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Artículos SCI



2016


Materiales Ópticos Multifuncionales

Cellular Viscosity in Prokaryotes and Thermal Stability of Low Molecular Weight Biomolecules

Cuecas, A; Cruces, J; Galisteo-Lopez, JF; Peng, XJ; Gonzalez, JM
Biophysical Journal, 111 (2016) 875–882

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Some low molecular weight biomolecules, i.e., NAD(P)H, are unstable at high temperatures. The use of these biomolecules by thermophilic microorganisms has been scarcely analyzed. Herein, NADH stability has been studied at different temperatures and viscosities. NADH decay increased at increasing temperatures. At increasing viscosities, NADH decay rates decreased. Thus, maintaining relatively high cellular viscosity in cells could result in increased stability of low molecular weight biomolecules (i.e., NADH) at high temperatures, unlike what was previously deduced from studies in diluted water solutions. Cellular viscosity was determined using a fluorescent molecular rotor in various prokaryotes covering the range from 10 to 100°C. Some mesophiles showed the capability of changing cellular viscosity depending on growth temperature. Thermophiles and extreme thermophiles presented a relatively high cellular viscosity, suggesting this strategy as a reasonable mechanism to thrive under these high temperatures. Results substantiate the capability of thermophiles and extreme thermophiles (growth range 50–80°C) to stabilize and use generally considered unstable, universal low molecular weight biomolecules. In addition, this study represents a first report, to our knowledge, on cellular viscosity measurements in prokaryotes and it shows the dependency of prokaryotic cellular viscosity on species and growth temperature.


Agosto, 2016 | DOI: 10.1016/j.bpj.2016.07.024

Materiales Ópticos Multifuncionales

Modified emission of extended light emitting layers by selective coupling to collective lattice resonances

Ramezani, Mohammad; Lozano, Gabriel; Verschuuren, Marc A.; Gomez-Rivas, Jaime
Physical Review B, 94 (2016) 12

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We demonstrate that the coupling between light emitters in extended polymer layers and modes supported by arrays of plasmonic particles can be selectively enhanced by accurate positioning of the emitters in regions where the electric field intensity of a given mode is maximized. The enhancement, which we measure to reach up to 70%, is due to the improved spatial overlap and coupling between the optical mode and emitters. This improvement of the coupling leads to a modification of the emission spectrum and the luminous efficacy of the sample.


Agosto, 2016 | DOI: 10.1103/PhysRevB.94.125406

Materiales de Diseño para la Energía y Medioambiente

Electrochemical Energy Storage Applications of CVD Grown Niobium Oxide Thin Films

Fiz, Raquel; Appel, Linus; Gutierrez-Pardo, Antonio; Ramirez-Rico, Joaquin; Mathur, Sanjay
ACS Applied Materials & Interfaces, 8 (2016) 21423–21430

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We report here on the controlled synthesis, characterization, and electrochemical properties of different polymorphs of niobium pentoxide grown by CVD of new single-source precursors. Nb2O5 films deposited at different temperatures showed systematic phase evolution from low-temperature tetragonal (TT-Nb2O5, T-Nb2O5) to high temperature monoclinic modifications (H–Nb2O5). Optimization of the precursor flux and substrate temperature enabled phase-selective growth of Nb2O5 nanorods and films on conductive mesoporous biomorphic carbon matrices (BioC). Nb2O5 thin films deposited on monolithic BioC scaffolds produced composite materials integrating the high surface area and conductivity of the carbonaceous matrix with the intrinsically high capacitance of nanostructured niobium oxide. Heterojunctions in Nb2O5/BioC composites were found to be beneficial in electrochemical capacitance. Electrochemical characterization of Nb2O5/BioC composites showed that small amounts of Nb2O5 (as low as 5%) in conjunction with BioCarbon resulted in a 7-fold increase in the electrode capacitance, from 15 to 104 F g–1, while imparting good cycling stability, making these materials ideally suited for electrochemical energy storage applications.


Agosto, 2016 | DOI: 10.1021/acsami.6b03945

Reactividad de Sólidos

On the Multicycle Activity of Natural Limestone/Dolomite for Thermochemical Energy Storage of Concentrated Solar Power

Sarrion, B; Valverde, JM; Perejon, A; Perez-Maqueda, L; Sanchez-Jimenez, PE
Energy Technology, 4 (2016) 1013-1019

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Cheap, efficient, and non-toxic energy storage technologies are urgently needed to handle the rapidly increasing penetration of intermittent renewable energies into the grid. This work explores the use of limestone and dolomite for energy storage in concentrated solar power (CSP) plants by means of the calcium looping (CaL) process based on the multicycle carbonation/calcination of CaO. An efficient integration of the CaL process into CSP plants involves high temperature carbonation and calcination at moderate temperatures in a close CO2 cycle for power generation. These conditions differ from those of the CaL process for CO2 capture, which lead to CaO deactivation as extensively reported in recent years. In contrast, we show that limestone- and dolomite-derived CaO give rise to a high residual conversion at CaL-CSP conditions and in short residence times, which would facilitate the development of a competitive and clean CSP technology with permanent energy storage.


Agosto, 2016 | DOI: 10.1002/ente.201600068

Materiales Coloidales

Confinement and surface effects on the physical properties of rhombohedral-shape hematite (alpha-Fe2O3) nanocrystals

Luna, C; Cuan-Guerra, AD; Barriga-Castro, ED; Nunez, NO; Mendoza-Resendez, R
Materials Research Bulletin, 80 (2016) 44-52

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Morphological, microstructural and vibrational properties of hematite (alpha-Fe2O3) nanocrystals with a rhombohedral shape and rounded edges, obtained by forced hydrolysis of iron(III) solutions under a fast nucleation, have been investigated in detail as a function of aging time. These studies allowed us to propose a detailed formation mechanism and revealed that these nanocrystals are composed of four {104} side facets, two {110} faces at the edges of the long diagonal of the nanocrystals and two {-441} facets as the top and bottom faces. Also, the presence of nanoscopic pores and fissures was evidenced. The vibrational bands of such nanocrystals were shifted to lower frequencies in comparison with bulk hematite ones as the nanocrystal size was reduced due to phonon confinement effects. Also, the indirect and direct transition band gaps displayed interesting dependences on the aging time arising from quantum confinementand surface effects 


Agosto, 2016 | DOI: 10.1016/j.materresbull.2016.03.029

 

 

 

 

 

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