2,144 research outputs found

    Can one detect a non-smooth null infinity?

    Get PDF
    It is shown that the precession of a gyroscope can be used to elucidate the nature of the smoothness of the null infinity of an asymptotically flat spacetime (describing an isolated body). A model for which the effects of precession in the non-smooth null infinity case are of order r2lnrr^{-2}\ln r is proposed. By contrast, in the smooth version the effects are of order r3r^{-3}. This difference should provide an effective criterion to decide on the nature of the smoothness of null infinity.Comment: 6 pages, to appear in Class. Quantum Gra

    Synthetic routes, characterization and photophysical properties of luminescent, surface functionalized nanodiamonds

    Get PDF
    The functionalization of small diameter (ca. 50 nm) polycarboxylated nanodiamond particles using amide coupling methodologies in both water and acetonitrile solvent has been investigated. In this manner, the surfaces of nanodiamond particles were adorned with different luminescent moieties, including a green fluorescent 1,8-naphthalimide species (Nap-1), and a red emitting ruthenium(II) tris-bipyridine complex (Ru-1), as well as dual functionalization with both luminophores. Comprehensive characterization of the surface functionalized nanodiamonds has been achieved using a combination of dynamic light scattering, nanoparticle tracking analysis, transmission electron microscopy, X-ray photoelectron spectroscopy, zeta potential measurements, microwave plasma atomic emission spectroscopy and time-resolved photophysics. The tendency of the functionalized nanodiamonds to aggregate reflects the degree of surface substitution, yielding small aggregates with typical particle sizes ca. 150 nm. This is likely to be driven by the reduction of the zeta potential, concomitant with the conversion of surface charged carboxylate groups to neutral amide functions. The results show that luminescent nanodiamond materials can be synthesised with tuneable photophysical properties

    On parallel Branch and Bound frameworks for Global Optimization

    Get PDF
    Branch and Bound (B&B) algorithms are known to exhibit an irregularity of the search tree. Therefore, developing a parallel approach for this kind of algorithms is a challenge. The efficiency of a B&B algorithm depends on the chosen Branching, Bounding, Selection, Rejection, and Termination rules. The question we investigate is how the chosen platform consisting of programming language, used libraries, or skeletons influences programming effort and algorithm performance. Selection rule and data management structures are usually hidden to programmers for frameworks with a high level of abstraction, as well as the load balancing strategy, when the algorithm is run in parallel. We investigate the question by implementing a multidimensional Global Optimization B&B algorithm with the help of three frameworks with a different level of abstraction (from more to less): Bobpp, Threading Building Blocks (TBB), and a customized Pthread implementation. The following has been found. The Bobpp implementation is easy to code, but exhibits the poorest scalability. On the contrast, the TBB and Pthread implementations scale almost linearly on the used platform. The TBB approach shows a slightly better productivity

    Physiological lentiviral vectors for the generation of improved CAR-T cells

    Full text link
    Anti-CD19 chimeric antigen receptor (CAR)-T cells have achieved impressive outcomes for the treatment of relapsed and refractory B-lineage neoplasms. However, important limitations still remain due to severe adverse events (i.e., cytokine release syndrome and neuroinflammation) and relapse of 40%-50% of the treated patients. Most CAR-T cells are generated using retroviral vectors with strong promoters that lead to high CAR expression levels, tonic signaling, premature exhaustion, and overstimulation, reducing efficacy and increasing side effects. Here, we show that lentiviral vectors (LVs) expressing the transgene through a WAS gene promoter (AW-LVs) closely mimic the T cell receptor (TCR)/CD3 expression kinetic upon stimulation. These AW-LVs can generate improved CAR-T cells as a consequence of their moderate and TCR-like expression profile. Compared with CAR-T cells generated with human elongation factor alpha (EF1 alpha)-driven-LVs, AW-CAR-T cells exhibited lower tonic signaling, higher proportion of naive and stem cell memory T cells, less exhausted phenotype, and milder secretion of tumor necrosis factor alpha (TNF-alpha) and interferon (IFN)-gamma after efficient destruction of CD19(+) lymphoma cells, both in vitro and in vivo. Moreover, we also showed their improved efficiency using an in vitro CD19(+) pancreatic tumor model. We finally demonstrated the feasibility of large-scale manufacturing of AW-CAR-T cells in guanosine monophosphate (GMP)-like conditions. Based on these data, we propose the use of AWLVs for the generation of improved CAR-T products

    Pressure-induced amorphization of YVO4:Eu3+ nanoboxes

    Full text link
    This is an author-created, un-copyedited version of an article published in Nanotechnology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://dx.doi.org/10.1088/0957-4484/27/2/025701A structural transformation from the zircon-type structure to an amorphous phase has been found in YVO4:Eu3+ nanoboxes at high pressures above 12.7 GPa by means of x-ray diffraction measurements. However, the pair distribution function of the high-pressure phase shows that the local structure of the amorphous phase is similar to the scheelite-type YVO4. These results are confirmed both by Raman spectroscopy and Eu3+ photoluminescence which detect the phase transition to a scheelite-type structure at 10.1 and 9.1 GPa, respectively. The irreversibility of the phase transition is observed with the three techniques after a maximum pressure in the upstroke of around 20 GPa. The existence of two D-5(0)-> F-7(0) photoluminescence peaks confirms the existence of two local environments for Eu3+, at least for the low-pressure phase. One environment is the expected for substituting Y3+ and the other is likely a disordered environment possibly found at the surface of the nanoboxes.This work has been performed under financial support from Spanish MINECO under the National Program of Materials (MAT2013-46649-C4-1/2/3/4-P) and the Consolider-Ingenio 2010 Program (MALTA CSD2007-00045). Funding by the Fundacion Caja Canarias (ENER-01) and the EU-FEDER funds is also acknowledged. JR-F thanks the Alexander von Humboldt Foundation for a postdoctoral fellowship and NS thanks the German Research Foundation (DFG) for financial support (Project RA2585/1-1). We acknowledge Diamond Light Source for time on beamline I15 under proposals EE3652 and EE6517. Parts of this research were carried out at the light source PETRA III at DESY (Hamburg), a member of the Helmholtz Association (HFG). We would like to thank H-P Liermann and W Morgenroth for assistance in using beamline P02.2.Ruiz Fuertes, J.; Gomis, O.; León Luis, SF.; Schrodt, N.; Manjón Herrera, FJ.; Ray, S.; Santamaría Pérez, D.... (2016). Pressure-induced amorphization of YVO4:Eu3+ nanoboxes. Nanotechnology. 27(2):025701-1-025701-8. https://doi.org/10.1088/0957-4484/27/2/025701S025701-1025701-8272Piot, L., Le Floch, S., Cornier, T., Daniele, S., & Machon, D. (2013). Amorphization in Nanoparticles. The Journal of Physical Chemistry C, 117(21), 11133-11140. doi:10.1021/jp401121cZhang, F. X., Wang, J. W., Lang, M., Zhang, J. M., Ewing, R. C., & Boatner, L. A. (2009). High-pressure phase transitions ofScPO4andYPO4. Physical Review B, 80(18). doi:10.1103/physrevb.80.184114Lacomba-Perales, R., Errandonea, D., Meng, Y., & Bettinelli, M. (2010). High-pressure stability and compressibility ofAPO4(A=La, Nd, Eu, Gd, Er, and Y) orthophosphates: An x-ray diffraction study using synchrotron radiation. Physical Review B, 81(6). doi:10.1103/physrevb.81.064113Yuan, H., Wang, K., Li, S., Tan, X., Li, Q., Yan, T., … Zou., B. (2012). Direct Zircon-to-Scheelite Structural Transformation in YPO4 and YPO4:Eu3+ Nanoparticles Under High Pressure. The Journal of Physical Chemistry C, 116(46), 24837-24844. doi:10.1021/jp3088995Mishra, A. K., Garg, N., Pandey, K. K., Shanavas, K. V., Tyagi, A. K., & Sharma, S. M. (2010). Zircon-monoclinic-scheelite transformation in nanocrystalline chromates. Physical Review B, 81(10). doi:10.1103/physrevb.81.104109Wang, L., Yang, W., Ding, Y., Ren, Y., Xiao, S., Liu, B., … Mao, H. (2010). Size-Dependent Amorphization of NanoscaleY2O3at High Pressure. Physical Review Letters, 105(9). doi:10.1103/physrevlett.105.095701Mukherjee, S., Kim, K., & Nair, S. (2007). Short, Highly Ordered, Single-Walled Mixed-Oxide Nanotubes Assemble from Amorphous Nanoparticles. Journal of the American Chemical Society, 129(21), 6820-6826. doi:10.1021/ja070124cŞopu, D., Albe, K., Ritter, Y., & Gleiter, H. (2009). From nanoglasses to bulk massive glasses. Applied Physics Letters, 94(19), 191911. doi:10.1063/1.3130209Ozawa, L., & Itoh, M. (2003). Cathode Ray Tube Phosphors. Chemical Reviews, 103(10), 3835-3856. doi:10.1021/cr0203490Zhu, Y., Xu, W., Zhang, H., Wang, W., Tong, L., Xu, S., … Song, H. (2012). Highly modified spontaneous emissions in YVO4:Eu3+ inverse opal and refractive index sensing application. Applied Physics Letters, 100(8), 081104. doi:10.1063/1.3688167Khan, A. F., Haranath, D., Yadav, R., Singh, S., Chawla, S., & Dutta, V. (2008). Controlled surface distribution and luminescence of YVO4:Eu3+ nanophosphor layers. Applied Physics Letters, 93(7), 073103. doi:10.1063/1.2973163Cho, Y.-S., & Huh, Y.-D. (2011). Preparation of Transparent Red-Emitting YVO4:Eu Nanophosphor Suspensions. Bulletin of the Korean Chemical Society, 32(1), 335-337. doi:10.5012/bkcs.2011.32.1.335Jayaraman, A., Kourouklis, G. A., Espinosa, G. P., Cooper, A. S., & Van Uitert, L. G. (1987). A high-pressure Raman study of yttrium vanadate (YVO4) and the pressure-induced transition from the zircon-type to the scheelite-type structure. Journal of Physics and Chemistry of Solids, 48(8), 755-759. doi:10.1016/0022-3697(87)90072-2Wang, X., Loa, I., Syassen, K., Hanfland, M., & Ferrand, B. (2004). Structural properties of the zircon- and scheelite-type phases ofYVO4at high pressure. Physical Review B, 70(6). doi:10.1103/physrevb.70.064109Manjón, F. J., Rodríguez-Hernández, P., Muñoz, A., Romero, A. H., Errandonea, D., & Syassen, K. (2010). Lattice dynamics ofYVO4at high pressures. Physical Review B, 81(7). doi:10.1103/physrevb.81.075202Boehler, R. (2006). New diamond cell for single-crystal x-ray diffraction. Review of Scientific Instruments, 77(11), 115103. doi:10.1063/1.2372734Mao, 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/jb091ib05p04673Hammersley, A. P., Svensson, S. O., Hanfland, M., Fitch, A. N., & Hausermann, D. (1996). Two-dimensional detector software: From real detector to idealised image or two-theta scan. High Pressure Research, 14(4-6), 235-248. doi:10.1080/08957959608201408Holland, T. J. B., & Redfern, S. A. T. (1997). Unit cell refinement from powder diffraction data: the use of regression diagnostics. Mineralogical Magazine, 61(404), 65-77. doi:10.1180/minmag.1997.061.404.07Kraus, W., & Nolze, G. (1996). POWDER CELL – a program for the representation and manipulation of crystal structures and calculation of the resulting X-ray powder patterns. Journal of Applied Crystallography, 29(3), 301-303. doi:10.1107/s0021889895014920Toby, B. H. (2001). EXPGUI, a graphical user interface forGSAS. Journal of Applied Crystallography, 34(2), 210-213. doi:10.1107/s0021889801002242Qiu, X., Thompson, J. W., & Billinge, S. J. L. (2004). PDFgetX2: a GUI-driven program to obtain the pair distribution function from X-ray powder diffraction data. Journal of Applied Crystallography, 37(4), 678-678. doi:10.1107/s0021889804011744Chupas, P. J., Qiu, X., Hanson, J. C., Lee, P. L., Grey, C. P., & Billinge, S. J. L. (2003). Rapid-acquisition pair distribution function (RA-PDF) analysis. Journal of Applied Crystallography, 36(6), 1342-1347. doi:10.1107/s0021889803017564Farrow, C. L., Juhas, P., Liu, J. W., Bryndin, D., Božin, E. S., Bloch, J., … Billinge, S. J. L. (2007). PDFfit2 and PDFgui: computer programs for studying nanostructure in crystals. Journal of Physics: Condensed Matter, 19(33), 335219. doi:10.1088/0953-8984/19/33/335219Trenque, I., Mornet, S., Duguet, E., & Gaudon, M. (2013). New Insights into Crystallite Size and Cell Parameters Correlation for ZnO Nanoparticles Obtained from Polyol-Mediated Synthesis. Inorganic Chemistry, 52(21), 12811-12817. doi:10.1021/ic402152fLangford, J. I., & Wilson, A. J. C. (1978). Scherrer after sixty years: A survey and some new results in the determination of crystallite size. Journal of Applied Crystallography, 11(2), 102-113. doi:10.1107/s0021889878012844Klotz, S., Chervin, J.-C., Munsch, P., & Le Marchand, G. (2009). Hydrostatic limits of 11 pressure transmitting media. Journal of Physics D: Applied Physics, 42(7), 075413. doi:10.1088/0022-3727/42/7/075413Jeong, I.-K., Proffen, T., Mohiuddin-Jacobs, F., & Billinge, S. J. L. (1999). Measuring Correlated Atomic Motion Using X-ray Diffraction. The Journal of Physical Chemistry A, 103(7), 921-924. doi:10.1021/jp9836978Frogley, M. D., Sly, J. L., & Dunstan, D. J. (1998). Pressure dependence of the direct band gap in tetrahedral semiconductors. Physical Review B, 58(19), 12579-12582. doi:10.1103/physrevb.58.12579Birch, F. (1978). Finite strain isotherm and velocities for single-crystal and polycrystalline NaCl at high pressures and 300°K. Journal of Geophysical Research, 83(B3), 1257. doi:10.1029/jb083ib03p01257Popescu, C., Sans, J. A., Errandonea, D., Segura, A., Villanueva, R., & Sapiña, F. (2014). Compressibility and Structural Stability of Nanocrystalline TiO2 Anatase Synthesized from Freeze-Dried Precursors. Inorganic Chemistry, 53(21), 11598-11603. doi:10.1021/ic501571uChen, G., Stump, N. A., Haire, R. G., Peterson, J. R., & Abraham, M. M. (1992). Pressure-induced phase transition in YVO4:Eu3+: A luminescence study at high pressure. Journal of Physics and Chemistry of Solids, 53(10), 1253-1257. doi:10.1016/0022-3697(92)90241-5Rivera-López, F., Martín, I. R., Da Silva, I., González-Silgo, C., Rodríguez-Mendoza, U. R., Lavín, V., … Fernández-Urban, J. (2006). Analysis of the Eu3+emission in a SrWO4laser matrix under pressure. High Pressure Research, 26(4), 355-359. doi:10.1080/08957950601105085Dieke, G. H., & Crosswhite, H. M. (1963). The Spectra of the Doubly and Triply Ionized Rare Earths. Applied Optics, 2(7), 675. doi:10.1364/ao.2.000675Lavı́n, V., Babu, P., Jayasankar, C. K., Martı́n, I. R., & Rodrı́guez, V. D. (2001). On the local structure of Eu3+ ions in oxyfluoride glasses. Comparison with fluoride and oxide glasses. The Journal of Chemical Physics, 115(23), 10935-10944. doi:10.1063/1.1420731Peacock, R. D. (s. f.). The intensities of lanthanide f ↔ f transitions. Rare Earths, 83-122. doi:10.1007/bfb0116556Oomen, E. W. J. L., & van Dongen, A. M. A. (1989). Europium (III) in oxide glasses. Journal of Non-Crystalline Solids, 111(2-3), 205-213. doi:10.1016/0022-3093(89)90282-2Song, H., Chen, B., Peng, H., & Zhang, J. (2002). Light-induced change of charge transfer band in nanocrystalline Y2O3:Eu3+. Applied Physics Letters, 81(10), 1776-1778. doi:10.1063/1.1501441Ray, 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.2013.07.02

    Frequency of Fabry disease in male and female haemodialysis patients in Spain

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Fabry disease (FD), an X-linked lysosomal storage disorder, is caused by a reduced activity of the lysosomal enzyme α-galactosidase A. The disorder ultimately leads to organ damage (including renal failure) in males and females. However, heterozygous females usually present a milder phenotype with a later onset and a slower progression.</p> <p>Methods</p> <p>A combined enzymatic and genetic strategy was used, measuring the activity of α-galactosidase A and genotyping the α-galactosidase A gene (<it>GLA</it>) in dried blood samples (DBS) of 911 patients undergoing haemodialysis in centers across Spain.</p> <p>Results</p> <p><it>GLA </it>alterations were found in seven unrelated patients (4 males and 3 females). Two novel mutations (p.Gly346AlafsX347 and p.Val199GlyfsX203) were identified as well as a previously described mutation, R118C. The R118C mutation was present in 60% of unrelated patients with <it>GLA </it>causal mutations. The D313Y alteration, considered by some authors as a pseudo-deficiency allele, was also found in two out of seven patients.</p> <p>Conclusions</p> <p>Excluding the controversial D313Y alteration, FD presents a frequency of one in 182 individuals (0.55%) within this population of males and females undergoing haemodialysis. Moreover, our findings suggest that a number of patients with unexplained and atypical symptoms of renal disease may have FD. Screening programmes for FD in populations of individuals presenting severe kidney dysfunction, cardiac alterations or cerebrovascular disease may lead to the diagnosis of FD in those patients, the study of their families and eventually the implementation of a specific therapy.</p
    corecore