7,356 research outputs found

    Finite-size effects and collective vibrations in the inner crust of neutron stars

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    We study the linear response of the inner crust of neutron stars within the Random Phase Approximation, employing a Skyrme-type interaction as effective interaction. We adopt the Wigner-Seitz approximation, and consider a single unit cell of the Coulomb lattice which constitutes the inner crust, with a nucleus at its center, surrounded by a sea of free neutrons. With the use of an appropriate operator, it is possible to analyze in detail the properties of the vibrations of the surface of the nucleus and their interaction with the modes of the sea of free neutrons, and to investigate the role of shell effects and of resonant states

    Relationship between leukocytosis and ischemic complications following aneurysmal subarachnoid hemorrhage.

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    The prognostic significance of admission leukocytosis with respect to ischemic complications of subarachnoid hemorrhage was retrospectively investigated in a series of patients with recently ruptured intracranial aneurysms. The present study concerned 47 consecutive cases admitted within 72 hours following the last hemorrhage, in the years 1982-1984. There was no difference in the admission WBC counts between patients who subsequently deteriorated due to ischemic complications and those who did not. However, the cell count rose significantly at the time of the clinical manifestations of ischemia, possibly as a result of structural damage of brain tissue and/or increased sympathetic and adrenocortical activity. The possible contribution of leukocytes to the pathogenesis of ischemic damage following subarachnoid hemorrhage--perhaps through the release of leukotrienes--will require further investigation

    Optimized random phase approximations for arbitrary reference systems: extremum conditions and thermodynamic consistence

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    The optimized random phase approximation (ORPA) for classical liquids is re-examined in the framework of the generating functional approach to the integral equations. We show that the two main variants of the approximation correspond to the addition of the same correction to two different first order approximations of the homogeneous liquid free energy. Furthermore, we show that it is possible to consistently use the ORPA with arbitrary reference systems described by continuous potentials and that the same approximation is equivalent to a particular extremum condition for the corresponding generating functional. Finally, it is possible to enforce the thermodynamic consistence between the thermal and the virial route to the equation of state by requiring the global extremum condition on the generating functional.Comment: 8 pages, RevTe

    The ATLAS Barrel Level-1 Muon Trigger Calibration

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    The ATLAS experiment uses a system of three concentric Resistive Plate Chambers detectors layers for the level-1 muon trigger in the air-core barrel toroid region. The trigger classifies muons within different programmable transverse momentum ranges, and tags the identified tracks with the corresponding bunch crossing number. The algorithm looks for hit coincidences within different detector layers inside the programmed geometrical road which defines the transverse momentum cut. The on-detector electronics providing the trigger and detector readout functionalities collects input signals coming from the RPC front-end. Because of the different time-of-flights and cables and optical fibres lengths, signals have to be adjusted in time in order to be correctly aligned before being processed. Programmable delay logics are provided in the trigger and readout system to allow for time adjustment, for hit signals as well as for LHC Timing, Trigger and Control signals. The trigger calibration provides the set of numbers used during electronics initialization for correctly aligning signals inside the trigger and readout system. The functionality scheme and the algorithm of the calibration are presented

    Radiogenomics in clear cell renal cell carcinoma: correlations between advanced CT imaging (texture analysis) and microRNAs expression

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    Purpose: A relevant challenge for the improvement of clear cell renal cell carcinoma management could derive from the identification of novel molecular biomarkers that could greatly improve the diagnosis, prognosis, and treatment choice of these neoplasms. In this study, we investigate whether quantitative parameters obtained from computed tomography texture analysis may correlate with the expression of selected oncogenic microRNAs. Methods: In a retrospective single-center study, multiphasic computed tomography examination (with arterial, portal, and urographic phases) was performed on 20 patients with clear cell renal cell carcinoma and computed tomography texture analysis parameters such as entropy, kurtosis, skewness, mean, and standard deviation of pixel distribution were measured using multiple filter settings. These quantitative data were correlated with the expression of selected microRNAs (miR-21-5p, miR-210-3p, miR-185-5p, miR-221-3p, miR-145-5p). Both the evaluations (microRNAs and computed tomography texture analysis) were performed on matched tumor and normal corticomedullar tissues of the same patients cohort. Results: In this pilot study, we evidenced that computed tomography texture analysis has robust parameters (eg, entropy, mean, standard deviation) to distinguish normal from pathological tissues. Moreover, a higher coefficient of determination between entropy and miR-21-5p expression was evidenced in tumor versus normal tissue. Interestingly, entropy and miR-21-5p show promising correlation in clear cell renal cell carcinoma opening to a radiogenomic strategy to improve clear cell renal cell carcinoma management. Conclusion: In this pilot study, a promising correlation between microRNAs and computed tomography texture analysis has been found in clear cell renal cell carcinoma. A clear cell renal cell carcinoma can benefit from noninvasive evaluation of texture parameters in adjunction to biopsy results. In particular, a promising correlation between entropy and miR-21-5p was found
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