4,680 research outputs found

    Transvesical endoscopic port in abdominal surgery: an updated perspective

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    Transvesical endoscopic port in abdominal surgery: an updated perspective.Natural orifice transluminal endoscopic surgery (NOTES) generated a huge hope among surgeons because it promised scarless surgery and eventually less pain and surgical stress. However, serious limitations regarding reliable visceral closing methods remain unsolved. This article provides an update in development and future applications of transvesical access in the field of surgery.(undefined

    Anisotropy parameters of superconducting MgB2_2

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    Data on macroscopic superconducting anisotropy of MgB2_2 are reviewed. The data are described within a weak coupling two-gaps anisotropic s-wave model of superconductivity. The calculated ratio of the upper critical fields γH=Hc2,ab/Hc2,c\gamma_H=H_{c2,ab}/H_{c2,c} increases with decreasing temperature in agreement with available data, whereas the calculated ratio of London penetration depths γλ=λc/λab\gamma_{\lambda}=\lambda_c/\lambda_{ab} decreases to reach 1.1\approx 1.1 at T=0. Possible macroscopic consequences of γλγH\gamma_{\lambda}\ne\gamma_H are discussed.Comment: accepted to Physica C, special MgB2 issu

    Angular dependence of the bulk nucleation field Hc2 of aligned MgB2 crystallites

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    Studies on the new MgB2 superconductor, with a critical temperature Tc ~ 39 K, have evidenced its potential for applications although intense magnetic relaxation effects limit the critical current density, Jc, at high magnetic fields. This means that effective pinning centers must be added into the material microstructure, in order to halt dissipative flux movements. Concerning the basic microscopic mechanism to explain the superconductivity in MgB2, several experimental and theoretical works have pointed to the relevance of a phonon-mediated interaction, in the framework of the BCS theory. Questions have been raised about the relevant phonon modes, and the gap and Fermi surface anisotropies, in an effort to interpret spectroscopic and thermal data that give values between 2.4 and 4.5 for the gap energy ratio. Preliminary results on the anisotropy of Hc2 have shown a ratio, between the in-plane and perpendicular directions, around 1.7 for aligned MgB2 crystallites and 1.8 for epitaxial thin films. Here we show a study on the angular dependence of Hc2 pointing to a Fermi velocity anisotropy around 2.5. This anisotropy certainly implies the use of texturization techniques to optimize Jc in MgB2 wires and other polycrystalline components.Comment: 10 pages + 4 Figs.; Revised version accepted in Phys. Rev.

    The concept of anorexia of aging in late life depression:A cross-sectional analysis of a cohort study.

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    INTRODUCTION: Anorexia of aging (AA) is classically associated with depression. However, robust evidence is lacking regarding general clinic populations. Our aim was to evaluate the association between AA and major depressive disorder (MDD) in geriatric outpatients from a middle-income country. METHODS: We conducted a cross-sectional analysis of a cohort study. MDD diagnosis was assessed with a psychiatric interview (SCID-5-CV) according to DSM-5 criteria. Depressive symptomatology was assessed by a 15-items Geriatric Depression Scale (GDS) and the PHQ-9 questionnaire. Appetite was measured with the Simple Nutrition Appetite Questionnaire (SNAQ), whereas AA was defined as a SNAQ score ≤13 points). Linear and logistic regression analysis adjusted for potential confounders were applied to assess the association between depressive symptomatology, MDD and AA. RESULTS: Of the total 339 participants, MDD was present in 65. AA was more frequent in patients with MDD compared to non-depressed patients (30.7 versus 7.7%; p<0.001). The SNAQ score was lower in depressed patients (14.5 vs. 16.6, p<0.001). Adjusted for confounding, linear and logistic regression showed a significant association between the GDS score, PHQ-9 score and MDD with the SNAQ score (p<0.001) and cut-off representing AA (p<0.001), respectively. Moreover, MDD and AA interacted significantly with their association with weight loss (p<0.001). CONCLUSIONS: Depression scales (even without somatic complaints) and MDD were associated with AA in geriatric outpatients. AA is associated with weight loss in MDD. Prospective studies should expand these findings

    The MOND Fundamental Plane

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    Modified Newtonian Dynamics (MOND) has been shown to be able to fit spiral galaxy rotation curves as well as giving a theoretical foundation for empirically determined scaling relations, such as the Tully - Fisher law, without the need for a dark matter halo. As a complementary analysis, one should investigate whether MOND can also reproduce the dynamics of early - type galaxies (ETGs) without dark matter. As a first step, we here show that MOND can indeed fit the observed central velocity dispersion σ0\sigma_0 of a large sample of ETGs assuming a simple MOND interpolating functions and constant anisotropy. We also show that, under some assumptions on the luminosity dependence of the Sersic n parameter and the stellar M/L ratio, MOND predicts a fundamental plane for ETGs : a log - linear relation among the effective radius ReffR_{eff}, σ0\sigma_0 and the mean effective intensity Ie\langle I_e \rangle. However, we predict a tilt between the observed and the MOND fundamental planes.Comment: 16 pages, 2 figures, 2 tables, accepted for publication on MNRA

    A magnetization and 11^{11}B NMR study of Mg1x_{1-x}Alx_xB2_2 superconductors

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    We demonstrate for the first time the magnetic field distribution of the pure vortex state in lightly doped Mg1x_{1-x}Alx_xB2_2 (x0.025x\leq 0.025) powder samples, by using 11^{11}B NMR in magnetic fields of 23.5 and 47 kOe. The magnetic field distribution at T=5 K is Al-doping dependent, revealing a considerable decrease of anisotropy in respect to pure MgB2_2. This result correlates nicely with magnetization measurements and is consistent with σ\sigma-band hole driven superconductivity for MgB2_2

    Longitudinal Association between Late-Life Depression (LLD) and Frailty:Findings from a Prospective Cohort Study (MiMiCS-FRAIL)

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    OBJECTIVES: The aim of the present study was to investigate whether late-life depression (LLD) is associated with incident frailty over time. DESIGN: Prospective cohort study, one-year follow-up. SETTING: Geriatric outpatient clinic, Southwestern of Brazil. PARTICIPANTS: 181 follow-up participants aged 60 years or over. MEASUREMENTS: Depressive disorders were classified as Major Depressive disorder (MDD) or Subthreshold Depression (STD) according to DSM-5 criteria. Depressive symptoms were assessed with validated versions of 15-item Geriatric Depression Scale (GDS-15) and 9-item Patient Health Questionnaire (PHQ-9). We performed binary logistic regressions to estimate the odds ratio (OR) for frailty in LLD adjusting for multiple confounders. Participants who were frail at baseline were excluded from the analyses according to measures of frailty (FRAIL questionnaire and 36-item Frailty Index, FI-36). We also estimated the risk ratio or relative risk (RR) and the risk difference (RD) for incident frailty. RESULTS: We observed a 2 to 4-fold increased risk for incident frailty among participants with LLD. The presence of a depressive disorder was significantly associated with the onset of frailty (adjusted OR for FRAIL and FI-36: 3.07 [95% CI = 1.03 - 9.17] and 3.76 [95% CI = 1.09 - 12.97], respectively. Notably, the risk for frailty due to LLD was significantly higher with the FI-36 compared to the FRAIL (RR: 3.03 versus 2.23). RD was of 17.3% and 12.7% with the FRAIL and the FI-36, respectively. CONCLUSION: Our data support the association between LLD and incident frailty over one year among geriatric outpatients, reinforcing longitudinal evidence from population-based studies
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