18,991 research outputs found

    Signatures of strong correlation effects in RIXS on Cuprates

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    Recently, spin excitations in doped cuprates are measured using the resonant inelastic X-ray scattering (RIXS). The paramagnon dispersions show the large hardening effect in the electron-doped systems and seemingly doping-independence in the hole-doped systems, with the energy scales comparable to that of the antiferromagnetic magnons. This anomalous hardening effect was partially explained by using the strong coupling t-J model but with a three-site term(Nature communications 5, 3314 (2014)). However we show that hardening effect is a signature of strong coupling physics even without including this extra term. By considering the t-t'-t"-J model and using the Slave-Boson (SB) mean field theory, we obtain, via the spin-spin susceptibility, the spin excitations in qualitative agreement with the experiments. These anomalies is mainly due to the doping-dependent bandwidth. We further discuss the interplay between particle-hole-like and paramagnon-like excitations in the RIXS measurements.Comment: 7 pages, 6 figure

    Retrieval of phase memory in two independent atomic ensembles by Raman process

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    In spontaneous Raman process in atomic cell at high gain, both the Stokes field and the accompanying collective atomic excitation (atomic spin wave) are coherent. We find that, due to the spontaneous nature of the process, the phases of the Stokes field and the atomic spin wave change randomly from one realization to another but are anti-correlated. The phases of the atomic ensembles are read out via another Raman process at a later time, thus realizing phase memory in atoms. The observation of phase correlation between the Stokes field and the collective atomic excitations is an important step towards macroscopic EPR-type entanglement of continuous variables between light and atoms

    Classification of Overlapped Audio Events Based on AT, PLSA, and the Combination of Them

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    Audio event classification, as an important part of Computational Auditory Scene Analysis, has attracted much attention. Currently, the classification technology is mature enough to classify isolated audio events accurately, but for overlapped audio events, it performs much worse. While in real life, most audio documents would have certain percentage of overlaps, and so the overlap classification problem is an important part of audio classification. Nowadays, the work on overlapped audio event classification is still scarce, and most existing overlap classification systems can only recognize one audio event for an overlap. In this paper, in order to deal with overlaps, we innovatively introduce the author-topic (AT) model which was first proposed for text analysis into audio classification, and innovatively combine it with PLSA (Probabilistic Latent Semantic Analysis). We propose 4 systems, i.e. AT, PLSA, AT-PLSA and PLSA-AT, to classify overlaps. The 4 proposed systems have the ability to recognize two or more audio events for an overlap. The experimental results show that the 4 systems perform well in classifying overlapped audio events, whether it is the overlap in training set or the overlap out of training set. Also they perform well in classifying isolated audio events

    Determination of incommensurate modulated structure in Bi2Sr1.6La0.4CuO6+{\delta} by aberration-corrected transmission electron microscopy

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    Incommensurate modulated structure (IMS) in Bi2Sr1.6La0.4CuO6+{\delta} (BSLCO) has been studied by aberration corrected transmission electron microscopy in combination with high-dimensional (HD) space description. Two images in the negative Cs imaging (NCSI) and passive Cs imaging (PCSI) modes were deconvoluted, respectively. Similar results as to IMS have been obtained from two corresponding projected potential maps (PPMs), but meanwhile the size of dots representing atoms in the NCSI PPM is found to be smaller than that in PCSI one. Considering that size is one of influencing factors of precision, modulation functions for all unoverlapped atoms in BSLCO were determined based on the PPM obtained from the NCSI image in combination with HD space description

    Sleep-disordered breathing is associated with depletion of circulating endothelial progenitor cells and elevation in pulmonary arterial pressure in patients with decompensated systolic heart failure

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    BACKGROUND: Sleep-disordered breathing (SDB) is known to occur frequently in and may predict worsening progression of patients with congestive heart failure (CHF). SDB is also known to play an important role in the development of idiopathic pulmonary arterial hypertension (PAH) via inducing endothelial dysfunction and vascular remodeling, a pathological process that can be significantly influenced by factors such as osteoprotegerin (OPG) and endothelial progenitor cells (EPCs). The objective of this study is to determine if CHF with SDB is associated with changes in OPG, EPCs, and PAH. METHODS: EPCs were isolated, cultured, and quantified from CHF patients with SDB (n = 52), or without SDB (n = 68). OPG and N-terminal pro-brain natriuretic peptide (NT-proBNP) from each group was analyzed and correlated with EPCs and the mean pulmonary artery pressure (mPAP) measured by right heart catheterization. RESULTS: A significant decrease in circulating EPCs (29.30 ± 9.01 vs. 45.17 ± 10.51 EPCs/× 200 field; P < 0.05) was found in CHF patients with SDB compared to those without SDB. Both OPG (789.83 ± 89.38 vs. 551.29 ± 42.12 pg/mL; P < 0.05) and NT-proBNP (5946.50 ± 1434.50 vs. 3028.60 ± 811.90 ng/mL; P < 0.05) were also significantly elevated in SDB CHF patients who also had significantly elevated mPAP (50.2 ± 9.5 vs. 36.4 ± 4.1 mm Hg; P < 0.05). EPC numbers correlated inversely with the episodes of apnea and hypopnea per hour (RDI, r = -0.45, P = 0.037) and blood level of OPG (r = -0.53, P = 0.011). Although NT-proBNP was also increased significantly in patients with SDB, it had no correlation with either EPCs or RDI. CONCLUSIONS: SDB due to hypoxemia from decompensated CHF is associated with (1) OPG elevation, (2) EPC depletion, and (3) mPAP elevation. The inverse relationship of circulating OPG with EPCs suggests a likely mechanism for hypoxemia and OPG in the development of pulmonary vascular dysfunction via depleting EPCs, thus worsening prognosis of CHF

    Ventricular divergence correlates with epicardial wavebreaks and predicts ventricular arrhythmia in isolated rabbit hearts during therapeutic hypothermia

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    INTRODUCTION: High beat-to-beat morphological variation (divergence) on the ventricular electrogram during programmed ventricular stimulation (PVS) is associated with increased risk of ventricular fibrillation (VF), with unclear mechanisms. We hypothesized that ventricular divergence is associated with epicardial wavebreaks during PVS, and that it predicts VF occurrence. METHOD AND RESULTS: Langendorff-perfused rabbit hearts (n = 10) underwent 30-min therapeutic hypothermia (TH, 30°C), followed by a 20-min treatment with rotigaptide (300 nM), a gap junction modifier. VF inducibility was tested using burst ventricular pacing at the shortest pacing cycle length achieving 1:1 ventricular capture. Pseudo-ECG (p-ECG) and epicardial activation maps were simultaneously recorded for divergence and wavebreaks analysis, respectively. A total of 112 optical and p-ECG recordings (62 at TH, 50 at TH treated with rotigaptide) were analyzed. Adding rotigaptide reduced ventricular divergence, from 0.13±0.10 at TH to 0.09±0.07 (p = 0.018). Similarly, rotigaptide reduced the number of epicardial wavebreaks, from 0.59±0.73 at TH to 0.30±0.49 (p = 0.036). VF inducibility decreased, from 48±31% at TH to 22±32% after rotigaptide infusion (p = 0.032). Linear regression models showed that ventricular divergence correlated with epicardial wavebreaks during TH (p<0.001). CONCLUSION: Ventricular divergence correlated with, and might be predictive of epicardial wavebreaks during PVS at TH. Rotigaptide decreased both the ventricular divergence and epicardial wavebreaks, and reduced the probability of pacing-induced VF during TH

    Highly phosphorescent platinum(II) emitters: photophysics, materials and biological applications

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    Minimal clinically important difference of the EORTC QLQ-CIPN20 for worsening peripheral neuropathy in patients receiving neurotoxic chemotherapy.

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    Context/objectivesThis is the first study to determine the minimal clinically important difference (MCID) of the European Organisation of Research and Treatment of Cancer Quality of Life Questionnaire-CIPN twenty-item scale (EORTC QLQ-CIPN20), a validated instrument designed to elicit cancer patients' experience of symptoms and functional limitations related to chemotherapy-induced peripheral neuropathy.MethodsCancer patients receiving neurotoxic chemotherapy completed EORTC QLQ-CIPN20 and the Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity [FACT/GOG-NTX] at baseline, second cycle of chemotherapy (T2, n = 287), and 12&nbsp;months after chemotherapy (T3, n = 191). Anchor-based approach used the validated FACT/GOG-NTX neurotoxicity (Ntx) subscale to identify optimal MCID cutoff for deterioration. Distribution-based approach used one-third standard deviation (SD), half SD, and one standard error of measurement of the total EORTC QLQ-CIPN20 score.ResultsThere was a moderate correlation between the change scores of the Ntx subscale and sensory and motor subscales of QLQ-CIPN20 (T2: r = - 0.722, p &lt; 0.001 and r = - 0.518, p &lt; 0.001, respectively; T3: r = - 0.699; p &lt; 0.001 and r = - 0.523, p &lt; 0.001, respectively). The correlation between the change scores of the Ntx subscale and the QLQ-CIPN20 autonomic subscale was poor (T2: r = - 0.354, p &lt; 0.001; T3: r = 0.286, p &lt; 0.001). Based on the MCID derived using distribution-based method, the MCID for the QLQ-CIPN20 sensory subscale was 2.5-5.9 (6.9% to 16.4% of the subdomain score) and for motor subscale was 2.6-5.0 (8.1%-15.6% of the subdomain score).ConclusionThe MCID for the EORTC QLQ-CIPN20 established using distribution-based approaches was 2.5-5.9 for the sensory subscale and 2.6-5.0 for the motor subscale. When noted in assessments even with small change in scores, clinicians can be alerted for appropriate intervention
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