421 research outputs found
X-Ray Reflection Nebulae with Large Equivalent Widths of Neutral Iron Ka Line in the Sgr C Region
This paper reports on the first results of the Suzaku observation in the Sgr
C region. We detected four diffuse clumps with strong line emission at 6.4keV,
Ka from neutral or low-ionized Fe. One of them, M359.38-0.00, is newly
discovered with Suzaku. The X-ray spectra of the two bright clumps,
M359.43-0.07 and M359.47-0.15, after subtracting the Galactic center diffuse
X-ray emission (GCDX), exhibit strong Ka line from FeI with large equivalent
widths (EWs) of 2.0-2.2keV and clear Kb of FeI. The GCDX in the Sgr C region is
composed of the 6.4keV- and 6.7keV-associated components. These are
phenomenologically decomposed by taking relations between EWs of the 6.4keV and
6.7keV lines. Then the former EWs against the associated continuum in the
bright clump regions are estimated to be 2.4(+2.3_-0.7)keV. Since the two
different approaches give similar large EWs of 2keV, we strongly suggest that
the 6.4keV clumps in the Sgr C region are due to X-ray reflection/fluorescence
(the X-ray reflection nebulae).Comment: Accepted for publication in PAS
Suzaku Spectroscopy of an X-Ray Reflection Nebula and a New Supernova Remnant Candidate in the Sgr B1 Region
We made a 100 ks observation of the Sagittarius (Sgr) B1 region at (l, b) =
(0.5, -0.1) near to the Galactic center (GC) with the Suzaku/XIS. Emission
lines of S XV, Fe I, Fe XXV, and Fe XXVI were clearly detected in the spectrum.
We found that the Fe XXV and Fe XXVI line emissions smoothly distribute over
the Sgr B1 and B2 regions connecting from the GC. This result suggests that the
GC hot plasma extends at least up to the Sgr B region with a constant
temperature. There are two diffuse X-ray sources in the observed region. One of
the two (G0.42-0.04) is newly discovered, and exhibits a strong S XV Ka
emission line, suggesting a candidate for a supernova remnant located in the GC
region. The other one (M0.51-0.10), having a prominent Fe I Ka emission line
and a strongly absorbed continuum, is likely to be an X-ray reflection nebula.
There is no near source bright enough to irradiate M0.51-0.10. However, the Fe
I Ka emission can be explained if Sgr A* was ~ 10^6 times brighter 300 years
ago, the light travel time for 100 pc to M0.51-0.10, than it is at present.Comment: 10 pages, 10 figure
Mail-in data collection at SPring-8 protein crystallography beamlines
A mail-in data collection system at SPring-8, which is a web application with automated beamline operation, has been developed
Iron and Nickel Line Diagnostics for the Galactic Center Diffuse Emission
We have observed the diffuse X-ray emission from the Galactic center (GC)
using the X-ray Imaging Spectrometer (XIS) on Suzaku. The high-energy
resolution and the low-background orbit provide excellent spectra of the GC
diffuse X-rays (GCDX). The XIS found many emission lines in the GCDX near the
energy of K-shell transitions of iron and nickel. The most pronounced features
are FeI K alpha at 6.4 keV and K-shell absorption edge at 7.1 keV, which are
from neutral and/or low ionization states of iron, and the K-shell lines at 6.7
keV and 6.9 keV from He-like (FeXXV K alpha) and hydrogenic (FeXXVI Ly alpha)
ions of iron. In addition, K alpha lines from neutral or low ionization nickel
(NiI K alpha) and He-like nickel (NiXXVII K alpha), and FeI K beta, FeXXV K
beta, FeXXVI Ly beta, FeXXV K gamma and FeXXVI Ly gamma are detected for the
first time. The line center energies and widths of FeXXV K alpha and FeXXVI Ly
alpha favor a collisional excitation (CE) plasma for the origin of the GCDX.
The electron temperature determined from the line flux ratio of FeXXV K alpha /
FeXXV K beta is similar to the ionization temperature determined from that of
FeXXV K alpha /FeXXVI Ly alpha. Thus it would appear that the GCDX plasma is
close to ionization equilibrium. The 6.7 keV flux and temperature distribution
to the galactic longitude is smooth and monotonic,in contrast to the integrated
point source flux distribution. These facts support the hypothesis that the
GCDX is truly diffuse emission rather than the integration of the outputs of a
large number of unresolved point sources. In addition, our results demonstrate
that the chemical composition of Fe in the interstellar gas near the GC is
constrained to be about 3.5 times solar.Comment: 11 pages, 19 figures. Accepted for publication in PASJ Suzaku Special
Issue (vol. 59 sp. 1
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Urinary type IV collagen (U-Col4) and albumin excretion is evaluated to monitor the development of diabetic kidney disease. However, U-Col4 excretion in the general population without diabetes has not yet been fully elucidated. In this study, 1067 participants without diabetes and with urinary albumin-creatinine ratio <300 mg/gCr (normo- or microalbuminuria) who underwent an annual health examination in 2004 were enrolled and observed for 5 years. They were divided according to the amount of U-Col4 or urinary albumin excreted. The decline in estimated glomerular filtration rate (eGFR) was calculated. In participants with eGFR ≥80 mL/min, abnormal U-Col4 excretion was indicated as a significant independent risk factor for 10% eGFR change per year, which is one of the prognostic factors for the development of end-stage kidney disease. Moreover, in contrast to urinary albumin excretion, U-Col4 excretion was not related to age or kidney function, suggesting that some individuals with abnormal U-Col4 excretion can have an independent hidden risk for the development of kidney dysfunction. In conclusion, it is important to measure U-Col4 excretion in the general population without diabetes to determine changes in renal features in every individual and help detect future complications such as diabetic kidney disease. If U-Col4 excretion is abnormal, kidney manifestation should be carefully followed up, even if the kidney function and urinalysis findings are normal
Increased amygdala reactivity following early life stress : a potential resilience enhancer role
Background: Amygdala hyper-reactivity is sometimes assumed to be a vulnerability factor that predates depression; however, in healthy people, who experience early life stress but do not become depressed, it may represent a resilience mechanism. We aimed to test these hypothesis examining whether increased amygdala activity in association with a history of early life stress (ELS) was negatively or positively associated with depressive symptoms and impact of negative life event stress in never-depressed adults.
Methods: Twenty-four healthy participants completed an individually tailored negative mood induction task during functional magnetic resonance imaging (fMRI) assessment along with evaluation of ELS.
Results: Mood change and amygdala reactivity were increased in never-depressed participants who reported ELS compared to participants who reported no ELS. Yet, increased amygdala reactivity lowered effects of ELS on depressive symptoms and negative life events stress. Amygdala reactivity also had positive functional connectivity with the bilateral DLPFC, motor cortex and striatum in people with ELS during sad memory recall.
Conclusions: Increased amygdala activity in those with ELS was associated with decreased symptoms and increased neural features, consistent with emotion regulation, suggesting that preservation of robust amygdala reactions may reflect a stress buffering or resilience enhancing factor against depression and negative stressful events
Effects of photodynamic therapy using talaporfin sodium (Laserphyrin® ) on wound healing in an animal model
Background: Photodynamic therapy (PDT) is an effective laser treatment for locally advanced carcinoma and is promising as neoadjuvant chemotherapy before surgery. The aim of this study was to clarify the adverse effects of PDT using a photosensitizer, talaporfin sodium (Laserphyrin®), for wound healing.Methodology: For PDT, a laser light with a wavelength of 660 nm and a frequency of 10 Hz with a total energy fluency of60 J/cm2 was used. Macroscopic and histological findings of wound healing after PDT were examined in vivo (4-week-old male BALB/c mice).Results: In Model 1, in which skin was cut at 0, 3, 7 days after PDT (n=3, each), wounds were similarly healed 7 days after cutting in all groups, and regenerating epithelium and the number of fibroblasts on histological findings were not different. In Model 2, in which skin defects were created before or after PDT, the size of the defects was larger at day 7 in the groups with skin defects before or after PDT in comparison with groups with no PDT.However, macroscopic wound healing at day 14 was complete in all groups and there were no significant differences among the groups by this point. Histological findings of skin defects at day 14 showed no significant difference in terms of regenerating epithelium and number of fibroblasts in each group with or without PDT.Conclusions: PDT did not influence wound healing and can be safely applied before surgical therapy
Development of ground pipeline system for high-level scientific data products of the Hisaki satellite mission and its application to planetary space weather
The Hisaki satellite is the first-ever space telescope mission dedicated to planetary sciences. Atmospheres and magnetospheres of our solar system planets are continuously monitored by the extreme ultraviolet (EUV) spectrometer onboard Hisaki. This paper describes a data pipeline system developed for processing high-level scientific and ancillary data products from the Hisaki mission. The telemetry data downlinked from the satellite are stored in a ground telemetry database, processed in the pipeline to imaging spectral data with a 1-min temporal resolution and ancillary data products, and then archived in a public database. The imaging spectra can be further reduced to higher-level data products for practical scientific use. For example, light curves of the power emitted from Jupiter’s aurora and plasma torus with a temporal resolution of 10-min can be reduced from the imaging spectral data; the reduced light curves reveal the transport processes of energy and mass in Jupiter’s magnetosphere and associated interplanetary solar wind conditions. Continuous monitoring with Hisaki will contribute considerably to our understanding of space weather relating to planets in our solar system
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