35,243 research outputs found

    Clinical applications of the progesterone receptor antagonist mifepristone during early pregnancy and its application in therapeutic abortion

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    Mifepristone (RU 38,486) is a new synthetic steroid which is antagonistic to progesterone at the receptor level. Mifepristone has been demonstrated to cause spontaneous abortion of early pregnancies when taken orally. When used in combination with a prostaglandin analogue the termination success rate is increased. The studies performed in this thesis were designed to further investigate the clinical effects of mifepristone in the first and second trimesters of pregnancy, and to study the mechanism of action of the drug. These studies examined: 1) . The efficacy and side-effects of mifepristone (600mg) in combination with a prostaglandin E1 lmg (Gemeprost) pessary for early termination of pregnancy. 2) . The effect of mifepristone on prostaglandin metabolite levels in the first and second trimesters of pregnancy. 3). The effect of mifepristone on progesterone and oestrogen receptor concentrations in the decidua and placenta in early pregnancy. 4). The physiological and clinical effects of progesterone inhibition with mifepristone in the second trimester. 5). The placental transfer of mifepristone during the second trimester and its influence upon maternal and fetal steroid concentrations

    Gravity in Dynamically Generated Dimensions

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    A theory of gravity in d+1d+1 dimensions is dynamically generated from a theory in dd dimensions. As an application we show how NN dynamically coupled gravity theories can reduce the effective Planck mass.Comment: 7 pages, LaTeX (Revtex

    Topological Interactions in Warped Extra Dimensions

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    Topological interactions will be generated in theories with compact extra dimensions where fermionic chiral zero modes have different localizations. This is the case in many warped extra dimension models where the right-handed top quark is typically localized away from the left-handed one. Using deconstruction techniques, we study the topological interactions in these models. These interactions appear as trilinear and quadrilinear gauge boson couplings in low energy effective theories with three or more sites, as well as in the continuum limit. We derive the form of these interactions for various cases, including examples of Abelian, non-Abelian and product gauge groups of phenomenological interest. The topological interactions provide a window into the more fundamental aspects of these theories and could result in unique signatures at the Large Hadron Collider, some of which we explore.Comment: 40 pages, 10 figures, 2 tables; modifications in the KK parity discussion, final version at JHE

    Gravitational Trapping Near Domain Walls and Stable Solitons

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    In this work, the behavior of test particles near a domain wall of a stable false vacuum bubble is studied. It is shown that matter is naturally trapped in the vicinity of a static domain wall, and also, that there is a discontinuity in the test particle's velocity when crossing the domain wall. The latter is unexpected as it stands in contrast to Newtonian theory, where infinite forces are not allowed. The weak field limit is defined in order to show that there is no conflict with the non-relativistic behavior of gravitational fields and particle motions under these conditions.Comment: 8 pages, 1 figure, problem is reanalyzed using a continuous coordinate syste

    Microscopic heat from the energetics of stochastic phenomena

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    The energetics of the stochastic process has shown the balance of energy on the mesoscopic level. The heat and the energy defined there are, however, generally different from their macroscopic counterpart. We show that this discrepancy can be removed by adding to these quantities the reversible heat associated with the mesoscopic free energy.Comment: 4 pages, 0 figur

    Deformation Energy Minima at Finite Mass Asymmetry

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    A very general saddle point nuclear shape may be found as a solution of an integro-differential equation without giving apriori any shape parametrization. By introducing phenomenological shell corrections one obtains minima of deformation energy for binary fission of parent nuclei at a finite (non-zero) mass asymmetry. Results are presented for reflection asymmetric saddle point shapes of thorium and uranium even-mass isotopes with A=226-238 and A=230-238 respectively.Comment: 5 pages, 2 Postscript figures, REVTeX, Version 4.

    Optimal Entanglement Enhancement for Mixed States

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    We consider the actions of protocols involving local quantum operations and classical communication (LQCC) on a single system consisting of two separated qubits. We give a complete description of the orbits of the space of states under LQCC and characterise the representatives with maximal entanglement of formation. We thus obtain a LQCC entanglement concentration protocol for a single given state (pure or mixed) of two qubits which is optimal in the sense that the protocol produces, with non-zero probability, a state of maximal possible entanglement of formation. This defines a new entanglement measure, the maximum extractable entanglement.Comment: Final version: to appear in Phys. Rev. Let

    Facile Si–H bond activation and hydrosilylation catalysis mediated by a nickel–borane complex

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    Metal–borane complexes are emerging as promising systems for study in the context of bifunctional catalysis. Herein we describe diphosphineborane nickel complexes that activate Si–H bonds and catalyze the hydrosilylation of aldehydes. Treatment of [^(Mes)DPB^(Ph)]Ni (1) ([^(Mes)DPB^Ph] = ^(Mes)B(o-Ph_2PC_6H_4)_2) with organosilanes affords the complexes [^(Mes)DPB^(Ph)](μ-H)NiE (E = SiH_2Ph (3), SiHPh_2 (4)). Complex 4 is in solution equilibrium with 1 and the thermodynamic and kinetic parameters of their exchange have been characterized by NMR spectroscopy. Complex 1 is a catalyst for the hydrosilylation of a range of para-substituted benzaldehydes. Mechanistic studies on this reaction via multinuclear NMR spectroscopy are consistent with the intermediacy of a borohydrido-Ni-siloxyalkyl species

    Infrared Quasi Fixed Points and Mass Predictions in the MSSM II: Large tan(beta) Scenario

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    We consider the infrared quasi fixed point solutions of the renormalization group equations for the Yukawa couplings and soft supersymmetry breaking parameters in the MSSM in the \underline{large tanβ\tan\beta} regime. The existence of IR quasi fixed points together with the values of gauge couplings, third generation quarks, lepton and Z-boson masses allows one to predict masses of the Higgs bosons and SUSY particles as functions of the only free parameter, m1/2m_{1/2}, or the gluino mass. The lightest Higgs boson mass for MSUSY1M_{SUSY} \approx 1 TeV is found to be mh=128.20.47.1±5m_h=128.2-0.4-7.1 \pm 5 GeV for μ>0\mu>0 and mh=120.60.13.8±5m_h=120.6-0.1-3.8 \pm 5 GeV for μ<0\mu<0.Comment: 15 pages, LateX file with 4 eps figures, corrected numbers, new column in table, last versio
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