219 research outputs found

    Origin of the anomalous mass renormalization in metallic quantum well states of correlated oxide SrVO3_3

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    InIn situsitu angle-resolved photoemission spectroscopy (ARPES) has been performed on SrVO3_3 ultrathin films, which show metallic quantum well (QW) states, to unveil the origin of the anomalous mass enhancement in the QW subbands. The line-shape analysis of the ARPES spectra reveals that the strength of the electron correlation increases as the subband bottom energy approaches the Fermi level. These results indicate that the anomalous subband-dependent mass enhancement mainly arises from the quasi-one-dimensional character of confined V 3d3d states as a result of their orbital-selective quantization.Comment: 6 pages, 3 figure

    Emergence of quantum critical behavior in metallic quantum-well states of strongly correlated oxides

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    Controlling quantum critical phenomena in strongly correlated electron systems, which emerge in the neighborhood of a quantum phase transition, is a major challenge in modern condensed matter physics. Quantum critical phenomena are generated from the delicate balance between long-range order and its quantum fluctuation. So far, the nature of quantum phase transitions has been investigated by changing a limited number of external parameters such as pressure and magnetic field. We propose a new approach for investigating quantum criticality by changing the strength of quantum fluctuation that is controlled by the dimensional crossover in metallic quantum well (QW) structures of strongly correlated oxides. With reducing layer thickness to the critical thickness of metal-insulator transition, crossover from a Fermi liquid to a non-Fermi liquid has clearly been observed in the metallic QW of SrVO3_3 by \textit{in situ} angle-resolved photoemission spectroscopy. Non-Fermi liquid behavior with the critical exponent α=1{\alpha} = 1 is found to emerge in the two-dimensional limit of the metallic QW states, indicating that a quantum critical point exists in the neighborhood of the thickness-dependent Mott transition. These results suggest that artificial QW structures provide a unique platform for investigating novel quantum phenomena in strongly correlated oxides in a controllable fashion.Comment: 6 pages, 3 figure

    A high-throughput direct FRET-based assay for analysing apoptotic proteases using flow cytometry and fluorescence-lifetime measurements

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    International audienceCytometry is a versatile and powerful method applicable to different fields, particularly pharmacology and biomedical studies. Based on the data obtained, cytometric studies are classified into high-throughput (HTP) or high-content screening (HCS) groups. However, assays combining the advantages of both are required to facilitate research. In this study, we developed a high-throughput system to profile cellular populations in terms of time- or dose-dependent responses to apoptotic stimulations, since apoptotic inducers are potent anti-cancer drugs. We previously established assay systems involving protease to monitor live cells for apoptosis using tuneable FRET-based bioprobes. These assays can be used for microscopic analyses or fluorescence-activated cell sorting. In this study, we developed FRET-based bioprobes to detect the activity of the apoptotic markers caspase-3 and caspase-9 via changes in bioprobe fluorescence lifetimes using a flow cytometer for direct estimation of FRET efficiencies. Different patterns of changes in the fluorescence lifetimes of these markers during apoptosis were observed, indicating a relationship between discrete steps in the apoptosis process. The findings demonstrate the feasibility of evaluating collective cellular dynamics during apoptosis

    Safety and Effectiveness of Ninjin'yoeito: A Utilization Study in Elderly Patients

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    Post-marketing surveillance studies of traditional Japanese medicine in Japan are limited, and currently there are no data for Ninjin'yoeito, which is often used for the elderly because of its efficacy. In this study, we aimed to investigate the post-marketing safety and efficacy of Ninjin'yoeito in elderly patients over 65 years of age in clinical practice in Japan. This survey was an open-label, non-comparative, prospective, multicenter, post-marketing survey conducted at 383 centers between February 2016 and March 2017. In the safety analysis of 808 patients, adverse reactions were reported in 25 patients (3.1%), most of whom had gastrointestinal disorders (2.1%). In the efficacy analysis, Ninjin'yoeito was found to significantly improve visual analog scale scores in fatigue/malaise and anorexia at weeks 8, 16, and 24, and weeks 8 and 24 after commencement of treatment, respectively. In addition, the Basic Checklist created by the Ministry of Health, Labor and Welfare of Japan was used as a secondary survey item. The proportion of patients expected to require nursing care significantly decreased after 24 weeks compared with the baseline in four domains (activities of daily living, motor function, oral function, and depression). On the basis of physician assessment, Ninjin'yoeito was rated as “effective” or “moderately effective” in 486 (90.5%) of 537 cases. As the checklist contains many aspects of frailty, Ninjin'yoeito might be beneficial in preventing frailty. The findings of the present study indicate the safety of Ninjin'yoeito in aged patients, although further integrated clinical trials are necessary to examine its efficacy

    Characteristics of acute congestive heart failure with normal ejection fraction and less elevated B-type natriuretic peptide

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    Abstract Background Heterogeneity in B-type natriuretic peptide (BNP) levels, especially among individuals with acute heart failure with normal left ventricular ejection fraction (HFNEF), can cause confusion in interpreting results. We investigated the characteristics of cases of acute HFNEF with only modestly elevated BNP. Methods One hundred forty-two patients with acute or acute exacerbation of chronic HFNEF were divided into two groups by BNP level: BNP Results In the NB group, a history of open-heart surgery (OHS) was more frequent (71% vs. 22%, p Conclusion We found associations between acute HFNEF with less elevated BNP and a history of OHS. In a patient suspected of HFNEF, a history of OHS is considered diagnostic evidence of presence of diastolic heart failure when plasma levels of BNP are less elevated.</p
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