50 research outputs found
Nucleosynthesis of Light and Heavy Elements in Baryon-Rich Outflows Associated with Gamma-Ray Bursts
Gamma-ray bursts (GRBs) must originate from low baryon load,
ultrarelativistic outflows; however, slower, more baryon-rich outflows (BROs)
should also arise in connection with GRBs as ``circum-jet winds'' and/or
``failed GRBs''. We study the possibility of nucleosynthesis within such BROs
by conducting detailed reaction network calculations in the framework of the
fireball model, showing that they can be interesting sites for synthesis of
heavy neutron capture elements, as well as of light elements such as deuterium.
These products may be observable in the companion stars of black hole binary
systems or in extremely metal-poor stars, offering an interesting probe of
conditions in the central engine.Comment: 5 pages, 2 figures, slightly modified version of article to be
published in Proc. of "GRBs in the Afterglow Era: 3rd Workshop (Rome 2002)
Nucleosynthesis in Baryon-Rich Outflows Associated With Gamma-Ray Bursts
Robust generation of gamma-ray bursts (GRBs) implies the formation of
outflows with very low baryon loads and highly relativistic velocities, but
more baryon-rich, slower outflows are also likely to occur in most GRB central
engine scenarios, either as ``circum-jet winds'' or ``failed GRBs''. Here we
study the possibility of nucleosynthesis within such baryon-rich outflows by
conducting detailed reaction network calculations in the framework of the basic
fireball model. It is shown that high baryon load fireballs attaining mildly
relativistic velocities can synthesize appreciable quantities of heavy neutron
capture elements with masses up to the platinum peak and beyond. Small but
interesting amounts of light elements such as deuterium and boron can also be
produced. Depending on the neutron excess and baryon load, the combination of
high entropy, rapid initial expansion and gradual expansion at later times can
cause the reaction flow to reach the fission regime, and its path can be
intermediate between those of the - and -processes (``-process''). The
nucleosynthetic signature of these outflows may be observable in the companion
stars of black hole binary systems and in the most metal-poor stars,
potentially offering an important probe of the inner conditions of the GRB
source. Contribution to the solar abundances for some heavy elements may also
be possible. The prospects for further developments in various directions are
discussed.Comment: ApJ, in press; 11 pages, 3 figure
Association between Mammographic Breast Density and Lifestyle in Japanese Women
A high mammographic breast density is considered to be a risk factor for breast cancer. However, only a small number of studies on the association between breast density and lifestyle have been performed. A cross-sectional study was performed using a survey with 29 questions on life history and lifestyle. The breast density on mammography was classified into 4 categories following the BI-RADS criteria. The subjects were 522 women with no medical history of breast cancer. The mean age was 53.3 years old. On multivariate analysis, only BMI was a significant factor determining breast density in premenopausal women (parameter estimate, -0.403;p value, 0.0005), and the density decreased as BMI rose. In postmenopausal women, BMI (parameter estimate, -0.196;p value, 0.0143) and number of deliveries (parameter estimate, -0.388;p value, 0.0186) were significant factors determining breast density;breast density decreased as BMI and number of deliveries increased. Only BMI and number of deliveries were identified as factors significantly influencing breast density. BMI was inversely correlated with breast density before and after menopause, whereas the influence of number of deliveries on breast density was significant only in postmenopausal women in their 50 and 60s
Linkage between prostate cancer incidence and different alleles of the human Y-linked tetranucleotide polymorphism DYS19
We studied the allele frequency distribution of the Y-chromosome linked tetranucleotide polymorphic microsatellite locus DYS19 in 90 prostate cancer Japanese patients from both Tokushima University hospital (Tokushima) and Saint Marianna University hospital (Kawasaki), Japan, comparing them to 99 matched male controls. Y-chromosomes from Japan as well as others from different geographical regions worldwide showed the five different alleles (A-E) with sizes varying from 186-202 bp, respectively. Comparison between DYS19 allelic frequency distribution among Japanese patients with prostate cancer and that of normal controls revealed significant differences regarding susceptibility or resistance to prostate cancer. We found that males with allele C of DYS19 are more susceptible to develop prostate cancer than males with other alleles (p=0.02). The Odds Ratio was 2.04 with a 95% confidence interval (0.75-2.42), compared with males having other alleles. In contrast, males with the D allele of DYS19 were less exposed to prostate cancer than other males (p=0.002); the Odds Ratio was 0.26 with a 95% confidence interval of (0.65-3.71). These findings support our hypothesis that male descendants from different Y-chromosomal origins are different regarding their susceptibility or resistance to develop prostate cancer (as a male-specific cancer)
Multiple transcripts of Ca 2ϩ channel ␣ 1 -subunits and a novel spliced variant of the ␣ 1C -subunit in rat ductus arteriosus
3 H]thymidine incorporation, suggesting that L-and T-type Ca 2ϩ channels are involved in smooth muscle cell proliferation in the DA. Third, we found that a novel alternatively spliced variant of the ␣ 1C-isoform was highly expressed in the neointimal cushion of the DA, where proliferating and migrating smooth muscle cells are abundant. The basic channel properties of the spliced variant did not differ from those of the conventional ␣1C-subunit. We conclude that multiple VDCC subunits were identified in the DA, and, in particular, ␣ 1C-and ␣1G-subunits were predominant in the DA. A novel spliced variant of the ␣1C-subunit gene may play a distinct role in neointimal cushion formation in the DA. alternative spliced; development; gene expression; fetal circulation THE DUCTUS ARTERIOSUS (DA) is a fetal arterial connection between the pulmonary artery and the descending aorta. After birth, the DA closes immediately, in accordance with its smooth muscle contraction. An increase in oxygen tension and a dramatic decline in circulating prostaglandins are the most important triggers of DA contraction (5). Generally, vascular smooth muscle contraction is induced by Ca 2ϩ / calmodulin-dependent phosphorylation of the regulatory myosin light chain, which is mediated by an increase in intracellular Ca 2ϩ . Ca 2ϩ influx through voltage-dependent Ca 2ϩ channels (VDCCs) and Ca 2ϩ release from intracellular stores are major sources of this increase (8, 26). Thus VDCCs must play an important role in vascular myogenic reactivity and tone of the DA. VDCCs are classified, according to their distinct electrophysiological and pharmacological properties, into low (Ttype) and high (L-, N-, P-, Q-, and R-type) VDCCs (20, In addition to their role in determining contractile state, a growing body of evidence has demonstrated that VDCCs play an important role in regulating differentiation and remodeling of vascular smooth muscle cells (SMCs) (14, In the present study, we identified multiple VDCC subunits in the DA by semiquantitative and quantitative RT-PCR and immunodetection. In particular, ␣ 1C -and ␣ 1G -subunits were predominant in the DA. Furthermore, we will demonstrate the identification of a novel spliced variant of the ␣ 1C -subunit gene that may play a role in neointimal cushion formation of the DA
Macrophage-dominant sialadenitis in human T-cell leukemia virus type I-associated myelopathy after living-donor liver transplantation.
A 64-year-old man who suffered from human T-cell leukemia virus type I (HTLV-I)-associated myelopathy (HAM) after living-donor liver transplantation (LDLT) for liver cirrhosis due to hepatitis C virus infection complained of xerostomia. Although exocrine function test results were positive, autoantibodies including anti-SS-A/SS-B antibodies and sialography showed negative findings. Labial salivary gland biopsy revealing infiltration of 60 counts of mononuclear cells (MNCs) in minor salivary glands led to a diagnosis of Sjögren\u27s syndrome-like sialadenitis. Immunohistochemistry demonstrated dominant CD68 staining and major histocompatibility complex class II on the surface of infiltrating MNCs. Herein we have reported a rare condition of macrophage-dominant sialadenitis in a patient with HAM after LDLT
Effects of palm cooling with CoolMitt
J-GLOBAL ID : 201901002195328127J-GLOBAL ID : 201901007563059516J-GLOBAL ID : 201801004201806465J-GLOBAL ID : 200901012516528555application/pdfdepartmental bulletin pape