910 research outputs found

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145329/1/cpmia2100.pd

    965-48 Ejection Fraction and Wall Thickness Correlate with Impaired Energy Metabolism in Patients with Dilated Cardiomyopathy

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    Using 31P-MR spectroscopy, abnormalities of cardiac energy metabolism have been demonstrated in patients with dilated cardiomyopathy (DCM). However. a detailed analysis of the correlations among energy metabolism, cardiac hemodynamics and myocardial hypertrophy obtained from 31P-MR, right and left heart catheterization and echocardiography has not been presented, 23 patients with DCM (left ventricular (LV) EF 34±3%; NYHA class 2.7±0.1; SE) underwent right and left heart catheterization and echocardiography±3 days before/after MR spectroscopy. Coronary artery disease was ruled out by coronary angiography. ECG-triggered. localized 31 P-MR spectra from the anteroseptal myocardium were acquired at rest (prone position) during 30min on a 1.5 T Philips Gyroscan MR system using ISIS localization, adiabatic pulses. and a 15 sec repetition time. Peak areas were corrected for T1 effects and for blood contamination. and were determined with Lorentzian line fits in the time domain. Linear correlations between creatine phosphate (CP)/ATP ratios and hemodynamic parameters were calculated.LV pressures and diameters. cardiac output, stroke volume, pulmonary arterial pressures, right atrial pressure and pulmonary arterial oxygen saturation did not correlate with CP/ATP. Thus, our data demonstrate that in DCM, the extent of high-energy phosphate depletion is related to the extent of mechanical dysfunction as well as to LV wall thickness

    Multifactorial diagnostic NIR imaging of CCK2R expressing tumors

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    AbstractOptical imaging-based diagnostics identify malignancies based on molecular changes instead of morphological criteria in a non-invasive, irradiation free process. The aim of this study was to improve imaging efficiency by the development of a new Cholecystokinin-2-receptor targeted fluorescent peptide that matches the clinical needs regarding biodistribution and pharmacokinetics while displaying superior target specificity. Furthermore we performed multifactorial imaging of Cholecystokinin-2-receptor and tumor metabolism, since simultaneous targeting of various tumor biomarkers could intensely increase tumor identification and characterization. Affinity and specificity of the fluorescent Cholecystokinin-2-receptor targeted minigastrin (dQ-MG-754) were tested in vitro. We conducted in vivo imaging of the dQ-MG-754 probe alone and in a multifactorial approach with a GLUT-1 targeted probe (IR800 2-DG) on subcutaneous xenograft bearing athymic nude mice up to 24 h after intravenous injection (n = 5/group), followed by ex vivo biodistribution analysis and histological examination. We found specific, high affinity binding (Kd = 1.77 nm ± 0.6 nm) of dQ-MG-754 to Cholecystokinin-2-receptor expressing cells and xenografts as well as favorable pharmacokinetics for fluorescence-guided endoscopy. We successfully performed multifactorial imaging for the simultaneous detection of the Cholecystokinin-2-receptor and GLUT-1 targeted probe. Prominent differences in uptake patterns of the two contrast agents could be detected. The results were validated by histological examinations. The multifactorial imaging approach presented in this study could facilitate cancer detection in diagnostic imaging and intraoperative and endoscopic applications. Especially the dQ-MG-754 probe bears great potential for translation to clinical endoscopy imaging, because it combines specific high affinity binding with renal elimination and a favorable biodistribution

    Precision neutron interferometric measurement of the nd coherent neutron scattering length and consequences for models of three-nucleon forces

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    We have performed the first high precision measurement of the coherent neutron scattering length of deuterium in a pure sample using neutron interferometry. We find b_nd = (6.665 +/- 0.004) fm in agreement with the world average of previous measurements using different techniques, b_nd = (6.6730 +/- 0.0045) fm. We compare the new world average for the nd coherent scattering length b_nd = (6.669 +/- 0.003) fm to calculations of the doublet and quartet scattering lengths from several modern nucleon-nucleon potential models with three-nucleon force (3NF) additions and show that almost all theories are in serious disagreement with experiment. This comparison is a more stringent test of the models than past comparisons with the less precisely-determined nuclear doublet scattering length of a_nd = (0.65 +/- 0.04) fm.Comment: 4 pages, 4 figure

    Feedback under the microscope: thermodynamic structure and AGN driven shocks in M87

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    (abridged) Using a deep Chandra exposure (574 ks), we present high-resolution thermodynamic maps created from the spectra of ∼\sim16,000 independent regions, each with ∼\sim1,000 net counts. The excellent spatial resolution of the thermodynamic maps reveals the dramatic and complex temperature, pressure, entropy and metallicity structure of the system. Excluding the 'X-ray arms', the diffuse cluster gas at a given radius is strikingly isothermal. This suggests either that the ambient cluster gas, beyond the arms, remains relatively undisturbed by AGN uplift, or that conduction in the intracluster medium (ICM) is efficient along azimuthal directions. We confirm the presence of a thick (∼\sim40 arcsec or ∼\sim3 kpc) ring of high pressure gas at a radius of ∼\sim180 arcsec (∼\sim14 kpc) from the central AGN. We verify that this feature is associated with a classical shock front, with an average Mach number M = 1.25. Another, younger shock-like feature is observed at a radius of ∼\sim40 arcsec (∼\sim3 kpc) surrounding the central AGN, with an estimated Mach number M > 1.2. As shown previously, if repeated shocks occur every ∼\sim10 Myrs, as suggested by these observations, then AGN driven weak shocks could produce enough energy to offset radiative cooling of the ICM. A high significance enhancement of Fe abundance is observed at radii 350 - 400 arcsec (27 - 31 kpc). This ridge is likely formed in the wake of the rising bubbles filled with radio-emitting plasma that drag cool, metal-rich gas out of the central galaxy. We estimate that at least ∼1.0×106\sim1.0\times10^6 solar masses of Fe has been lifted and deposited at a radius of 350-400 arcsec; approximately the same mass of Fe is measured in the X-ray bright arms, suggesting that a single generation of buoyant radio bubbles may be responsible for the observed Fe excess at 350 - 400 arcsec.Comment: 18 pages, 16 figures. Accepted to MNRA

    Depth-Resolved Composition and Electronic Structure of Buried Layers and Interfaces in a LaNiO3_3/SrTiO3_3 Superlattice from Soft- and Hard- X-ray Standing-Wave Angle-Resolved Photoemission

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    LaNiO3_3 (LNO) is an intriguing member of the rare-earth nickelates in exhibiting a metal-insulator transition for a critical film thickness of about 4 unit cells [Son et al., Appl. Phys. Lett. 96, 062114 (2010)]; however, such thin films also show a transition to a metallic state in superlattices with SrTiO3_3 (STO) [Son et al., Appl. Phys. Lett. 97, 202109 (2010)]. In order to better understand this transition, we have studied a strained LNO/STO superlattice with 10 repeats of [4 unit-cell LNO/3 unit-cell STO] grown on an (LaAlO3_3)0.3_{0.3}(Sr2_2AlTaO6_6)0.7_{0.7} substrate using soft x-ray standing-wave-excited angle-resolved photoemission (SWARPES), together with soft- and hard- x-ray photoemission measurements of core levels and densities-of-states valence spectra. The experimental results are compared with state-of-the-art density functional theory (DFT) calculations of band structures and densities of states. Using core-level rocking curves and x-ray optical modeling to assess the position of the standing wave, SWARPES measurements are carried out for various incidence angles and used to determine interface-specific changes in momentum-resolved electronic structure. We further show that the momentum-resolved behavior of the Ni 3d eg and t2g states near the Fermi level, as well as those at the bottom of the valence bands, is very similar to recently published SWARPES results for a related La0.7_{0.7}Sr0.3_{0.3}MnO3_3/SrTiO3_3 superlattice that was studied using the same technique (Gray et al., Europhysics Letters 104, 17004 (2013)), which further validates this experimental approach and our conclusions. Our conclusions are also supported in several ways by comparison to DFT calculations for the parent materials and the superlattice, including layer-resolved density-of-states results

    Universal behavior of multiplicity differences in quark-hadron phase transition

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    The scaling behavior of factorial moments of the differences in multiplicities between well separated bins in heavy-ion collisions is proposed as a probe of quark-hadron phase transition. The method takes into account some of the physical features of nuclear collisions that cause some difficulty in the application of the usual method. It is shown in the Ginzburg-Landau theory that a numerical value γ\gamma of the scaling exponent can be determined independent of the parameters in the problem. The universality of γ\gamma characterizes quark-hadron phase transition, and can be tested directly by appropriately analyzed data.Comment: 15 pages, including 4 figures (in epsf file), Latex, submitted to Phys. Rev.
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