56 research outputs found
Detection of OH absorption against PSR B1849+00
We have searched for OH absorption against seven pulsars using the Arecibo
telescope. In both OH mainlines (at 1665 and 1667 MHz), deep and narrow
absorption features were detected toward PSR B1849+00. In addition, we have
detected several absorption and emission features against B33.6+0.1, a nearby
supernova remnant (SNR). The most interesting result of this study is that a
pencil-sharp absorption sample against the PSR differs greatly from the
large-angle absorption sample observed against the SNR. If both the PSR and the
SNR probe the same molecular cloud then this finding has important implications
for absorption studies of the molecular medium, as it shows that the statistics
of absorbing OH depends on the size of the background source. We also show that
the OH absorption against the PSR most likely originates from a small (<30
arcsec) and dense (>10^5 cm^-3) molecular clump.Comment: 12 pages, 8 figures. Accepted for publication in Ap
Infrared Dark Clouds in the Small Magellanic Cloud?
We have applied the unsharp-masking technique to the 24 m image of the
Small Magellanic Cloud (SMC), obtained with the Spitzer Space Telescope, to
search for high-extinction regions. This technique has been used to locate very
dense and cold interstellar clouds in the Galaxy, particularly infrared dark
clouds (IRDCs). Fifty five candidate regions of high-extinction, namely
high-contrast regions (HCRs), have been identified from the generated
decremental contrast image of the SMC. Most HCRs are located in the southern
bar region and mainly distributed in the outskirts of CO clouds, but most
likely contain a significant amount of H2. HCRs have a peak-contrast at 24
m of 2 - 2.5 % and a size of 8 - 14 pc. This corresponds to the size of
typical and large Galactic IRDCs, but Galactic IRDCs are 2 - 3 times darker at
24 m than our HCRs. To constrain the physical properties of the HCRs, we
have performed NH3, N2H+, HNC, HCO+, and HCN observations toward one of the
HCRs, HCR LIRS36-EAST, using the Australia Telescope Compact Array and the
Mopra single-dish radio telescope. We did not detect any molecular line
emission, however, our upper limits to the column densities of molecular
species suggest that HCRs are most likely moderately dense with n ~ 10^{3}
cm-3. This volume density is in agreement with predictions for the cool atomic
phase in low metallicity environments. We suggest that HCRs may be tracing
clouds at the transition from atomic to molecule-dominated medium, and could be
a powerful way to study early stages of gas condensation in low metallicity
galaxies. Alternatively, if made up of dense molecular clumps < 0.5 pc in size,
HCRs could be counterparts of Galactic IRDCs, and/or regions with highly
unusual abundance of very small dust grains.Comment: accepted for publication in the Astronomical Journa
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
Levetiracetam versus phenytoin for second-line treatment of paediatric convulsive status epilepticus (EcLiPSE): a multicentre, open-label, randomised trial
Background Phenytoin is the recommended second-line intravenous anticonvulsant for treatment of paediatric convulsive status epilepticus in the UK; however, some evidence suggests that levetiracetam could be an effective and safer alternative. This trial compared the efficacy and safety of phenytoin and levetiracetam for second-line management of paediatric convulsive status epilepticus.Methods This open-label, randomised clinical trial was undertaken at 30 UK emergency departments at secondary and tertiary care centres. Participants aged 6 months to under 18 years, with convulsive status epilepticus requiring second-line treatment, were randomly assigned (1:1) using a computer-generated randomisation schedule to receive levetiracetam (40 mg/kg over 5 min) or phenytoin (20 mg/kg over at least 20 min), stratified by centre. The primary outcome was time from randomisation to cessation of convulsive status epilepticus, analysed in the modified intention-to-treat population (excluding those who did not require second-line treatment after randomisation and those who did not provide consent). This trial is registered with ISRCTN, number ISRCTN22567894.Findings Between July 17, 2015, and April 7, 2018, 1432 patients were assessed for eligibility. After exclusion of ineligible patients, 404 patients were randomly assigned. After exclusion of those who did not require second-line treatment and those who did not consent, 286 randomised participants were treated and had available data: 152 allocated to levetiracetam, and 134 to phenytoin. Convulsive status epilepticus was terminated in 106 (70%) children in the levetiracetam group and in 86 (64%) in the phenytoin group. Median time from randomisation to cessation of convulsive status epilepticus was 35 min (IQR 20 to not assessable) in the levetiracetam group and 45 min (24 to not assessable) in the phenytoin group (hazard ratio 1·20, 95% CI 0·91â1·60; p=0·20). One participant who received levetiracetam followed by phenytoin died as a result of catastrophic cerebral oedema unrelated to either treatment. One participant who received phenytoin had serious adverse reactions related to study treatment (hypotension considered to be immediately life-threatening [a serious adverse reaction] and increased focal seizures and decreased consciousness considered to be medically significant [a suspected unexpected serious adverse reaction]). Interpretation Although levetiracetam was not significantly superior to phenytoin, the results, together with previously reported safety profiles and comparative ease of administration of levetiracetam, suggest it could be an appropriate alternative to phenytoin as the first-choice, second-line anticonvulsant in the treatment of paediatric convulsive status epilepticus
Serum levels of the proinflammatory cytokine interleukin-6 vary based on diagnoses in individuals with lumbar intervertebral disc diseases
Genomic investigations of unexplained acute hepatitis in children
Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children
LâeÌcriture engageÌe du XXIe sieÌcle : lâautofiction au-delaÌ dâun « mauvais genre »
Cet article explore le rapport entre lâautofiction au XXIĂšme siĂšcle et les mouvements socio-politiques reconceptualisant lâidentitĂ© en examinant la façon dont ce genre vĂ©hicule des commentaires sur les notions de lâaltĂ©ritĂ©, de lâĂ©trangetĂ©, et de lâappartenance. LâĂ©tude dâAutoportrait en vert de Marie Nâdiaye et de Mes mauvaises pensĂ©es de Nina Bouraoui dĂ©montrent la possibilitĂ© de voir dans lâemploi du privĂ©, de lâintime, et du personnel une provocation visant Ă dĂ©clencher une rĂ©flexion quant Ă la dĂ©pendance des notions dâidentitĂ© qui reposent sur des hiĂ©rarchies binaires. Lâaxe principal de cette Ă©tude est dâexaminer comment cette Ă©criture, en sâauto-rĂ©fĂ©renciant, interroge sa propre Ă©volution, celle du rĂŽle de lâĆuvre littĂ©raire et de lâauteur. Elle se penche sur lâemploi de lâautofiction Ă des fins explicitement politiques, capable de crĂ©er un espace littĂ©raire commun â un « territoire » partagĂ© â depuis lequel lâauteur et le lecteur peuvent interroger le rĂŽle attribuĂ© aujourdâhui aux marqueurs dâidentitĂ© et Ă la notion de diffĂ©rence.Cet article explore le rapport entre lâautofiction au XXIĂšme siĂšcle et les mouvements socio-politiques reconceptualisant lâidentitĂ© en examinant la façon dont ce genre vĂ©hicule des commentaires sur les notions de lâaltĂ©ritĂ©, de lâĂ©trangetĂ©, et de lâappartenance. LâĂ©tude dâAutoportrait en vert de Marie Nâdiaye et de Mes mauvaises pensĂ©es de Nina Bouraoui dĂ©montrent la possibilitĂ© de voir dans lâemploi du privĂ©, de lâintime, et du personnel une provocation visant Ă dĂ©clencher une rĂ©flexion quant Ă la dĂ©pendance des notions dâidentitĂ© qui reposent sur des hiĂ©rarchies binaires. Lâaxe principal de cette Ă©tude est dâexaminer comment cette Ă©criture, en sâauto-rĂ©fĂ©renciant, interroge sa propre Ă©volution, celle du rĂŽle de lâĆuvre littĂ©raire et de lâauteur. Elle se penche sur lâemploi de lâautofiction Ă des fins explicitement politiques, capable de crĂ©er un espace littĂ©raire commun â un « territoire » partagĂ© â depuis lequel lâauteur et le lecteur peuvent interroger le rĂŽle attribuĂ© aujourdâhui aux marqueurs dâidentitĂ© et Ă la notion de diffĂ©rence
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