605 research outputs found

    Lepton Flavour Violation in charged leptons within SUSY-seesaw

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    In this paper we review our main results for Lepton Flavour Violating (LFV) semileptonic tau decays and muon-electron conversion in nuclei within the context of two Constrained SUSY-Seesaw Models, the CMSSM and the NUHM. The relevant spectrum is that of the Minimal Supersymmetric Standard Model extended by three right handed neutrinos, νRi\nu_{R_i} and their corresponding SUSY partners, ν~Ri{\tilde \nu}_{R_i}, (i=1,2,3i=1,2,3). We use the seesaw mechanism for neutrino mass generation and choose a parameterisation of this mechanism that allows us to incorporate the neutrino data in our analysis of LFV processes. In addition to the full one-loop results for the rates of these processes, we will also review the set of simple formulas, valid at large tanβ\tan \beta, which are very useful to compare with present experimental bounds. The sensitivity to SUSY and Higgs sectors in these processes will also be discussed. This is a very short summary of the works in Refs. \cite{Arganda:2008jj} and \cite{Arganda:2007jw} to which we refer the reader for more details.Comment: 6 pages, 6 figures. To be published in the proceedings of the Tau08 Conference, Novosibirsk, Russia, 22-25 September 200

    Comparative population plasma and tissue pharmacokinetics of micafungin in critically ill patients with severe burn injuries and patients with complicated intra-abdominal infection

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    Severely burned patients have altered drug pharmacokinetics (PKs), but it is unclear how different they are from those in other critically ill patient groups. The aim of the present study was to compare the population pharmacokinetics of micafungin in the plasma and burn eschar of severely burned patients with those of micafungin in the plasma and peritoneal fluid of postsurgical critically ill patients with intra-abdominal infection. Fifteen burn patients were compared with 10 patients with intra-abdominal infection; all patients were treated with 100 to 150 mg/day of micafungin. Micafungin concentrations in serial blood, peritoneal fluid, and burn tissue samples were determined and were subjected to a population pharmacokinetic analysis. The probability of target attainment was calculated using area under the concentration-time curve from 0 to 24 h/MIC cutoffs of 285 for Candida parapsilosis and 3,000 for non-parapsilosis Candida spp. by Monte Carlo simulations. Twenty-five patients (18 males; median age, 50 years; age range, 38 to 67 years; median total body surface area burned, 50%; range of total body surface area burned, 35 to 65%) were included. A three-compartment model described the data, and only the rate constant for the drug distribution from the tissue fluid to the central compartment was statistically significantly different between the burn and intra-abdominal infection patients (0.47 +/- 0.47 versus 0.15 +/- 0.06 h(-1), respectively; P< 0.05). Most patients would achieve plasma PK/pharma-codynamic (PD) targets of 90% for non-parapsilosis Candida spp. and C. parapsilosis with MICs of 0.008 and 0.064 mg/liter, respectively, for doses of 100 mg daily and 150 mg daily. The PKs of micafungin were not significantly different between burn patients and intra-abdominal infection patients. After the first dose, micafungin at 100 mg/day achieved the PK/PD targets in plasma for MIC values of < 0.008 mg/liter and < 0.064 mg/liter for non-parapsilosis Candida spp. and Candida parapsilosis species, respectively

    A novel behavioral fish model of nociception for testing analgesics

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    Pain is a major symptom in many medical conditions, and often interferes significantly with a person's quality of life. Although a priority topic in medical research for many years, there are still few analgesic drugs approved for clinical use. One reason is the lack of appropriate animal models that faithfully represent relevant hallmarks associated with human pain. Here we propose zebrafish (Danio rerio) as a novel short-term behavioral model of nociception, and analyse its sensitivity and robustness. Firstly, we injected two different doses of acetic acid as the noxious stimulus. We studied individual locomotor responses of fish to a threshold level of nociception using two recording systems: a video tracking system and an electric biosensor (the MOBS system). We showed that an injection dose of 10% acetic acid resulted in a change in behavior that could be used to study nociception. Secondly, we validated our behavioral model by investigating the effect of the analgesic morphine. In time-course studies, first we looked at the dose-response relationship of morphine and then tested whether the effect of morphine could be modulated by naloxone, an opioid antagonist. Our results suggest that a change in behavioral responses of zebrafish to acetic acid is a reasonable model to test analgesics. The response scales with stimulus intensity, is attenuated by morphine, and the analgesic effect of morphine is blocked with naloxone. The change in behavior of zebrafish associated with the noxious stimulus can be monitored with an electric biosensor that measures changes in water impedance. © 2011 by the authors; licensee MDPI, Basel, Switzerland

    HADES RV Programme with HARPS-N at TNG VI. GJ 3942 b behind dominant activity signals

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    Short- to mid-term magnetic phenomena on the stellar surface of M-type stars cannot only resemble the effects of planets in radial velocity data, but also may hide them. We analyze 145 spectroscopic HARPS-N observations of GJ 3942 taken over the past five years and additional photometry to disentangle stellar activity effects from genuine Doppler signals as a result of the orbital motion of the star around the common barycenter with its planet. To achieve this, we use the common methods of pre-whitening, and treat the correlated red noise by a first-order moving average term and by Gaussian-process regression following an MCMC analysis. We identify the rotational period of the star at 16.3 days and discover a new super-Earth, GJ 3942 b, with an orbital period of 6.9 days and a minimum mass of 7.1 Me. An additional signal in the periodogram of the residuals is present but we cannot claim it to be related to a second planet with sufficient significance at this point. If confirmed, such planet candidate would have a minimum mass of 6.3 Me and a period of 10.4 days, which might indicate a 3:2 mean-motion resonance with the inner planet

    STM Spectroscopy of ultra-flat graphene on hexagonal boron nitride

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    Graphene has demonstrated great promise for future electronics technology as well as fundamental physics applications because of its linear energy-momentum dispersion relations which cross at the Dirac point. However, accessing the physics of the low density region at the Dirac point has been difficult because of the presence of disorder which leaves the graphene with local microscopic electron and hole puddles, resulting in a finite density of carriers even at the charge neutrality point. Efforts have been made to reduce the disorder by suspending graphene, leading to fabrication challenges and delicate devices which make local spectroscopic measurements difficult. Recently, it has been shown that placing graphene on hexagonal boron nitride (hBN) yields improved device performance. In this letter, we use scanning tunneling microscopy to show that graphene conforms to hBN, as evidenced by the presence of Moire patterns in the topographic images. However, contrary to recent predictions, this conformation does not lead to a sizable band gap due to the misalignment of the lattices. Moreover, local spectroscopy measurements demonstrate that the electron-hole charge fluctuations are reduced by two orders of magnitude as compared to those on silicon oxide. This leads to charge fluctuations which are as small as in suspended graphene, opening up Dirac point physics to more diverse experiments than are possible on freestanding devices.Comment: Nature Materials advance online publication 13/02/201

    Morphine Use in the ED and Outcomes of Patients With Acute Heart Failure A Propensity Score-Matching Analysis Based on the EAHFE Registry

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    OBJECTIVE: The objective was to determine the relationship between short-term mortality and intravenous morphine use in ED patients who received a diagnosis of acute heart failure (AHF). METHODS: Consecutive patients with AHF presenting to 34 Spanish EDs from 2011 to 2014 were eligible for inclusion. The subjects were divided into those with (M) or without IV morphine treatment (WOM) groups during ED stay. The primary outcome was 30-day all-cause mortality, and secondary outcomes were mortality at different intermediate time points, in-hospital mortality, and length of hospital stay. We generated a propensity score to match the M and WOM groups that were 1:1 according to 46 different epidemiological, baseline, clinical, and therapeutic factors. We investigated independent risk factors for 30-day mortality in patients receiving morphine. RESULTS: We included 6,516 patients (mean age, 81 [SD, 10] years; 56% women): 416 (6.4%) in the M and 6,100 (93.6%) in the WOM group. Overall, 635 (9.7%; M, 26.7%; WOM, 8.6%) died by day 30. After propensity score matching, 275 paired patients constituted each group. Patients receiving morphine had a higher 30-day mortality (55 [20.0%] vs 35 [12.7%] deaths; hazard ratio, 1.66; 95% CI, 1.09-2.54; P=.017). In patients receiving morphine, death was directly related to glycemia (P=.013) and inversely related to the baseline Barthel index and systolic BP (P=.021) at ED arrival (P=.021). Mortality was increased at every intermediate time point, although the greatest risk was at the shortest time (at 3 days: 22 [8.0%] vs 7 [2.5%] deaths; OR, 3.33; 95% CI, 1.40-7.93; P=.014). In-hospital mortality did not increase (39 [14.2%] vs 26 [9.1%] deaths; OR, 1.65; 95% CI, 0.97-2.82; P=.083) and LOS did not differ between groups (median [interquartile range] in M, 8 [7]; WOM, 8 [6]; P=.79). CONCLUSIONS: This propensity score-matched analysis suggests that the use of IV morphine in AHF could be associated with increased 30-day mortality.Peer reviewe

    Emergence of Superlattice Dirac Points in Graphene on Hexagonal Boron Nitride

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    The Schr\"odinger equation dictates that the propagation of nearly free electrons through a weak periodic potential results in the opening of band gaps near points of the reciprocal lattice known as Brillouin zone boundaries. However, in the case of massless Dirac fermions, it has been predicted that the chirality of the charge carriers prevents the opening of a band gap and instead new Dirac points appear in the electronic structure of the material. Graphene on hexagonal boron nitride (hBN) exhibits a rotation dependent Moir\'e pattern. In this letter, we show experimentally and theoretically that this Moir\'e pattern acts as a weak periodic potential and thereby leads to the emergence of a new set of Dirac points at an energy determined by its wavelength. The new massless Dirac fermions generated at these superlattice Dirac points are characterized by a significantly reduced Fermi velocity. The local density of states near these Dirac cones exhibits hexagonal modulations indicating an anisotropic Fermi velocity.Comment: 16 pages, 6 figure
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