232 research outputs found
CO J=3-2 Emission from the "Water Fountain" Sources IRAS 16342-3814 and IRAS 18286-0959
We observed CO J=3-2 emission from the "water fountain" sources, which
exhibit high-velocity collimated stellar jets traced by water maser emission,
with the Atacama Submillimeter Telescope Experiment (ASTE) 10 m telescope. We
detected the CO emission from two sources, IRAS 16342-3814 and IRAS 18286-0959.
The IRAS 16342-3814 CO emission exhibits a spectrum that is well fit to a
Gaussian profile, rather than to a parabolic profile, with a velocity width
(FWHM) of 158+/-6 km/s and an intensity peak at VLSR = 50+/-2 km/s. The mass
loss rate of the star is estimated to be ~2.9x10^-5 M_sun/yr. Our
morpho-kinematic models suggest that the CO emission is optically thin and
associated with a bipolar outflow rather than with a (cold and relatively
small) torus. The IRAS 18286-0959 CO emission has a velocity width (FWHM) of
3.0+/-0.2 km/s, smaller than typically seen in AGB envelopes. The narrow
velocity width of the CO emission suggests that it originates from either an
interstellar molecular cloud or a slowly-rotating circumstellar envelope that
harbors the water maser source.Comment: 10 pages, 4 figure, accepted for publication in the Publications of
the Astronomical Society of Japan, Vol. 61, No.6, 2009 December issu
Extremely Strong ^{13}CO J=3-2 Line in the "Water Fountain" IRAS 16342-3814: Evidence for the Hot-Bottom Burning
We observed four "water fountain" sources in the CO J=3-2 line emission with
the Atacama Submillimeter Telescope Experiment (ASTE) 10 m telescope in
2010-2011. The water fountain sources are evolved stars that form high-velocity
collimated jets traced by water maser emission. The CO line was detected only
from IRAS 16342-3814. The present work confirmed that the ^{12}CO to ^{13}CO
line intensity ratio is ~1.5 at the systemic velocity. We discuss the origins
of the very low ^{12}CO to ^{13}CO intensity ratio, as possible evidence for
the "hot-bottom burning" in an oxygen-rich star, and the CO intensity variation
in IRAS 16342-3814.Comment: 10 pages, 3 figures, accepted for publication to the Publications of
the Astronomical Society of Japan, Vol. 64, No.
Circumstellar molecular composition of the oxygen-rich AGB star IK~Tau: II. In-depth non-LTE chemical abundance analysis
Aims: Little information exists on the circumstellar molecular abundance
stratifications of many molecules. The aim is to study the circumstellar
chemical abundance pattern of 11 molecules and isotopologs (CO,
CO, SiS, SiO, SiO, SiO, HCN, CN, CS, SO, SO) in
the oxygen-rich evolved star IK~Tau. Methods: We have performed an in-depth
analysis of a large number of molecular emission lines excited in the
circumstellar envelope around IK~Tau. The analysis is done based on a non-local
thermodynamic equilibrium (non-LTE) radiative transfer analysis, which
calculates the temperature and velocity structure in a self-consistent way. The
chemical abundance pattern is coupled to theoretical outer wind model
predictions including photodestruction and cosmic ray ionization. Not only the
integrated line intensities, but also the line shapes, are used as diagnostic
tool to study the envelope structure. Results: The deduced wind acceleration is
much slower than predicted from classical theories. SiO and SiS are depleted in
the envelope, possibly due to the adsorption onto dust grains. For HCN and CS a
clear difference with respect to inner wind non-equilibrium predictions is
found, either indicating uncertainties in the inner wind theoretical modeling
or the possibility that HCN and CS (or the radical CN) participate in the dust
formation. The low signal-to-noise profiles of SO and CN prohibit an accurate
abundance determination; the modeling of high-excitation SO lines is
cumbersome, possibly related to line misidentifications or problems with the
collisional rates. The SiO isotopic ratios (SiO/SiO and
SiO/SiO) point toward an enhancement in SiO compared to
results of classical stellar evolution codes. Predictions for HO lines in
the spectral range of the Herschel/HIFI mission are performed. [abbreviated]Comment: 24 pagees, accepted for publication in Astronomy & Astrophysic
The structure of the Galactic bar
We present a deep near-infrared wide-angle photometric analysis of the
structure of the inner Galactic bar and central disk. The presence of a
triaxial structure at the centre of the Galaxy is confirmed, consistent with a
bar inclined at 22+/-5.5 deg from the Sun-Galactic centre line, extending to
about 2.5 kpc from the Galactic centre and with a rather small axis ratio. A
feature at l=-9.8 deg not aligned with this triaxiality suggests the existence
of a second structure in the inner Galaxy, a double triaxiality or an inner
ring. We argue that this is likely to be the signature of the end of the
Galactic bar, at about 2.5-3 kpc, which is circumscribed by an inner
pseudo-ring. No thick dust lane preceding the bar is detected, and a hole in
the disc's dust distribution inside the bar radius is inferred.Comment: 12 pages, 8 figures. Accepted for publication in MNRA
Antiretroviral activity of 5-azacytidine during treatment of a HTLV-1 positive myelodysplastic syndrome with autoimmune manifestations
Myelodysplastic syndromes (MDS) are often accompanied by autoimmune phenomena. The underlying mechanisms for these associations remain uncertain, although T cell activation seems to be important. Human T-lymphotropic virus (HTLV-1) has been detected in patients with myelodysplastic syndromes, mostly in regions of the world which are endemic for the virus, and where association of HTLV-1 with rheumatological manifestation is not rare. We present here the case of a 58 year old man who presented with cytopenias, leukocytoclastic vasculitis of the skin and glomerulopathy, and was diagnosed as MDS (refractory anemia with excess blasts - RAEB 1). The patient also tested positive for HTLV-1 by PCR. After 8 monthly cycles of 5-azacytidine he achieved a complete hematologic remission. Following treatment, a second PCR for HTLV-1 was carried out and found to be negative. This is the first report in the literature of a HTLV-1-positive MDS with severe autoimmune manifestations, which was treated with the hypomethylating factor 5-azacitidine, achieving cytogenetic remission with concomitant resolution of the autoimmune manifestations, as well as HTLV-1-PCR negativity. HTLV-1-PCR negativity may be due to either immune mediated clearance of the virus, or a potential antiretroviral effect of 5-azacytidine. 5-azacytidine is known for its antiretroviral effects, although there is no proof of its activity against HTLV-1 infection in vivo
Calcium ion currents mediating oocyte maturation events
During maturation, the last phase of oogenesis, the oocyte undergoes several changes which prepare it to be ovulated and fertilized. Immature oocytes are arrested in the first meiotic process prophase, that is morphologically identified by a germinal vesicle. The removal of the first meiotic block marks the initiation of maturation. Although a large number of molecules are involved in complex sequences of events, there is evidence that a calcium increase plays a pivotal role in meiosis re-initiation. It is well established that, during this process, calcium is released from the intracellular stores, whereas less is known on the role of external calcium entering the cell through the plasma membrane ion channels. This review is focused on the functional role of calcium currents during oocyte maturation in all the species, from invertebrates to mammals. The emerging role of specific L-type calcium channels will be discussed
Functional genetic polymorphisms and female reproductive disorders: Part II—endometriosis
BACKGROUNDEndometriosis has a strong genetic component, and numerous genetic studies have been reported.METHODSWe have systematically reviewed these studies and included 114 in our final selection.RESULTSWe found no consistent evidence linking endometriosis with specific polymorphisms in genes encoding inflammatory mediators, proteins involved in sex steroid metabolism, vascular function and tissue remodelling. Although a number of polymorphisms have been associated with endometriosis in selected populations, the associations have not been independently confirmed, either because only single studies were carried out on these markers/genes or because other studies reported no association. The most solid evidence linking specific polymorphisms to endometriosis came from studies investigating glutathione-S-transferase, a phase II detoxification enzyme. Carriage of the GSTT1 null deletion variant showed consistent association with endometriosis with a 29% increased risk; however, it cannot be excluded that this result was due to publication bias, and this association should be independently confirmed in large-scale, well-designed case\u2013control studies.CONCLUSIONSThe evidence of an association between genetic polymorphisms and endometriosis is weak. Carriage of the GSTT1 null deletion may moderately increase the risk of this disease. We suggest that the methodology of association studies should be improved in order to identify and validate associations in endometriosis
Periodate-treated, non-anticoagulant heparin-carrying polystyrene (NAC-HCPS) affects angiogenesis and inhibits subcutaneous induced tumour growth and metastasis to the lung
Periodate-treated, non-anticoagulant heparin-carrying polystyrene consists of about ten periodate-oxidized, alkaline-degraded low molecular weight-heparin chains linked to a polystyrene core and has a markedly lower anti-coagulant activity than heparin. In this study, we evaluated the effect of non-anticoagulant heparin-carrying polystyrene on tumour growth and metastasis. Non-anticoagulant heparin-carrying polystyrene has a higher activity to inhibit vascular endothelial growth factor-165-, fibroblast growth factor-2- or hepatocyte growth factor-induced human microvascular endothelial cell growth than heparin, ten periodate-oxidized-heparin and ten periodate-oxidized-low molecular weight-heparin, which is probably due to the heparin-clustering effect of non-anticoagulant heparin-carrying polystyrene. Non-anticoagulant heparin-carrying polystyrene inhibited human microvascular endothelial cell, B16 melanoma and Lewis lung cancer cell adhesion to Matrigel-coated plates. Non-anticoagulant heparin-carrying polystyrene also showed strong inhibitory activities in the tubular formation of endothelial cells on Matrigel and B16-melanoma and Lewis lung cancer cell invasion in a Matrigel-coated chamber assay. In vivo studies showed that growth of subcutaneous induced tumours and lung metastasis of B16-melanoma and Lewis lung cancer cells were more effectively inhibited by non-anticoagulant heparin-carrying polystyrene than ten periodate-oxidized-heparin and ten periodate-oxidized-low molecular weight-heparin. Furthermore, non-anticoagulant heparin-carrying polystyrene markedly reduced the number of CD34-positive vessels in subcutaneous Lewis lung cancer tumours, indicating a strong inhibition of angiogenesis. These results suggest that non-anticoagulant heparin-carrying polystyrene has an inhibitory activity on angiogenesis and tumour invasion and may be very useful in cancer therapy
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