117 research outputs found

    Correlation Functions in Berkovits' Pure Spinor Formulation

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    We use Berkovits' pure spinor quantization to compute various three-point tree correlation functions in position-space for the Type IIB superstring. We solve the constraint equations for the vertex operators and obtain explicit expressions for the graviton and axion components of the vertex operators. Using these operators we compute tree level correlation functions in flat space and discuss their extension to the AdS5 X S5 background.Comment: 10 pages, harvmac, to appear in Mod. Phys. Lett. A., corrected typographical error in the reference

    A Representation of Symmetry Generators for Type IIB Superstring on a Plane Wave in the U(4) Formalism

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    We calculate the symmetry currents for the type IIB superstring on a maximally super-symmetric plane wave background using the N=(2,2) superconformally covariant U(4) formulation developed by Berkovits, Maldacena and Maoz. An explicit realization of the U(4) generators together with 16 fermionic generators is obtained in terms of the N=(2,2) worldsheet fields. Because the action is no longer quadratic, we use a light-cone version to display the currents in terms of the covariant worldsheet variables

    FORMULATION & DEVELOPMENT OF PELLETS OF TOLTERODINE TARTRATE: A QUALITATIVE STUDY ON WURSTER BASED FLUIDIZED BED COATING TECHNOLOGY

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    In recent pharmaceutical applications, multiparticulate dosage forms are gaining much importance over single-unit dosage forms. The purpose of designing multiparticulate dosage form is to develop a reliable formulation that has all the advantages of a single unit formulation and yet devoid of the danger of alteration in drug release profile and formulation behavior due to unit to unit variation. The aim of present work is qualitative study on  formulation of multiparticulate modified release pellets of Tolterodine Tartrate, by “Wurster Based Fluidized Bed Coating Processâ€(layering technique).The  main  purpose  of  the  present  study  was  to  investigate  the  feasibility  of  the  wurster  process for preparing extended release pellets and subsequently comparing the release profile of the pellets so prepared with a marketed reference product in various media. Additionally, the effects of some independent process variables were evaluated. The effect of the various process parameters i.e. inlet air temperature, product temperature, exhaust temperature, atomization speed, spray pump speed, atomization air volume and air flow on the wurster process was studied. The results suggested that the values of process parameters greatly vary with the physical properties of the drug, polymers and solvents used in process for layering of pellets. Key Words: non-pariel-seeds (N.P.S), E.R coating (extended release coating), Wurster technology, process parameter

    A Representation of Symmetry Generators for the Type IIB Superstring on a Plane Wave in the U(4) Formalism

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    We calculate the symmetry currents for the type IIB superstring on a maximally supersymmetric plane wave background using the N=(2,2) superconformally covariant U(4) formulation developed by Berkovits, Maldacena and Maoz. An explicit realization of the U(4) generators together with 16 fermionic generators is obtained in terms of the N=(2,2) worldsheet fields. Because the action is no longer quadratic, we use a light-cone version to display the currents in terms of the covariant worldsheet variables.Comment: 9 pages, harvmac, Corrected some typographical errors, Added reference

    Bulk Entanglement Entropy and Matrices

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    Motivated by the Bekenstein Hawking formula and the area law behaviour of entanglement entropy, we propose that in any UV finite theory of quantum gravity with a smooth spacetime, the total entropy for a pure state in a co-dimension one spatial region, to leading order, is given by S=A4GNS={A\over 4 G_N}, where AA is the area of the co-dimension two boundary. In the context of DpDp brane holography we show that for some specially chosen regions bulk entanglement can be mapped to ``target space" entanglement in the boundary theory. Our conjecture then leads to a precise proposal for target space entanglement in the boundary theory at strong coupling and large NN. In particular it leads to the conclusion that the target space entanglement would scale like O(N2)O(N^2) which is quite plausible in a system with O(N2)O(N^2) degrees of freedom. Recent numerical advances in studying the D0 brane system hold out the hope that this proposal can be tested in a precise way in the future.Comment: Submitted 11 March 2020 to the Peter Freund Memorial Volume. J Phys

    DEVELOPMENT AND EVALUATION OF LAMOTRIGINE SOYA LECITHIN SOLID DISPERSION: IN VITRO AND PHARMACODYNAMIC INVESTIGATION

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    Objective: Epilepsy is a common neurodegenerative disorder characterized by spontaneous and repeated attacks of convulsions. It requires immediate pharmacotherapy to prevent its progression to status epilepticus. However, most of the anticonvulsant drugs are poorly water-soluble and demonstrate the delayed onset of action. Thus there is a need to improve its solubility for the better pharmaceutical profile. The objective of the present investigation was to enhance the solubility of lamotrigine incorporating soya lecithin as a phospholipid carrier by solid dispersion technique Methods: Solid dispersions of lamotrigine were prepared with soya lecithin by the solvent method. The effect of concentration of phospholipid and solvents on aqueous solubility and dissolution profile of lamotrigine was analyzed. Results: Ethanol increased lamotrigine solubility with soya lecithin in ratio 5:1. X-ray diffraction and scanning electron micrograph indicated a smaller crystallite size of lamotrigine with fairly uniform size distribution in the lamotrigine-soya lecithin solid dispersion. The resultant solid dispersion also significantly delayed the onset of clonic convulsion (875.8 s) as compared to control (85.5 s) and offered complete protection (100%) against the pentylenetetrazole induced seizures in the rat as compared to control (33.33%). Also, solid dispersion with maximum drug content (77.68%) and dissolution rate (91.40%) was formulated as an orodispersible tablet and characterized for its pharmaceutical properties. Conclusion: It can be concluded that the solid dispersion of lamotrigine incorporated with soya lecithin demonstrated enhanced solubility and dissolution rate may have potential clinical application

    Gauge Invariant Target Space Entanglement in D-Brane Holography

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    It has been suggested in arXiv:2004.00613 that in Dp-brane holography, entanglement in the target space of the D-brane Yang-Mills theory provides a precise notion of bulk entanglement in the gravity dual. We expand on this discussion by providing a gauge invariant characterization of operator sub-algebras corresponding to such entanglement. This is achieved by finding a projection operator which imposes a constraint characterizing the target space region of interest. By considering probe branes in the Coloumb branch we provide motivation for why the operator sub-algebras we consider are appropriate for describing a class of measurements carried out with low-energy probes in the corresponding bulk region of interest. We derive expressions for the corresponding Renyi entropies in terms of path integrals which can be directly used in numerical calculations

    A C-Function For Non-Supersymmetric Attractors

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    We present a c-function for spherically symmetric, static and asymptotically flat solutions in theories of four-dimensional gravity coupled to gauge fields and moduli. The c-function is valid for both extremal and non-extremal black holes. It monotonically decreases from infinity and in the static region acquires its minimum value at the horizon, where it equals the entropy of the black hole. Higher dimensional cases, involving pp-form gauge fields, and other generalisations are also discussed.Comment: References adde

    Band Structure of the Fractional Quantum Hall Effect

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    The eigenstates of interacting electrons in the fractional quantum Hall phase typically form fairly well defined bands in the energy space. We show that the composite fermion theory gives insight into the origin of these bands and provides an accurate and complete microscopic description of the strongly correlated many-body states in the low-energy bands. Thus, somewhat like in Landau's fermi liquid theory, there is a one-to-one correspondence between the low energy Hilbert space of strongly interacting electrons in the fractinal quantum Hall regime and that of weakly interacting electrons in the integer quantum Hall regime.Comment: 10 page
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