126 research outputs found

    Insight on Hole-Hole Interaction and Magnetic Order from Dichroic Auger-Photoelectron Coincidence Spectra

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    The absence of sharp structures in the core-valence-valence Auger line shapes of partially filled bands has severely limited the use of electron spectroscopy in magnetic crystals and other correlated materials. Here by a novel interplay of experimental and theoretical techniques we achieve a combined understanding of the Photoelectron, Auger %M23M45M45M_{23}M_{45}M_{45} and Auger-Photoelectron Coincidence Spectra (APECS) of CoO. This is a prototype antiferromagnetic material in which the recently discovered Dichroic Effect in Angle Resolved (DEAR) APECS reveals a complex pattern in the strongly correlated Auger line shape. A calculation of the \textit{unrelaxed} spectral features explains the pattern in detail, labeling the final states by the total spin. The present theoretical analysis shows that the dichroic effect arises from a spin-dependence of the angular distribution of the photoelectron-Auger electron pair detected in coincidence, and from the selective power of the dichroic technique in assigning different weights to the various spin components. Since the spin-dependence of the angular distribution exists in the antiferromagnetic state but vanishes at the N\'eel temperature, the DEAR-APECS technique detects the phase transition from its local effects, thus providing a unique tool to observe and understand magnetic correlations in such circumstances, where the usual methods (neutron diffraction, specific heat measurements) are not applicable.Comment: Accepted by: Physical Review Letter

    Right ventricular function in AL amyloidosis: characteristics and prognostic implication

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    AIM: The importance of right ventricle (RV) dysfunction in AL amyloidosis has been underestimated. This study was designed to comprehensively evaluate RV function and its prognostic role in patients with AL amyloidosis with and without echocardiographic evidence of cardiac involvement. METHOD AND RESULTS: Fifty-two biopsy-proven AL amyloidosis patients underwent a thorough echocardiographic evaluation. Twenty-seven patients (CA) met the international echocardiographic criteria for cardiac involvement [left ventricular (LV) wall thickness >/= 12 mm] and 25 patients had no cardiac amyloidosis features (NCA). Patients were compared with a sex- age-matched control group. Patients and controls underwent traditional, tissue Doppler (TDI), speckle-tracking left and RV echocardiographic evaluation. No difference was observed between groups in RV diastolic diameter, whereas CA patients showed increased RV free wall thickness (P< 0.0001). Compared with controls and NCA patients, traditional echocardiography, TDI, and speckle-tracking evaluation detected significantly (P< 0.0001) depressed RV longitudinal systolic function in CA patients. No difference was observed between groups at Doppler diastolic evaluation, whereas at tricuspidal annulus TDI analysis, CA subject showed significantly lower E' and A' values with increased E/E' ratio (P< 0.0001). Over a 19 months median follow-up period, 18 patients died. Cox multivariate analysis showed that N-terminal pro-Brain natriuretic peptide and RV longitudinal strain were the strongest death predictor. CONCLUSION: Our data show that in patients with AL amyloidosis, RV involvement develops later than LV amyloid deposition but when it occurs, prognosis dramatically worsens. Moreover RV longitudinal strain was the only echocardiographic predictor of prognosis. We suggest that RV function analysis should be performed routinely as a part of echocardiographic evaluation in these patients

    Classification of Unbalanced and Bowed Rotors under Uncertainty Using Wavelet Time Scattering, LSTM, and SVM

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    A growing interest in intelligent fault detection may sometimes lead to practical issues when existing malfunctions reveal analogous indications and the number of observations is limited. This article addresses the classification problem of two identical malfunctions, i.e., unbalancing and shaft bow in rotary machines, where only 56 observations were utilized for the training. The faulty systems are modeled in ABAQUS/CAE; a data set for each fault is created by simulation under various physical and operational conditions employing the uncertainty concept. The wavelet time scattering (WTS) technique extracts low-variance presentations from signals. With respect to the classification procedure of the faulted rotor systems, two models are examined with the extracted features from WTS as the input. Initially, a long short-term memory (LSTM) network is trained and tested, and then, the capability of a support vector machine (SVM) model is inquired. Ultimately, the classification models are trained and tested using the raw time series data and the extracted features to compare the effectiveness of the suggested methods, i.e., WTS. The employed approach for feature extraction demonstrated remarkable effectiveness in addressing a potential hurdle in identifying faults in rotating systems: the ability to differentiate between unbalanced and bowed rotors, irrespective of the classification model utilized

    Prevalence of anxiety and depression symptoms in a sample of outpatients with ATTR cardiac amyloidosis

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    Patients with ATTR cardiac amyloidosis (ATTR-CA) face rare disease that could negatively influence psychological well-being with consequences on the course of the disease and quality of life. However, to date, no study analyzed the prevalence of anxiety and depression in patients with ATTR-CA and which clinical and sociodemographic characteristics are linked with these psychopathological conditions. A total of 109 consecutive patients (83% males) aged 62–90 years with ATTR-CA were recruited. In order to better understand the prevalence of anxiety and depression in ATTR-CA, a control group composed by 33 individuals equaling gender, education, and age were recruited. The level of anxiety and depression was measured using the Italian version of the Hospital Anxiety and Depression Scale (HADS). Sociodemographic and clinic characteristics were registered. Almost half of patients (49%) reported a clinical level of depression or anxiety, or both. ATTR-CA patients reported higher levels of anxiety and depression than control group. Results showed that older patients with ATTR-CA, especially females, with more advanced disease could be more at risk to develop an anxious disorder. Furthermore, being a woman, and presenting with a greater severity of symptoms, would appear to be a risk factor for developing a depressive disorder. Overall, these results highlighted the high presence of anxiety and depression in ATTR-CA patients, suggesting to physicians to pay attention to the psychological well-being of ATTR-CA patients. In fact, a psychological support for patients with high level of psychopathological disease could reduce disease burden and improve quality of life in ATTR-CA population
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