10,428 research outputs found

    Chern-Simons--Antoniadis-Savvidy forms and standard supergravity

    Full text link
    In the context of the so called the Chern--Simons--Antoniadis--Savvidy (ChSAS) forms, we use the methods for FDA decomposition in 1-forms to construct a four-dimensional ChSAS supergravity action for the Maxwell superalgebra. On the another hand, we use the Extended Cartan Homotopy Formula to find a method that allows the separation of the ChSAS action into bulk and boundary contributions and permits the splitting of the bulk Lagrangian into pieces that reflect the particular subspace structure of the gauge algebra.Comment: 14 page

    Supergravity and the Poincare group

    Full text link
    An action for 3+1-dimensional supergravity genuinely invariant under the Poincare supergroup is proposed. The construction of the action is carried out considering a bosonic lagrangian invariant under both local Lorentz rotations and local Poincare translations as well as under diffeomorphism, and therefore the Poincare algebra closes off-shell. Since the lagrangian is invariant under the Poincare supergroup, the supersymmetry algebra closes off shell without the need of auxiliary fields.Comment: 6 pages, Late

    SOPDEs and Nonlinear Connections

    Full text link
    The canonical k-tangent structure on Tk1Q=TQ.k..TQT^1_kQ=TQ\oplus\stackrel{k}...\oplus TQ allows us to characterize nonlinear connections on Tk1QT^1_kQ and to develop G\"unther's (k-symplectic) Lagrangian formalism. We study the relationship between nonlinear connections and second-order partial differential equations (SOPDEs), which appear in G\"unther's Lagrangian formalism.Comment: 14 p

    Supergravity with cosmological constant and the AdS group

    Full text link
    It is shown that the supersymmetric extension of the Stelle-West formalism permits the construction of an action for (3+1)(3+1)-dimensional N=1 supergravity with cosmological constant genuinely invariant under the OSp(4/1).OSp(4/1). Since the action is invariant under the supersymmetric extension of the AdSAdS group, the supersymmetry algebra closes off shell without the need for auxiliary fields. The limit case m0m\to 0, i.e.(3+1)(3+1) -dimensional N=1 supergravity invariant under the Poincar\'{e} supergroup is also discussed.Comment: 10 page

    Preparation and Characterization of Cerium (III) Doped Captopril Nanoparticles and Study of their Photoluminescence Properties

    Get PDF
    Indexación: Web of Science. DOAJ.In this research Ce3+ doped Captopril nanoparticles (Ce3+ doped CAP-NP) were prepared by a cold welding process and have been studied. Captopril may be applied in the treatment of hypertension and some types of congestive heart failure and for preventing kidney failure due to high blood pressure and diabetes. CAP-NP was synthesized by a cold welding process. The cerium nitrate was added at a ratio of 10% and the optical properties have been studied by photoluminescence (PL). The synthesized compounds were characterized by Fourier transform infrared spectroscopy. The size of CAP-NP was calculated by X-ray diffraction (XRD). The size of CAP-NP was in the range of 50 nm. Morphology of surface of synthesized nanoparticles was studied by scanning electron microscopy (SEM). Finally the luminescence properties of undoped and doped CAP-NP were compared. PL spectra from undoped CAP-NP show a strong pack in the range of 546 nm after doped cerium ion into the captopril appeared two bands at 680 and 357 nm, which is ascribed to the well-known 5d–4f emission band of the cerium.http://www.degruyter.com/view/j/chem.2016.14.issue-1/chem-2016-0008/chem-2016-0008.xm

    Higher dimensional gravity invariant under the Poincare group

    Full text link
    It is shown that the Stelle-West Grignani-Nardelli-formalism allows, both when odd dimensions and when even dimensions are considered, constructing actions for higher dimensional gravity invariant under local Lorentz rotations and under local Poincar\`{e} translations. It is also proved that such actions have the same coefficients as those obtained by Troncoso and Zanelli in ref. Class. Quantum Grav. 17 (2000) 4451.Comment: 7 pages, Latex, accepted in Phys. Rev.

    High-Resolution Three-Dimensional NMR Structure Of The KRAS Proto-Oncogene Promoter Reveals Key Features Of A G-Quadruplex Involved In Transcriptional Regulation

    Get PDF
    Non-canonical base pairing within guanine-rich DNA and RNA sequences can produce G-quartets, whose stacking leads to the formation of a G-quadruplex (G4). G4s can coexist with canonical duplex DNA in the human genome and have been suggested to suppress gene transcription, and much attention has therefore focused on studying G4s in promotor regions of disease-related genes. For example, the human KRAS proto-oncogene contains a nuclease-hypersensitive element located upstream of the major transcription start site. The KRAS nuclease-hypersensitive element (NHE) region contains a G-rich element (22RT; 5′-AGGGCGGTGTGGGAATAGGGAA-3′) and encompasses a Myc-associated zinc finger-binding site that regulates KRAS transcription. The NEH region therefore has been proposed as a target for new drugs that control KRAS transcription, which requires detailed knowledge of the NHE structure. In this study, we report a high-resolution NMR structure of the G-rich element within the KRAS NHE. We found that the G-rich element forms a parallel structure with three G-quartets connected by a four-nucleotide loop and two short one-nucleotide double-chain reversal loops. In addition, a thymine bulge is found between G8 and G9. The loops of different lengths and the presence of a bulge between the G-quartets are structural elements that potentially can be targeted by small chemical ligands that would further stabilize the structure and interfere or block transcriptional regulators such as Myc-associated zinc finger from accessing their binding sites on the KRAS promoter. In conclusion, our work suggests a possible new route for the development of anticancer agents that could suppress KRAS expression
    corecore