlook2019 https://www.bp.com/content/dam/bp/business-sites/en/global/corporate/pdfs/energy-economics/energy-outlook/bp-energy-outlook-2019.pdf.J. Bluestein J. Rackley ICF International technical report2010 Coverage of Petroleum Sector Greenhouse Gas Emissions under Climate Policy.Huber, G. W., Iborra, S., & Corma, A. (2006). Synthesis of Transportation Fuels from Biomass:  Chemistry, Catalysts, and Engineering. Chemical Reviews, 106(9), 4044-4098. doi:10.1021/cr068360dFache, M., Boutevin, B., & Caillol, S. (2015). Vanillin Production from Lignin and Its Use as a Renewable Chemical. ACS Sustainable Chemistry & Engineering, 4(1), 35-46. doi:10.1021/acssuschemeng.5b01344Volf, I., & Popa, V. I. (2018). Integrated Processing of Biomass Resources for Fine Chemical Obtaining. Biomass as Renewable Raw Material to Obtain Bioproducts of High-Tech Value, 113-160. doi:10.1016/b978-0-444-63774-1.00004-1Chio, C., Sain, M., & Qin, W. (2019). Lignin utilization: A review of lignin depolymerization from various aspects. Renewable and Sustainable Energy Reviews, 107, 232-249. doi:10.1016/j.rser.2019.03.008Wang, H., Pu, Y., Ragauskas, A., & Yang, B. (2019). From lignin to valuable products–strategies, challenges, and prospects. Bioresource Technology, 271, 449-461. doi:10.1016/j.biortech.2018.09.072Corma, A., Iborra, S., & Velty, A. (2007). Chemical Routes for the Transformation of Biomass into Chemicals. Chemical Reviews, 107(6), 2411-2502. doi:10.1021/cr050989dVohra, M., Manwar, J., Manmode, R., Padgilwar, S., & Patil, S. (2014). Bioethanol production: Feedstock and current technologies. Journal of Environmental Chemical Engineering, 2(1), 573-584. doi:10.1016/j.jece.2013.10.013Claassen, P. A. M., van Lier, J. B., Lopez Contreras, A. M., van Niel, E. W. J., Sijtsma, L., Stams, A. J. M., … Weusthuis, R. A. (1999). Utilisation of biomass for the supply of energy carriers. Applied Microbiology and Biotechnology, 52(6), 741-755. doi:10.1007/s002530051586Kamm, B., & Kamm, M. (2004). Principles of biorefineries. Applied Microbiology and Biotechnology, 64(2), 137-145. doi:10.1007/s00253-003-1537-7Banerjee, S., Mudliar, S., Sen, R., Giri, B., Satpute, D., Chakrabarti, T., & Pandey, R. A. (2010). Commercializing lignocellulosic bioethanol: technology bottlenecks and possible remedies. Biofuels, Bioproducts and Biorefining, 4(1), 77-93. doi:10.1002/bbb.188Howard, R. L., Abotsi, E., Jansen, van R. E. L., & Howard, S. (2003). Lignocellulose biotechnology: issues of bioconversion and enzyme production. African Journal of Biotechnology, 2(12), 602-619. doi:10.5897/ajb2003.000-1115Kleinert, M., & Barth, T. (2008). Towards a Lignincellulosic Biorefinery: Direct One-Step Conversion of Lignin to Hydrogen-Enriched Biofuel. Energy & Fuels, 22(2), 1371-1379. doi:10.1021/ef700631wBajpai, P. (2018). Wood-Based Products and Chemicals. Biermann’s Handbook of Pulp and Paper, 233-247. doi:10.1016/b978-0-12-814240-0.00008-2Zakzeski, J., Bruijnincx, P. C. A., Jongerius, A. L., & Weckhuysen, B. M. (2010). The Catalytic Valorization of Lignin for the Production of Renewable Chemicals. Chemical Reviews, 110(6), 3552-3599. doi:10.1021/cr900354uAmen-Chen, C., Pakdel, H., & Roy, C. (2001). Production of monomeric phenols by thermochemical conversion of biomass: a review. Bioresource Technology, 79(3), 277-299. doi:10.1016/s0960-8524(00)00180-2Reale, S., Di Tullio, A., Spreti, N., & De Angelis, F. (2004). Mass spectrometry in the biosynthetic and structural investigation of lignins. Mass Spectrometry Reviews, 23(2), 87-126. doi:10.1002/mas.10072Dorrestijn, E., Laarhoven, L. J. J., Arends, I. W. C. E., & Mulder, P. (2000). The occurrence and reactivity of phenoxyl linkages in lignin and low rank coal. Journal of Analytical and Applied Pyrolysis, 54(1-2), 153-192. doi:10.1016/s0165-2370(99)00082-0Evans, R. J., Milne, T. A., & Soltys, M. N. (1986). Direct mass-spectrometric studies of the pyrolysis of carbonaceous fuels. Journal of Analytical and Applied Pyrolysis, 9(3), 207-236. doi:10.1016/0165-2370(86)80012-2Chen, Z., & Wan, C. (2017). Biological valorization strategies for converting lignin into fuels and chemicals. Renewable and Sustainable Energy Reviews, 73, 610-621. doi:10.1016/j.rser.2017.01.166Pu, Y., Zhang, D., Singh, P. M., & Ragauskas, A. J. (2008). The new forestry biofuels sector. Biofuels, Bioproducts and Biorefining, 2(1), 58-73. doi:10.1002/bbb.48Yuan, Z., Cheng, S., Leitch, M., & Xu, C. (Charles). (2010). Hydrolytic degradation of alkaline lignin in hot-compressed water and ethanol. Bioresource Technology, 101(23), 9308-9313. doi:10.1016/j.biortech.2010.06.140Reiter, J., Strittmatter, H., Wiemann, L. O., Schieder, D., & Sieber, V. (2013). Enzymatic cleavage of lignin β-O-4 aryl ether bonds via net internal hydrogen transfer. Green Chemistry, 15(5), 1373. doi:10.1039/c3gc40295aBehling, R., Valange, S., & Chatel, G. (2016). Heterogeneous catalytic oxidation for lignin valorization into valuable chemicals: what results? What limitations? What trends? Green Chemistry, 18(7), 1839-1854. doi:10.1039/c5gc03061gCollinson, S. R., & Thielemans, W. (2010). The catalytic oxidation of biomass to new materials focusing on starch, cellulose and lignin. Coordination Chemistry Reviews, 254(15-16), 1854-1870. doi:10.1016/j.ccr.2010.04.007Pandey, M. P., & Kim, C. S. (2010). Lignin Depolymerization and Conversion: A Review of Thermochemical Methods. Chemical Engineering & Technology, 34(1), 29-41. doi:10.1002/ceat.201000270Mathias, A. L., & Rodrigues, A. E. (1995). Production of Vanillin by Oxidation of Pine Kraft Lignins with Oxygen. Holzforschung, 49(3), 273-278. doi:10.1515/hfsg.1995.49.3.273Villar, J. C., Caperos, A., & García-Ochoa, F. (2001). Oxidation of hardwood kraft-lignin to phenolic derivatives with oxygen as oxidant. Wood Science and Technology, 35(3), 245-255. doi:10.1007/s002260100089Calvo-Flores, F. G., & Dobado, J. A. (2010). Lignin as Renewable Raw Material. ChemSusChem, 3(11), 1227-1235. doi:10.1002/cssc.201000157’T Hart, B. A., Simons, J. M., Shoshan, K.-S., Bakker, N. P. M., & Labadie, R. P. (1990). Antiarthritic activity of the newly developed neutrophil oxidative burst antagonist apocynin. Free Radical Biology and Medicine, 9(2), 127-131. doi:10.1016/0891-5849(90)90115-yStefanska, J., Sarniak, A., Wlodarczyk, A., Sokolowska, M., Pniewska, E., Doniec, Z., … Pawliczak, R. (2012). Apocynin reduces reactive oxygen species concentrations in exhaled breath condensate in asthmatics. Experimental Lung Research, 38(2), 90-99. doi:10.3109/01902148.2011.649823Yancheva, D., Velcheva, E., Glavcheva, Z., Stamboliyska, B., & Smelcerovic, A. (2016). Insights in the radical scavenging mechanism of syringaldehyde and generation of its anion. Journal of Molecular Structure, 1108, 552-559. doi:10.1016/j.molstruc.2015.12.054Srinivasulu, C., Ramgopal, M., Ramanjaneyulu, G., Anuradha, C. M., & Suresh Kumar, C. (2018). Syringic acid (SA) ‒ A Review of Its Occurrence, Biosynthesis, Pharmacological and Industrial Importance. Biomedicine & Pharmacotherapy, 108, 547-557. doi:10.1016/j.biopha.2018.09.069Baker, C. J., Mock, N. M., Whitaker, B. D., Roberts, D. P., Rice, C. P., Deahl, K. L., & Aver’yanov, A. A. (2005). Involvement of acetosyringone in plant–pathogen recognition. Biochemical and Biophysical Research Communications, 328(1), 130-136. doi:10.1016/j.bbrc.2004.12.153Liu, C., Wu, S., Zhang, H., & Xiao, R. (2019). Catalytic oxidation of lignin to valuable biomass-based platform chemicals: A review. Fuel Processing Technology, 191, 181-201. doi:10.1016/j.fuproc.2019.04.007Levec, J., & Pintar, A. (2007). Catalytic wet-air oxidation processes: A review. Catalysis Today, 124(3-4), 172-184. doi:10.1016/j.cattod.2007.03.035Xiang, Q., & Lee, Y. Y. (2001). Production of Oxychemicals from Precipitated Hardwood Lignin. Applied Biochemistry and Biotechnology, 91-93(1-9), 71-80. doi:10.1385/abab:91-93:1-9:71Santos, S. G., Marques, A. P., Lima, D. L. D., Evtuguin, D. V., & Esteves, V. I. (2010). Kinetics of Eucalypt Lignosulfonate Oxidation to Aromatic Aldehydes by Oxygen in Alkaline Medium. Industrial & Engineering Chemistry Research, 50(1), 291-298. doi:10.1021/ie101402tWu, G., Heitz, M., & Chornet, E. (1994). Improved Alkaline Oxidation Process for the Production of Aldehydes (Vanillin and Syringaldehyde) from Steam-Explosion Hardwood Lignin. Industrial & Engineering Chemistry Research, 33(3), 718-723. doi:10.1021/ie00027a034Bhargava, S., Jani, H., Tardio, J., Akolekar, D., & Hoang, M. (2007). Catalytic Wet Oxidation of Ferulic Acid (A Model Lignin Compound) Using Heterogeneous Copper Catalysts. Industrial & Engineering Chemistry Research, 46(25), 8652-8656. doi:10.1021/ie070085dDeng, H., Lin, L., Sun, Y., Pang, C., Zhuang, J., Ouyang, P., … Liu, S. (2008). Activity and Stability of Perovskite-Type Oxide LaCoO3 Catalyst in Lignin Catalytic Wet Oxidation to Aromatic Aldehydes Process. Energy & Fuels, 23(1), 19-24. doi:10.1021/ef8005349Deng, H., Lin, L., Sun, Y., Pang, C., Zhuang, J., Ouyang, P., … Liu, S. (2008). Perovskite-type Oxide LaMnO3: An Efficient and Recyclable Heterogeneous Catalyst for the Wet Aerobic Oxidation of Lignin to Aromatic Aldehydes. Catalysis Letters, 126(1-2), 106-111. doi:10.1007/s10562-008-9588-0Ansaloni, S., Russo, N., & Pirone, R. (2017). Wet Air Oxidation of Industrial Lignin Case Study: Influence of the Dissolution Pretreatment and Perovskite-type Oxides. Waste and Biomass Valorization, 9(11), 2165-2179. doi:10.1007/s12649-017-9947-4Deng, H., Lin, L., & Liu, S. (2010). Catalysis of Cu-Doped Co-Based Perovskite-Type Oxide in Wet Oxidation of Lignin To Produce Aromatic Aldehydes. Energy & Fuels, 24(9), 4797-4802. doi:10.1021/ef100768eZhang, J., Deng, H., & Lin, L. (2009). Wet Aerobic Oxidation of Lignin into Aromatic Aldehydes Catalysed by a Perovskite-type Oxide: LaFe1-xCuxO3 (x=0, 0.1, 0.2). Molecules, 14(8), 2747-2757. doi:10.3390/molecules14082747Gao, P., Li, C., Wang, H., Wang, X., & Wang, A. (2013). Perovskite hollow nanospheres for the catalytic wet air oxidation of lignin. Chinese Journal of Catalysis, 34(10), 1811-1815. doi:10.1016/s1872-2067(12)60691-3Gale, M., Cai, C. M., & Gilliard‐Abdul‐Aziz, K. L. (2020). Heterogeneous Catalyst Design Principles for the Conversion of Lignin into High‐Value Commodity Fuels and Chemicals. ChemSusChem, 13(8), 1947-1966. doi:10.1002/cssc.202000002Pepper, J. M., Baylis, P. E. T., & Adler, E. (1959). THE ISOLATION AND PROPERTIES OF LIGNINS OBTAINED BY THE ACIDOLYSIS OF SPRUCE AND ASPEN WOODS IN DIOXANE–WATER MEDIUM. Canadian Journal of Chemistry, 37(8), 1241-1248. doi:10.1139/v59-183Yuan, T.-Q., Sun, S.-N., Xu, F., & Sun, R.-C. (2011). Characterization of Lignin Structures and Lignin–Carbohydrate Complex (LCC) Linkages by Quantitative 13C and 2D HSQC NMR Spectroscopy. Journal of Agricultural and Food Chemistry, 59(19), 10604-10614. doi:10.1021/jf2031549Bauer, S., Sorek, H., Mitchell, V. D., Ibáñez, A. B., & Wemmer, D. E. (2012). Characterization of Miscanthus giganteus Lignin Isolated by Ethanol Organosolv Process under Reflux Condition. Journal of Agricultural and Food Chemistry, 60(33), 8203-8212. doi:10.1021/jf302409dWen, J.-L., Sun, S.-L., Xue, B.-L., & Sun, R.-C. (2013). Recent Advances in Characterization of Lignin Polymer by Solution-State Nuclear Magnetic Resonance (NMR) Methodology. Materials, 6(1), 359-391. doi:10.3390/ma6010359Peterson, D. J., & Loening, N. M. (2007). QQ-HSQC: a quick, quantitative heteronuclear correlation experiment for NMR spectroscopy. Magnetic Resonance in Chemistry, 45(11), 937-941. doi:10.1002/mrc.2073Sette, M., Wechselberger, R., & Crestini, C. (2011). Elucidation of Lignin Structure by Quantitative 2D NMR. Chemistry - A European Journal, 17(34), 9529-9535. doi:10.1002/chem.201003045Tarabanko, V. E., Petukhov, D. V., & Selyutin, G. E. (2004). New Mechanism for the Catalytic Oxidation of Lignin to Vanillin. Kinetics and Catalysis, 45(4), 569-577. doi:10.1023/b:kica.0000038087.95130.a5Rinesch, T., Mottweiler, J., Puche, M., Concepción, P., Corma, A., & Bolm, C. (2017). Mechanistic Investigation of the Catalyzed Cleavage for the Lignin β-O-4 Linkage: Implications for Vanillin and Vanillic Acid Formation. ACS Sustainable Chemistry & Engineering, 5(11), 9818-9825. doi:10.1021/acssuschemeng.7b01725Sette, M., Lange, H., & Crestini, C. (2013). QUANTITATIVE HSQC ANALYSES OF LIGNIN: A PRACTICAL COMPARISON. Computational and Structural Biotechnology Journal, 6(7), e201303016. doi:10.5936/csbj.201303016Bujanovic, B., Ralph, S., Reiner, R., Hirth, K., & Atalla, R. (2010). Polyoxometalates in Oxidative Delignification of Chemical Pulps: Effect on Lignin. Materials, 3(3), 1888-1903. doi:10.3390/ma3031888Casimiro, F. M., Costa, C. A. E., Botelho, C. M., Barreiro, M. F., & Rodrigues, A. E. (2019). Kinetics of Oxidative Degradation of Lignin-Based Phenolic Compounds in Batch Reactor. Industrial & Engineering Chemistry Research, 58(36), 16442-16449. doi:10.1021/acs.iecr.9b02818Dabral, S., Hernández, J. G., Kamer, P. C. J., & Bolm, C. (2017). Organocatalytic Chemoselective Primary Alcohol Oxidation and Subsequent Cleavage of Lignin Model Compounds and Lignin. ChemSusChem, 10(13), 2707-2713. doi:10.1002/cssc.201700703Schutyser, W., Renders, T., Van den Bosch, S., Koelewijn, S.-F., Beckham, G. T., & Sels, B. F. (2018). Chemicals from lignin: an interplay of lignocellulose fractionation, depolymerisation, and upgrading. Chemical Society Reviews, 47(3), 852-908. doi:10.1039/c7cs00566kSubbotina, E., Velty, A., Samec, J. S. M., & Corma, A. (2020). Zeolite‐Assisted Lignin‐First Fractionation of Lignocellulose: Overcoming Lignin Recondensation through Shape‐Selective Catalysis. ChemSusChem, 13(17), 4528-4536. doi:10.1002/cssc.202000330Mattsson, C., Andersson, S.-I., Belkheiri, T., Åmand, L.-E., Olausson, L., Vamling, L., & Theliander, H. (2016). Using 2D NMR to characterize the structure of the low and high molecular weight fractions of bio-oil obtained from LignoBoost™ kraft lignin depolymerized in subcritical water. Biomass and Bioenergy, 95, 364-377. doi:10.1016/j.biombioe.2016.09.004Rinaldi, R., Jastrzebski, R., Clough, M. T., Ralph, J., Kennema, M., Bruijnincx, P. C. A., & Weckhuysen, B. M. (2016). Paving the Way for Lignin Valorisation: Recent Advances in Bioengineering, Biorefining and Catalysis. Angewandte Chemie International Edition, 55(29), 8164-8215. doi:10.1002/anie.201510351Rinaldi, R., Jastrzebski, R., Clough, M. T., Ralph, J., Kennema, M., Bruijnincx, P. C. A., & Weckhuysen, B. M. (2016). Wege zur Verwertung von Lignin: Fortschritte in der Biotechnik, der Bioraffination und der Katalyse. Angewandte Chemie, 128(29), 8296-8354. doi:10.1002/ange.201510351Tarabanko, V. E., Fomova, N. A., Kuznetsov, B. N., Ivanchenko, N. M., & Kudryashev, A. V. (1995). On the mechanism of vanillin formation in the catalytic oxidation of lignin with oxygen. Reaction Kinetics & Catalysis Letters, 55(1), 161-170. doi:10.1007/bf02075847Venica, A. D., Chen, C.-L., & Gratzl, J. S. (2008). Soda–AQ delignification of poplar wood. Part 1: Reaction mechanism and pulp properties. Holzforschung, 62(6). doi:10.1515/hf.2008.118Gaspa, S., Amura, I., Porcheddu, A., & De Luca, L. (2017). Anhydrides from aldehydes or alcohols via oxidative cross-coupling. New Journal of Chemistry, 41(3), 931-939. doi:10.1039/c6nj02625

    Fisheries and Prestige. Review and update of studies on the effects of the Prestige oil spill

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    The Prestige oil tanker sank in November 2002 and leaked around 60 000 mt. of heavy oil (type M-100) into the sea. Immediately after the accident, closed areas were established. Among the fleets affected by the closures were four of the most important in ICES Division VIIIc and Sub-division IXa North (bottom trawl, pair trawl, purse seine targeting sardine and hand line targeting mackerel) as they exploit considerable resources, some outside biological safety limits. A fall in effort was observed in all of them, mainly in the first quarter and in sub-divisions VIIIc West and IXa North, although it failed to lead to a very large reduction in the total annual effort of each of the fleets, with the exception of hand line. Pair trawlers can make two types of fishing trip, but differences in specific composition among the three years analysed were not found in either of them. In the case of trawl, five kinds of fishing trips were identified, and changes were only found in the type that targets Norway lobster, hake, megrim and monk (HMMN), with a fall in the presence of Norway lobster

    Degradability of cross-linked polyurethanes based on synthetic polyhydroxybutyrate and modified with polylactide

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    In many areas of application of conventional non-degradable cross-linked polyurethanes (PUR), there is a need for their degradation under the influence of specific environmental factors. It is practiced by incorporation of sensitive to degradation compounds (usually of natural origin) into the polyurethane structure, or by mixing them with polyurethanes. Cross-linked polyurethanes (with 10 and 30%wt amount of synthetic poly([R,S]-3-hydroxybutyrate) (R,S-PHB) in soft segments) and their physical blends with poly([d,l]-lactide) (PDLLA) were investigated and then degraded under hydrolytic (phosphate buffer solution) and oxidative (CoCl2/H2O2) conditions. The rate of degradation was monitored by changes of samples mass, morphology of surface and their thermal properties. Despite the small weight losses of samples, the changes of thermal properties of polymers and topography of their surface indicated that they were susceptible to gradual degradation under oxidative and hydrolytic conditions. Blends of PDLLA and polyurethane with 30 wt% of R,S-PHB in soft segments and PUR/PDLLA blends absorbed more water and degraded faster than polyurethane with low amount of R,S-PHB

    UGT1A and TYMS genetic variants predict toxicity and response of colorectal cancer patients treated with first-line irinotecan and fluorouracil combination therapy

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    BACKGROUND: The impact of thymidylate synthase (TYMS) and UDP-glucoronosyltransferase 1A (UGT1A) germline polymorphisms on the outcome of colorectal cancer (CRC) patients treated with irinotecan plus 5-fluorouracil (irinotecan/5FU) is still controversial. Our objective was to define a genetic-based algorithm to select patients to be treated with irinotecan/5FU. METHODS: Genotyping of TYMS (5'TRP and 3'UTR), UGT1A1*28, UGT1A9*22 and UGT1A7*3 was performed in 149 metastatic CRC patients treated with irinotecan/5FU as first-line chemotherapy enrolled in a randomised phase 3 study. Their association with response, toxicity and survival was investigated by univariate and multivariate statistical analysis. RESULTS: TYMS 3TRP/3TRP genotype was the only independent predictor of tumour response (OR=5.87, 95% confidence interval (CI)=1.68-20.45; P=0.005). UGT1A1*28/*28 was predictive for haematologic toxicity (OR=6.27, 95% CI=1.09-36.12; P=0.04), specifically for neutropenia alone (OR=6.40, 95% CI=1.11-37.03; P=0.038) or together with diarrhoea (OR=18.87, 95% CI=2.14-166.67; P=0.008). UGT1A9*1/*1 was associated with non-haematologic toxicity (OR=2.70, 95% CI=1.07-6.82; P=0.035). Haplotype VII (all non-favourable alleles) was associated with non-haematologic toxicity (OR=2.11, 95% CI-1.12-3.98; P-0.02). CONCLUSION: TYMS and UGT1A polymorphisms influence on tumour response and toxicities derived from irinotecan/5FU treatment in CRC patients. A genetic-based algorithm to optimise treatment individualisation is proposed. British Journal of Cancer (2010) 103, 581-589. doi:10.1038/sj.bjc.6605776 www.bjcancer.com Published online 13 July 2010 (C) 2010 Cancer Research U

    Genome-wide association filtering using a highly locus-specific transmission/disequilibrium test

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    Multimarker transmission/disequilibrium tests (TDTs) are powerful association and linkage tests used to perform genome-wide filtering in the search for disease susceptibility loci. In contrast to case/control studies, they have a low rate of false positives for population stratification and admixture. However, the length of a region found in association with a disease is usually very large because of linkage disequilibrium (LD). Here, we define a multimarker proportional TDT (mTDTP) designed to improve locus specificity in complex diseases that has good power compared to the most powerful multimarker TDTs. The test is a simple generalization of a multimarker TDT in which haplotype frequencies are used to weight the effect that each haplotype has on the whole measure. Two concepts underlie the features of the metric: the ‘common disease, common variant’ hypothesis and the decrease in LD with chromosomal distance. Because of this decrease, the frequency of haplotypes in strong LD with common disease variants decreases with increasing distance from the disease susceptibility locus. Thus, our haplotype proportional test has higher locus specificity than common multimarker TDTs that assume a uniform distribution of haplotype probabilities. Because of the common variant hypothesis, risk haplotypes at a given locus are relatively frequent and a metric that weights partial results for each haplotype by its frequency will be as powerful as the most powerful multimarker TDTs. Simulations and real data sets demonstrate that the test has good power compared with the best tests but has remarkably higher locus specificity, so that the association rate decreases at a higher rate with distance from a disease susceptibility or disease protective locus

    Effectiveness and Safety of the Sequential Use of a Second and Third Anti-TNF Agent in Patients with Inflammatory Bowel Disease: Results from the Eneida Registry

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    Background: The effectiveness of the switch to another anti-tumor necrosis factor (anti-TNF) agent is not known. The aim of this study was to analyze the effectiveness and safety of treatment with a second and third anti-TNF drug after intolerance to or failure of a previous anti-TNF agent in inflammatory bowel disease (IBD) patients. Methods: We included patients diagnosed with IBD from the ENEIDA registry who received another anti-TNF after intolerance to or failure of a prior anti-TNF agent. Results: A total of 1122 patients were included. In the short term, remission was achieved in 55% of the patients with the second anti-TNF. The incidence of loss of response was 19% per patient-year with the second anti-TNF. Combination therapy (hazard ratio [HR], 2.4; 95% confidence interval [CI], 1.8-3; P < 0.0001) and ulcerative colitis vs Crohn''s disease (HR, 1.6; 95% CI, 1.1-2.1; P = 0.005) were associated with a higher probability of loss of response. Fifteen percent of the patients had adverse events, and 10% had to discontinue the second anti-TNF. Of the 71 patients who received a third anti-TNF, 55% achieved remission. The incidence of loss of response was 22% per patient-year with a third anti-TNF. Adverse events occurred in 7 patients (11%), but only 1 stopped the drug. Conclusions: Approximately half of the patients who received a second anti-TNF achieved remission; nevertheless, a significant proportion of them subsequently lost response. Combination therapy and type of IBD were associated with loss of response. Remission was achieved in almost 50% of patients who received a third anti-TNF; nevertheless, a significant proportion of them subsequently lost response

    CIBERER : Spanish national network for research on rare diseases: A highly productive collaborative initiative

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    Altres ajuts: Instituto de Salud Carlos III (ISCIII); Ministerio de Ciencia e Innovación.CIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research
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