163 research outputs found

    About the Electrospray Ionization Source in Mass Spectrometry: Electrochemistry and On-chip Reactions

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    The present work shows that the electrochemical properties of electrospray ionization (ESI) can be used to add functions to the process. As example, we show how the choice of the electrode material can be used to study interactions between metal ions and biomolecules in mass spectrometry (MS). In positive ionization MS, an electrospray device acts as anode, which implies oxidation reactions. Sacrificial electrodes (made of copper or zinc) are used to supply the electrospray current and to produce cations that are able to react on-line with compounds of interest. Thus, the interactions between copper ions and ligands or peptides were investigated by using a copper electrode. Another example is the in situ electrogeneration of a dinuclear zinc(II) complex for the mass tagging of phosphopeptides when working with a zinc electrode. In order to perform these reactions on the same microchip, a dual-channel microsprayer was used, where one channel was dedicated to the tag electrogeneration and the other to the infusion of a phosphopeptides solution. Finally, this dual-channel microsprayer was used to study complexation at liquid-liquid interfaces in biphasic ESI-MS, such as thioether crowns and lead ions or peptides and phospholipids complexes. These examples illustrate the use of electrochemistry and on-chip reactions in ESI-MS analysis

    Nickel exsolution driven phase transformation from an n=2 to an n=1 Ruddlesden Popper manganite for methane steam reforming reaction in SOFC conditions

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    This is the peer reviewed version of the following article: S. Vecino-Mantilla, P. Gauthier-Maradei, M. Huvé, J. M. Serra, P. Roussel, G. H. Gauthier, ChemCatChem 2019, 11, 4631, which has been published in final form at https://doi.org/10.1002/cctc.201901002. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] An original way to perform the exsolution of Ni nanoparticles on a ceramic support was explored for the development of methane steam reforming catalyst in SOFC anode conditions. The n=2 Ruddlesden-Popper (RP) phase La1.5Sr1.5Mn1.5Ni0.5O7 +/-delta has been synthesized by the Pechini method and subsequently reduced with an H-2-N-2 mixture at different temperatures and reducing times to induce the formation of two phases: LaSrMnO4 (n=1 RP) decorated with metallic Ni nanoparticles. Preliminary measurements of catalytic behavior for the steam reforming have been carried out in a reduction-reaction process with a mixture of 82 mol %CH4, 18 mol %N-2 and low steam to carbon ratio (S/C=0.15). The catalyst exhibits a selectivity for CO production (0.97), 14.60 mol % CH4 conversion and around 24.19 mol % H-2 production. Such catalytic behavior was maintained for more than 4 h, with a constant rate of hydrogen production and CH4 conversion rate.The authors acknowledge the financial support of the Colombian Administrative Department of Science, Technology and Innovation COLCIENCIAS (Project #110265842833 "Symmetrical high temperature Fuel Cell operating with Colombian natural gas" (contract #038-2015) and S. Vecino-Mantilla's Ph.D. scholarship (call #647)) and of the Spanish National Research Council CSIC (Project #COOPA20112). The authors are also grateful to UIS' X-Ray Laboratory (Parque Tecnologico Guatiguara) for XRD measurements, UPV's Electronic Microscopy Laboratory for the FESEM analysis, and finally to Margarita Vecino-Mantilla, Carolina Cardenas-Velandia, Santiago Paez-Duque, Ivan Suarez-Acelas (UIS), Maria Fabuel (UPV) and Olivier Gardoll (UCCS) for their contribution to materials synthesis and characterization. As well as Santiago Palencia, Monica Sandoval (UIS) and Caroline Pirovano (UCCS) are warmly acknowledged for useful discussions.Vecino-Mantilla, S.; Gauthier-Maradei, P.; Huvé, M.; Serra Alfaro, JM.; Roussel, P.; Gauthier, GH. (2019). Nickel exsolution driven phase transformation from an n=2 to an n=1 Ruddlesden Popper manganite for methane steam reforming reaction in SOFC conditions. ChemCatChem. 11(18):4631-4641. https://doi.org/10.1002/cctc.201901002S463146411118Ghezel-Ayagh, H., & Borglum, B. P. (2017). Review of Progress in Solid Oxide Fuel Cells at FuelCell Energy. ECS Transactions, 78(1), 77-86. doi:10.1149/07801.0077ecstPark, B. H., & Choi, G. M. (2014). Ex-solution of Ni nanoparticles in a La0.2Sr0.8Ti1−xNixO3−δ alternative anode for solid oxide fuel cell. Solid State Ionics, 262, 345-348. doi:10.1016/j.ssi.2013.10.016Chung, Y. S., Kim, T., Shin, T. H., Yoon, H., Park, S., Sammes, N. M., … Chung, J. S. (2017). In situ preparation of a La1.2Sr0.8Mn0.4Fe0.6O4 Ruddlesden–Popper phase with exsolved Fe nanoparticles as an anode for SOFCs. Journal of Materials Chemistry A, 5(14), 6437-6446. doi:10.1039/c6ta09692aSun, Y., Li, J., Zeng, Y., Amirkhiz, B. S., Wang, M., Behnamian, Y., & Luo, J. (2015). A-site deficient perovskite: the parent for in situ exsolution of highly active, regenerable nano-particles as SOFC anodes. Journal of Materials Chemistry A, 3(20), 11048-11056. doi:10.1039/c5ta01733eHu, Y., Bouffanais, Y., Almar, L., Morata, A., Tarancon, A., & Dezanneau, G. (2013). La2−xSrxCoO4−δ (x = 0.9, 1.0, 1.1) Ruddlesden-Popper-type layered cobaltites as cathode materials for IT-SOFC application. International Journal of Hydrogen Energy, 38(7), 3064-3072. doi:10.1016/j.ijhydene.2012.12.047Li, Y., Zhang, W., Zheng, Y., Chen, J., Yu, B., Chen, Y., & Liu, M. (2017). Controlling cation segregation in perovskite-based electrodes for high electro-catalytic activity and durability. Chemical Society Reviews, 46(20), 6345-6378. doi:10.1039/c7cs00120gKharton, V. ., Yaremchenko, A. ., Shaula, A. ., Patrakeev, M. ., Naumovich, E. ., Logvinovich, D. ., … Marques, F. M. . (2004). Transport properties and stability of Ni-containing mixed conductors with perovskite- and K2NiF4-type structure. Journal of Solid State Chemistry, 177(1), 26-37. doi:10.1016/s0022-4596(03)00261-5Skinner, S. (2000). Oxygen diffusion and surface exchange in La2−xSrxNiO4+δ. Solid State Ionics, 135(1-4), 709-712. doi:10.1016/s0167-2738(00)00388-xBalachandran, P. V., Puggioni, D., & Rondinelli, J. M. (2013). Crystal-Chemistry Guidelines for Noncentrosymmetric A2BO4 Ruddlesden−Popper Oxides. Inorganic Chemistry, 53(1), 336-348. doi:10.1021/ic402283cAutret, C., Martin, C., Hervieu, M., Retoux, R., Raveau, B., André, G., & Bourée, F. (2004). Structural investigation of Ca2MnO4 by neutron powder diffraction and electron microscopy. Journal of Solid State Chemistry, 177(6), 2044-2052. doi:10.1016/j.jssc.2004.02.012Dailly, J., Fourcade, S., Largeteau, A., Mauvy, F., Grenier, J. C., & Marrony, M. (2010). Perovskite and A2MO4-type oxides as new cathode materials for protonic solid oxide fuel cells. Electrochimica Acta, 55(20), 5847-5853. doi:10.1016/j.electacta.2010.05.034ZHAO, H., MAUVY, F., LALANNE, C., BASSAT, J., FOURCADE, S., & GRENIER, J. (2008). New cathode materials for ITSOFC: Phase stability, oxygen exchange and cathode properties of La2−xNiO4+δ. Solid State Ionics, 179(35-36), 2000-2005. doi:10.1016/j.ssi.2008.06.019Yoo, Y.-S., Choi, M., Hwang, J.-H., Im, H.-N., Singh, B., & Song, S.-J. (2015). La2NiO4+δ as oxygen electrode in reversible solid oxide cells. Ceramics International, 41(5), 6448-6454. doi:10.1016/j.ceramint.2015.01.083Das, A., Xhafa, E., & Nikolla, E. (2016). Electro- and thermal-catalysis by layered, first series Ruddlesden-Popper oxides. Catalysis Today, 277, 214-226. doi:10.1016/j.cattod.2016.07.014Liping, S., Lihua, H., Hui, Z., Qiang, L., & Pijolat, C. (2008). La substituted Sr2MnO4 as a possible cathode material in SOFC. Journal of Power Sources, 179(1), 96-100. doi:10.1016/j.jpowsour.2007.12.090Jin, C., Yang, Z., Zheng, H., Yang, C., & Chen, F. (2012). La0.6Sr1.4MnO4 layered perovskite anode material for intermediate temperature solid oxide fuel cells. Electrochemistry Communications, 14(1), 75-77. doi:10.1016/j.elecom.2011.11.008Sandoval, M. V., Pirovano, C., Capoen, E., Jooris, R., Porcher, F., Roussel, P., & Gauthier, G. H. (2017). In-depth study of the Ruddlesden-Popper LaxSr2−xMnO4±δ family as possible electrode materials for symmetrical SOFC. International Journal of Hydrogen Energy, 42(34), 21930-21943. doi:10.1016/j.ijhydene.2017.07.062Li-Ping, S., Qiang, L., Li-Hua, H., Hui, Z., Guo-Ying, Z., Nan, L., … Pijolat, C. (2011). Synthesis and performance of Sr1.5LaxMnO4 as cathode materials for intermediate temperature solid oxide fuel cell. Journal of Power Sources, 196(14), 5835-5839. doi:10.1016/j.jpowsour.2011.03.016Shen, J., Yang, G., Zhang, Z., Zhou, W., Wang, W., & Shao, Z. (2016). Tuning layer-structured La0.6Sr1.4MnO4+δ into a promising electrode for intermediate-temperature symmetrical solid oxide fuel cells through surface modification. Journal of Materials Chemistry A, 4(27), 10641-10649. doi:10.1039/c6ta02986hThommy, L., Joubert, O., Hamon, J., & Caldes, M.-T. (2016). Impregnation versus exsolution: Using metal catalysts to improve electrocatalytic properties of LSCM-based anodes operating at 600 °C. International Journal of Hydrogen Energy, 41(32), 14207-14216. doi:10.1016/j.ijhydene.2016.06.088Irvine, J. T. S., Neagu, D., Verbraeken, M. C., Chatzichristodoulou, C., Graves, C., & Mogensen, M. B. (2016). Evolution of the electrochemical interface in high-temperature fuel cells and electrolysers. Nature Energy, 1(1). doi:10.1038/nenergy.2015.14Zhou, J., Shin, T.-H., Ni, C., Chen, G., Wu, K., Cheng, Y., & Irvine, J. T. S. (2016). In Situ Growth of Nanoparticles in Layered Perovskite La0.8Sr1.2Fe0.9Co0.1O4−δ as an Active and Stable Electrode for Symmetrical Solid Oxide Fuel Cells. Chemistry of Materials, 28(9), 2981-2993. doi:10.1021/acs.chemmater.6b00071Hua, B., Li, M., Sun, Y.-F., Li, J.-H., & Luo, J.-L. (2017). Enhancing Perovskite Electrocatalysis of Solid Oxide Cells Through Controlled Exsolution of Nanoparticles. ChemSusChem, 10(17), 3333-3341. doi:10.1002/cssc.201700936Yang, C., Li, J., Lin, Y., Liu, J., Chen, F., & Liu, M. (2015). In situ fabrication of CoFe alloy nanoparticles structured (Pr0.4Sr0.6)3(Fe0.85Nb0.15)2O7 ceramic anode for direct hydrocarbon solid oxide fuel cells. Nano Energy, 11, 704-710. doi:10.1016/j.nanoen.2014.12.001Zhang, W., & Zheng, W. (2014). Exsolution-Mimic Heterogeneous Surfaces: Towards Unlimited Catalyst Design. ChemCatChem, 7(1), 48-50. doi:10.1002/cctc.201402757Liu, S., Zhang, W., Deng, T., Wang, D., Wang, X., Zhang, X., … Zheng, W. (2017). Mechanistic Origin of Enhanced CO Catalytic Oxidation over Co3 O4 /LaCoO3 at Lower Temperature. ChemCatChem, 9(16), 3102-3106. doi:10.1002/cctc.201700937Arrivé, C., Delahaye, T., Joubert, O., & Gauthier, G. (2013). Exsolution of nickel nanoparticles at the surface of a conducting titanate as potential hydrogen electrode material for solid oxide electrochemical cells. Journal of Power Sources, 223, 341-348. doi:10.1016/j.jpowsour.2012.09.062Gao, Y., Chen, D., Saccoccio, M., Lu, Z., & Ciucci, F. (2016). From material design to mechanism study: Nanoscale Ni exsolution on a highly active A-site deficient anode material for solid oxide fuel cells. Nano Energy, 27, 499-508. doi:10.1016/j.nanoen.2016.07.013Sun, Y.-F., Zhang, Y.-Q., Chen, J., Li, J.-H., Zhu, Y.-T., Zeng, Y.-M., … Luo, J.-L. (2016). New Opportunity for in Situ Exsolution of Metallic Nanoparticles on Perovskite Parent. Nano Letters, 16(8), 5303-5309. doi:10.1021/acs.nanolett.6b02757Ouellette, R. J., & Rawn, J. D. (2014). Organometallic Chemistry of Transition Metal Elements and Introduction to Retrosynthesis. Organic Chemistry, 567-593. doi:10.1016/b978-0-12-800780-8.00017-6Yaremchenko, A. A., Bannikov, D. O., Kovalevsky, A. V., Cherepanov, V. A., & Kharton, V. V. (2008). High-temperature transport properties, thermal expansion and cathodic performance of Ni-substituted LaSr2Mn2O7−δ. Journal of Solid State Chemistry, 181(11), 3024-3032. doi:10.1016/j.jssc.2008.07.038Chupakhina, T. I., Bazuev, G. V., & Zabolotskaya, E. V. (2010). Synthesis and magnetic properties of a new layered oxide La1.5Sr1.5Mn1.25Ni0.75O6.67. Russian Journal of Inorganic Chemistry, 55(2), 247-253. doi:10.1134/s0036023610020178Jardiel, T., Caldes, M. T., Moser, F., Hamon, J., Gauthier, G., & Joubert, O. (2010). New SOFC electrode materials: The Ni-substituted LSCM-based compounds (La0.75Sr0.25)(Cr0.5Mn0.5−xNix)O3−δ and (La0.75Sr0.25)(Cr0.5−xNixMn0.5)O3−δ. Solid State Ionics, 181(19-20), 894-901. doi:10.1016/j.ssi.2010.05.012Svoboda, K., Siewiorek, A., Baxter, D., Rogut, J., & Pohořelý, M. (2008). Thermodynamic possibilities and constraints for pure hydrogen production by a nickel and cobalt-based chemical looping process at lower temperatures. Energy Conversion and Management, 49(2), 221-231. doi:10.1016/j.enconman.2007.06.036Bhardwaj, A., Kaur, J., Wuest, M., & Wuest, F. (2017). In situ click chemistry generation of cyclooxygenase-2 inhibitors. Nature Communications, 8(1). doi:10.1038/s41467-016-0009-6Zhu, J., Li, H., Zhong, L., Xiao, P., Xu, X., Yang, X., … Li, J. (2014). Perovskite Oxides: Preparation, Characterizations, and Applications in Heterogeneous Catalysis. ACS Catalysis, 4(9), 2917-2940. doi:10.1021/cs500606gBroux, T., Prestipino, C., Bahout, M., Hernandez, O., Swain, D., Paofai, S., … Greaves, C. (2013). Unprecedented High Solubility of Oxygen Interstitial Defects in La1.2Sr0.8MnO4+δ up to δ ∼ 0.42 Revealed by In Situ High Temperature Neutron Powder Diffraction in Flowing O2. Chemistry of Materials, 25(20), 4053-4063. doi:10.1021/cm402194qMUNNINGS, C., SKINNER, S., AMOW, G., WHITFIELD, P., & DAVIDSON, I. (2006). Structure, stability and electrical properties of the La(2−x)SrxMnO4±δ solid solution series. Solid State Ionics, 177(19-25), 1849-1853. doi:10.1016/j.ssi.2006.01.009Li, R. K., & Greaves, C. (2000). Synthesis and Characterization of the Electron-Doped Single-Layer Manganite La1.2Sr0.8MnO4−δ and Its Oxidized Phase La1.2Sr0.8MnO4+δ. Journal of Solid State Chemistry, 153(1), 34-40. doi:10.1006/jssc.2000.8735Wang, Y., Shih, K., & Jiang, X. (2012). Phase transformation during the sintering of γ-alumina and the simulated Ni-laden waste sludge. Ceramics International, 38(3), 1879-1886. doi:10.1016/j.ceramint.2011.10.015Senff, D., Reutler, P., Braden, M., Friedt, O., Bruns, D., Cousson, A., … Revcolevschi, A. (2005). Crystal and magnetic structure ofLa1−xSr1+xMnO4: Role of the orbital degree of freedom. Physical Review B, 71(2). doi:10.1103/physrevb.71.024425Larochelle, S., Mehta, A., Lu, L., Mang, P. K., Vajk, O. P., Kaneko, N., … Greven, M. (2005). Structural and magnetic properties of the single-layer manganese oxideLa1−xSr1+xMnO4. Physical Review B, 71(2). doi:10.1103/physrevb.71.024435Bieringer, M., & Greedan, J. E. (2002). Structure and magnetism in BaLaMnO4 +/– δ (δ = 0.00, 0.10) and BaxSr1 – xLaMnO4. Disappearance of magnetic order for x > 0.30. Journal of Materials Chemistry, 12(2), 279-287. doi:10.1039/b104405mKitchen, H. J., Saratovsky, I., & Hayward, M. A. (2010). Topotactic reduction as a synthetic route for the preparation of low-dimensional Mn(II) oxide phases: The structure and magnetism of LaAMnO4-x (A = Sr, Ba). Dalton Transactions, 39(26), 6098. doi:10.1039/b923966aBandyopadhyay, J., & Gupta, K. P. (1977). Low temperature lattice parameter of nickel and some nickel-cobalt alloys and Grüneisen parameter of nickel. Cryogenics, 17(6), 345-347. doi:10.1016/0011-2275(77)90130-8Lai, K.-Y., & Manthiram, A. (2018). Evolution of Exsolved Nanoparticles on a Perovskite Oxide Surface during a Redox Process. Chemistry of Materials, 30(8), 2838-2847. doi:10.1021/acs.chemmater.8b01029Blasse, G. (1965). New compositions with K2NiF4 structure. Journal of Inorganic and Nuclear Chemistry, 27(12), 2683-2684. doi:10.1016/0022-1902(65)80178-6Moritomo, Y., Tomioka, Y., Asamitsu, A., Tokura, Y., & Matsui, Y. (1995). Magnetic and electronic properties in hole-doped manganese oxides with layered structures:La1−xSr1+xMnO4. Physical Review B, 51(5), 3297-3300. doi:10.1103/physrevb.51.3297Ganguly, P., & Rao, C. N. R. (1984). Crystal chemistry and magnetic properties of layered metal oxides possessing the K2NiF4 or related structures. Journal of Solid State Chemistry, 53(2), 193-216. doi:10.1016/0022-4596(84)90094-xBenabad, A., Daoudi, A., Salmon, R., & Le Flem, G. (1977). Les phases SrLnMnO4 (Ln = La, Nd, Sm, Gd), BaLnMnO4 (Ln = La, Nd) et M1+xLa1−xMnO4 (M = Sr, Ba). Journal of Solid State Chemistry, 22(2), 121-126. doi:10.1016/0022-4596(77)90028-7Wu, W. B., Huang, D. J., Guo, G. Y., Lin, H.-J., Hou, T. Y., Chang, C. F., … Jo, T. (2004). Orbital polarization of LaSrMnO4 studied by soft X-ray linear dichroism. Journal of Electron Spectroscopy and Related Phenomena, 137-140, 641-645. doi:10.1016/j.elspec.2004.02.072GONZALEZDELACRUZ, V., HOLGADO, J., PERENIGUEZ, R., & CABALLERO, A. (2008). Morphology changes induced by strong metal–support interaction on a Ni–ceria catalytic system. Journal of Catalysis, 257(2), 307-314. doi:10.1016/j.jcat.2008.05.009Dulub, O., Hebenstreit, W., & Diebold, U. (2000). Imaging Cluster Surfaces with Atomic Resolution: The Strong Metal-Support Interaction State of Pt Supported onTiO2(110). Physical Review Letters, 84(16), 3646-3649. doi:10.1103/physrevlett.84.3646Wei, T., Jia, L., Zheng, H., Chi, B., Pu, J., & Li, J. (2018). LaMnO3-based perovskite with in-situ exsolved Ni nanoparticles: a highly active, performance stable and coking resistant catalyst for CO2 dry reforming of CH4. Applied Catalysis A: General, 564, 199-207. doi:10.1016/j.apcata.2018.07.031A. Adamson A. Gat Physical Chemistry of Surfaces John Wiley & Sons Inc. New York 1997.Oh, T.-S., Rahani, E. K., Neagu, D., Irvine, J. T. S., Shenoy, V. B., Gorte, R. J., & Vohs, J. M. (2015). Evidence and Model for Strain-Driven Release of Metal Nanocatalysts from Perovskites during Exsolution. The Journal of Physical Chemistry Letters, 6(24), 5106-5110. doi:10.1021/acs.jpclett.5b02292Blander, M., & Katz, J. L. (1975). Bubble nucleation in liquids. AIChE Journal, 21(5), 833-848. doi:10.1002/aic.690210502Kelchner, C. L., Plimpton, S. J., & Hamilton, J. C. (1998). Dislocation nucleation and defect structure during surface indentation. Physical Review B, 58(17), 11085-11088. doi:10.1103/physrevb.58.11085Neagu, D., Tsekouras, G., Miller, D. N., Ménard, H., & Irvine, J. T. S. (2013). In situ growth of nanoparticles through control of non-stoichiometry. Nature Chemistry, 5(11), 916-923. doi:10.1038/nchem.1773Raabe, O. G. (1971). Particle size analysis utilizing grouped data and the log-normal distribution. Journal of Aerosol Science, 2(3), 289-303. doi:10.1016/0021-8502(71)90054-1Pauw, B. R., Kästner, C., & Thünemann, A. F. (2017). Nanoparticle size distribution quantification: results of a small-angle X-ray scattering inter-laboratory comparison. Journal of Applied Crystallography, 50(5), 1280-1288. doi:10.1107/s160057671701010xNeagu, D., Oh, T.-S., Miller, D. N., Ménard, H., Bukhari, S. M., Gamble, S. R., … Irvine, J. T. S. (2015). Nano-socketed nickel particles with enhanced coking resistance grown in situ by redox exsolution. Nature Communications, 6(1). doi:10.1038/ncomms9120Hansen, T. W., DeLaRiva, A. T., Challa, S. R., & Datye, A. K. (2013). Sintering of Catalytic Nanoparticles: Particle Migration or Ostwald Ripening? Accounts of Chemical Research, 46(8), 1720-1730. doi:10.1021/ar3002427Lif, J., Skoglundh, M., & Löwendahl, L. (2002). Sintering of nickel particles supported on γ-alumina in ammonia. Applied Catalysis A: General, 228(1-2), 145-154. doi:10.1016/s0926-860x(01)00957-7Agüero, F. N., Beltrán, A. M., Fernández, M. A., & Cadús, L. E. (2019). Surface nickel particles generated by exsolution from a perovskite structure. Journal of Solid State Chemistry, 273, 75-80. doi:10.1016/j.jssc.2019.02.036Asoro, M. A., Ferreira, P. J., & Kovar, D. (2014). In situ transmission electron microscopy and scanning transmission electron microscopy studies of sintering of Ag and Pt nanoparticles. Acta Materialia, 81, 173-183. doi:10.1016/j.actamat.2014.08.028Girona, K., Sailler, S., Gélin, P., Bailly, N., Georges, S., & Bultel, Y. (2014). Modelling of gradual internal reforming process over Ni-YSZ SOFC anode with a catalytic layer. The Canadian Journal of Chemical Engineering, 93(2), 285-296. doi:10.1002/cjce.22113W. K. B. W. Ramli Exsolved Base Metal Catalyst Systems with Anchored Nanoparticles for Carbon Monoxide (CO) and Nitric Oxides (NO Oxidation Newcastle University 2017.Sadykov, V., Mezentseva, N., Alikina, G., Bunina, R., Pelipenko, V., Lukashevich, A., … Rietveld, B. (2009). Nanocomposite catalysts for internal steam reforming of methane and biofuels in solid oxide fuel cells: Design and performance. Catalysis Today, 146(1-2), 132-140. doi:10.1016/j.cattod.2009.02.035Atkinson, A., Barnett, S., Gorte, R. J., Irvine, J. T. S., McEvoy, A. J., Mogensen, M., … Vohs, J. (2004). Advanced anodes for high-temperature fuel cells. Nature Materials, 3(1), 17-27. doi:10.1038/nmat1040Dicks, A. . (1998). Advances in catalysts for internal reforming in high temperature fuel cells. Journal of Power Sources, 71(1-2), 111-122. doi:10.1016/s0378-7753(97)02753-5Roy, P. S., Park, N.-K., & Kim, K. (2014). Metal foam-supported Pd–Rh catalyst for steam methane reforming and its application to SOFC fuel processing. International Journal of Hydrogen Energy, 39(9), 4299-4310. doi:10.1016/j.ijhydene.2014.01.004Postole, G., Bosselet, F., Bergeret, G., Prakash, S., & Gélin, P. (2014). On the promoting effect of H2S on the catalytic H2 production over Gd-doped ceria from CH4/H2O mixtures for solid oxide fuel cell applications. Journal of Catalysis, 316, 149-163. doi:10.1016/j.jcat.2014.05.011Cheah, S. K., Massin, L., Aouine, M., Steil, M. C., Fouletier, J., & Gélin, P. (2018). Methane steam reforming in water deficient conditions on Ir/Ce0.9Gd0.1O2-x catalyst: Metal-support interactions and catalytic activity enhancement. Applied Catalysis B: Environmental, 234, 279-289. doi:10.1016/j.apcatb.2018.04.048Bartholomew, C. H. (1982). Carbon Deposition in Steam Reforming and Methanation. Catalysis Reviews, 24(1), 67-112. doi:10.1080/03602458208079650M. P. Pechini Method of Preparing Lead and Alkaline Earth Titanates and Niobates and Coating Method Using the Same to Form a Capacitor 1967 US3330697 A.Petříček, V., Dušek, M., & Palatinus, L. (2014). Crystallographic Computing System JANA2006: General features. Zeitschrift für Kristallographie - Crystalline Materials, 229(5). doi:10.1515/zkri-2014-173

    The effect of microencapsulated phase change materials on the rheology of geopolymer and Portland cement mortars

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    The effect of microencapsulated phase‐change materials (MPCM) on the rheological properties of pre‐set geopolymer and Portland cement mortars was examined. Microcapsules with hydrophilic and hydrophobic shells were compared. The shear rate dependency of the viscosities fitted well to a double Carreau model. The zero shear viscosities are higher for geopolymer mortar, illustrating poorer workability. The time evolution of the viscosities was explored at shear rates of 1 and 10 s−1. New empirical equations were developed to quantify the time‐dependent viscosity changes. The highest shear rate disrupted the buildup of the mortar structures much more than the lower shear rate. Microcapsules with a hydrophobic shell affect the rheological properties much less than the microcapsules with a hydrophilic shell, due to the higher water adsorption onto the hydrophilic microcapsules. Shear forces was found to break down the initial structures within geopolymer mortars more easily than for Portland cement mortars, while the geopolymer reaction products are able to withstand shear forces better than Portland cement hydration products. Initially, the viscosity of geopolymer mortars increases relatively slowly during due to formation of geopolymer precursors; at longer times, there is a steeper viscosity rise caused by the development of a 3D‐geopolymer network. Disruption of agglomerates causes the viscosities of portland cement mortars to decrease during the first few minutes, after which the hydration process (increasing viscosities) competes with shear‐induced disruption of the structures (decreasing viscosities), resulting in a complex viscosity behavior.publishedVersio

    Generation of cattle knockout for galactose‐α1,3‐galactose and N‐glycolylneuraminic acid antigens

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    Two well-characterized carbohydrate epitopes are absent in humans but present in other mammals. These are galactose-α1,3-galactose (αGal) and N-glycolylneuraminic acid (Neu5Gc) which are introduced by the activities of two enzymes including α(1,3) galactosyltransferase (encoded by the GGTA1 gene) and CMP-Neu5Gc hydroxylase (encoded by the CMAH gene) that are inactive in humans but present in cattle. Hence, bovine-derived products are antigenic in humans who receive bioprosthetic heart valves (BHVs) or those that suffer from red meat syndrome. Using programmable nucleases, we disrupted (knockout, KO) GGTA1 and CMAH genes encoding for the enzymes that catalyse the synthesis of αGal and Neu5Gc, respectively, in both male and female bovine fibroblasts. The KO in clonally selected fibroblasts was detected by polymerase chain reaction (PCR) and confirmed by Sanger sequencing. Selected fibroblasts colonies were used for somatic cell nuclear transfer (SCNT) to produce cloned embryos that were implanted in surrogate recipient heifers. Fifty-three embryos were implanted in 33 recipients heifers; 3 pregnancies were carried to term and delivered 3 live calves. Primary cell cultures were established from the 3 calves and following molecular analyses confirmed the genetic deletions. FACS analysis showed the double-KO phenotype for both antigens confirming the mutated genotypes. Availability of such cattle double-KO model lacking both αGal and Neu5Gc offers a unique opportunity to study the functionality of BHV manufactured with tissues of potentially lower immunogenicity, as well as a possible new clinical approaches to help patients with red meat allergy syndrome due to the presence of these xenoantigens in the diet

    Differential Immune Response to Bioprosthetic Heart Valve Tissues in the α1,3Galactosyltransferase-Knockout Mouse Model

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    Structural valve deterioration (SVD) of bioprosthetic heart valves (BHVs) has great clinical and economic consequences. Notably, immunity against BHVs plays a major role in SVD, especially when implanted in young and middle-aged patients. However, the complex pathogenesis of SVD remains to be fully characterized, and analyses of commercial BHVs in standardized-preclinical settings are needed for further advancement. Here, we studied the immune response to commercial BHV tissue of bovine, porcine, and equine origin after subcutaneous implantation into adult a1,3-galactosyltransferase-knockout (Gal KO) mice. The levels of serum anti-galactose a1,3-galactose (Gal) and -non-Gal IgM and IgG antibodies were determined up to 2 months post-implantation. Based on histological analyses, all BHV tissues studied triggered distinct infiltrating cellular immune responses that related to tissue degeneration. Increased anti-Gal antibody levels were found in serum after ATS 3f and Freedom/Solo implantation but not for Crown or Hancock II grafts. Overall, there were no correlations between cellular-immunity scores and post-implantation antibodies, suggesting these are independent factors differentially affecting the outcome of distinct commercial BHVs. These findings provide further insights into the understanding of SVD immunopathogenesis and highlight the need to evaluate immune responses as a confounding factor

    Characterization of immunogenic Neu5Gc in bioprosthetic heart valves

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    Background: The two common sialic acids (Sias) in mammals are N-acetylneuraminic acid (Neu5Ac) and its hydroxylated form N-glycolylneuraminic acid (Neu5Gc). Unlike most mammals, humans cannot synthesize Neu5Gc that is considered foreign and recognized by circulating antibodies. Thus, Neu5Gc is a potential xenogenic carbohydrate antigen in bioprosthetic heart valves (BHV) that tend to deteriorate in time within human patients. Methods: We investigated Neu5Gc expression in non-engineered animal-derived cardiac tissues and in clinically used commercial BHV, and evaluated Neu5Gc immunogenicity on BHV through recognition by human anti-Neu5Gc IgG. Results: Neu5Gc was detected by immunohistochemistry in porcine aortic valves and in porcine and bovine pericardium. Qualitative analysis of Sia linkages revealed Siaa2-3> Siaa2-6 on porcine/bovine pericardium while the opposite in porcine aortic/pulmonary valve cusps. Similarly, six commercial BHV containing either porcine aortic valve or porcine/bovine/equine pericardium revealed Siaa2-3> Siaa2-6 expression. Quantitative analysis of Sia by HPLC showed porcine/bovine pericardium express 4-fold higher Neu5Gc levels compared to the porcine aortic/pulmonary valves, with Neu5Ac at 6-fold over Neu5Gc. Likewise, Neu5Gc was expressed on commercial BHV (186.3 +/- 16.9 pmol Sia/mu g protein), with Neu5Ac at 8-fold over Neu5Gc. Affinity-purified human anti-Neu5Gc IgG showing high specificity toward Neu5Gc-glycans (with no binding to Neu5Ac-glycans) on a glycan microarray, strongly bound to all tested commercial BHV, demonstrating Neu5Gc immune recognition in cardiac xenografts. Conclusions: We conclusively demonstrated Neu5Gc expression in native cardiac tissues, as well as in six commercial BHV. These Neu5Gc xeno-antigens were recognized by human anti-Neu5Gc IgG, supporting their immunogenicity. Altogether, these findings suggest BHV-Neu5Gc/anti-Neu5Gc may play a role in valve deterioration warranting further investigation

    The Baleares 2013 Calibration Campaign of Jason-2 and Saral Altimeters

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    The 2013 Balearic campaign GNSS position analysis of the 2013 will be performed with different softwares by different groups (similarly as it is being done in the International GNSS Service for their different products), in order improve the high demanded accuracy for JASON2 and SARAL altimeters precise calibration. In particular JPL GIPSY-OASIS software will be used, with the undifferenced PPP ambiguity fixing strategy. In order to improve the results accuracy, two similar networks are being processed. The first network includes the deployed GNSS receivers and the reference stations. The second one is a control network, defined by using the permanent receivers in the California dense network with a similar distribution as the main altimeter campaign network. In this case, the position of the receivers plying the role of buoys are being processed in the same kinematic way than the actual buoys, in order to compare them with the very accurate positions obtained with GIPSY-OASIS static processing.Postprint (published version

    Real-world outcomes of treatment with insulin glargine 300 U/mL versus standard-of-care in people with uncontrolled type 2 diabetes mellitus

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    Objective: To compare real-world outcomes with newer (insulin glargine 300 U/mL; Gla-300) versus standard of care (SoC) basal insulins (BIs) in the REACH (insulin-naive; NCT02967224) and REGAIN (basal insulin-treated; NCT02967211) studies in participants with uncontrolled type 2 diabetes (T2DM) in Europe and Brazil. Methods: In these open-label, parallel-group, pragmatic studies, patients (HbA(1c) > 7.0%) were randomized to Gla-300 or SoC BI for a 6-month treatment period (to demonstrate non-inferiority of Gla-300 vs SoC BIs for HbA(1c) change [non-inferiority margin 0.3%]) and a 6-month extension period (continuing with their assigned treatment). Insulin titration/other medication changes were at investigator/patient discretion post-randomization. Results: Overall, 703 patients were randomized to treatment in REACH (Gla-300, n = 352; SoC, n = 351) and 609 (Gla-300, n = 305, SoC, n = 304) in REGAIN. The primary outcome, non-inferiority of Gla-300 versus SoC for HbA(1c) change from baseline to month 6, was met in REACH (least squares [LS] mean difference 0.12% [95% CI -0.046 to 0.281]) but not REGAIN (LS mean difference 0.17% [0.015-0.329]); no between-treatment difference in HbA(1c) change was shown after 12 months in either study. BI dose increased minimally from baseline to 12 months in REACH (Gla-300, +0.17 U/kg; SoC, +0.15 U/kg) and REGAIN (Gla-300, +0.11 U/kg; SoC, +0.07 U/kg). Hypoglycemia incidence was low and similar between treatment arms in both studies. Conclusions: In both REACH and REGAIN, no differences in glycemic control or hypoglycemia outcomes with Gla-300 versus SoC BIs were seen over 12 months. However, the suboptimal insulin titration in REACH and REGAIN limits comparisons of outcomes between treatment arms and suggests that more titration instruction/support may be required for patients to fully derive the benefits from newer basal insulin formulations

    Oxidative Stress in Structural Valve Deterioration : A Longitudinal Clinical Study

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    The cause of structural valve deterioration (SVD) is unclear. Therefore, we investigated oxidative stress markers in sera from patients with bioprosthetic heart valves (BHVs) and their association with SVD. Blood samples were taken from SVD (Phase A) and BHV patients during the first 24 (Phase B1) and >48 months (Phase B2) after BHV implantation to assess total antioxidant capacity (TAC), malondialdehyde (MDA), and nitrotyrosine (NT). The results show that MDA levels increased significantly 1 month after surgery in all groups but were higher at 6 months only in incipient SVD patients. NT levels increased gradually for the first 24 months after implantation in the BHV group. Patients with transcatheter aortic valve implantation (TAVI) showed even higher levels of stress markers. After >48 months, MDA and NT continued to increase in BHV patients with a further elevation after 60-72 months; however, these levels were significantly lower in the incipient and established SVD groups. In conclusion, oxidative stress may play a significant role in SVD, increasing early after BHV implantation, especially in TAVI cases, and also after 48 months' follow-up, but decreasing when SVD develops. Oxidative stress potentially represents a target of therapeutic intervention and a biomarker of BHV dysfunctio
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