568 research outputs found
Chronic β-blocker therapy improves outcome and reduces treatment costs in chronic type B aortic dissection
Objectives: To compare the medical treatment of chronic type B aortic dissection with β-blockers versus other antihypertensive treatments in terms of their requirement for surgical intervention and treatment costs. Methods: Case records of the 130 patients treated for aortic dissection type B in this unit between 1988 and 1997 were reviewed. Seventy-eight of 130 patients with chronic dissection have received isolated medical treatment. Seventy-one of 78 patients were discharged alive. Fifty-one of 71 received β-blocker treatment, 20/71 were treated with other antihypertensive drugs. Results: Surgery for aortic dissection became necessary in 20/71 patients (28%) during follow-up (mean, 4.2 years): 10/51 in the β-blocker group and 9/20 in the other antihypertensive drug group. The freedom from subsequent aortic operation was 80 and 47%, respectively (P=0.001). Indications for emergency surgery were increased aortic diameter (79%), symptomatic aortic aneurysm (11%), and renal artery hypoperfusion (5%). The median hospitalization time during follow-up (dissection-related) was 2 days for patients who received β-blockers and 16 days for patients who received other antihypertensive drug treatments (P=0.001). The cost of treatment/patient per year amounted to 644 and 12 748 euros, respectively. Conclusions: A substantial proportion of patients with chronic type B dissection who receive initial medical management will later need surgery. Long-term treatment with β-blockers reduces the progression of aortic dilatation, the incidence of subsequent hospital admissions, as well as the incidence of late dissection-related aortic procedures and the cost of treatment. Patients with chronic type B dissection need, in addition to frequent follow-up of aortic diameter, continuous treatment with β-blocking agent
The JCMT Gould Belt Survey: the effect of molecular contamination in SCUBA-2 observations of Orion A
Thermal emission from cold dust grains in giant molecular clouds can be used
to probe the physical properties, such as density, temperature and emissivity
in star-forming regions. We present the SCUBA-2 shared-risk observations at 450
m and 850 m of the Orion A molecular cloud complex taken at the James
Clerk Maxwell Telescope (JCMT). Previous studies showed that molecular emission
lines can contribute significantly to the measured fluxes in those continuum
bands. We use the HARP CO J=3-2 integrated intensity map for Orion A in
order to evaluate the molecular line contamination and its effects on the
SCUBA-2 maps. With the corrected fluxes, we have obtained a new spectral index
map for the thermal emission of dust in the well-known integral-shaped
filament. Furthermore, we compare a sample of 33 sources, selected over the
Orion A molecular cloud complex for their high CO J=3-2 line
contamination, to 27 previously identified clumps in OMC-4. This allows us to
quantify the effect of line contamination on the ratio of 850 m to 450
m flux densities and how it modifies the deduced spectral index of
emissivity for the dust grains. We also show that at least one
Spitzer-identified protostellar core in OMC-5 has a CO J=3-2
contamination level of 16 %. Furthermore, we find the strongest contamination
level (44 %) towards a young star with disk near OMC-2. This work is part of
the JCMT Gould Belt Legacy Survey.Comment: 13 pages, 6 figures, Accepted for publication in Monthly Notices of
the Royal Astronomical Society (MNRAS
The JCMT Gould Belt Survey: a quantitative comparison between SCUBA-2 data reduction methods
Performing ground-based submillimetre observations is a difficult task as the measurements are subject to absorption and emission from water vapour in the Earth's atmosphere and time variation in weather and instrument stability. Removing these features and other artefacts from the data is a vital process which affects the characteristics of the recovered astronomical structure we seek to study. In this paper, we explore two data reduction methods for data taken with the Submillimetre Common-User Bolometer Array-2 (SCUBA-2) at the James Clerk Maxwell Telescope (JCMT). The JCMT Legacy Reduction 1 (JCMT LR1) and The Gould Belt Legacy Survey Legacy Release 1 (GBS LR1) reduction both use the same software (starlink) but differ in their choice of data reduction parameters. We find that the JCMT LR1 reduction is suitable for determining whether or not compact emission is present in a given region and the GBS LR1 reduction is tuned in a robust way to uncover more extended emission, which better serves more in-depth physical analyses of star-forming regions. Using the GBS LR1 method, we find that compact sources are recovered well, even at a peak brightness of only three times the noise, whereas the reconstruction of larger objects requires much care when drawing boundaries around the expected astronomical signal in the data reduction process. Incorrect boundaries can lead to false structure identification or it can cause structure to be missed. In the JCMT LR1 reduction, the extent of the true structure of objects larger than a point source is never fully recovered
The JCMT Gould Belt Survey: the effect of molecular contamination in SCUBA-2 observations of Orion A
JOURThis is the final version of the article. It was first published by Oxford Journals for the Royal Astronomical Society via http://dx.doi.org/ 10.1093/mnras/stv3009Thermal emission from cold dust grains in giant molecular clouds can be used to probe the physical properties, such as density, temperature and emissivity in star-forming regions. We present the Submillimetre Common-User Bolometer Array (SCUBA-2) shared-risk observations at 450 and 850 μm of the Orion A molecular cloud complex taken at the James Clerk Maxwell Telescope (JCMT). Previous studies showed that molecular emission lines can contribute significantly to the measured fluxes in those continuum bands. We use the Heterodyne Array Receiver Programme 12CO J = 3-2 integrated intensity map for Orion A in order to evaluate the molecular line contamination and its effects on the SCUBA-2 maps. With the corrected fluxes, we have obtained a new spectral index α map for the thermal emission of dust in the well-known integral-shaped filament. Furthermore, we compare a sample of 33 sources, selected over the Orion A molecular cloud complex for their high 12CO J = 3-2 line contamination, to 27 previously identified clumps in OMC 4. This allows us to quantify the effect of line contamination on the ratio of 850-450 μm flux densities and how it modifies the deduced spectral index of emissivity β for the dust grains. We also show that at least one Spitzer-identified protostellar core in OMC 5 has a 12CO J = 3-2 contamination level of 16 per cent. Furthermore, we find the strongest contamination level (44 per cent) towards a young star with disc near OMC 2. This work is part of the JCMT Gould Belt Legacy Survey
Molecular line contamination in the SCUBA-2 450 {\mu}m and 850 {\mu}m continuum data
Observations of the dust emission using millimetre/submillimetre bolometer
arrays can be contaminated by molecular line flux, such as flux from 12CO. As
the brightest molecular line in the submillimetre, it is important to quantify
the contribution of CO flux to the dust continuum bands. Conversion factors
were used to convert molecular line integrated intensities to flux detected by
bolometer arrays in mJy per beam. These factors were calculated for 12CO line
integrated intensities to the SCUBA-2 850 {\mu}m and 450 {\mu}m bands. The
conversion factors were then applied to HARP 12CO 3-2 maps of NGC 1333 in the
Perseus complex and NGC 2071 and NGC 2024 in the Orion B molecular cloud
complex to quantify the respective 12CO flux contribution to the 850 {\mu}m
dust continuum emission. Sources with high molecular line contamination were
analysed in further detail for molecular outflows and heating by nearby stars
to determine the cause of the 12CO contribution. The majority of sources had a
12CO 3-2 flux contribution under 20 per cent. However, in regions of molecular
outflows, the 12CO can dominate the source dust continuum (up to 79 per cent
contamination) with 12CO fluxes reaching \sim 68 mJy per beam.Comment: Accepted 2012 April 19 for publication in MNRAS. 21 pages, 13
figures, 3 table
Fibroblast activation protein is induced by inflammation and degrades type I collagen in thin-cap fibroatheromata
Aims Collagen degradation in atherosclerotic plaques with thin fibrous caps renders them more prone to rupture. Fibroblast activation protein (FAP) plays a role in arthritis and tumour formation through its collagenase activity. However, the significance of FAP in thin-cap human fibroatheromata remains unknown. Methods and results We detected enhanced FAP expression in type IV-V human aortic atheromata (n = 12), compared with type II-III lesions (n = 9; P < 0.01) and healthy aortae (n = 8; P < 0.01) by immunostaining and western blot analyses. Fibroblast activation protein was also increased in thin-cap (<65 µm) vs. thick-cap (≥65 µm) human coronary fibroatheromata (n = 12; P < 0.01). Fibroblast activation protein was expressed by human aortic smooth muscle cells (HASMC) as shown by colocalization on immunofluorescent aortic plaque stainings (n = 10; P < 0.01) and by flow cytometry in cell culture. Although macrophages did not express FAP, macrophage burden in human aortic plaques correlated with FAP expression (n = 12; R2= 0.763; P < 0.05). Enzyme-linked immunosorbent assays showed a time- and dose-dependent up-regulation of FAP in response to human tumour necrosis factor α (TNFα) in HASMC (n = 6; P < 0.01). Moreover, supernatants from peripheral blood-derived macrophages induced FAP expression in cultured HASMC (n = 6; P < 0.01), an effect abolished by blocking TNFα (n = 6; P < 0.01). Fibroblast activation protein associated with collagen-poor regions in human coronary fibrous caps and digested type I collagen and gelatin in vitro (n = 6; P < 0.01). Zymography revealed that FAP-mediated collagenase activity was neutralized by an antibody directed against the FAP catalytic domain both in HASMC (n = 6; P < 0.01) and in fibrous caps of atherosclerotic plaques (n = 10; P < 0.01). Conclusion Fibroblast activation protein expression in HASMC is induced by macrophage-derived TNFα. Fibroblast activation protein associates with thin-cap human coronary fibroatheromata and contributes to type I collagen breakdown in fibrous cap
Fibroblast activation protein is induced by inflammation and degrades type I collagen in thin-cap fibroatheromata
Aims Collagen degradation in atherosclerotic plaques with thin fibrous caps renders them more prone to rupture. Fibroblast activation protein (FAP) plays a role in arthritis and tumour formation through its collagenase activity. However, the significance of FAP in thin-cap human fibroatheromata remains unknown. Methods and results We detected enhanced FAP expression in type IV-V human aortic atheromata (n = 12), compared with type II-III lesions (n = 9; P < 0.01) and healthy aortae (n = 8; P < 0.01) by immunostaining and western blot analyses. Fibroblast activation protein was also increased in thin-cap (<65 µm) vs. thick-cap (≥65 µm) human coronary fibroatheromata (n = 12; P < 0.01). Fibroblast activation protein was expressed by human aortic smooth muscle cells (HASMC) as shown by colocalization on immunofluorescent aortic plaque stainings (n = 10; P < 0.01) and by flow cytometry in cell culture. Although macrophages did not express FAP, macrophage burden in human aortic plaques correlated with FAP expression (n = 12; R(2)= 0.763; P < 0.05). Enzyme-linked immunosorbent assays showed a time- and dose-dependent up-regulation of FAP in response to human tumour necrosis factor α (TNFα) in HASMC (n = 6; P < 0.01). Moreover, supernatants from peripheral blood-derived macrophages induced FAP expression in cultured HASMC (n = 6; P < 0.01), an effect abolished by blocking TNFα (n = 6; P < 0.01). Fibroblast activation protein associated with collagen-poor regions in human coronary fibrous caps and digested type I collagen and gelatin in vitro (n = 6; P < 0.01). Zymography revealed that FAP-mediated collagenase activity was neutralized by an antibody directed against the FAP catalytic domain both in HASMC (n = 6; P < 0.01) and in fibrous caps of atherosclerotic plaques (n = 10; P < 0.01). Conclusion Fibroblast activation protein expression in HASMC is induced by macrophage-derived TNFα. Fibroblast activation protein associates with thin-cap human coronary fibroatheromata and contributes to type I collagen breakdown in fibrous caps
The JCMT Gould Belt Survey: Evidence for radiative heating in Serpens MWC 297 and its influence on local star formation
We present SCUBA-2 450micron and 850micron observations of the Serpens MWC
297 region, part of the JCMT Gould Belt Survey of nearby star-forming regions.
Simulations suggest that radiative feedback influences the star-formation
process and we investigate observational evidence for this by constructing
temperature maps. Maps are derived from the ratio of SCUBA-2 fluxes and a two
component model of the JCMT beam for a fixed dust opacity spectral index of
beta = 1.8. Within 40 of the B1.5Ve Herbig star MWC 297, the submillimetre
fluxes are contaminated by free-free emission with a spectral index of
1.03+-0.02, consistent with an ultra-compact HII region and polar winds/jets.
Contamination accounts for 73+-5 per cent and 82+-4 per cent of peak flux at
450micron and 850micron respectively. The residual thermal disk of the star is
almost undetectable at these wavelengths. Young Stellar Objects are confirmed
where SCUBA-2 850micron clumps identified by the fellwalker algorithm coincide
with Spitzer Gould Belt Survey detections. We identify 23 objects and use Tbol
to classify nine YSOs with masses 0.09 to 5.1 Msun. We find two Class 0, one
Class 0/I, three Class I and three Class II sources. The mean temperature is
15+-2K for the nine YSOs and 32+-4K for the 14 starless clumps. We observe a
starless clump with an abnormally high mean temperature of 46+-2K and conclude
that it is radiatively heated by the star MWC 297. Jeans stability provides
evidence that radiative heating by the star MWC 297 may be suppressing clump
collapse.Comment: 24 pages, 13 figures, 7 table
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The Merit(nTOF-11) High Intensity Liquid Mercury Target Experiment at the CERN PS
The MERIT(nTOF-11) experiment is a proof-ofprinciple test of a target system for a high power proton beam to be used as front-end for a neutrino factory or a muon collider. The experiment took data in autumn 2007 with the fast-extracted beam from the CERN Proton Synchrotron (PS) to a maximum intensity of per pulse. The target system, based on a free mercury jet, is capable of intercepting a 4-MW proton beam inside a 15-T magnetic field required to capture the low energy secondary pions as the source for intense muon beams. Partice detectors installed around the target setup measure the secondary particle flux out of the target and can probe cavitation effects in the mercury jet when excited by an intense proton beam.Preliminary results of the data analysis will be presented here
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