18 research outputs found

    Vibrational spectra and intramolecular vibrational redistribution in highly excited deuterobromochlorofluoromethane CDBrClF : experiment and theory

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    The rovibrational spectra of deuterobromochlorofluoromethane (CDBrClF) were measured at intermediate (0.1 cm−1) and high resolution (0.0024 cm−1 full bandwidth, half-maximum) by interferometric Fourier transform infrared spectroscopy in the range from the far infrared at 200 cm−1 to the near infrared (12 000 cm−1) covering all the fundamentals and CD stretching overtones up to polyad N=5. The spectra are completely analyzed in terms of their vibrational assignments to fundamentals, combinations and overtones. At high excitation the analysis reveals the dominant anharmonic coupling between four high frequency vibrational modes; the CD stretching (ν1), two CD bending (ν2,ν3), and the CF stretching mode (ν4). The analysis is carried out using effective model Hamiltonians including three and four vibrational degrees of freedom. We also present vibrational variational calculations on a grid in a four-dimensional normal coordinate subspace. The potential energy and the dipole moment function are calculated ab initio on this grid using self-consistent field second order Møller–Plesset perturbation theory (MP2). Experimental and theoretical results for band positions and integrated intensities as well as effective spectroscopic parameters are found to be in good agreement. The important anharmonic coupling between the CD chromophore and the CF stretching vibration can be described by an effective cubic Fermi resonance coupling constant k′sff≈(50±10) cm−1, which leads to intramolecular vibrational redistribution between the CD and CF chromophores on the femtosecond time scale. Time dependent intramolecular vibrational redistribution processes in CDBrClF are derived in various representations, including time dependent probability densities (“wave packets”) in coordinate space and finally time dependent entropy

    Abnormal esophageal motility during a solid test meal in systemic sclerosis-detection even in very early disease and association with disease progression

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    OBJECTIVE This study assessed whether high-resolution manometry (HRM) with a test meal can detect clinically relevant, abnormal motility already in very early systemic sclerosis (SSc) and whether this finding is associated with subsequent disease progression. METHODS This prospective, longitudinal cohort study recruited 68 consecutive SSc patients (group #1: 32 established disease (ACR, American College of Rheumatology /EULAR, The European League against Rheumatism 2013 and ACR 1980 criteria fulfilled); group #2: 24 early disease (only ACR/EULAR 2013 fulfilled); group #3: 12 very early disease (clinical expert diagnosis of SSc) and 72 healthy controls. HRM evaluated esophageal motility for water swallows and a solid test meal. RESULTS Systemic sclerosis patients had less frequent effective esophageal contractions during the test meal compared to healthy controls even in very early disease (0.15, 1.0, 2.1 per minute for groups #1, #2, and #3, vs 2.5 per minute in health; P < 0.001, P < 0.001, and P < 0.0085, respectively). Ineffective motility at HRM was associated with a higher modified Rodnan skin score at baseline. Moreover, at mean 18 (10-31) months of follow-up, the presence of ineffective motility at baseline was associated with progression of skin disease (P = 0.01). Cox proportional hazard regression analysis identified hypotensive peristalsis in the test meal (<15% effective solid swallows) and low distal contractile integral (DCI; <400 mm Hg·cm·s) as predictors for skin aggravation, but not for new organ involvement. CONCLUSION Ineffective motility during a test meal is present already in patients with very early SSc. Findings on HRM studies are associated with disease severity at baseline, and low percentage of effective swallows in test meal and low mean DCI are both predictors of skin progression during follow-up

    Intraplate Earthquakes in Europe—Source Parameters from Regional Moment Tensor Analysis

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    Plate tectonics provides a highly successful framework to describe a wide range of geological observations invoking the motion of lithospheric plates. In its simplest form the plates are rigid and earthquakes are confined to boundaries where plates move relative to each other
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