A multicenter, randomized controlled trial comparing a single intra-articular injection of Gel-200, a new cross-linked formulation of hyaluronic acid, to phosphate buffered saline for treatment of osteoarthritis of the knee

Objective To compare the safety and efficacy of a single intra-articular (IA) injection of a new cross-linked hyaluronic acid product, Gel-200, with phosphate buffered saline (PBS, control) in a multi-center randomized controlled trial in patients with symptomatic osteoarthritis (OA) of the knee. Design Patients were randomized 2:1 to receive a single injection of Gel-200 or PBS, after joint aspiration. The primary measure of effectiveness was Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscores by 100-mm Visual Analog Scale (VAS); secondary outcomes included: total WOMAC, physical function, and stiffness subscores; patient and physician global assessments of disease activity, Outcome Measures in Rheumatology Clinical Trials and Osteoarthritis Research Society International (OMERACT–OARSI) strict responders, as well as safety of Gel-200. Results Of 379 patients randomized, safety was evaluated in 377 and efficacy in 375 (98.9% randomized) in the intent-to-treat population. Effectiveness of Gel-200 by WOMAC pain subscores was statistically significant at week 13 (P = 0.037). Mean improvements from baseline in WOMAC pain subscores consistently favored Gel-200 at each visit. Effectiveness of Gel-200 treatment was statistically significant over weeks 3–13 by WOMAC total score, physical function, and physician global evaluations (P \u3c 0.05). The number of “strict” OMERACT–OARSI responders was statistically significant from weeks 6 to 13 (P = 0.022). Adverse events were not significantly different between treatment groups, including serious adverse events considered related to study treatment. Conclusions This trial demonstrated that a single injection of Gel-200 was well tolerated and relieved pain associated with symptomatic OA of the knee over 13 weeks. Trial registration number ClinicalTrials.gov NTC 00449696

Analysis of the upconversion emission of yttrium orthoaluminate nanoperovskite co-doped with Er3+/Yb3+ ions for thermal sensing applications

[EN] The upconversion emissions of yttrium orthoaluminate nano-perovskite co-doped with Er3+/Yb3+ have been studied. Strong green and red upconversion emissions, which can be observed by naked eyes, were observed when exciting the sample at 980 nm. In particular, the green band was monitored as a function of temperature and the obtained results suggest that this nano-perovskite can be used as an optical temperature sensor by exciting in the infrared range. The viability of YAP: Er3+/Yb3+ nano-perovskite in laser heating applications has been tested and discussed.This research was partially supported MINECO (MAT2013-46649-C4-2/4-P, MAT2015-71070-REDC, and MAT2016-75586-C4-2/4-P), and by the EU-FEDER. M.A. Hernández-Rodríguez thanks to MINECO for FPI grant (BES-2014-068666).Hernández-Rodríguez, M.; Lozano-Gorrín, A.; Lavin, V.; Rodriguez-Mendoza, U.; Martin, I.; Manjón, F. (2018). Analysis of the upconversion emission of yttrium orthoaluminate nanoperovskite co-doped with Er3+/Yb3+ ions for thermal sensing applications. Journal of Luminescence. 202:316-321. https://doi.org/10.1016/j.jlumin.2018.05.078S31632120

X-ray nanoimaging of Nd3+ optically active ions embedded in Sr0.5Ba0.5Nb2O6 nanocrystals

[EN] The spatial distribution of Sr0.5Ba0.5Nb2O6 nanocrystals is analyzed in a borate-based glass-ceramic by a synchrotron hard X-ray nanoimaging tool. Based on X-ray excited optical luminescence, we examined 2D projections of the Nd3+ optically active ions in the Sr0.5Ba0.5Nb2O6 nanocrystals, as well as in the glassy phase where they are embedded. Our findings reveal areas of agglomerations and/or clusters of nanocrystals ascribed to the diffusion coefficients of their constituent elements. They are characterized by high Nd3+ concentrations that may act as heterogeneous agents for the nucleation and growth of these nanocrystals. (C) 2017 Optical Society of AmericaMINECO, EU-FEDER and CSIC through the projects MAT2013-46649-C4-4-P, MAT201571070-REDC, MAT2016-75586-C4-2-P, MAT2016-75586-C4-4-P, 201550I021 and 201660I001, respectively. JAS acknowledges the Spanish Program Ramón y Cajal for his fellowship. We also thank the ESRF for the beam time allocated and experimental facilities.Martínez-Criado, G.; Alén, B.; Sans-Tresserras, JÁ.; Lozano-Gorrín, A.; Haro-González, P.; Martin, I.; Lavin, V. (2017). X-ray nanoimaging of Nd3+ optically active ions embedded in Sr0.5Ba0.5Nb2O6 nanocrystals. Optical Materials Express. 7(7):2424-2431. https://doi.org/10.1364/OME.7.002424S2424243177Nagata, K., Yamamoto, Y., Igarashi, H., & Okazaki, K. (1981). Properties of the hot-pressed strontium barium niobate ceramics. Ferroelectrics, 38(1), 853-856. doi:10.1080/00150198108209556Imai, T., Yagi, S., Yamazaki, H., & Ono, M. (1999). Effects of Heat Treatment on Photorefractive Sensitivity of Ce- and Eu-Doped Strontium Barium Niobate. Japanese Journal of Applied Physics, 38(Part 1, No. 4A), 1984-1988. doi:10.1143/jjap.38.1984Volk, T., Isakov, D., Salobutin, V., Ivleva, L., Lykov, P., Ramzaev, V., & Wöhlecke, M. (2004). Effects of Ni doping on properties of strontium–barium–niobate crystals. Solid State Communications, 130(3-4), 223-226. doi:10.1016/j.ssc.2004.01.039Romero, J. J., Andreeta, M. R. B., Andreeta, E. R. M., Bausá, L. E., Hernandes, A. C., & García Solé, J. (2004). Growth and characterization of Nd-doped SBN single crystal fibers. Applied Physics A, 78(7), 1037-1042. doi:10.1007/s00339-003-2151-3Chayapiwut, N., Honma, T., Benino, Y., Fujiwara, T., & Komatsu, T. (2005). Synthesis of Sm3+-doped strontium barium niobate crystals in glass by samarium atom heat processing. Journal of Solid State Chemistry, 178(11), 3507-3513. doi:10.1016/j.jssc.2005.09.002Haro-González, P., Martín, I. R., Martín, L. L., León-Luis, S. F., Pérez-Rodríguez, C., & Lavín, V. (2011). Characterization of Er3+ and Nd3+ doped Strontium Barium Niobate glass ceramic as temperature sensors. Optical Materials, 33(5), 742-745. doi:10.1016/j.optmat.2010.11.026Ivleva, L. I., Volk, T. R., Isakov, D. V., Gladkii, V. V., Polozkov, N. M., & Lykov, P. A. (2002). Growth and ferroelectric properties of Nd-doped strontium–barium niobate crystals. Journal of Crystal Growth, 237-239, 700-702. doi:10.1016/s0022-0248(01)01997-2Marcinkevičius, A., Juodkazis, S., Watanabe, M., Miwa, M., Matsuo, S., Misawa, H., & Nishii, J. (2001). Femtosecond laser-assisted three-dimensional microfabrication in silica. Optics Letters, 26(5), 277. doi:10.1364/ol.26.000277Sato, R., Benino, Y., Fujiwara, T., & Komatsu, T. (2001). YAG laser-induced crystalline dot patterning in samarium tellurite glasses. Journal of Non-Crystalline Solids, 289(1-3), 228-232. doi:10.1016/s0022-3093(01)00736-0Haro-González, P., Martín, L. L., González-Pérez, S., & Martín, I. R. (2010). Formation of Nd3+ doped Strontium Barium Niobate nanocrystals by two different methods. Optical Materials, 32(10), 1389-1392. doi:10.1016/j.optmat.2010.03.011Haro-González, P., Martín, I. R., & Creus, A. H. (2010). Nanocrystals distribution inside the writing lines in a glass matrix using Argon laser irradiation. Optics Express, 18(2), 582. doi:10.1364/oe.18.000582Haro-González, P., Martín, I. R., Arbelo-Jorge, E., González-Pérez, S., Cáceres, J. M., & Núñez, P. (2008). Laser irradiation in Nd3+ doped strontium barium niobate glass. Journal of Applied Physics, 104(1), 013112. doi:10.1063/1.2952011Kowalska, D., Haro-González, P., Martín, I. R., & Cáceres, J. M. (2010). Analysis of the optical properties of Er3+-doped strontium barium niobate nanocrystals using time-resolved laser spectroscopy. Applied Physics A, 99(4), 771-776. doi:10.1007/s00339-010-5716-yPellicer-Porres, J., Segura, A., Martínez-Criado, G., Rodríguez-Mendoza, U. R., & Lavín, V. (2012). Formation of nanostructures in Eu3+doped glass–ceramics: an XAS study. Journal of Physics: Condensed Matter, 25(2), 025303. doi:10.1088/0953-8984/25/2/025303Martínez-Criado, G., Alén, B., Sans, J. A., Homs, A., Kieffer, I., Tucoulou, R., … Yi, G. (2012). Spatially resolved X-ray excited optical luminescence. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 284, 36-39. doi:10.1016/j.nimb.2011.08.013Martínez-Criado, G., Sans, J. A., Segura-Ruiz, J., Tucoulou, R., Solé, A. V., Homs, A., … Alén, B. (2011). X-ray excited optical luminescence imaging of InGaN nano-LEDs. physica status solidi (c), 9(3-4), 628-630. doi:10.1002/pssc.201100430Villanova, J., Segura-Ruiz, J., Lafford, T., & Martinez-Criado, G. (2012). Synchrotron microanalysis techniques applied to potential photovoltaic materials. Journal of Synchrotron Radiation, 19(4), 521-524. doi:10.1107/s0909049512021383Smith, J., Akbari-Sharbaf, A., Ward, M. J., Murphy, M. W., Fanchini, G., & Kong Sham, T. (2013). Luminescence properties of defects in nanocrystalline ZnO. Journal of Applied Physics, 113(9), 093104. doi:10.1063/1.4794001Armelao, L., Heigl, F., Jürgensen, A., Blyth, R. I. R., Regier, T., Zhou, X.-T., & Sham, T. K. (2007). X-ray Excited Optical Luminescence Studies of ZnO and Eu-Doped ZnO Nanostructures. The Journal of Physical Chemistry C, 111(28), 10194-10200. doi:10.1021/jp071379fMartínez-Criado, G., Villanova, J., Tucoulou, R., Salomon, D., Suuronen, J.-P., Labouré, S., … Morse, J. (2016). ID16B: a hard X-ray nanoprobe beamline at the ESRF for nano-analysis. Journal of Synchrotron Radiation, 23(1), 344-352. doi:10.1107/s1600577515019839Jamieson, P. B., Abrahams, S. C., & Bernstein, J. L. (1968). Ferroelectric Tungsten Bronze‐Type Crystal Structures. I. Barium Strontium Niobate Ba0.27Sr0.75Nb2O5.78. The Journal of Chemical Physics, 48(11), 5048-5057. doi:10.1063/1.1668176Haro-González, P., Martín, I. R., & Hernández Creus, A. (2011). Nanocrystals formation on Ho3+ doped strontium barium niobate glass. Journal of Luminescence, 131(4), 657-661. doi:10.1016/j.jlumin.2010.11.011Lavı́n, V., Rodrı́guez-Mendoza, U. R., Martı́n, I. R., & Rodrı́guez, V. D. (2003). Optical spectroscopy analysis of the Eu3+ ions local structure in calcium diborate glasses. Journal of Non-Crystalline Solids, 319(1-2), 200-216. doi:10.1016/s0022-3093(02)01914-2Chernaya, T. S., Volk, T. R., Verin, I. A., Ivleva, L. I., & Simonov, V. I. (2002). Atomic structure of (Sr0.50Ba0.50)Nb2O6 single crystals in the series of (SrxBa1 − x )Nb2O6 compounds. Crystallography Reports, 47(2), 213-216. doi:10.1134/1.1466494Erbil, A., Cargill III, G. S., Frahm, R., & Boehme, R. F. (1988). Total-electron-yield current measurements for near-surface extended x-ray-absorption fine structure. Physical Review B, 37(5), 2450-2464. doi:10.1103/physrevb.37.2450Solé, V. A., Papillon, E., Cotte, M., Walter, P., & Susini, J. (2007). A multiplatform code for the analysis of energy-dispersive X-ray fluorescence spectra. Spectrochimica Acta Part B: Atomic Spectroscopy, 62(1), 63-68. doi:10.1016/j.sab.2006.12.002Martínez-Criado, G., Homs, A., Alén, B., Sans, J. A., Segura-Ruiz, J., Molina-Sánchez, A., … Yi, G.-C. (2012). Probing Quantum Confinement within Single Core–Multishell Nanowires. Nano Letters, 12(11), 5829-5834. doi:10.1021/nl303178uMartínez-Criado, G., Segura-Ruiz, J., Alén, B., Eymery, J., Rogalev, A., Tucoulou, R., & Homs, A. (2014). Exploring Single Semiconductor Nanowires with a Multimodal Hard X-ray Nanoprobe. Advanced Materials, 26(46), 7873-7879. doi:10.1002/adma.201304345Shyu, J.-J., & Wang, J.-R. (2000). Crystallization and Dielectric Properties of SrO-BaO-Nb2O5-SiO2Tungsten-Bronze Glass-Ceramics. Journal of the American Ceramic Society, 83(12), 3135-3140. doi:10.1111/j.1151-2916.2000.tb01694.

Structural, Vibrational, and Elastic Properties of Yttrium Orthoaluminate Nanoperovskite at High Pressures

"This document is the Accepted Manuscript version of a Published Work that appeared in final form in The Journal of Physical Chemistry C, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/page/policy/articlesonrequest/index.html."[EN] The structural and vibrational properties of nanocrystalline yttrium orthoaluminate perovskite (YAlO3) under compression have been experimentally studied. Experimental results have been compared to ab initio simulations of. bulk YAlO3, in the framework of the density functional theory. Furthermore, they have been complemented with an ab initio study of its elastic properties at different pressures. Calculated total and partial phonon density of states have allowed us to understand the contribution of the different atoms and structural units, YO12 dodecahedra and AlO6 octahedra, to the vibrational modes. The calculated infrared-active modes and their pressure dependence are also reported. Finally, the pressure dependences of the, elastic constants and the mechanical stability of the perovskite structure have been analyzed in detail, showing that this phase is mechanically stable until 92 GPa. In fact, experimental results up to 30 GPa show no evidence of any phase transition. A previously proposed possible phase transition in YAlO3 above 80 GPa is also discussed.This research was partially supported by MINECO (MAT2013-46649-C4-2/3/4-P, MAT2015-71070-REDC, and MAT2016-75586-C4-2/3/4-P) and by EU-FEDER funds. M.A.H.-R. thanks MINECO for an FPI grant (BES-2014-068666).Hernández-Rodríguez, M.; Monteseguro, V.; Lozano-Gorrín, A.; Manjón, F.; González-Platas, J.; Rodríguez-Hernández, P.; Muñoz, A.... (2017). Structural, Vibrational, and Elastic Properties of Yttrium Orthoaluminate Nanoperovskite at High Pressures. The Journal of Physical Chemistry C. 121(28):15353-15367. https://doi.org/10.1021/acs.jpcc.7b04245S15353153671212

Chemical pressure effects on the spectroscopic properties of Nd3+-doped gallium nano-garnets

[EN] Nd3+-doped RE3Ga5O12 (RE = Gd, Y, and Lu) nano-crystalline garnets of 40-45 nm in size have been synthesized by a sol-gel method. With the decrease of the RE atom size, the chemical pressure related to the decreasing volumes of the GaO4 tetrahedral, GaO6 octahedral and REO8 dodecahedral units drive the nano-garnets toward a more compacted structure, which is evidenced by the change of the vibrational phonon mode frequencies. The chemical pressure also increases the crystal-field strength felt by the RE3+ ions while decreases the orthorhombic distortion of the REO8 local environment. These effects alter the absorption and emission properties of the Nd3+ ion measured in the near-infrared luminescence range from 0.87 to 1.43 ¿m associated with the 4 F3/2¿4 IJ (J = 9/2, 11/2, 13/2) transitions. The 4 F3/2 luminescence decay curves show non-exponential behavior due to dipole-dipole energy transfer interactions among Nd3+ ions that increases with pressure.Authors are grateful to The Governments of Spain and India for the Indo-Spanish Joint Programme of Bilateral Cooperation in Science and Technology (PRI-PIBIN-2011-1153/DST-INT-Spain-P-38-11). Dr. Venkatramu is grateful to DAE-BRNS, Government of India for the award of DAE Research Award for Young Scientist (No. 2010/20/34/5/BRNS/2223). This work have been partially supported by MINECO under The National Program of Materials (MAT2013-46649-C4-2-P/-3-P/-4-P), The Consolider-Ingenio 2010 Program (MALTA CSD2007-00045), by Fundacion CajaCanarias (ENER-01), and by the EU-FEDER funds. V. Monteseguro wishes to thank MICINN for the FPI grant (BES-2011-044596). Authors also thank Agencia Canaria de Investigacion, Innovacion y Sociedad de la Informacion for the funds given to Universidad de La Laguna, co-financed by The European Social Fund by a percentage of 85%.Monteseguro, V.; Rathaiah, M.; Linganna, K.; Lozano-Gorrin, AD.; Hernandez-Rodriguez, MA.; Martin, IR.; Babu, P.... (2015). Chemical pressure effects on the spectroscopic properties of Nd3+-doped gallium nano-garnets. Optical Materials Express. 5(8):1661-1673. https://doi.org/10.1364/OME.5.001661S1661167358Pollnau, M., Hardman, P. ., Clarkson, W. ., & Hanna, D. . (1998). Upconversion, lifetime quenching, and ground-state bleaching in Nd3+:LiYF4. Optics Communications, 147(1-3), 203-211. doi:10.1016/s0030-4018(97)00524-5Brandle, C. D., & Barns, R. L. (1974). Crystal stoichiometry of Czochralski grown rare-earth gallium garnets. Journal of Crystal Growth, 26(1), 169-170. doi:10.1016/0022-0248(74)90223-1Venkatramu, V., Giarola, M., Mariotto, G., Enzo, S., Polizzi, S., Jayasankar, C. K., … Speghini, A. (2010). Nanocrystalline lanthanide-doped Lu3Ga5O12garnets: interesting materials for light-emitting devices. Nanotechnology, 21(17), 175703. doi:10.1088/0957-4484/21/17/175703Speghini, A., Piccinelli, F., & Bettinelli, M. (2011). Synthesis, characterization and luminescence spectroscopy of oxide nanopowders activated with trivalent lanthanide ions: The garnet family. Optical Materials, 33(3), 247-257. doi:10.1016/j.optmat.2010.10.039Krsmanović, R., Morozov, V. A., Lebedev, O. I., Polizzi, S., Speghini, A., Bettinelli, M., & Tendeloo, G. V. (2007). Structural and luminescence investigation on gadolinium gallium garnet nanocrystalline powders prepared by solution combustion synthesis. Nanotechnology, 18(32), 325604. doi:10.1088/0957-4484/18/32/325604Naccache, R., Vetrone, F., Speghini, A., Bettinelli, M., & Capobianco, J. A. (2008). Cross-Relaxation and Upconversion Processes in Pr3+ Singly Doped and Pr3+/Yb3+ Codoped Nanocrystalline Gd3Ga5O12: The Sensitizer/Activator Relationship. The Journal of Physical Chemistry C, 112(20), 7750-7756. doi:10.1021/jp711494dAntic-Fidancev, E., Hölsä, J., Lastusaari, M., & Lupei, A. (2001). Dopant-host relationships in rare-earth oxides and garnets doped with trivalent rare-earth ions. Physical Review B, 64(19). doi:10.1103/physrevb.64.195108Rodríguez-Carvajal, J. (1993). Recent advances in magnetic structure determination by neutron powder diffraction. Physica B: Condensed Matter, 192(1-2), 55-69. doi:10.1016/0921-4526(93)90108-iMonteseguro, V., Rodríguez-Hernández, P., Ortiz, H. M., Venkatramu, V., Manjón, F. J., Jayasankar, C. K., … Muñoz, A. (2015). Structural, elastic and vibrational properties of nanocrystalline lutetium gallium garnet under high pressure. Physical Chemistry Chemical Physics, 17(14), 9454-9464. doi:10.1039/c4cp05903dRay, S., León-Luis, S. F., Manjón, F. J., Mollar, M. A., Gomis, Ó., Rodríguez-Mendoza, U. R., … Lavín, V. (2014). Broadband, site selective and time resolved photoluminescence spectroscopic studies of finely size-modulated Y2O3:Eu3+ phosphors synthesized by a complex based precursor solution method. Current Applied Physics, 14(1), 72-81. doi:10.1016/j.cap.2013.07.027Nekvasil, V. (1978). The Crystal Field for Nd3+ in Garnets. Physica Status Solidi (b), 87(1), 317-323. doi:10.1002/pssb.2220870137Rodríguez-Mendoza, U. R., León-Luis, S. F., Muñoz-Santiuste, J. E., Jaque, D., & Lavín, V. (2013). Nd3+-doped Ca3Ga2Ge3O12garnet: A new optical pressure sensor. Journal of Applied Physics, 113(21), 213517. doi:10.1063/1.4809217Kaminska, A., Buczko, R., Paszkowicz, W., Przybylińska, H., Werner-Malento, E., Suchocki, A., … Saxena, S. (2011). Merging of the4F3/2level states of Nd3+ions in the photoluminescence spectra of gadolinium-gallium garnets under high pressure. Physical Review B, 84(7). doi:10.1103/physrevb.84.075483Allik, T. H., Stewart, S. A., Sardar, D. K., Quarles, G. J., Powell, R. C., Morrison, C. A., … Pinto, A. A. (1988). Preparation, structure, and spectroscopic properties ofNd3+:{La1−xLux}3[Lu1−yGay]2Ga3O12crystals. Physical Review B, 37(16), 9129-9139. doi:10.1103/physrevb.37.9129Wu, K., Yao, B., Zhang, H., Yu, H., Wang, Z., Wang, J., & Jiang, M. (2010). Growth and properties of Nd:Lu3Ga5O12 laser crystal by floating-zone method. Journal of Crystal Growth, 312(24), 3631-3636. doi:10.1016/j.jcrysgro.2010.09.029Jia, Z., Arcangeli, A., Tao, X., Zhang, J., Dong, C., Jiang, M., … Tonelli, M. (2009). Efficient Nd3+→Yb3+ energy transfer in Nd3+,Yb3+:Gd3Ga5O12 multicenter garnet crystal. Journal of Applied Physics, 105(8), 083113. doi:10.1063/1.3115442Guillot-Noel, O., Bellamy, B., Viana, B., & Gourier, D. (1999). Correlation between rare-earth oscillator strengths and rare-earth–valence-band interactions in neodymium-dopedYMO4(M=V,P, As),Y3Al5O12,andLiYF4matrices. Physical Review B, 60(3), 1668-1677. doi:10.1103/physrevb.60.1668Demidovich, A. A., Shkadarevich, A. P., Danailov, M. B., Apai, P., Gasmi, T., Gribkovskii, V. P., … Batay, L. E. (1998). Comparison of cw laser performance of Nd:KGW, Nd:YAG, Nd:BEL, and Nd:YVO 4 under laser diode pumping. Applied Physics B: Lasers and Optics, 67(1), 11-15. doi:10.1007/s003400050467Inokuti, M., & Hirayama, F. (1965). Influence of Energy Transfer by the Exchange Mechanism on Donor Luminescence. The Journal of Chemical Physics, 43(6), 1978-1989. doi:10.1063/1.1697063Lupei, V., & Lupei, A. (2000). Emission dynamics of the4F3/2level ofNd3+in YAG at low pump intensities. Physical Review B, 61(12), 8087-8098. doi:10.1103/physrevb.61.8087Maeda, K., Wada, N., Umino, M., Abe, M., Takada, Y., Nakano, N., & Kuroda, H. (1984). Concentration Dependence of Fluorescence Lifetime of Nd3+-Doped Gd3Ga5O12Lasers. Japanese Journal of Applied Physics, 23(Part 2, No. 10), L759-L760. doi:10.1143/jjap.23.l759Geusic, J. E., Marcos, H. M., & Van Uitert, L. G. (1964). LASER OSCILLATIONS IN Nd‐DOPED YTTRIUM ALUMINUM, YTTRIUM GALLIUM AND GADOLINIUM GARNETS. Applied Physics Letters, 4(10), 182-184. doi:10.1063/1.1753928Löhring, J., Nicklaus, K., Kujath, N., & Hoffmann, D. (2007). Diode pumped Nd:YGG laser for direct generation of pulsed 935 nm radiation for water vapour measurements. Solid State Lasers XVI: Technology and Devices. doi:10.1117/12.708220Maunier, C., Doualan, J. L., Moncorgé, R., Speghini, A., Bettinelli, M., & Cavalli, E. (2002). Growth, spectroscopic characterization, and laser performance of Nd:LuVO_4, a new infrared laser material that is suitable for diode pumping. Journal of the Optical Society of America B, 19(8), 1794. doi:10.1364/josab.19.00179

Autonomic pain responses during sleep: a study of heart rate variability

The autonomic nervous system (ANS) reacts to nociceptive stimulation during sleep, but whether this reaction is contingent to cortical arousal, and whether one of the autonomic arms (sympathetic/parasympathetic) predominates over the other remains unknown. We assessed ANS reactivity to nociceptive stimulation during all sleep stages through heart rate variability, and correlated the results with the presence of cortical arousal measured in concomitant 32-channel EEG. Fourteen healthy volunteers underwent whole-night polysomnography during which nociceptive laser stimuli were applied over the hand. RR intervals (RR) and spectral analysis by wavelet transform were performed to assess parasympathetic (HF(WV)) and sympathetic (LF(WV) and LF(WV)/HF(WV) ratio) reactivity. During all sleep stages, RR significantly decreased in reaction to nociceptive stimulations, reaching a level similar to that of wakefulness, at the 3rd beat post-stimulus and returning to baseline after seven beats. This RR decrease was associated with an increase in sympathetic LF(WV) and LF(WV)/HF(WV) ratio without any parasympathetic HF(WV) change. Albeit RR decrease existed even in the absence of arousals, it was significantly higher when an arousal followed the noxious stimulus. These results suggest that the sympathetic-dependent cardiac activation induced by nociceptive stimuli is modulated by a sleep dependent phenomenon related to cortical activation and not by sleep itself, since it reaches a same intensity whatever the state of vigilance

Flexible Communication Avoiding Matrix Multiplication on FPGA with High-Level Synthesis

Data movement is the dominating factor affecting performance and energy in modern computing systems. Consequently, many algorithms have been developed to minimize the number of I/O operations for common computing patterns. Matrix multiplication is no exception, and lower bounds have been proven and implemented both for shared and distributed memory systems. Reconfigurable hardware platforms are a lucrative target for I/O minimizing algorithms, as they offer full control of memory accesses to the programmer. While bounds developed in the context of fixed architectures still apply to these platforms, the spatially distributed nature of their computational and memory resources requires a decentralized approach to optimize algorithms for maximum hardware utilization. We present a model to optimize matrix multiplication for FPGA platforms, simultaneously targeting maximum performance and minimum off-chip data movement, within constraints set by the hardware. We map the model to a concrete architecture using a high-level synthesis tool, maintaining a high level of abstraction, allowing us to support arbitrary data types, and enables maintainability and portability across FPGA devices. Kernels generated from our architecture are shown to offer competitive performance in practice, scaling with both compute and memory resources. We offer our design as an open source project to encourage the open development of linear algebra and I/O minimizing algorithms on reconfigurable hardware platforms

Academic Performance and Behavioral Patterns

Identifying the factors that influence academic performance is an essential part of educational research. Previous studies have documented the importance of personality traits, class attendance, and social network structure. Because most of these analyses were based on a single behavioral aspect and/or small sample sizes, there is currently no quantification of the interplay of these factors. Here, we study the academic performance among a cohort of 538 undergraduate students forming a single, densely connected social network. Our work is based on data collected using smartphones, which the students used as their primary phones for two years. The availability of multi-channel data from a single population allows us to directly compare the explanatory power of individual and social characteristics. We find that the most informative indicators of performance are based on social ties and that network indicators result in better model performance than individual characteristics (including both personality and class attendance). We confirm earlier findings that class attendance is the most important predictor among individual characteristics. Finally, our results suggest the presence of strong homophily and/or peer effects among university students