19,053 research outputs found

    Crystal structure and physical properties of EuPtIn4_{4} intermetallic antiferromagnet

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    We report the synthesis of EuPtIn4_{4} single crystalline platelets by the In-flux technique. This compound crystallizes in the orthorhombic Cmcm structure with lattice parameters a=4.542(1)a=4.542(1) \AA, b=16.955(2)b=16.955(2) \AA \, and c=7.389(1)c=7.389(1) \AA. Measurements of magnetic susceptibility, heat capacity, electrical resistivity, and electron spin resonance (ESR) reveal that EuPtIn4_{4} is a metallic Curie-Weiss paramagnet at high temperatures and presents antiferromagnetic (AFM) ordering below TN=13.3T_{N}=13.3 K. In addition, we observe a successive anomaly at T∗=12.6T^{*} = 12.6 K and a spin-flop transition at Hc∼2.5H_{c} \sim 2.5 T applied along the acac-plane. In the paramagnetic state, a single Eu2+^{2+} Dysonian ESR line with a Korringa relaxation rate of b=4.1(2)b = 4.1(2) Oe/K is observed. Interestingly, even at high temperatures, both ESR linewidth and electrical resistivity reveal a similar anisotropy. We discuss a possible common microscopic origin for the observed anisotropy in these physical quantities likely associated with an anisotropic magnetic interaction between Eu2+^{2+} 4ff electrons mediated by conduction electrons.Comment: 5 pages, 5 figure

    Warming up brane-antibrane inflation

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    We show that, in constructions with additional intersecting D-branes, brane-antibrane inflation may naturally occur in a warm regime, such that strong dissipative effects damp the inflaton's motion, greatly alleviating the associated eta-problem. We illustrate this for D3-antiD3 inflation in flat space with additional flavor D7-branes, where for both a Coulomb-like or a quadratic hybrid potential a sufficient number of e-folds may be obtained for perturbative couplings and O(10-10^4) branes. This is in clear contrast with the corresponding cold scenarios, thus setting the stage for more realistic constructions within fully stabilized compactifications. Such models generically predict a negligible amount of tensor perturbations and non-gaussianity f_NL \sim O(10).Comment: 8 pages, 2 figures; version to be published in Physical Review

    Lactoferrin's anti-cancer properties. Safety, selectivity, and wide range of action

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    Despite recent advances in cancer therapy, current treatments, including radiotherapy, chemotherapy, and immunotherapy, although beneficial, present attendant side effects and long-term sequelae, usually more or less affecting quality of life of the patients. Indeed, except for most of the immunotherapeutic agents, the complete lack of selectivity between normal and cancer cells for radio- and chemotherapy can make them potential antagonists of the host anti-cancer self-defense over time. Recently, the use of nutraceuticals as natural compounds corroborating anti-cancer standard therapy is emerging as a promising tool for their relative abundance, bioavailability, safety, low-cost effectiveness, and immuno-compatibility with the host. In this review, we outlined the anti-cancer properties of Lactoferrin (Lf), an iron-binding glycoprotein of the innate immune defense. Lf shows high bioavailability after oral administration, high selectivity toward cancer cells, and a wide range of molecular targets controlling tumor proliferation, survival, migration, invasion, and metastasization. Of note, Lf is able to promote or inhibit cell proliferation and migration depending on whether it acts upon normal or cancerous cells, respectively. Importantly, Lf administration is highly tolerated and does not present significant adverse effects. Moreover, Lf can prevent development or inhibit cancer growth by boosting adaptive immune response. Finally, Lf was recently found to be an ideal carrier for chemotherapeutics, even for the treatment of brain tumors due to its ability to cross the blood-brain barrier, thus globally appearing as a promising tool for cancer prevention and treatment, especially in combination therapies

    Novel features of the energy momentum tensor of a Casimir apparatus in a weak gravitational field

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    The influence of the gravity acceleration on the regularized energy-momentum tensor of the quantized electromagnetic field between two plane parallel conducting plates is derived. A perturbative expansion, to first order in the constant acceleration parameter, of the Green functions involved and of the energy-momentum tensor is derived by means of the covariant geodesic point splitting procedure. The energy-momentum tensor is covariantly conserved and satisfies the expected relation between gauge-breaking and ghost parts.Comment: 8 pages, based on a talk given by Luigi Rosa at the QFEXT07 Conference, Leipzig. Equation (13) and the formulae for rho and energy E stored in the Casimir device have been amended, jointly with related discussio
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