64 research outputs found
Suzaku and Optical Spectroscopic Observations of SS 433 in the 2006 April Multiwavelength Campaign
We report results of the 2006 April multi-wavelengths campaign of SS 433,
focusing on X-ray data observed with Suzaku at two orbital phases (in- and
out-of- eclipse) and simultaneous optical spectroscopic observations. By
analyzing the Fe25 K_alpha lines originating from the jets, we detect rapid
variability of the Doppler shifts, dz/dt ~ 0.019/0.33 day^-1, which is larger
than those expected from the precession and/or nodding motion. This phenomenon
probably corresponding to "jitter" motions observed for the first time in
X-rays, for which significant variability both in the jet angle and intrinsic
speed is required. From the time lag of optical Doppler curves from those of
X-rays, we estimate the distance of the optical jets from the base to be ~(3-4)
\times 10^14 cm. Based on the radiatively cooling jet model, we determine the
innermost temperature of the jets to be T_0 = 13 +/- 2 keV and 16 +/- 3 keV
(the average of the blue and red jets) for the out-of-eclipse and in-eclipse
phase, respectively, from the line intensity ratio of Fe25 K_alpha and Fe26
K_alpha. While the broad band continuum spectra over the 5--40 keV band in
eclipse is consistent with a multi-temperature bremsstrahlung emission expected
from the jets, and its reflection component from cold matter, the
out-of-eclipse spectrum is harder than the jet emission with the base
temperature determined above, implying the presence of an additional hard
component.Comment: 12 pages, 15 figures, accepted for publication in PAS
Establishment of Rat Embryonic Stem Cells and Making of Chimera Rats
The rat is a reference animal model for physiological studies and for the analysis of multigenic human diseases such as hypertension, diabetes, neurological disorders, and cancer. The rats have long been used in extensive chemical carcinogenesis studies. Thus, the rat embryonic stem (rES) cell is an important resource for the study of disease models. Attempts to derive ES cells from various mammals, including the rat, have not succeeded. Here we have established two independent rES cells from Wister rat blastocysts that have undifferentiated characters such as Nanog and Oct3/4 genes expression and they have stage-specific embryonic antigen (SSEA) -1, -3, -4, and TRA-1-81 expression. The cells were successfully cultured in an undifferentiated state and can be possible over 18 passages with maintaining more than 40% of normal karyotype. Their pluripotent potential was confirmed by the differentiation into derivatives of the endoderm, mesoderm, and ectoderm. Most importantly, the rES cells are capable of producing chimera rats. Therefore, we established pluripotent rES cell lines that are widely used to produce genetically modified experimental rats for study of human diseases
Genetic and Molecular Analysis of Wild-Derived Arrhythmic Mice
A new circadian variant was isolated by screening the intercross offspring of wild-caught mice (Mus musculus castaneus). This variant was characterized by an initial maintenance of damped oscillations and subsequent loss of rhythmicity after being transferred from light-dark (LD) cycles to constant darkness (DD). To map the genes responsible for the persistence of rhythmicity (circadian ratio) and the length of free-running period (ฯ), quantitative trait locus (QTL) analysis was performed using F2 mice obtained from an F1 cross between the circadian variant and C57BL/6J mice. As a result, a significant QTL with a main effect for circadian ratio (Arrhythmicity; Arrh-1) was mapped on Chromosome (Chr) 8. For ฯ, four significant QTLs, Short free-running period (Sfp-1) (Chr 1), Sfp-2 (Chr 6), Sfp-3 (Chr 8), Sfp-4 (Chr 11) were determined. An epistatic interaction was detected between Chr 3 (Arrh-2) and Chr 5 (Arrh-3). An in situ hybridization study of clock genes and mouse Period1::luciferase (mPer1::luc) real-time monitoring analysis in the suprachiasmatic nucleus (SCN) suggested that arrhythmicity in this variant might not be attributed to core circadian mechanisms in the SCN neurons. Our strategy using wild-derived variant mice may provide a novel opportunity to evaluate circadian and its related disorders in human that arise from the interaction between multiple variant genes
The Protective Role of Astaxanthin for UV-Induced Skin Deterioration in Healthy PeopleโA Randomized, Double-Blind, Placebo-Controlled Trial
Skin is a major safeguard tissue in humans. Because biological barrier function is deteriorated by several kinds of stresses including exposure to ultra-violet (UV) rays, the protection and treatment of skin conditions by dietary supplements are important. We therefore evaluated the effects of dietary supplementation with an algal food-derived antioxidant, astaxanthin, on UV-induced skin deterioration. Twenty-three healthy Japanese participants were recruited to a 10-week double-blind placebo-controlled study. They were assigned to the astaxanthin group supplemented with a capsule containing 4 mg of astaxanthin or the placebo group. To assess the protective role of astaxanthin for UV-induced skin deterioration, we determined the minimal erythema dose (MED) and analyzed UV-induced changes of moisture and transepidermal water loss (TEWL) at baseline and after 9 weeks of supplementation. Subjective skin conditions were assessed by the visual analog scale. The astaxanthin group showed increased MED compared with placebo. In addition, the astaxanthin group had a reduced loss of skin moisture in the irradiated area compared with placebo. Subjective skin conditions for “improvement of rough skin” and “texture” in non-irradiated areas were significantly improved by astaxanthin. Astaxanthin seems protective against UV-induced skin deterioration and helps maintain healthy skin in healthy people
Effects of Composite Supplement Containing Collagen Peptide and Ornithine on Skin Conditions and Plasma IGF-1 LevelsโA Randomized, Double-Blind, Placebo-Controlled Trial
Aging-associated changes of skin conditions are a major concern for maintaining quality of life. Therefore, the improvement of skin conditions by dietary supplementation is a topic of public interest. In this study, we hypothesized that a composite supplement containing fish derived-collagen peptide and ornithine (CPO) could improve skin conditions by increasing plasma growth hormone and/or insulin-like growth factor-1 (IGF-1) levels. Twenty-two healthy Japanese participants were enrolled in an 8-week double-blind placebo-controlled pilot study. They were assigned to either a CPO group, who were supplemented with a drink containing CPO, or an identical placebo group. We examined skin conditions including elasticity and transepidermal water loss (TEWL), as well as plasma growth hormone and IGF-1 levels. Skin elasticity and TEWL were significantly improved in the CPO group compared with the placebo group. Furthermore, only the CPO group showed increased plasma IGF-1 levels after 8 weeks of supplementation compared with the baseline. Our results might suggest the novel possibility for the use of CPO to improve skin conditions by increasing plasma IGF-1 levels
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The Protective Role of Astaxanthin for UV-Induced Skin Deterioration in Healthy PeopleโA Randomized, Double-Blind, Placebo-Controlled Trial
A Five-layer ฯ-Aromatic Structure Formed through Self-assembly of a Porphyrin Trimer and Two Aromatic Guests.
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