196 research outputs found

    Geometry of Higher-Dimensional Black Hole Thermodynamics

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    We investigate thermodynamic curvatures of the Kerr and Reissner-Nordstr\"om (RN) black holes in spacetime dimensions higher than four. These black holes possess thermodynamic geometries similar to those in four dimensional spacetime. The thermodynamic geometries are the Ruppeiner geometry and the conformally related Weinhold geometry. The Ruppeiner geometry for d=5d=5 Kerr black hole is curved and divergent in the extremal limit. For d6d \geq 6 Kerr black hole there is no extremality but the Ruppeiner curvature diverges where one suspects that the black hole becomes unstable. The Weinhold geometry of the Kerr black hole in arbitrary dimension is a flat geometry. For RN black hole the Ruppeiner geometry is flat in all spacetime dimensions, whereas its Weinhold geometry is curved. In d5d \geq 5 the Kerr black hole can possess more than one angular momentum. Finally we discuss the Ruppeiner geometry for the Kerr black hole in d=5d=5 with double angular momenta.Comment: 8 pages, 2 figures, RevTex, References adde

    Towards NNLO accuracy for epsilon '/epsilon

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    The quantity ε/ε\varepsilon'/\varepsilon measures direct CP violation in Kaon decays. Recent SM predictions show a 2.9σ2.9\sigma tension with data, with the theoretical uncertainty dominating. As rapid progress on the lattice is bringing nonperturbative long-distance effects under control, a more precise knowledge of short-distance contributions is needed. We describe the first NNLO results for ε/ε\varepsilon'/\varepsilon and discuss future prospects, as well as issues of scheme dependence and the separation of perturbative and nonperturbative effects. Finally we also comment on the solution of the renormalisation-group evolution in one of the talks at this conference and present the correct solution.Comment: 8 pages, Proceedings of the Kaon 2016 Conferenc

    Analysis of the secular problem for triple star systems

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    The long-term dynamics of the three-body problem is studied. the goal is to study the motion of a planet (m(1)) around a star (m(0)) that is perturbed by a third-body (m(2)) (a planet or a brown dwarf star). the gravitational potential is developed in closed form up to the fourth order. Taking into account the triple system, it is shown here the evolution of some orbital parameters of the planet (m(1)). A comparison considering models with different orders for the disturbing potential is presented. We show that the behavior of the orbit of the inner planet can flip from prograde to retrograde trajectories. This is due to the third-order term, which strongly affects the eccentricity and inclination. We show that the effect of the fourth order term is to change the times when the phenomenon occurs.Universidade Federal de São Paulo, UNIFESP ICT, Sao Jose Dos Campos, SP, BrazilUniversidade Federal de São Paulo, UNIFESP ICT, Sao Jose Dos Campos, SP, BrazilWeb of Scienc

    Decellularized aortic conduits: could their cryopreservation affect post-implantation outcomes? A morpho-functional study on porcine homografts

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    Decellularized porcine aortic valve conduits (AVCs) implanted in a Vietnamese Pig (VP) experimental animal model were matched against decellularized and then cryopreserved AVCs to assess the effect of cryopreservation on graft hemodynamic performance and propensity to in vivo repopulation by host\u2019s cells. VPs (n = 12) underwent right ventricular outflow tract substitution using AVC allografts and were studied for 15-month follow-up. VPs were randomized into two groups, receiving AVCs treated with decellularization alone (D; n = 6) or decellularization/cryopreservation (DC; n = 6), respectively. Serial echocardiography was carried out to follow up hemodynamic function. All explanted AVCs were processed for light and electron microscopy. No signs of dilatation, progressive stenosis, regurgitation, and macroscopic calcification were echocardiographically observed in both D and DC groups. Explanted D grafts exhibited near-normal features, whereas the presence of calcification, inflammatory infiltrates, and disarray of elastic lamellae occurred in some DC grafts. In the unaltered regions of AVCs from both groups, almost complete re-endothelialization was observed for both valve cusps and aorta walls. In addition, side-by-side repopulation by recipient\u2019s fibroblasts, myofibroblasts, and smooth muscle cells was paralleled by ongoing tissue remodeling, as revealed by the ultrastructural identification of typical canals of collagen fibrillogenesis and elastogenesis-related features. Incipient neo-vascularization and re-innervation of medial and adventitial tunicae of grafted aortic walls were also detected for both D and DC groups. Cryopreservation did not affect post-implantation AVC hemodynamic behavior and was topically propensive to cell repopulation and tissue renewal, although graft deterioration including calcification was present in several areas. Thus, these preliminary data provide essential information on feasibility of decellularization and cryopreservation coupling in the perspective of treatment optimization and subsequent clinical trials using similarly treated human allografts as innovative heart valve substitutes

    Vasomotor symptoms and management of women undergoing treatment for breast cancer: literature review with focus on the therapeutic potential of cytoplasmic pollen extract

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    Objective: Effective management of vasomotor symptoms (VMS) in patients undergoing treatment for breast cancer (BC) represents a critical but frequent unmet need. This review summarizes the epidemiology, pathophysiology, and clinical features of VMS in patients with BC and provides a synopsis of the complementary and alternative medicine (CAM) approaches in relieving VMS with a focus on purified cytoplasm of pollen (PCP). Methods: The literature on VMS epidemiology, pathophysiology, clinical burden, and CAM treatment in healthy women and patients with BC was reviewed. Results: VMS are common in patients with BC undergoing hormonal treatment and negatively impact quality of life, leading to treatment discontinuation in up to 25% of patients with detrimental impact on risk of BC recurrence and overall survival. CAM approaches to treat VMS in patients with BC include vitamin E, phytoestrogens, and black cohosh, even if there is a lack of solid evidence to guide clinicians in the choice of treatment. PCP, obtained according to standards of good manufacturing practice, has a definite pharmacological mechanism of action, is devoid of estrogen activity, and has shown clinical efficacy on menopause-associated symptoms with a favorable safety profile and high compliance. As such, it appears to represent a valid management option to improve quality of life in patients with pre- and postmenopausal BC. Conclusions: Physicians should actively investigate the presence and impact of VMS in patients receiving therapy for BC. Additional and appropriately sized randomized clinical trials are needed to provide clear evidence on how to best meet the needs of patients with BC suffering from menopause-associated symptoms

    Hybrid membranes for blood-contacting surfaces: preliminary characterization

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    The hemocompatibility of any mechanical circulatory support device is mostly conditioned by the nature of the blood-contacting surface. Hybrid membranes as the inner surfaces of the artificial ventricle were produced by coupling a polymeric material (polycarbonate urethane) with decellularized biological tissues (animal pericardia). Physicochemical and mechanical characteristics of the hybrid membranes were carefully evaluated confirming satisfactory features in terms of composition and mechanical resistance

    Partial restoration of chiral symmetry in cold nuclear matter: the phi-meson case

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    The work presented at this workshop is divided into two parts. In the first part, the mass and decay width of the φ-meson in cold nuclear matter are computed in an effective Lagrangian approach. The medium dependence of these properties are obtained by evaluating kaon-antikaon loop contributions to the φ-meson self-energy, employing medium-modified kaon masses calculated using the quark-meson coupling model. The loop integral is regularized with a dipole form factor, and the sensitivity of the results to the choice of cutoff mass in the form factor is investigated. At normal nuclear matter density, we find a downward shift of the phgr mass by a few percent, while the decay width is enhanced by an order of magnitude. Our results support the literature which suggest that one should observe a small downward mass shift and a large broadening of the decay width. In the second part, we present φ-meson-nucleus bound state energies and absorption widths for four selected nuclei, calculated by solving the KleinGordon equation with complex optical potentials. The attractive potential for the φ-meson in the nuclear medium originates from the in-medium enhanced KK loop in the phgr-meson self-energy. The results suggest that the φ-meson should form bound states with all the nuclei considered. However, the identification of the signal for these predicted bound states will need careful investigation because of their sizable absorption widths.J J Cobos-Martínez, K. Tsushima, G. Krein and A. W. Thoma
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