8 research outputs found

    Ultraviolet Continuum Color Variability of Luminous Sloan Digital Sky Survey QSOs

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    We examine whether the spectral energy distribution of UV continuum emission of active galactic nuclei changes during flux variation. We used multi-epoch photometric data of QSOs in the Stripe 82 observed by the SDSS Legacy Survey and selected 10 bright QSOs observed with high photometric accuracies, in the redshift range of z = 1.0-2.4 where strong broad emission lines such as Ly\alpha and CIV do not contaminate SDSS filters, to examine spectral variation of the UV continuum emission with broadband photometries. All target QSOs showed clear flux variations during the monitoring period 1998-2007, and the multi-epoch flux data in two different bands obtained on the same night showed a linear flux-to-flux relationship for all target QSOs. Assigning the flux in the longer wavelength to the x-axis in the flux-to-flux diagram, the x-intercept of the best-fit linear regression line was positive for most targets, which means that their colors in the observing bands become bluer as they become brighter. Then, the host-galaxy flux was estimated on the basis of the correlation between the stellar mass of the bulge of the host galaxy and the central black hole mass. We found that the longer-wavelength flux of the host galaxy was systematically smaller than that of the fainter extension of the best-fit regression line at the same shorter-wavelength flux for most targets. This result strongly indicates that the spectral shape of the continuum emission of QSOs in the UV region usually becomes bluer as it becomes brighter. We found that the multi-epoch flux-to-flux plots could be fitted well with the standard accretion disk model changing the mass accretion rate with a constant black hole mass for most targets. This finding strongly supports the standard accretion disk model for UV continuum emission of QSOs.Comment: 43 pages, 31 figures, accepted for publication in Ap

    Comparable effect of tolvaptan in heart failure patients with preserved or reduced ejection fraction

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    Background: It is unclear that the difference in efficacy of tolvaptan (TLV) on the length of hospital stay for both heart failure (HF) preserved ejection fraction (EF) (HFpEF) and reduced EF (HFrEF) patients. Methods: We investigated 369 patients who were hospitalized with HF from February 2011 to June 2016 and initiated TLV. Patients who died in hospital, transferred hospital or clinical scenario 4 or 5 were excluded. Finally, we analyzed 108 patients with HFpEF and 96 patients with HFrEF. We evaluated the relationship between the length of hospital stay and the date of TLV initiation. Moreover, we compared the early use (within the median) and delayed use (the median or later) of TLV. Results: The date of TLV initiation was statistically associated with the length of hospital stay in both HFpEF and HFrEF (HFpEF: r = 0.625, P < 0.001, HFrEF: r = 0.618, P < 0.001). In HFpEF, the length of hospital stay in delayed use group was significantly longer than the early use group (22.2 ± 10.7 days and 38.1 ± 22.6 days, P < 0.001). The result was similar in HFrEF (22.0 ± 15.0 days and 32.1 ± 22.0 days, P = 0.008). On the other hand, there were no statistically significant differences in the length of hospital stay after initiation of TLV in both HFpEF and HFrEF. Other findings (including the severity of HF) were similar between the early use group and the delayed group in HFpEF and HFrEF. Conclusions: The time until TLV initiation after hospitalization was related to the length of hospital stay in HFpEF and HFrEF patients

    Azelnidipine is a useful medication for the treatment of heart failure preserved ejection fraction

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    Background: The optimal therapy in patients with heart failure preserved ejection fraction (HFpEF) and hypertension (HT) has not been revealed. The beta blocker (BB) and the renin angiotensin aldosterone system inhibitor (RAAS-I) are recommend as class IIa in patients with HFpEF. The calcium channel blocker (CCB), a major anti-hypertensive drugs in Japan, is also recommend as class IIa in patients with HFpEF. However, the difference between azelnidipine, an L type CCB, and cilnidipine, an N type CCB, is unclear. We investigated the difference between azelnidipine and cilnidipine in patients with HFpEF and HT. Methods: Twenty-five consecutive HFpEF patients treated with BB and RAAS-I from April 2013 to March 2015 were enrolled. Initially, cilnidipine was used, and then switched to azelnidipine. Age, gender, blood pressure (BP), heart rate (HR), blood tests, echocardiography, and cardiac-scintigraphy (123I-metaiodobenzylguanidine: MIBG) were measured before and after six months from azelnidipine administration. Results: There was no statistically significant difference in BP. B type natriuretic peptides were significantly reduced (pre-state: 195.4 ± 209.7 pg/ml and post-state: 140.7 ± 136.4 pg/ml, p = 0.050). In echocardiography, the TEI index tended to be decreased (pre-state: 0.47 ± 0.15 and post-state: 0.42 ± 0.08, p = 0.057). As for MIBG, there was no significant change in the heart/mediastinum ratio. However, the washout rate was significantly reduced (pre-state: 44.7 ± 12.2 and post-state: 40.7 ± 12.1, p = 0.011). In addition, there was no statistically significant change, although HR tended to decrease by switching to azelnidipine (pre-state: 62.7 ± 11.6 and post-state: 61.8 ± 16.5, p = 0.373). Conclusions: In patients with HT and HFpEF, azelnidipine improved the severity of HF and cardiac sympathetic nerve activity compared with cilnidipine

    Bisoprolol transdermal patch improves orthostatic hypotension in patients with chronic heart failure and hypertension

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    β blockers (BBs) play an important role in heart failure (HF) treatment. However, orthostatic hypotension (OH) is sometimes caused by BBs. The bisoprolol transdermal patch works more slowly and is long acting compared with the bisoprolol fumarate tablet. The risk of OH may be reduced by using the bisoprolol transdermal patch. We evaluated 57 consecutive patients who were taking the bisoprolol fumarate tablet for chronic HF with hypertension from November 2016 to September 2017. We switched the patients to the bisoprolol transdermal patch. Because 12 of 57 subjects could not continue using the bisoprolol transdermal patch, we analyzed the remaining 45 patients. We investigated BP, blood tests, and changes in BP from supine to standing positions before and after 6 months of switching from tablet to patch. OH was diagnosed by observing a systolic/diastolic BP drop of at least 20/10 mmHg or an absolute systolic BP (sBP) of <90 mmHg from the standing position. No significant changes were observed in the BP and BPs from supine to standing positions, whereas log brain natriuretic peptide was significantly reduced after switching from patch to tablet (2.102 to 2.070pg/dl, P = .039). OH, which occurred in originally 17 patients, showed improvement and eventually appeared in 4 patients. In these patients, changes in BP from supine to standing positions were also significantly improved (changes in sBP, −11 to −6mmHg, P = .016). This study demonstrated that switching from the bisoprolol fumarate tablet to transdermal patch reduced the morbidity of OH in HF patients
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