550 research outputs found
Avaliação de variabilidade genética e correlações fenotípicas entre caracteres do pendão e produção de grãos de híbridos simples de milho (Zea mays L.).
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High-Flow Vascular Malformations in Children.
Children can have a variety of intracranial vascular anomalies ranging from small and incidental with no clinical consequences to complex lesions that can cause substantial neurologic deficits, heart failure, or profoundly affect development. In contrast to high-flow lesions with direct arterial-to-venous shunts, low-flow lesions such as cavernous malformations are associated with a lower likelihood of substantial hemorrhage, and a more benign course. Management of vascular anomalies in children has to incorporate an understanding of how treatment strategies may affect the normal development of the central nervous system. In this review, we discuss the etiologies, epidemiology, natural history, and genetic risk factors of three high-flow vascular malformations seen in children: brain arteriovenous malformations, intracranial dural arteriovenous fistulas, and vein of Galen malformations
Resíduos sólidos de uva e compostos com capacidade oxi-redox favorável.
O objetivo deste estudo foi determinar a diferença existente entre os resíduos dos cultivares Isabel, Niágara, Chardonnay, Pinot Noir e uma mistura de cultivares em relação à concentração dos agentes oxi-redoxf para exploração industrial e comercial.Resumo
Genetic characterization of Mycobacterium tuberculosis in the West Bank, Palestinian Territories
BACKGROUND: The World Health Organization (WHO) declared human tuberculosis (TB) a global health emergency and launched the “Global Plan to Stop Tuberculosis” which aims to save a million lives by 2015. Global control of TB is increasingly dependent on rapid and accurate genetic typing of species of the Mycobacterium tuberculosis (MTB) complex including M. tuberculosis. The aim of this study was to identify and genetically characterize the MTB isolates circulating in the West Bank, Palestinian Territories. Genotyping of the MTB isolates from patients with pulmonary TB was carried out using two molecular genetic techniques, spoligotyping and mycobacterial interspersed repetitive units-variable number of tandem repeat (MIRU-VNTR) supported by analysis of the MTB specific deletion 1 (TbD1). FINDINGS: A total of 17 MTB patterns were obtained from the 31 clinical isolates analyzed by spoligotyping; corresponding to 2 orphans and 15 shared-types (SITs). Fourteen SITs matched a preexisting shared-type in the SITVIT2 database, whereas a single shared-type SIT3348 was newly created. The most common spoligotyping profile was SIT53 (T1 variant), identified in 35.5 % of the TB cases studied. Genetic characterization of 22 clinical isolates via the 15 loci MIRU-VNTR typing distinguished 19 patterns. The 15-loci MIT144 and MIT145 were newly created within this study. Both methods determined the present of M. bovis strains among the isolates. CONCLUSIONS: Significant diversity among the MTB isolates circulating in the West Bank was identified with SIT53-T1 genotype being the most frequent strain. Our results are used as reference database of the strains circulating in our region and may facilitate the implementation of an efficient TB control program
Structural and vibrational study of cubic Sb2O3 under high pressure
We report an experimental and theoretical study of antimony oxide (Sb 2O 3) in its cubic phase (senarmontite) under high pressure. X-ray diffraction and Raman scattering measurements up to 18 and 25 GPa, respectively, have been complemented with ab initio total-energy and lattice-dynamics calculations. X-ray diffraction measurements do not provide evidence of a space-group symmetry change in senarmontite up to 18 GPa. However, Raman scattering measurements evidence changes in the pressure coefficients of the Raman mode frequencies at 3.5 and 10 GPa, respectively. The behavior of the Raman modes with increasing pressure up to 25 GPa is fully reproduced by the lattice-dynamics calculations in cubic Sb 2O 3. Therefore, the combined analysis of both experiments and lattice-dynamics calculations suggest the occurrence of two isostructural phase transformations at 3.5 and 10 GPa, respectively. Total-energy calculations show that the isostructural phase transformations occur through local atomic displacements in which senarmontite loses its molecular character to become a three-dimensional solid. In addition, our calculations provide evidence that cubic senarmontite cannot undergo a phase transition to orthorhombic valentinite at high pressure, and that a phase transition to a ß-Bi 2O 3-type structure is possible above 25 GPa. © 2012 American Physical Society.Financial support from the Spanish Consolider Ingenio 2010 Program (Project No. CDS2007-00045) is acknowledged. The work was also supported by Spanish MICCIN under Projects No. CTQ2009-14596-C02-01 and No. MAT2010-21270-C04-01/04 as well as from Comunidad de Madrid and European Social Fund, S2009/PPQ-1551 4161893 (QUIMAPRES) and from Vicerrectorado de Investigacion de la Universitat Politecnica de Valencia under projects UPV2011-0914 PAID-05-11 and UPV2011-0966 PAID-06-11. Spanish Fundacio Bancaixa Project No. P1-1A2009-08 and Brazilian Capes/Fundacion Carolina (BEX 3939/10-3) are also acknowledged.Pereira, ALJ.; Gracia, L.; Santamaría-Pérez, D.; Vilaplana Cerda, RI.; Manjón Herrera, FJ.; Errandonea, D.; Nalin, M.... (2012). Structural and vibrational study of cubic Sb2O3 under high pressure. Physical Review B. 85(17):174108-1-174108-11. https://doi.org/10.1103/PhysRevB.85.174108S174108-1174108-118517Youk, J. H., Kambour, R. P., & MacKnight, W. J. (2000). Polymerization of Ethylene Terephthalate Cyclic Oligomers with Antimony Trioxide†. Macromolecules, 33(10), 3594-3599. doi:10.1021/ma991838dZabinski, J. S., Donley, M. S., & McDevitt, N. T. (1993). Mechanistic study of the synergism between Sb2O3 and MoS2 lubricant systems using Raman spectroscopy. Wear, 165(1), 103-108. doi:10.1016/0043-1648(93)90378-yGhosh, A., & Chakravorty, D. (1991). Transport properties of semiconducting CuO-Sb2O3-P2O5glasses. Journal of Physics: Condensed Matter, 3(19), 3335-3342. doi:10.1088/0953-8984/3/19/012Gopalakrishnan, P. S., & Manohar, H. (1975). Kinetics and mechanism of the transformation in antimony trioxide from orthorhombic valentinite to cubic senarmontite. Journal of Solid State Chemistry, 15(1), 61-67. doi:10.1016/0022-4596(75)90271-6Zachariasen, W. H. (1932). THE ATOMIC ARRANGEMENT IN GLASS. Journal of the American Chemical Society, 54(10), 3841-3851. doi:10.1021/ja01349a006Matsumoto, A., Koyama, Y., Togo, A., Choi, M., & Tanaka, I. (2011). Electronic structures of dynamically stable As2O3, Sb2O3, and Bi2O3crystal polymorphs. Physical Review B, 83(21). doi:10.1103/physrevb.83.214110Miller, P. J., & Cody, C. A. (1982). Infrared and Raman investigation of vitreous antimony trioxide. Spectrochimica Acta Part A: Molecular Spectroscopy, 38(5), 555-559. doi:10.1016/0584-8539(82)80146-3Svensson, C. (1975). Refinement of the crystal structure of cubic antimony trioxide, Sb2O3. Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, 31(8), 2016-2018. doi:10.1107/s0567740875006759Wood, C., van Pelt, B., & Dwight, A. (1972). The Optical Properties of Amorphous and Crystalline Sb2O3. Physica Status Solidi (b), 54(2), 701-706. doi:10.1002/pssb.2220540234Nalin, M., Messaddeq, Y., Ribeiro, S. J. L., Poulain, M., Briois, V., Brunklaus, G., … Eckert, H. (2004). Structural organization and thermal properties of the Sb2O3–SbPO4glass system. J. Mater. Chem., 14(23), 3398-3405. doi:10.1039/b406075jOrosel, D., Dinnebier, R. E., Blatov, V. A., & Jansen, M. (2012). Structure of a new high-pressure–high-temperature modification of antimony(III) oxide, γ-Sb2O3, from high-resolution synchrotron powder diffraction data. Acta Crystallographica Section B Structural Science, 68(1), 1-7. doi:10.1107/s0108768111046751Grzechnik, A. (1999). Compressibility and Vibrational Modes in Solid As4O6. Journal of Solid State Chemistry, 144(2), 416-422. doi:10.1006/jssc.1999.8189Soignard, E., Amin, S. A., Mei, Q., Benmore, C. J., & Yarger, J. L. (2008). High-pressure behavior ofAs2O3: Amorphous-amorphous and crystalline-amorphous transitions. Physical Review B, 77(14). doi:10.1103/physrevb.77.144113Chouinard, C., & Desgreniers, S. (1999). Bi2O3 under hydrostatic pressure: observation of a pressure-induced amorphization. Solid State Communications, 113(3), 125-129. doi:10.1016/s0038-1098(99)00463-9Geng, A., Cao, L., Wan, C., & Ma, Y. (2011). High-pressure Raman investigation of the semiconductor antimony oxide. physica status solidi (c), 8(5), 1708-1711. doi:10.1002/pssc.201000786Manjón, F. J., & Errandonea, D. (2009). Pressure-induced structural phase transitions in materials and earth sciences. physica status solidi (b), 246(1), 9-31. doi:10.1002/pssb.200844238Mao, H. K., Xu, J., & Bell, P. M. (1986). Calibration of the ruby pressure gauge to 800 kbar under quasi-hydrostatic conditions. Journal of Geophysical Research, 91(B5), 4673. doi:10.1029/jb091ib05p04673Rodríguez-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-iErrandonea, D., Santamaria-Perez, D., Bondarenko, T., & Khyzhun, O. (2010). New high-pressure phase of HfTiO4 and ZrTiO4 ceramics. Materials Research Bulletin, 45(11), 1732-1735. doi:10.1016/j.materresbull.2010.06.061Errandonea, D., Santamaria-Perez, D., Achary, S. N., Tyagi, A. K., Gall, P., & Gougeon, P. (2011). High-pressure x-ray diffraction study of CdMoO4 and EuMoO4. Journal of Applied Physics, 109(4), 043510-043510-5. doi:10.1063/1.3553850Stroppa, D. G., Montoro, L. A., Beltrán, A., Conti, T. G., da Silva, R. O., Andrés, J., … Ramirez, A. J. (2009). Unveiling the Chemical and Morphological Features of Sb−SnO2Nanocrystals by the Combined Use of High-Resolution Transmission Electron Microscopy and ab Initio Surface Energy Calculations. Journal of the American Chemical Society, 131(40), 14544-14548. doi:10.1021/ja905896uBecke, A. D. (1993). Density‐functional thermochemistry. III. The role of exact exchange. The Journal of Chemical Physics, 98(7), 5648-5652. doi:10.1063/1.464913Lee, C., Yang, W., & Parr, R. G. (1988). Development of the Colle-Salvetti correlation-energy formula into a functional of the electron density. Physical Review B, 37(2), 785-789. doi:10.1103/physrevb.37.785Beltrán, A., Gracia, L., & Andrés, J. (2006). Density Functional Theory Study of the Brookite Surfaces and Phase Transitions between Natural Titania Polymorphs. The Journal of Physical Chemistry B, 110(46), 23417-23423. doi:10.1021/jp0643000Grimme, S. (2006). Semiempirical GGA-type density functional constructed with a long-range dispersion correction. Journal of Computational Chemistry, 27(15), 1787-1799. doi:10.1002/jcc.20495Bučko, T., Hafner, J., Lebègue, S., & Ángyán, J. G. (2010). Improved Description of the Structure of Molecular and Layered Crystals: Ab Initio DFT Calculations with van der Waals Corrections. The Journal of Physical Chemistry A, 114(43), 11814-11824. doi:10.1021/jp106469xBirch, F. (1952). Elasticity and constitution of the Earth’s interior. Journal of Geophysical Research, 57(2), 227-286. doi:10.1029/jz057i002p00227Whitten, A. E., Dittrich, B., Spackman, M. A., Turner, P., & Brown, T. C. (2004). Charge density analysis of two polymorphs of antimony(iii) oxide. Dalton Transactions, (1), 23. doi:10.1039/b312550eKroumova, E., Aroyo, M. I., Perez-Mato, J. M., Kirov, A., Capillas, C., Ivantchev, S., & Wondratschek, H. (2003). Bilbao Crystallographic Server : Useful Databases and Tools for Phase-Transition Studies. Phase Transitions, 76(1-2), 155-170. doi:10.1080/0141159031000076110Cody, C. A., DiCarlo, L., & Darlington, R. K. (1979). Vibrational and thermal study of antimony oxides. Inorganic Chemistry, 18(6), 1572-1576. doi:10.1021/ic50196a036Gilliam, S. J., Jensen, J. O., Banerjee, A., Zeroka, D., Kirkby, S. J., & Merrow, C. N. (2004). A theoretical and experimental study of Sb4O6: vibrational analysis, infrared, and Raman spectra. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 60(1-2), 425-434. doi:10.1016/s1386-1425(03)00245-2Mestl, G., Ruiz, P., Delmon, B., & Knozinger, H. (1994). Sb2O3/Sb2O4 in reducing/oxidizing environments: an in situ Raman spectroscopy study. The Journal of Physical Chemistry, 98(44), 11276-11282. doi:10.1021/j100095a008Blower, S. K., & Greaves, C. (1988). The structure of β-Bi2O3 from powder neutron diffraction data. Acta Crystallographica Section C Crystal Structure Communications, 44(4), 587-589. doi:10.1107/s0108270187011661Johansson, B., & Li, S. (2009). Itinerantf-electron elements. Philosophical Magazine, 89(22-24), 1793-1799. doi:10.1080/14786430902917632Akahama, Y., Kobayashi, M., & Kawamura, H. (1991). High-Pressure X-Ray Diffraction Study on Electronics-dTransition in Zirconium. Journal of the Physical Society of Japan, 60(10), 3211-3214. doi:10.1143/jpsj.60.3211Occelli, F., Farber, D. L., Badro, J., Aracne, C. M., Teter, D. M., Hanfland, M., … Couzinet, B. (2004). Experimental Evidence for a High-Pressure Isostructural Phase Transition in Osmium. Physical Review Letters, 93(9). doi:10.1103/physrevlett.93.095502Zarechnaya, E., Dubrovinskaia, N., Caracas, R., Merlini, M., Hanfland, M., Filinchuk, Y., … Dubrovinsky, L. (2010). Pressure-induced isostructural phase transformation inγ-B28. Physical Review B, 82(18). doi:10.1103/physrevb.82.184111Chatterjee, A., Singh, A. K., & Jayaraman, A. (1972). Pressure-Induced Electronic Collapse and Structural Changes in Rare-Earth Monochalcogenides. Physical Review B, 6(6), 2285-2291. doi:10.1103/physrevb.6.2285Chefki, M., Abd-Elmeguid, M. M., Micklitz, H., Huhnt, C., Schlabitz, W., Reehuis, M., & Jeitschko, W. (1998). Pressure-induced Transition of the Sublattice Magnetization inEuCo2P2: Change from Local MomentEu(4f)to ItinerantCo(3d)Magnetism. Physical Review Letters, 80(4), 802-805. doi:10.1103/physrevlett.80.802Caracas, R., & Gonze, X. (2004). Structural, electronic, and dynamical properties of calaveriteAuTe2under pressure. Physical Review B, 69(14). doi:10.1103/physrevb.69.144114Svane, A., Strange, P., Temmerman, W. M., Szotek, Z., Winter, H., & Petit, L. (2001). Pressure-Induced Valence Transitions in Rare Earth Chalcogenides and Pnictides. physica status solidi (b), 223(1), 105-116. doi:10.1002/1521-3951(200101)223:13.0.co;2-iYoo, C. S., Maddox, B., Klepeis, J.-H. P., Iota, V., Evans, W., McMahan, A., … Pickett, W. E. (2005). First-Order Isostructural Mott Transition in Highly Compressed MnO. Physical Review Letters, 94(11). doi:10.1103/physrevlett.94.115502Rosner, H., Koudela, D., Schwarz, U., Handstein, A., Hanfland, M., Opahle, I., … Richter, M. (2006). Magneto-elastic lattice collapse in YCo5. Nature Physics, 2(7), 469-472. doi:10.1038/nphys341Polian, A., Gauthier, M., Souza, S. M., Trichês, D. M., Cardoso de Lima, J., & Grandi, T. A. (2011). Two-dimensional pressure-induced electronic topological transition in Bi2Te3. Physical Review B, 83(11). doi:10.1103/physrevb.83.113106Vilaplana, R., Gomis, O., Manjón, F. J., Segura, A., Pérez-González, E., Rodríguez-Hernández, P., … Kucek, V. (2011). High-pressure vibrational and optical study of Bi2Te3. Physical Review B, 84(10). doi:10.1103/physrevb.84.104112Vilaplana, R., Santamaría-Pérez, D., Gomis, O., Manjón, F. J., González, J., Segura, A., … Kucek, V. (2011). Structural and vibrational study of Bi2Se3under high pressure. Physical Review B, 84(18). doi:10.1103/physrevb.84.184110Sakai, N., Kajiwara, T., Takemura, K., Minomura, S., & Fujii, Y. (1981). Pressure-induced phase transition in Sb2Te3. Solid State Communications, 40(12), 1045-1047. doi:10.1016/0038-1098(81)90248-9Souza, S. M., Trichês, D. M., Poffo, C. M., de Lima, J. C., Grandi, T. A., & de Biasi, R. S. (2011). Structural, thermal, optical, and photoacoustic study of nanocrystalline Bi2Te3 produced by mechanical alloying. Journal of Applied Physics, 109(1), 013512. doi:10.1063/1.3520658Åberg, D., Erhart, P., Crowhurst, J., Zaug, J. M., Goncharov, A. F., & Sadigh, B. (2010). Pressure-induced phase transition in the electronic structure of palladium nitride. Physical Review B, 82(10). doi:10.1103/physrevb.82.10411
Bulk photochromism in a tungstate-phosphate glass: A new optical memory material?
In this work, we present a new photochromic tungstate based glass which have both absorption coefficient and refractive index modified under laser exposure. The photosensitive effect is superficial under ultraviolet (UV) irradiation but occurs in the entire volume of the glass under visible irradiation. The effect can be obtained in any specific point inside the volume using an infrared femtosecond laser. In addition, the photosensitive phenomenon can be erased by specific heat treatment. This glass can be useful to substitute actual data storage supports and is a promising material for 3-dimensional (3D) and holographic optical storage.1251
Plasmonic Structures Fabricated By Interference Lithography For Sensor Applications
In this work we demonstrate the use of holographic lithography for generation of large area plasmonic periodic structures. Submicrometric array of holes, with different periods and thickness, were recorded in gold films, in areas of about 1 cm2, with homogeneity similar to that of samples recorded by Focused Ion Beam. In order to check the plasmonic properties, we measured the transmission spectra of the samples. The spectra exhibit the typical surface plasmon resonances (SPR) in the infrared whose position and width present the expected behavior with the period of the array and film thickness. The shift of the peak position with the permittivity of the surrounding medium demonstrates the feasebility of the sample as large area sensors. © 2009 SPIE.7394Ebbesen, T.W., Lezec, H.J., Ghaemy, H.F., Thio, T., Wolff, P.A., Extraordinary optical transmission through sub-wavelenght hole arrays (1998) Nature, 391, pp. 667-669Ghaemy, H.F., Thio, T., Grupp, D.E., Ebbesen, T.W., Lezec, H.J., Surface plasmons enhance optical transmission through subwavelenght holes (1998) Phys. Rev. B, 58, pp. 6779-6782Lal, S., Link, S., Halas, N.J., Nano-optics from sensing to waveguiding (2007) Nature Photonics, 1, pp. 641-648Barnes, W.L., Dereux, A., Ebbesen, T.W., Surface plasmon subwavelength optics (2003) Nature, 424, pp. 824-830Brolo, A.G., Arctander, E., Gordon, R., Leathem, B., Kavanagh, K.L., Nanohole-Enhanced Raman Scattering (2004) Nano Lett, 4, pp. 2015-2018Brolo, A.G., Gordon, R., Leathem, B., Kavanagh, K.L., Surface plasmon sensor based on the enhanced light transmission through arrays of nanoholes in gold films (2004) Langmuir, 20, pp. 4813-4815Brueck, S.R.J., Optical and Interferometric Lithography- Nanotechnology Enablers (2005) Proc. IEEE, 93, pp. 1704-1721Lai, N.D., Liang, W.P., Lin, J.H., Hsu, C.C., Lin, C.H., Fabrication of two- and three-dimensional periodic structures by multi-exposure of two-beam interference technique (2005) Opt. Express, 13, pp. 9605-9611Frejlich, J., Cescato, L., Mendes, G.F., Analysis of an active stabilization system for holographic setup (1988) Appl. Opt, 27, pp. 1967-197
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