Enhanced conductivity of sodium versus lithium salts. Sodium metallacarboranes as electrolyte

[EN] The development of new types of ion conducting materials is one of the most important challenges in the field of energy. Lithium salt polymer electrolytes have been the most convenient, and thus the most widely used in the design of the new generation of batteries. However, in this work, we have observed that Na+ ions provide a higher conductivity, or at least a comparable conductivity to that of Li+ ions in the same basic material. This provides an excellent possibility to use Na+ ions in the design of a new generation of batteries, instead of lithium, to enhance conductivity and ensure wide supply. Our results indicate that the dc-conductivity is larger when the anion is [Co(C2B9H11)(2)](-), [COSANE](-), compared to tetraphenylborate, [TPB](-). Our data also prove that the dc-conductivity behavior of Li+ and Na+ salts is opposite with the two anions. At 40 C-omicron, the conductivity values change from 1.05 x 10(-2) S cm(-1) (Li[COSANE]) and 1.75 x 10(-2) S cm(-1) (Na[COSANE]) to 2.8 x 10(-3) S cm(-1) (Li[TPB]) and 1.5 x 10(-3) S cm(-1) (Na[TPB]). These findings indicate that metallacarboranes can be useful components of mixed matrix membranes (MMMs), providing excellent conductivity when the medium contains sufficient amounts of ionic components and a certain degree of humidity.This research has been supported by the ENE/2015-69203-R and CTQ2013-44670-R projects, granted by the Ministerio de Economia y Competitividad (MINECO), Spain; the Generalitat de Catalunya (2014/SGR/149) and FP7-OCEAN-2013: Proposal number: 614168. C. V. thanks COST CM1302 project. I. F. is enrolled in the PhD program of the UAB.Fuentes, I.; Andrio, A.; Teixidor, F.; Viñas, C.; Compañ Moreno, V. (2017). Enhanced conductivity of sodium versus lithium salts. Sodium metallacarboranes as electrolyte. Physical Chemistry Chemical Physics. 15177(15186):15177-15186. https://doi.org/10.1039/c7cp02526bS15177151861517715186Bakangura, E., Wu, L., Ge, L., Yang, Z., & Xu, T. (2016). Mixed matrix proton exchange membranes for fuel cells: State of the art and perspectives. Progress in Polymer Science, 57, 103-152. doi:10.1016/j.progpolymsci.2015.11.004Lufrano, F., Baglio, V., Staiti, P., Antonucci, V., & Arico’, A. S. (2013). Performance analysis of polymer electrolyte membranes for direct methanol fuel cells. Journal of Power Sources, 243, 519-534. doi:10.1016/j.jpowsour.2013.05.180Jiang, S. P. (2014). Functionalized mesoporous structured inorganic materials as high temperature proton exchange membranes for fuel cells. J. Mater. Chem. A, 2(21), 7637-7655. doi:10.1039/c4ta00121dHeo, Y., Im, H., & Kim, J. (2013). The effect of sulfonated graphene oxide on Sulfonated Poly (Ether Ether Ketone) membrane for direct methanol fuel cells. Journal of Membrane Science, 425-426, 11-22. doi:10.1016/j.memsci.2012.09.019Mishra, A. K., Kim, N. H., Jung, D., & Lee, J. H. (2014). Enhanced mechanical properties and proton conductivity of Nafion–SPEEK–GO composite membranes for fuel cell applications. Journal of Membrane Science, 458, 128-135. doi:10.1016/j.memsci.2014.01.073Rambabu, G., & Bhat, S. D. (2014). Simultaneous tuning of methanol crossover and ionic conductivity of sPEEK membrane electrolyte by incorporation of PSSA functionalized MWCNTs: A comparative study in DMFCs. Chemical Engineering Journal, 243, 517-525. doi:10.1016/j.cej.2014.01.030Kango, S., Kalia, S., Celli, A., Njuguna, J., Habibi, Y., & Kumar, R. (2013). Surface modification of inorganic nanoparticles for development of organic–inorganic nanocomposites—A review. Progress in Polymer Science, 38(8), 1232-1261. doi:10.1016/j.progpolymsci.2013.02.003Zeng, J., He, B., Lamb, K., De Marco, R., Shen, P. K., & Jiang, S. P. (2013). Phosphoric acid functionalized pre-sintered meso-silica for high temperature proton exchange membrane fuel cells. Chemical Communications, 49(41), 4655. doi:10.1039/c3cc41716fPaddison, S. J. (2003). Proton Conduction Mechanisms at Low Degrees of Hydration in Sulfonic Acid–Based Polymer Electrolyte Membranes. Annual Review of Materials Research, 33(1), 289-319. doi:10.1146/annurev.matsci.33.022702.155102Peighambardoust, S. J., Rowshanzamir, S., & Amjadi, M. (2010). Review of the proton exchange membranes for fuel cell applications. International Journal of Hydrogen Energy, 35(17), 9349-9384. doi:10.1016/j.ijhydene.2010.05.017Kreuer, K.-D. (1996). Proton Conductivity:  Materials and Applications. Chemistry of Materials, 8(3), 610-641. doi:10.1021/cm950192aKreuer, K.-D., Paddison, S. J., Spohr, E., & Schuster, M. (2004). Transport in Proton Conductors for Fuel-Cell Applications:  Simulations, Elementary Reactions, and Phenomenology. Chemical Reviews, 104(10), 4637-4678. doi:10.1021/cr020715fWang, C., Chalkova, E., Lute, C. D., Fedkin, M. V., Komarneni, S., Chung, T. C. M., & Lvov, S. N. (2010). Proton Conductive Inorganic Materials for Temperatures Up to 120°C and Relative Humidity Down to 5%. Journal of The Electrochemical Society, 157(11), B1634. doi:10.1149/1.3486113Hara, S. (2002). Proton-conducting properties of hydrated tin dioxide as an electrolyte for fuel cells at intermediate temperature. Solid State Ionics, 154-155, 679-685. doi:10.1016/s0167-2738(02)00517-9Yang, Q., Kapoor, M. P., & Inagaki, S. (2002). Sulfuric Acid-Functionalized Mesoporous Benzene−Silica with a Molecular-Scale Periodicity in the Walls. Journal of the American Chemical Society, 124(33), 9694-9695. doi:10.1021/ja026799rMargolese, D., Melero, J. A., Christiansen, S. C., Chmelka, B. F., & Stucky, G. D. (2000). Direct Syntheses of Ordered SBA-15 Mesoporous Silica Containing Sulfonic Acid Groups. Chemistry of Materials, 12(8), 2448-2459. doi:10.1021/cm0010304Jin, Y. G., Qiao, S. Z., Xu, Z. P., Diniz da Costa, J. C., & Lu, G. Q. (2009). Porous Silica Nanospheres Functionalized with Phosphonic Acid as Intermediate-Temperature Proton Conductors. The Journal of Physical Chemistry C, 113(8), 3157-3163. doi:10.1021/jp810112cFujita, S., Koiwai, A., Kawasumi, M., & Inagaki, S. (2013). Enhancement of Proton Transport by High Densification of Sulfonic Acid Groups in Highly Ordered Mesoporous Silica. Chemistry of Materials, 25(9), 1584-1591. doi:10.1021/cm303950uPonomareva, V. ., & Lavrova, G. . (2001). The investigation of disordered phases in nanocomposite proton electrolytes based on MeHSO4 (Me=Rb, Cs, K). Solid State Ionics, 145(1-4), 197-204. doi:10.1016/s0167-2738(01)00957-2Vijayakumar, M., Bain, A. D., & Goward, G. R. (2009). Investigations of Proton Conduction in the Monoclinic Phase of RbH2PO4 Using Multinuclear Solid-State NMR. The Journal of Physical Chemistry C, 113(41), 17950-17957. doi:10.1021/jp903408vHara, S., Takano, S., & Miyayama, M. (2004). Proton-Conducting Properties and Microstructure of Hydrated Tin Dioxide and Hydrated Zirconia. The Journal of Physical Chemistry B, 108(18), 5634-5639. doi:10.1021/jp0370369Kozawa, Y., Suzuki, S., Miyayama, M., Okumiya, T., & Traversa, E. (2010). Proton conducting membranes composed of sulfonated poly(etheretherketone) and zirconium phosphate nanosheets for fuel cell applications. Solid State Ionics, 181(5-7), 348-353. doi:10.1016/j.ssi.2009.12.017Abbaraju, R. R., Dasgupta, N., & Virkar, A. V. (2008). Composite Nafion Membranes Containing Nanosize TiO[sub 2]∕SnO[sub 2] for Proton Exchange Membrane Fuel Cells. Journal of The Electrochemical Society, 155(12), B1307. doi:10.1149/1.2994079Chalkova, E., Fedkin, M. V., Wesolowski, D. J., & Lvov, S. N. (2005). Effect of TiO[sub 2] Surface Properties on Performance of Nafion-Based Composite Membranes in High Temperature and Low Relative Humidity PEM Fuel Cells. Journal of The Electrochemical Society, 152(9), A1742. doi:10.1149/1.1971216Sahu, A. K., Selvarani, G., Pitchumani, S., Sridhar, P., & Shukla, A. K. (2007). A Sol-Gel Modified Alternative Nafion-Silica Composite Membrane for Polymer Electrolyte Fuel Cells. Journal of The Electrochemical Society, 154(2), B123. doi:10.1149/1.2401031González-Cardoso, P., Stoica, A.-I., Farràs, P., Pepiol, A., Viñas, C., & Teixidor, F. (2010). Additive Tuning of Redox Potential in Metallacarboranes by Sequential Halogen Substitution. Chemistry - A European Journal, 16(22), 6660-6665. doi:10.1002/chem.200902558Pepiol, A., Teixidor, F., Sillanpää, R., Lupu, M., & Viñas, C. (2011). Stepwise Sequential Redox Potential Modulation Possible on a Single Platform. Angewandte Chemie International Edition, 50(52), 12491-12495. doi:10.1002/anie.201105668Tarrés, M., Arderiu, V. S., Zaulet, A., Viñas, C., Fabrizi de Biani, F., & Teixidor, F. (2015). How to get the desired reduction voltage in a single framework! Metallacarborane as an optimal probe for sequential voltage tuning. Dalton Transactions, 44(26), 11690-11695. doi:10.1039/c5dt01464fTeixidor, F., Viñas, C., Demonceau, A., & Nuñez, R. (2003). Boron clusters: Do they receive the deserved interest? Pure and Applied Chemistry, 75(9), 1305-1313. doi:10.1351/pac200375091305Olid, D., Núñez, R., Viñas, C., & Teixidor, F. (2013). Methods to produce B–C, B–P, B–N and B–S bonds in boron clusters. Chemical Society Reviews, 42(8), 3318. doi:10.1039/c2cs35441aBauduin, P., Prevost, S., Farràs, P., Teixidor, F., Diat, O., & Zemb, T. (2011). A Theta-Shaped Amphiphilic Cobaltabisdicarbollide Anion: Transition From Monolayer Vesicles to Micelles. Angewandte Chemie International Edition, 50(23), 5298-5300. doi:10.1002/anie.201100410Brusselle, D., Bauduin, P., Girard, L., Zaulet, A., Viñas, C., Teixidor, F., … Diat, O. (2013). Lyotropic Lamellar Phase Formed from Monolayered θ-Shaped Carborane-Cage Amphiphiles. Angewandte Chemie International Edition, 52(46), 12114-12118. doi:10.1002/anie.201307357Gassin, P.-M., Girard, L., Martin-Gassin, G., Brusselle, D., Jonchère, A., Diat, O., … Bauduin, P. (2015). Surface Activity and Molecular Organization of Metallacarboranes at the Air–Water Interface Revealed by Nonlinear Optics. Langmuir, 31(8), 2297-2303. doi:10.1021/acs.langmuir.5b00125Ďorďovič, V., Tošner, Z., Uchman, M., Zhigunov, A., Reza, M., Ruokolainen, J., … Matějíček, P. (2016). Stealth Amphiphiles: Self-Assembly of Polyhedral Boron Clusters. Langmuir, 32(26), 6713-6722. doi:10.1021/acs.langmuir.6b01995Uchman, M., Ďorďovič, V., Tošner, Z., & Matějíček, P. (2015). Classical Amphiphilic Behavior of Nonclassical Amphiphiles: A Comparison of Metallacarborane Self-Assembly with SDS Micellization. Angewandte Chemie International Edition, 54(47), 14113-14117. doi:10.1002/anie.201506545Núñez, R., Romero, I., Teixidor, F., & Viñas, C. (2016). Icosahedral boron clusters: a perfect tool for the enhancement of polymer features. Chemical Society Reviews, 45(19), 5147-5173. doi:10.1039/c6cs00159aNúñez, R., Tarrés, M., Ferrer-Ugalde, A., de Biani, F. F., & Teixidor, F. (2016). Electrochemistry and Photoluminescence of Icosahedral Carboranes, Boranes, Metallacarboranes, and Their Derivatives. Chemical Reviews, 116(23), 14307-14378. doi:10.1021/acs.chemrev.6b00198Masalles, C., Borrós, S., Viñas, C., & Teixidor, F. (2000). Are Low-Coordinating Anions of Interest as Doping Agents in Organic Conducting Polymers? Advanced Materials, 12(16), 1199-1202. doi:10.1002/1521-4095(200008)12:163.0.co;2-wMasalles, C., Borrós, S., Viñas, C., & Teixidor, F. (2002). Surface Layer Formation on Polypyrrole Films. Advanced Materials, 14(6), 449-452. doi:10.1002/1521-4095(20020318)14:63.0.co;2-4Fabre, B., Clark, J. C., & Vicente, M. G. H. (2006). Synthesis and Electrochemistry of Carboranylpyrroles. Toward the Preparation of Electrochemically and Thermally Resistant Conjugated Polymers. Macromolecules, 39(1), 112-119. doi:10.1021/ma051508vHao, E., Fabre, B., Fronczek, F. R., & Vicente, M. G. H. (2007). Syntheses and Electropolymerization of Carboranyl-Functionalized Pyrroles and Thiophenes. Chemistry of Materials, 19(25), 6195-6205. doi:10.1021/cm701935nMasalles, C., Teixidor, F., Borrós, S., & Viñas, C. (2002). Cobaltabisdicarbollide anion [Co(C2B9H11)2]− as doping agent on intelligent membranes for ion capture. Journal of Organometallic Chemistry, 657(1-2), 239-246. doi:10.1016/s0022-328x(02)01432-8Masalles, C., Llop, J., Viñas, C., & Teixidor, F. (2002). Extraordinary Overoxidation Resistance Increase in Self-Doped Polypyrroles by Using Non-conventional Low Charge-Density Anions. Advanced Materials, 14(11), 826. doi:10.1002/1521-4095(20020605)14:113.0.co;2-cSuárez-Guevara, J., Ruiz, V., & Gómez-Romero, P. (2014). Stable graphene–polyoxometalate nanomaterials for application in hybrid supercapacitors. Phys. Chem. Chem. Phys., 16(38), 20411-20414. doi:10.1039/c4cp03321cCarrette, L., Friedrich, K. A., & Stimming, U. (2000). Fuel Cells: Principles, Types, Fuels, and Applications. ChemPhysChem, 1(4), 162-193. doi:10.1002/1439-7641(20001215)1:43.0.co;2-zCorma, A., García, H., & Llabrés i Xamena, F. X. (2010). Engineering Metal Organic Frameworks for Heterogeneous Catalysis. Chemical Reviews, 110(8), 4606-4655. doi:10.1021/cr9003924Son, H.-J., Jin, S., Patwardhan, S., Wezenberg, S. J., Jeong, N. C., So, M., … Hupp, J. T. (2013). Light-Harvesting and Ultrafast Energy Migration in Porphyrin-Based Metal–Organic Frameworks. Journal of the American Chemical Society, 135(2), 862-869. doi:10.1021/ja310596aRen, Y., Chia, G. H., & Gao, Z. (2013). Metal–organic frameworks in fuel cell technologies. Nano Today, 8(6), 577-597. doi:10.1016/j.nantod.2013.11.004Fernández-Carretero, F. J., Compañ, V., & Riande, E. (2007). Hybrid ion-exchange membranes for fuel cells and separation processes. Journal of Power Sources, 173(1), 68-76. doi:10.1016/j.jpowsour.2007.07.011J. C. Maxwell , A treatise of Electricity & Magnetism, Dover, NY, 1954Wagner, K. W. (1914). Erklärung der dielektrischen Nachwirkungsvorgänge auf Grund Maxwellscher Vorstellungen. Archiv für Elektrotechnik, 2(9), 371-387. doi:10.1007/bf01657322Wagner, K. W. (1914). Dielektrische Eigenschaften von verschiedenen Isolierstoffen. Archiv für Elektrotechnik, 3(3-4), 67-106. doi:10.1007/bf01657563Klein, R. J., Zhang, S., Dou, S., Jones, B. H., Colby, R. H., & Runt, J. (2006). Modeling electrode polarization in dielectric spectroscopy: Ion mobility and mobile ion concentration of single-ion polymer electrolytes. The Journal of Chemical Physics, 124(14), 144903. doi:10.1063/1.2186638Coelho, R. (1983). Sur la relaxation d’une charge d’espace. Revue de Physique Appliquée, 18(3), 137-146. doi:10.1051/rphysap:01983001803013700Macdonald, J. R. (1953). Theory of ac Space-Charge Polarization Effects in Photoconductors, Semiconductors, and Electrolytes. Physical Review, 92(1), 4-17. doi:10.1103/physrev.92.4Munar, A., Andrio, A., Iserte, R., & Compañ, V. (2011). Ionic conductivity and diffusion coefficients of lithium salt polymer electrolytes measured with dielectric spectroscopy. Journal of Non-Crystalline Solids, 357(16-17), 3064-3069. doi:10.1016/j.jnoncrysol.2011.04.012Compañ, V., Smith So/rensen, T., Diaz‐Calleja, R., & Riande, E. (1996). Diffusion coefficients of conductive ions in a copolymer of vinylidene cyanide and vinyl acetate obtained from dielectric measurements using the model of Trukhan. Journal of Applied Physics, 79(1), 403-411. doi:10.1063/1.360844Wang, Y., Fan, F., Agapov, A. L., Saito, T., Yang, J., Yu, X., … Sokolov, A. P. (2014). Examination of the fundamental relation between ionic transport and segmental relaxation in polymer electrolytes. Polymer, 55(16), 4067-4076. doi:10.1016/j.polymer.2014.06.085Sangoro, J. R., Iacob, C., Agapov, A. L., Wang, Y., Berdzinski, S., Rexhausen, H., … Kremer, F. (2014). Decoupling of ionic conductivity from structural dynamics in polymerized ionic liquids. Soft Matter, 10(20), 3536-3540. doi:10.1039/c3sm53202jWeingärtner, H. (2014). The static dielectric permittivity of ionic liquids. Journal of Molecular Liquids, 192, 185-190. doi:10.1016/j.molliq.2013.07.020Huang, M.-M., Jiang, Y., Sasisanker, P., Driver, G. W., & Weingärtner, H. (2011). Static Relative Dielectric Permittivities of Ionic Liquids at 25 °C. Journal of Chemical & Engineering Data, 56(4), 1494-1499. doi:10.1021/je101184sSadakiyo, M., Yamada, T., & Kitagawa, H. (2009). Rational Designs for Highly Proton-Conductive Metal−Organic Frameworks. Journal of the American Chemical Society, 131(29), 9906-9907. doi:10.1021/ja9040016Barbosa, P., Rosero-Navarro, N. C., Shi, F.-N., & Figueiredo, F. M. L. (2015). Protonic Conductivity of Nanocrystalline Zeolitic Imidazolate Framework 8. Electrochimica Acta, 153, 19-27. doi:10.1016/j.electacta.2014.11.093Krause, C., Sangoro, J. R., Iacob, C., & Kremer, F. (2010). Charge Transport and Dipolar Relaxations in Imidazolium-Based Ionic Liquids. The Journal of Physical Chemistry B, 114(1), 382-386. doi:10.1021/jp908519uRivera, A., & Rössler, E. A. (2006). Evidence of secondary relaxations in the dielectric spectra of ionic liquids. Physical Review B, 73(21). doi:10.1103/physrevb.73.212201Sangoro, J. R., Mierzwa, M., Iacob, C., Paluch, M., & Kremer, F. (2012). Brownian dynamics determine universality of charge transport in ionic liquids. RSC Advances, 2(12), 5047. doi:10.1039/c2ra20560bNamikawa, H. (1974). Multichannel conduction in alkali silicate glasses. Journal of Non-Crystalline Solids, 14(1), 88-100. doi:10.1016/0022-3093(74)90021-0Namikawa, H. (1975). Characterization of the diffusion process in oxide glasses based on the correlation between electric conduction and dielectric relaxation. Journal of Non-Crystalline Solids, 18(2), 173-195. doi:10.1016/0022-3093(75)90019-8Macdonald, J. R. (2010). Addendum to «Fundamental questions relating to ion conduction in disordered solids». Journal of Applied Physics, 107(10), 101101. doi:10.1063/1.335970

Stabilization of 2,6-Diarylanilinum Cation by Through-Space Cation-pi Interactions

Energetically favorable cation-pi interactions play important roles in numerous molecular recognition processes in chemistry and biology. Herein, we present synergistic experimental and computational physical organic chemistry studies on 2,6-diarylanilines that contain flanking meta/parasubstituted aromatic rings adjacent to the central anilinium ion. A combination of measurements of pK(a) values, structural analyses of 2,6-diarylanilinium cations, and quantum chemical analyses based on the quantitative molecular orbital theory and a canonical energy decomposition analysis (EDA) scheme reveal that through-space cation-pi interactions essentially contribute to observed trends in proton affinities and pK(a) values of 2,6-diarylanilines

Structural and dielectric properties of Cobaltacarborane Composite Polybenzimidazole Membranes as solid polymer electrolytes at high temperature

[EN] The conductivity of a series of composite membranes, based on polybenzimidazole (PBI) containing the metallacarborane salt M[Co(C2B9H11)(2)], M[COSANE] and tetraphenylborate, M[B(C6H5)(4)], M[TPB] both anions having the same number of atoms and the same negative charge, has been investigated. Different cations (M = H+, Li+ and Na+) have been studied and the composite membranes have been characterized by water uptake, swelling ratios, ATR FT-IR, thermogravimetric analysis and electrochemical impedance spectroscopy to explore the dielectric response and ion dynamics in composite membranes. Our results show that conductivity increases with increasing temperature and it is higher for H+ than for Li+ and Na+ for all temperatures under study. The mobility of Li+ is greater in [COSANE](-) than in [TPB](-) composite PBI@membranes while for Na+ it is the opposite. The temperature dependence of the conductivity of the composite was followed by a typical Arrhenius behaviour with two different regions: (1) between 20 and 100 degrees C, and (2) between 100 and 150 degrees C. Using the analysis of electrode polarization (EP) based on the Thrukhan theory we have calculated the ionic diffusion coefficients and the density of carriers. From the double logarithmic plot of the imaginary part of the conductivity (sigma '') versus frequency in the entire range of temperatures studied we have determined for each sample at each temperature, the frequency values of the onset (f(ON)) and full development of electrode polarization (f(MAX)), respectively, which permit us to calculate static permittivity.We gratefully acknowledge Spanish Ministerio de Economia y Competitividad (MINECO) for financial support by the ENE/2015-69203-R project and CTQ2016-75150-R project, and Generalitat de Catalunya (2014/SGR/149). I. Fuentes is enrolled in the PhD program of the UAB. The authors acknowledge Dr Oscar Sahuquillo for technical assistance in TGA.Fuentes, I.; Andrio Balado, A.; Garcia Bernabe, A.; Escorihuela Fuentes, J.; Viñas, C.; Teixidor, F.; Compañ Moreno, V. (2018). Structural and dielectric properties of Cobaltacarborane Composite Polybenzimidazole Membranes as solid polymer electrolytes at high temperature. Physical Chemistry Chemical Physics. 20(15):10173-10185. https://doi.org/10.1039/c8cp00372fS10173101852015I. E. A. Statistics, IEA, Paris, France, 2016Li, W., Dahn, J. R., & Wainwright, D. S. (1994). Rechargeable Lithium Batteries with Aqueous Electrolytes. Science, 264(5162), 1115-1118. doi:10.1126/science.264.5162.1115Lee, H., Yanilmaz, M., Toprakci, O., Fu, K., & Zhang, X. (2014). A review of recent developments in membrane separators for rechargeable lithium-ion batteries. Energy Environ. Sci., 7(12), 3857-3886. doi:10.1039/c4ee01432dAnothumakkool, B., Torris A. T., A., Veeliyath, S., Vijayakumar, V., Badiger, M. V., & Kurungot, S. (2016). High-Performance Flexible Solid-State Supercapacitor with an Extended Nanoregime Interface through in Situ Polymer Electrolyte Generation. ACS Applied Materials & Interfaces, 8(2), 1233-1241. doi:10.1021/acsami.5b09677Huang, C., Zhang, J., Snaith, H. J., & Grant, P. S. (2016). Engineering the Membrane/Electrode Interface To Improve the Performance of Solid-State Supercapacitors. ACS Applied Materials & Interfaces, 8(32), 20756-20765. doi:10.1021/acsami.6b05789Wang, Y., Chen, K. S., Mishler, J., Cho, S. C., & Adroher, X. C. (2011). A review of polymer electrolyte membrane fuel cells: Technology, applications, and needs on fundamental research. Applied Energy, 88(4), 981-1007. doi:10.1016/j.apenergy.2010.09.030Kraytsberg, A., & Ein-Eli, Y. (2014). Review of Advanced Materials for Proton Exchange Membrane Fuel Cells. Energy & Fuels, 28(12), 7303-7330. doi:10.1021/ef501977kLufrano, F., Baglio, V., Staiti, P., Antonucci, V., & Arico’, A. S. (2013). Performance analysis of polymer electrolyte membranes for direct methanol fuel cells. Journal of Power Sources, 243, 519-534. doi:10.1016/j.jpowsour.2013.05.180Awang, N., Ismail, A. F., Jaafar, J., Matsuura, T., Junoh, H., Othman, M. H. D., & Rahman, M. A. (2015). Functionalization of polymeric materials as a high performance membrane for direct methanol fuel cell: A review. Reactive and Functional Polymers, 86, 248-258. doi:10.1016/j.reactfunctpolym.2014.09.019Nunes, S. (2002). Inorganic modification of proton conductive polymer membranes for direct methanol fuel cells. Journal of Membrane Science, 203(1-2), 215-225. doi:10.1016/s0376-7388(02)00009-1Jung, D. H., Cho, S. Y., Peck, D. H., Shin, D. R., & Kim, J. S. (2003). Preparation and performance of a Nafion®/montmorillonite nanocomposite membrane for direct methanol fuel cell. Journal of Power Sources, 118(1-2), 205-211. doi:10.1016/s0378-7753(03)00095-8Song, M.-K., Park, S.-B., Kim, Y.-T., Kim, K.-H., Min, S.-K., & Rhee, H.-W. (2004). Characterization of polymer-layered silicate nanocomposite membranes for direct methanol fuel cells. Electrochimica Acta, 50(2-3), 639-643. doi:10.1016/j.electacta.2003.12.078GAOWEN, Z., & ZHENTAO, Z. (2005). Organic/inorganic composite membranes for application in DMFC. Journal of Membrane Science, 261(1-2), 107-113. doi:10.1016/j.memsci.2005.03.036Hande, V. R., Rath, S. K., Rao, S., & Patri, M. (2011). Cross-linked sulfonated poly (ether ether ketone) (SPEEK)/reactive organoclay nanocomposite proton exchange membranes (PEM). Journal of Membrane Science, 372(1-2), 40-48. doi:10.1016/j.memsci.2011.01.042Shimizu, G. K. H. (2005). Assembly of metal ions and ligands with adaptable coordinative tendencies as a route to functional metal-organic solids. Journal of Solid State Chemistry, 178(8), 2519-2526. doi:10.1016/j.jssc.2005.07.003Li, Q., He, R., Jensen, J. O., & Bjerrum, N. J. (2003). Approaches and Recent Development of Polymer Electrolyte Membranes for Fuel Cells Operating above 100 °C. Chemistry of Materials, 15(26), 4896-4915. doi:10.1021/cm0310519Hurd, J. A., Vaidhyanathan, R., Thangadurai, V., Ratcliffe, C. I., Moudrakovski, I. L., & Shimizu, G. K. H. (2009). Anhydrous proton conduction at 150 °C in a crystalline metal–organic framework. Nature Chemistry, 1(9), 705-710. doi:10.1038/nchem.402Araya, S. S., Zhou, F., Liso, V., Sahlin, S. L., Vang, J. R., Thomas, S., … Kær, S. K. (2016). A comprehensive review of PBI-based high temperature PEM fuel cells. International Journal of Hydrogen Energy, 41(46), 21310-21344. doi:10.1016/j.ijhydene.2016.09.024González-Cardoso, P., Stoica, A.-I., Farràs, P., Pepiol, A., Viñas, C., & Teixidor, F. (2010). Additive Tuning of Redox Potential in Metallacarboranes by Sequential Halogen Substitution. Chemistry - A European Journal, 16(22), 6660-6665. doi:10.1002/chem.200902558Pepiol, A., Teixidor, F., Sillanpää, R., Lupu, M., & Viñas, C. (2011). Stepwise Sequential Redox Potential Modulation Possible on a Single Platform. Angewandte Chemie International Edition, 50(52), 12491-12495. doi:10.1002/anie.201105668Tarrés, M., Arderiu, V. S., Zaulet, A., Viñas, C., Fabrizi de Biani, F., & Teixidor, F. (2015). How to get the desired reduction voltage in a single framework! Metallacarborane as an optimal probe for sequential voltage tuning. Dalton Transactions, 44(26), 11690-11695. doi:10.1039/c5dt01464fOlid, D., Núñez, R., Viñas, C., & Teixidor, F. (2013). Methods to produce B–C, B–P, B–N and B–S bonds in boron clusters. Chemical Society Reviews, 42(8), 3318. doi:10.1039/c2cs35441aBauduin, P., Prevost, S., Farràs, P., Teixidor, F., Diat, O., & Zemb, T. (2011). A Theta-Shaped Amphiphilic Cobaltabisdicarbollide Anion: Transition From Monolayer Vesicles to Micelles. Angewandte Chemie International Edition, 50(23), 5298-5300. doi:10.1002/anie.201100410Brusselle, D., Bauduin, P., Girard, L., Zaulet, A., Viñas, C., Teixidor, F., … Diat, O. (2013). Lyotropic Lamellar Phase Formed from Monolayered θ-Shaped Carborane-Cage Amphiphiles. Angewandte Chemie International Edition, 52(46), 12114-12118. doi:10.1002/anie.201307357Gassin, P.-M., Girard, L., Martin-Gassin, G., Brusselle, D., Jonchère, A., Diat, O., … Bauduin, P. (2015). Surface Activity and Molecular Organization of Metallacarboranes at the Air–Water Interface Revealed by Nonlinear Optics. Langmuir, 31(8), 2297-2303. doi:10.1021/acs.langmuir.5b00125Ďorďovič, V., Tošner, Z., Uchman, M., Zhigunov, A., Reza, M., Ruokolainen, J., … Matějíček, P. (2016). Stealth Amphiphiles: Self-Assembly of Polyhedral Boron Clusters. Langmuir, 32(26), 6713-6722. doi:10.1021/acs.langmuir.6b01995Uchman, M., Ďorďovič, V., Tošner, Z., & Matějíček, P. (2015). Classical Amphiphilic Behavior of Nonclassical Amphiphiles: A Comparison of Metallacarborane Self-Assembly with SDS Micellization. Angewandte Chemie International Edition, 54(47), 14113-14117. doi:10.1002/anie.201506545Núñez, R., Romero, I., Teixidor, F., & Viñas, C. (2016). Icosahedral boron clusters: a perfect tool for the enhancement of polymer features. Chemical Society Reviews, 45(19), 5147-5173. doi:10.1039/c6cs00159aNúñez, R., Tarrés, M., Ferrer-Ugalde, A., de Biani, F. F., & Teixidor, F. (2016). Electrochemistry and Photoluminescence of Icosahedral Carboranes, Boranes, Metallacarboranes, and Their Derivatives. Chemical Reviews, 116(23), 14307-14378. doi:10.1021/acs.chemrev.6b00198Masalles, C., Borrós, S., Viñas, C., & Teixidor, F. (2000). Are Low-Coordinating Anions of Interest as Doping Agents in Organic Conducting Polymers? Advanced Materials, 12(16), 1199-1202. doi:10.1002/1521-4095(200008)12:163.0.co;2-wMasalles, C., Borrós, S., Viñas, C., & Teixidor, F. (2002). Surface Layer Formation on Polypyrrole Films. Advanced Materials, 14(6), 449-452. doi:10.1002/1521-4095(20020318)14:63.0.co;2-4Fabre, B., Clark, J. C., & Vicente, M. G. H. (2006). Synthesis and Electrochemistry of Carboranylpyrroles. Toward the Preparation of Electrochemically and Thermally Resistant Conjugated Polymers. Macromolecules, 39(1), 112-119. doi:10.1021/ma051508vHao, E., Fabre, B., Fronczek, F. R., & Vicente, M. G. H. (2007). Syntheses and Electropolymerization of Carboranyl-Functionalized Pyrroles and Thiophenes. Chemistry of Materials, 19(25), 6195-6205. doi:10.1021/cm701935nMasalles, C., Teixidor, F., Borrós, S., & Viñas, C. (2002). Cobaltabisdicarbollide anion [Co(C2B9H11)2]− as doping agent on intelligent membranes for ion capture. Journal of Organometallic Chemistry, 657(1-2), 239-246. doi:10.1016/s0022-328x(02)01432-8Masalles, C., Llop, J., Viñas, C., & Teixidor, F. (2002). Extraordinary Overoxidation Resistance Increase in Self-Doped Polypyrroles by Using Non-conventional Low Charge-Density Anions. Advanced Materials, 14(11), 826. doi:10.1002/1521-4095(20020605)14:113.0.co;2-cFuentes, I., Andrio, A., Teixidor, F., Viñas, C., & Compañ, V. (2017). Enhanced conductivity of sodium versus lithium salts measured by impedance spectroscopy. Sodium cobaltacarboranes as electrolytes of choice. Physical Chemistry Chemical Physics, 19(23), 15177-15186. doi:10.1039/c7cp02526bMauritz, K. A., & Moore, R. B. (2004). State of Understanding of Nafion. Chemical Reviews, 104(10), 4535-4586. doi:10.1021/cr0207123Alberti, G., Narducci, R., & Sganappa, M. (2008). Effects of hydrothermal/thermal treatments on the water-uptake of Nafion membranes and relations with changes of conformation, counter-elastic force and tensile modulus of the matrix. Journal of Power Sources, 178(2), 575-583. doi:10.1016/j.jpowsour.2007.09.034Sukumar, P. R., Wu, W., Markova, D., Ünsal, Ö., Klapper, M., & Müllen, K. (2007). Functionalized Poly(benzimidazole)s as Membrane Materials for Fuel Cells. Macromolecular Chemistry and Physics, 208(19–20), 2258-2267. doi:10.1002/macp.200700390Pu, H., Liu, L., Chang, Z., & Yuan, J. (2009). Organic/inorganic composite membranes based on polybenzimidazole and nano-SiO2. Electrochimica Acta, 54(28), 7536-7541. doi:10.1016/j.electacta.2009.08.011Singha, S., & Jana, T. (2014). Structure and Properties of Polybenzimidazole/Silica Nanocomposite Electrolyte Membrane: Influence of Organic/Inorganic Interface. ACS Applied Materials & Interfaces, 6(23), 21286-21296. doi:10.1021/am506260jKutcherlapati, S. R., Koyilapu, R., & Jana, T. (2017). Poly(N -vinyl imidazole) grafted silica nanofillers: Synthesis by RAFT polymerization and nanocomposites with polybenzimidazole. Journal of Polymer Science Part A: Polymer Chemistry, 56(4), 365-375. doi:10.1002/pola.28917Maity, S., Singha, S., & Jana, T. (2015). Low acid leaching PEM for fuel cell based on polybenzimidazole nanocomposites with protic ionic liquid modified silica. Polymer, 66, 76-85. doi:10.1016/j.polymer.2015.03.040Reyes-Rodriguez, J. L., Escorihuela, J., García-Bernabé, A., Giménez, E., Solorza-Feria, O., & Compañ, V. (2017). Proton conducting electrospun sulfonated polyether ether ketone graphene oxide composite membranes. RSC Advances, 7(84), 53481-53491. doi:10.1039/c7ra10484gDyre, J. C., & Schrøder, T. B. (2000). Universality of ac conduction in disordered solids. Reviews of Modern Physics, 72(3), 873-892. doi:10.1103/revmodphys.72.873Roling, B., Martiny, C., & Brückner, S. (2001). Ion transport in glass: Influence of glassy structure on spatial extent of nonrandom ion hopping. Physical Review B, 63(21). doi:10.1103/physrevb.63.214203Serghei, A., Tress, M., Sangoro, J. R., & Kremer, F. (2009). Electrode polarization and charge transport at solid interfaces. Physical Review B, 80(18). doi:10.1103/physrevb.80.184301Pu, H., Lou, L., Guan, Y., Chang, Z., & Wan, D. (2012). Proton exchange membranes based on semi-interpenetrating polymer networks of polybenzimidazole and perfluorosulfonic acid polymer with hollow silica spheres as micro-reservoir. Journal of Membrane Science, 415-416, 496-503. doi:10.1016/j.memsci.2012.05.036Tominaka, S., & Cheetham, A. K. (2014). Intrinsic and extrinsic proton conductivity in metal-organic frameworks. RSC Adv., 4(97), 54382-54387. doi:10.1039/c4ra11473fBarbosa, P., Rosero-Navarro, N. C., Shi, F.-N., & Figueiredo, F. M. L. (2015). Protonic Conductivity of Nanocrystalline Zeolitic Imidazolate Framework 8. Electrochimica Acta, 153, 19-27. doi:10.1016/j.electacta.2014.11.093Krause, C., Sangoro, J. R., Iacob, C., & Kremer, F. (2010). Charge Transport and Dipolar Relaxations in Imidazolium-Based Ionic Liquids. The Journal of Physical Chemistry B, 114(1), 382-386. doi:10.1021/jp908519uRivera, A., & Rössler, E. A. (2006). Evidence of secondary relaxations in the dielectric spectra of ionic liquids. Physical Review B, 73(21). doi:10.1103/physrevb.73.212201Maity, S., & Jana, T. (2014). Polybenzimidazole Block Copolymers for Fuel Cell: Synthesis and Studies of Block Length Effects on Nanophase Separation, Mechanical Properties, and Proton Conductivity of PEM. ACS Applied Materials & Interfaces, 6(9), 6851-6864. doi:10.1021/am500668cChuang, S.-W., Hsu, S. L.-C., & Hsu, C.-L. (2007). Synthesis and properties of fluorine-containing polybenzimidazole/montmorillonite nanocomposite membranes for direct methanol fuel cell applications. Journal of Power Sources, 168(1), 172-177. doi:10.1016/j.jpowsour.2007.03.021Mustarelli, P., Quartarone, E., Grandi, S., Carollo, A., & Magistris, A. (2008). Polybenzimidazole-Based Membranes as a Real Alternative to Nafion for Fuel Cells Operating at Low Temperature. Advanced Materials, 20(7), 1339-1343. doi:10.1002/adma.200701767Lobato, J., Cañizares, P., Rodrigo, M. A., Úbeda, D., & Pinar, F. J. (2011). Enhancement of the fuel cell performance of a high temperature proton exchange membrane fuel cell running with titanium composite polybenzimidazole-based membranes. Journal of Power Sources, 196(20), 8265-8271. doi:10.1016/j.jpowsour.2011.06.011Sørensen, T. S., & Compañ, V. (1995). Complex permittivity of a conducting, dielectric layer containing arbitrary binary Nernst–Planck electrolytes with applications to polymer films and cellulose acetate membranes. J. Chem. Soc., Faraday Trans., 91(23), 4235-4250. doi:10.1039/ft9959104235Sørensen, T. S., Compañ, V., & Diaz-Calleja, R. (1996). Complex permittivity of a film of poly[4-(acryloxy)phenyl-(4-chlorophenyl)methanone] containing free ion impurities and the separation of the contributions from interfacial polarization, Maxwell–Wagner–Sillars effects and dielectric relaxations of the polymer chains. J. Chem. Soc., Faraday Trans., 92(11), 1947-1957. doi:10.1039/ft9969201947Munar, A., Andrio, A., Iserte, R., & Compañ, V. (2011). Ionic conductivity and diffusion coefficients of lithium salt polymer electrolytes measured with dielectric spectroscopy. Journal of Non-Crystalline Solids, 357(16-17), 3064-3069. doi:10.1016/j.jnoncrysol.2011.04.012Macdonald, J. R. (1953). Theory of ac Space-Charge Polarization Effects in Photoconductors, Semiconductors, and Electrolytes. Physical Review, 92(1), 4-17. doi:10.1103/physrev.92.4Coelho, R. (1983). Sur la relaxation d’une charge d’espace. Revue de Physique Appliquée, 18(3), 137-146. doi:10.1051/rphysap:01983001803013700Klein, R. J., Zhang, S., Dou, S., Jones, B. H., Colby, R. H., & Runt, J. (2006). Modeling electrode polarization in dielectric spectroscopy: Ion mobility and mobile ion concentration of single-ion polymer electrolytes. The Journal of Chemical Physics, 124(14), 144903. doi:10.1063/1.2186638Coelho, R. (1991). On the static permittivity of dipolar and conductive media — an educational approach. Journal of Non-Crystalline Solids, 131-133, 1136-1139. doi:10.1016/0022-3093(91)90740-wJönsson, M., Welch, K., Hamp, S., & Strømme, M. (2006). Bacteria Counting with Impedance Spectroscopy in a Micro Probe Station. The Journal of Physical Chemistry B, 110(20), 10165-10169. doi:10.1021/jp060148qBandara, T. M. W. J., Dissanayake, M. A. K. L., Albinsson, I., & Mellander, B.-E. (2011). Mobile charge carrier concentration and mobility of a polymer electrolyte containing PEO and Pr4N+I− using electrical and dielectric measurements. Solid State Ionics, 189(1), 63-68. doi:10.1016/j.ssi.2011.03.004Pasini Cabello, S. D., Mollá, S., Ochoa, N. A., Marchese, J., Giménez, E., & Compañ, V. (2014). New bio-polymeric membranes composed of alginate-carrageenan to be applied as polymer electrolyte membranes for DMFC. Journal of Power Sources, 265, 345-355. doi:10.1016/j.jpowsour.2014.04.093García-Bernabé, A., Rivera, A., Granados, A., Luis, S. V., & Compañ, V. (2016). Ionic transport on composite polymers containing covalently attached and absorbed ionic liquid fragments. Electrochimica Acta, 213, 887-897. doi:10.1016/j.electacta.2016.08.018Compañ, V., Molla, S., García Verdugo, E., Luis, S. V., & Burguete, M. I. (2012). Synthesis and characterization of the conductivity and polarization processes in supported ionic liquid-like phases (SILLPs). Journal of Non-Crystalline Solids, 358(9), 1228-1237. doi:10.1016/j.jnoncrysol.2012.02.02

Helicobacter pylori Dampens HLA-II Expression on Macrophages via the Up-Regulation of miRNAs Targeting CIITA

Macrophages have a major role in infectious and inflammatory diseases, and the available data suggest that Helicobacter pylori persistence can be explained in part by the failure of the bacterium to be killed by professional phagocytes. Macrophages are cells ready to kill the engulfed pathogen, through oxygen-dependent and -independent mechanisms; however, their killing potential can be further augmented by the intervention of T helper (Th) cells upon the specific recognition of human leukocyte antigen (HLA)-II\u2013peptide complexes on the surface of the phagocytic cells. As it pertains to H. pylori, the bacterium is engulfed by macrophages, but it interferes with the phagosome maturation process leading to phagosomes with an altered degradative capacity, and to megasomes, wherein H. pylori resists killing. We recently showed that macrophages infected with H. pylori strongly reduce the expression of HLA-II molecules on the plasma membrane and this compromises the bacterial antigen presentation to Th lymphocytes. In this work, we demonstrate that H. pylori hampers HLA-II expression in macrophages, activated or non-activated by IFN-\u3b3, by down-regulating the expression of the class II major histocompatibility complex transactivator (CIITA), the \u201cmaster control factor\u201d for the expression of HLA class II genes. We provided evidence that this effect relies on the up-regulation of let-7f-5p, let-7i-5p, miR-146b-5p, and -185-5p targeting CIITA. MiRNA expression analysis performed on biopsies from H. pylori-infected patients confirmed the up-regulation of let-7i-5p, miR-146b-5p, and -185-5p in gastritis, in pre-invasive lesions, and in gastric cancer. Taken together, our results suggest that specific miRNAs may be directly involved in the H. pylori infection persistence and may contribute to confer the risk of developing gastric neoplasia in infected patients

Craving and Anxiety Responses as Indicators of the Efficacy of Virtual Reality-Cue Exposure Therapy in Patients Diagnosed with Alcohol use Disorder

Introduction: Virtual Reality (VR) technology has shown promising results as an assessment and treatment instrument in substance use disorders, particularly in attempts to reduce craving. A common application of the VR technology in treatment is based on cue-exposure therapy (CET). Following from previous results, the present case series is part of a larger project aiming to test the efficacy of the Virtual Reality-Cue Exposure Therapy (VR-CET) versus Cognitive-Behavioral Therapy (CBT). Method: Eight patients between ages 40 and 55 (Mage = 49, SD = 5.54) from the Addictive Behaviors Unit at the Hospital Clinic of Barcelona participated in this study after providing written informed consent. Patients were randomly assigned to the VR-CET group (three patients) or the CBT group (five patients). The protocol of the clinical trial consisted of a pre-treatment session (the initial assessment session), six sessions of CBT or VR-CET, and a post-treatment session (post-assessment session). The VR-CET sessions consisted of exposure to alcohol-related cues and environments aiming to reduce anxiety and craving responses to alcohol-related stimuli. The CBT sessions consisted of classical standardized therapy for the treatment of addictions, as previously applied in other clinical trials. In the pre- and post-treatment sessions, patients completed several measures of alcohol craving and anxiety and visual analog scales (VAS) during VR exposure. Results: Our data indicated a significant reduction in both groups in all scores of craving and anxiety responses, as assessed by the different instruments. In addition, the VR-CET group obtained lower scores on anxiety and craving responses than the CBT group. Conclusions: In this ongoing project, the first phase of the clinical trial showed significant improvements in terms of craving and anxiety reduction in both groups, emphasizing that VR-CET can be as efficient as CBT. In addition, patients in the VR-CET group obtained slightly better scores than patients in the CBT group, suggesting the clinical potential of the VR technology in the treatment of substance use disorders. We propose that VR-based CET can be a useful complement to existing treatment methods for AUD patients

Cobaltabis(dicarbollide) ([o-COSAN]−) as Multifunctional Chemotherapeutics: A Prospective Application in Boron Neutron Capture Therapy (BNCT) for Glioblastoma

Purpose: The aim of our study was to assess if the sodium salt of cobaltabis(dicarbollide) and its di-iodinated derivative (Na[o-COSAN] and Na[8,8′-I2-o-COSAN]) could be promising agents for dual anti-cancer treatment (chemotherapy + BNCT) for GBM. Methods: The biological activities of the small molecules were evaluated in vitro with glioblastoma cells lines U87 and T98G in 2D and 3D cell models and in vivo in the small model animal Caenorhabditis elegans (C. elegans) at the L4-stage and using the eggs. Results: Our studies indicated that only spheroids from the U87 cell line have impaired growth after treatment with both compounds, suggesting an increased resistance from T98G spheroids, contrary to what was observed in the monolayer culture, which highlights the need to employ 3D models for future GBM studies. In vitro tests in U87 and T98G cells conclude that the amount of 10B inside the cells is enough for BNCT irradiation. BNCT becomes more effective on T98G after their incubation with Na[8,8′-I2-o-COSAN], whereas no apparent cell-killing effect was observed for untreated cells. Conclusions: These small molecules, particularly [8,8′-I2-o-COSAN]−, are serious candidates for BNCT now that the facilities of accelerator-based neutron sources are more accessible, providing an alternative treatment for resistant glioblastoma

Attentional bias, alcohol craving, and anxiety implications of the virtual reality cue-exposure therapy in severe alcohol use disorder: a case report

Aims: Attentional bias (AB), alcohol craving, and anxiety have important implications in the development and maintenance of alcohol use disorder (AUD). The current study aims to test the effectiveness of a Virtual Reality Cue-Exposure Therapy (VR-CET) to reduce levels of alcohol craving and anxiety and prompt changes in AB toward alcohol content. Method: A 49-year-old male participated in this study, diagnosed with severe AUD, who also used tobacco and illicit substances on an occasional basis and who made several failed attempts to cease substance misuse. The protocol consisted of six VR-CET booster sessions and two assessment sessions (pre- and post-VR-CET) over the course of 5 weeks. The VR-CET program consisted of booster therapy sessions based on virtual reality (VR) exposure to preferred alcohol-related cues and contexts. The initial and final assessment sessions were focused on exploring AB, alcohol craving, and anxiety using paper-and-pencil instruments and the eye-tracking (ET) and VR technologies at different time points. Results: Pre and post assessment sessions indicated falls on the scores of all instruments assessing alcohol craving, anxiety, and AB. Conclusions: This case report, part of a larger project, demonstrates the effectiveness of the VR-CET booster sessions in AUD. In the post-treatment measurements, a variety of instruments showed a change in the AB pattern and an improvement in craving and anxiety responses. As a result of the systematic desensitization, virtual exposure gradually reduced the responses to significant alcohol-related cues and contexts. The implications for AB, anxiety and craving are discussed

Ion Transport across Biological Membranes by Carborane-Capped Gold Nanoparticles

Carborane-capped gold nanoparticles (Au/carborane NPs, 2-3 nm) can act as artificial ion transporters across biological membranes. The particles themselves are large hydrophobic anions that have the ability to disperse in aqueous media and to partition over both sides of a phospholipid bilayer membrane. Their presence therefore causes a membrane potential that is determined by the relative concentrations of particles on each side of the membrane according to the Nernst equation. The particles tend to adsorb to both sides of the membrane and can flip across if changes in membrane potential require their repartitioning. Such changes can be made either with a potentiostat in an electrochemical cell or by competition with another partitioning ion, for example, potassium in the presence of its specific transporter valinomycin. Carborane-capped gold nanoparticles have a ligand shell full of voids, which stem from the packing of near spherical ligands on a near spherical metal core. These voids are normally filled with sodium or potassium ions, and the charge is overcompensated by excess electrons in the metal core. The anionic particles are therefore able to take up and release a certain payload of cations and to adjust their net charge accordingly. It is demonstrated by potential-dependent fluorescence spectroscopy that polarized phospholipid membranes of vesicles can be depolarized by ion transport mediated by the particles. It is also shown that the particles act as alkali-ion-specific transporters across free-standing membranes under potentiostatic control. Magnesium ions are not transported

Mechanism of biomolecular recognition of trimethyllysine by the fluorinated aromatic cage of KDM5A PHD3 finger

The understanding of biomolecular recognition of posttranslationally modified histone proteins is centrally important to the histone code hypothesis. Despite extensive binding and structural studies on the readout of histones, the molecular language by which posttranslational modifications on histone proteins are read remains poorly understood. Here we report physical-organic chemistry studies on the recognition of the positively charged trimethyllysine by the electron-rich aromatic cage containing PHD3 finger of KDM5A. The aromatic character of two tryptophan residues that solely constitute the aromatic cage of KDM5A was fine-tuned by the incorporation of fluorine substituents. Our thermodynamic analyses reveal that the wild-type and fluorinated KDM5A PHD3 fingers associate equally well with trimethyllysine. This work demonstrates that the biomolecular recognition of trimethyllysine by fluorinated aromatic cages is associated with weaker cation-π interactions that are compensated by the energetically more favourable trimethyllysine-mediated release of high-energy water molecules that occupy the aromatic cage