Broad-band spectral analysis of the Galactic Ridge X-ray Emission

Detailed spectral analysis of the Galactic X-ray background emission, or the Galactic Ridge X-ray Emission (GRXE), is presented. To study the origin of the emission, broad-band and high-quality GRXE spectra were produced from 18 pointing observations with Suzaku in the Galactic bulge region, with the total exposure of 1 Ms. The spectra were successfully fitted by a sum of two major spectral components; a spectral model of magnetic accreting white dwarfs with a mass of 0.66 (0.59-0.75) solar, and a softer optically-thin thermal emission with a plasma temperature of 1.2-1.5 keV which is attributable to coronal X-ray sources. When combined with previous studies which employed high spatial resolution of the Chandra satellite (e.g. Revnivtsev et al. 2009, Nature), the present spectroscopic result gives another strong support to a scenario that the GRXE is essentially an assembly of numerous discrete faint X-ray stars. The detected GRXE flux in the hard X-ray band was used to estimate the number density of the unresolved hard X-ray sources. When integrated over a luminosity range of ~10^30-10^34 erg/s, the result is consistent with a value which was reported previously by directly resolving faint point sources.Comment: accepted for publication in Ap

Potential application of measuring serum infliximab levels in rheumatoid arthritis management: A retrospective study based on KURAMA cohort data

Infliximab (IFX) therapy has considerably improved the treatment of rheumatoid arthritis (RA). However, some patients still do not respond adequately to IFX therapy, or the efficacy of the treatment diminishes over time. Although previous studies have reported a relationship between serum IFX levels and therapeutic efficacy, the potential applications of IFX therapeutic drug monitoring (TDM) in clinical practice remain unclear. The purpose of this study was to investigate the potential applications of IFX TDM by analyzing a Japanese cohort database. Data were collected retrospectively from the Kyoto University Rheumatoid Arthritis Management Alliance cohort between January 1, 2011, and December 31, 2018. Serum IFX levels were measured using a liquid chromatography-tandem mass spectrometer. Out of the 311 RA patients that used IFX, 41 were eligible for the analysis. Serum IFX levels were significantly higher in responders than in non-responders. An optimal cut-off value was determined to be 0.32 μg/mL based on a receiver operating characteristic curve. At the IFX measurement point, a better therapeutic response was observed in the high IFX group (n = 32) than in the low IFX group (n = 9). Conversely, at the maximum effect point, when DAS28-ESR was the lowest between IFX introduction and measurement points, there were no differences in responder proportions between the low and high IFX groups. IFX primary ineffectiveness could be avoided with appropriate dose escalation without blood concentration measurement in clinical practice. In conclusion, IFX TDM could facilitate the identification of secondary non-responders and in turn, proper IFX use

Infliximab Treatment Persistence among Japanese Patients with Chronic Inflammatory Diseases: A Retrospective Japanese Claims Data Study

Infliximab (IFX) has contributed to the treatment of several chronic inflammatory diseases, including Crohn's disease (CD), ulcerative colitis (UC), psoriasis (Pso), and rheumatoid arthritis (RA). However, the loss of response in some patients with long-term IFX therapy has been a major problem. Randomized controlled trials (RCTs) are limited in their short duration and lack of generalizability to the real-world population. We aimed to describe the persistence rates of IFX therapy to estimate its long-term effectiveness in clinical practice. Claims data from the Japan Medical Data Center database from January 2005 to June 2017 were used. The study population was identified based on the International Classification of Diseases, 10th Revision and the Anatomical Therapeutic Chemical Classification System. The 5-year persistence rates of IFX therapy were estimated using the Kaplan-Meier method. Overall, 281, 235, 41, and 222 patients with CD, UC, Pso, and RA, respectively, were selected. The 5-year persistence rates for IFX claims were 62.9, 38.9, 22.1, and 28.1% in patients with CD, UC, Pso, and RA, respectively. Patients with CD and UC administered IFX beyond the median dose had higher persistence rates. In patients with RA, female sex and no prior use of other biologics were associated with longer persistence. In conclusion, IFX persistence rates differed across chronic inflammatory diseases, which did not correspond to the results of the major RCTs. Factors associated with longer IFX persistence were identified in each disease group. Our findings may provide useful information to facilitate the proper use of IFX

Relationship between Functional Visual Acuity and Useful Field of View in Elderly Drivers.

To investigate the relationship between the functional visual acuity (FVA) and useful field of view (UFOV) in elderly drivers and assess the usefulness of the FVA test to screen driving aptitude in elderly drivers.This study included 45 elderly drivers (31 men, 14 women; mean age, 68.1 years) and 30 younger drivers (26 men, 4 women; mean age, 34.2 years) who drive regularly. All participants underwent measurement of the binocular corrected distant visual acuity (CDVA), binocular corrected distant FVA (CDFVA), and Visual Field with Inhibitory Tasks Elderly Version (VFIT-EV) to measure UFOV. The tear function and cognitive status also were evaluated.The CDVA, the CDFVA, cognitive status, and the correct response rate (CAR) of the VFIT-EV were significantly worse in the elderly group than in the control group (P = 0.000 for all parameters). The cognitive status was correlated significantly with the CDVA (r = -0.301, P = 0.009), CDFVA (r = -0.402, P = 0.000), and the CAR of the VFIT-EV (r = 0.348, P = 0.002) in all subjects. The results of the tear function tests were not correlated with the CDVA, CDFVA, or VFIT-EV in any subjects. Stepwise regression analysis for all subjects in the elderly and control groups showed that the CDFVA predicted the CAR most significantly among the clinical factors evaluated.The FVA test is a promising method to screen the driving aptitude, including both visual and cognitive functions, in a short time

VARIABLE-COMPLIANCE-TYPE CONSTITUTIVE MODEL FOR METHANE HYDRATE BEARING SEDIMENT

In order to evaluate a methane gas productivity of methane hydrate reservoirs, it is necessary to develop a numeric simulator predicting gas production behavior. For precise assessment of long-term gas productivity, it is important to develop a mathematical model which describes mechanical behaviors of methane hydrate reservoirs in consideration of their time-dependent properties and to introduce it into the numeric simulator. In this study, based on previous experimental results of triaxial compression tests of Toyoura sand containing synthetic methane hydrate, stress-strain relationships were formulated by variable-compliance-type constitutive model. The suggested model takes into account the time-dependent property obtained from laboratory investigation that time dependency of methane hydrate bearing sediment is influenced by methane hydrate saturation and effective confining pressure. Validity of the suggested model should be verified by other laboratory experiments on time-dependent behaviors of methane hydrate bearing sediment.Non UBCUnreviewe

Strain-Rate Dependence of Triaxial Compressive Strength of Artificial Methane-Hydrate-Bearing Sediment

In this study, drained triaxial compression tests were conducted on artificial methane-hydrate-bearing sediment samples to obtain the strain-rate dependence. In the tests, an axial load was applied at a constant or alternating strain rate. On the basis of the results, we examined the strain-rate dependence of the peak strength and residual strength and considered the deformation mechanism of the specimen. We found that the strain-rate dependence of the artificial methane-hydrate-bearing sediment is as strong as or slightly stronger than that of frozen sand and is stronger than that of many other geomaterials

FVA Measurement System and results of typical cases.

<p><b>(A)</b> FVA Measurement System (AS-28, Kowa). <b>(B)</b> Representative printout of a typical case with good FVA. The blue line denotes the Landolt corrected VA. The red line shows the time-wise changes in the VA during testing. The green line denotes the mean logMAR VA during 60 seconds, defined as the FVA. The yellow dots indicate the number of correct responses and the blue arrows indicate spontaneous blinks. FVA (logMAR), -0.08; VMR, 0.99; max/min logMAR VAs, -0.18/0.05, respectively; ART, 1.47 seconds. <b>(C)</b> Representative printout of a typical case with low FVA. FVA (logMAR), 0.19; VMR, 0.83; max/min logMAR VA, 0.05/0.52, respectively; ART, 1.46 seconds.</p

Correlation between the CDFVA and the CAR of the VFIT-EV.

<p>The correlation between the CDFVA and the CAR of the VFIT-EV is significant (r = -0.606, <i>P</i> = 0.000). The triangles indicate the data from the elderly group, and the squares indicate the data from the control group.</p