144 research outputs found

    Kiri tundmatule

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    http://tartu.ester.ee/record=b1859784~S1*es

    Temperature dependent spatial oscillations in the correlations of the XXZ spin chain

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    We study the correlation for the XXZ chain in the massless attractive (ferromagnetic) region at positive temperatures by means of a numerical study of the quantum transfer matrix. We find that there is a range of temperature where the behavior of the correlation for large separations is oscillatory with an incommensurate period which depends on temperature.Comment: 4 pages, REVTEX, 6 table

    P-wave indices as predictors of atrial fibrillation

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    Abstract Background P‐wave duration (PDURATION) and P‐wave area (PAREA) have been linked to risk of atrial fibrillation (AF), but they do not improve the efficacy of Framingham AF risk score. We suggest the incorporation of both variables in one index, the P‐wave area/P‐wave duration (PAREA/DURATION) index, which may be considered an expression of the average amplitude of the P wave that reflects aspects of P‐wave morphology. Objective To assess the prognostic value of P‐wave area/P‐wave duration index (PAREA/DURATION index) in lead II together with other P‐wave indices (PWIs) in incidence of AF in the Copenhagen Holter Study. Methods The study included 632 men and women, between 55 and 75 years with no apparent heart disease or AF. Baseline standard 12‐lead Electrocardiography (ECGs) were analyzed manually. Results The median follow‐up time was 14.7 (14.5;14.9) years. A total of 68 cases of AF and 233 cases of death were recorded. The restricted cubic spline method showed a U‐shaped association between PAREA/DURATION and rate of AF. The lowest quintile of PAREA/DURATION index in lead II was associated with increased rate of AF, HR 2.80 (1.64–4.79). The addition of the new index to the Framingham model for AF improved the model in this population. The PAREA in lead II in its lowest quintile was also associated with increased rate of AF, HR 2.16 (1.25–3.75), but did not improve the Framingham model. PDURATION and P‐wave terminal force (PTF) were not significantly associated with AF. Conclusion A flat P wave as expressed by a small PAREA/DURATION index in lead II is associated with increased rate of incident AF beyond known AF risk factors

    Line shapes of dynamical correlation functions in Heisenberg chains

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    We calculate line shapes of correlation functions by use of complete diagonalization data of finite chains and analytical implications from conformal field theory, density of states, and Bethe ansatz. The numerical data have different finite size accuracy in case of the imaginary and real parts in the frequency and time representations of spin-correlation functions, respectively. The low temperature, conformally invariant regime crosses over at T∗≈0.7JT^*\approx 0.7J to a diffusive regime that in turn connects continuously to the high temperature, interacting fermion regime. The first moment sum rule is determined.Comment: 13 pages REVTEX, 18 figure

    Chest computed tomography features of heart failure:A prospective observational study in patients with acute dyspnea

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    BACKGROUND: Pulmonary congestion is a key component of heart failure (HF) that chest computed tomography (CT) can detect. However, no guideline describes which of many anticipated CT signs are most associated with HF in patients with undifferentiated dyspnea. METHODS: In a prospective observational single-center study, we included consecutive patients ≥ 50 years admitted with acute dyspnea to the emergency department. Patients underwent immediate clinical examination, blood sampling, echocardiography, and CT. Two radiologists independently evaluated all images. Acute HF (AHF) was adjudicated by an expert panel blinded to radiology images. LASSO and logistic regression identified the independent CT signs of AHF. RESULTS: Among 232 patients, 102 (44%) had AHF. Of 18 examined CT signs, 5 were associated with AHF (multivariate odds ratio, 95% confidence interval): enlarged heart (20.38, 6.86–76.16), bilateral interlobular thickening (11.67, 1.78–230.99), bilateral pleural effusion (6.39, 1.98–22.85), and increased vascular diameter (4.49, 1.08–33.92). Bilateral ground-glass opacification (2.07, 0.95–4.52) was a consistent fifth essential sign, although it was only significant in univariate analysis. Eighty-eight (38%) patients had none of the five CT signs corresponding to a 68% specificity and 86% sensitivity for AHF, while two or more of the five CT signs occurred in 68 (29%) patients, corresponding to 97% specificity and 67% sensitivity. A weighted score based on these five CT signs had an 0.88 area under the curve to detect AHF. CONCLUSIONS: Five CT signs seem sufficient to assess the risk of AHF in the acute setting. The absence of these signs indicates a low probability, one sign makes AHF highly probable, and two or more CT signs mean almost certain AHF

    The VIRUS-P Exploration of Nearby Galaxies (VENGA): The X CO Gradient in NGC 628

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    We measure the radial profile of the ^(12)CO(1-0) to H_2 conversion factor (X_(CO)) in NGC 628. The Hα emission from the VENGA integral field spectroscopy is used to map the star formation rate (SFR) surface density (Σ_(SFR)). We estimate the molecular gas surface density (Σ_(H2)) from Σ_(SFR) by inverting the molecular star formation law (SFL), and compare it to the CO intensity to measure X_(CO). We study the impact of systematic uncertainties by changing the slope of the SFL, using different SFR tracers (Hα versus far-UV plus 24 μm), and CO maps from different telescopes (single-dish and interferometers). The observed X_(CO) profile is robust against these systematics, drops by a factor of two from R ~ 7 kpc to the center of the galaxy, and is well fit by a gradient Δlog(X_(CO)) = 0.06 ± 0.02 dex kpc^(–1). We study how changes in X_(CO) follow changes in metallicity, gas density, and ionization parameter. Theoretical models show that the gradient in X_(CO) can be explained by a combination of decreasing metallicity, and decreasing Σ_(H2) with radius. Photoelectric heating from the local UV radiation field appears to contribute to the decrease of X_(CO) in higher density regions. Our results show that galactic environment plays an important role at setting the physical conditions in star-forming regions, in particular the chemistry of carbon in molecular complexes, and the radiative transfer of CO emission. We caution against adopting a single X_(CO) value when large changes in gas surface density or metallicity are present

    Rationale and Design of the First Double-Blind, Placebo-Controlled Trial with Allogeneic Adipose Tissue-Derived Stromal Cell Therapy in Patients with Ischemic Heart Failure:A Phase II Danish Multicentre Study

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    Background. Ischemic heart failure (IHF) has a poor prognosis in spite of optimal therapy. We have established a new allogeneic Cardiology Stem Cell Centre adipose-derived stromal cell (CSCC_ASC) product from healthy donors. It is produced without animal products, in closed bioreactor systems and cryopreserved as an off-the-shelf product ready to use. Study Design. A multicentre, double-blind, placebo-controlled phase II study with direct intramyocardial injections of allogeneic CSCC_ASC in patients with chronic IHF. A total of 81 patients will be randomised at 2 : 1 to CSCC_ASC or placebo. There is no HLA tissue type matching needed between the patients and the donors. Methods. The treatment will be delivered by direct injections into the myocardium. The primary endpoint is change in the left ventricle endsystolic volume at 6-month follow-up. Secondary endpoints are safety and changes in left ventricle ejection fraction, myocardial mass, stroke volume, and cardiac output. Other secondary endpoints are change in clinical symptoms, 6-minute walking test, and the quality of life after 6 and 12 months. Conclusion. The aim of the present study is to demonstrate safety and the regenerative efficacy of the allogeneic CSCC_ASC product from healthy donors in a double-blind, placebo-controlled, multicentre study in patients with IHF

    Prime Focus Spectrograph (PFS) for the Subaru Telescope: Overview, recent progress, and future perspectives

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    PFS (Prime Focus Spectrograph), a next generation facility instrument on the 8.2-meter Subaru Telescope, is a very wide-field, massively multiplexed, optical and near-infrared spectrograph. Exploiting the Subaru prime focus, 2394 reconfigurable fibers will be distributed over the 1.3 deg field of view. The spectrograph has been designed with 3 arms of blue, red, and near-infrared cameras to simultaneously observe spectra from 380nm to 1260nm in one exposure at a resolution of ~1.6-2.7A. An international collaboration is developing this instrument under the initiative of Kavli IPMU. The project is now going into the construction phase aiming at undertaking system integration in 2017-2018 and subsequently carrying out engineering operations in 2018-2019. This article gives an overview of the instrument, current project status and future paths forward.Comment: 17 pages, 10 figures. Proceeding of SPIE Astronomical Telescopes and Instrumentation 201

    Chest computed tomography features of heart failure: A prospective observational study in patients with acute dyspnea

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    Background: Pulmonary congestion is a key component of heart failure (HF) that chest computed tomography (CT) can detect. However, no guideline describes which of many anticipated CT signs are most associated with HF in patients with undifferentiated dyspnea.Methods: In a prospective observational single-center study, we included consecutive patients ≥ 50 years admitted with acute dyspnea to the emergency department. Patients underwent immediate clinical examination, blood sampling, echocardiography, and CT. Two radiologists independently evaluated all images. Acute HF (AHF) was adjudicated by an expert panel blinded to radiology images. LASSO and logistic regression identified the independent CT signs of AHF.Results: Among 232 patients, 102 (44%) had AHF. Of 18 examined CT signs, 5 were associated with AHF (multivariate odds ratio, 95% confidence interval): enlarged heart (20.38, 6.86–76.16), bilateral interlobular thickening (11.67, 1.78–230.99), bilateral pleural effusion (6.39, 1.98–22.85), and increased vascular diameter (4.49, 1.08–33.92). Bilateral ground-glass opacification (2.07, 0.95–4.52) was a consistent fifth essential sign, although it was only significant in univariate analysis. Eighty-eight (38%) patients had none of the five CT signs corresponding to a 68% specificity and 86% sensitivity for AHF, while two or more of the five CT signs occurred in 68 (29%) patients, corresponding to 97% specificity and 67% sensitivity. A weighted score based on these five CT signs had an 0.88 area under the curve to detect AHF.Conclusions: Five CT signs seem sufficient to assess the risk of AHF in the acute setting. The absence of these signs indicates a low probability, one sign makes AHF highly probable, and two or more CT signs mean almost certain AHF

    Rationale and Design of the First Double-Blind, Placebo-Controlled Trial with Allogeneic Adipose Tissue-Derived Stromal Cell Therapy in Patients with Ischemic Heart Failure: A Phase II Danish Multicentre Study

    Get PDF
    Background. Ischemic heart failure (IHF) has a poor prognosis in spite of optimal therapy. We have established a new allogeneic Cardiology Stem Cell Centre adipose-derived stromal cell (CSCC_ASC) product from healthy donors. It is produced without animal products, in closed bioreactor systems and cryopreserved as an off-the-shelf product ready to use. Study Design. A multicentre, double-blind, placebo-controlled phase II study with direct intramyocardial injections of allogeneic CSCC_ASC in patients with chronic IHF. A total of 81 patients will be randomised at 2 : 1 to CSCC_ASC or placebo. There is no HLA tissue type matching needed between the patients and the donors. Methods. The treatment will be delivered by direct injections into the myocardium. The primary endpoint is change in the left ventricle endsystolic volume at 6-month follow-up. Secondary endpoints are safety and changes in left ventricle ejection fraction, myocardial mass, stroke volume, and cardiac output. Other secondary endpoints are change in clinical symptoms, 6-minute walking test, and the quality of life after 6 and 12 months. Conclusion. The aim of the present study is to demonstrate safety and the regenerative efficacy of the allogeneic CSCC_ASC product from healthy donors in a double-blind, placebo-controlled, multicentre study in patients with IHF
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