| 1. |
- Aad, G, et al.
(författare)
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- 2015
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swepub:Mat__t
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| 2. |
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| 3. |
- Selsing, J., et al.
(författare)
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The X-shooter GRB afterglow legacy sample (XS-GRB)
- 2019
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Ingår i: Astronomy and Astrophysics. - : EDP SCIENCES S A. - 0004-6361 .- 1432-0746. ; 623
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Tidskriftsartikel (refereegranskat)abstract
- In this work we present spectra of all gamma-ray burst (GRB) afterglows that have been promptly observed with the X-shooter spectrograph until 31/03/2017. In total, we have obtained spectroscopic observations of 103 individual GRBs observed within 48 hours of the GRB trigger. Redshifts have been measured for 97 per cent of these, covering a redshift range from 0.059 to 7.84. Based on a set of observational selection criteria that minimise biases with regards to intrinsic properties of the GRBs, the follow-up effort has been focused on producing a homogeneously selected sample of 93 afterglow spectra for GRBs discovered by the Swift satellite. We here provide a public release of all the reduced spectra, including continuum estimates and telluric absorption corrections. For completeness, we also provide reductions for the 18 late-time observations of the underlying host galaxies. We provide an assessment of the degree of completeness with respect to the parent GRB population, in terms of the X-ray properties of the bursts in the sample and find that the sample presented here is representative of the full Swift sample. We have constrained the fraction of dark bursts to be <28 per cent and confirm previous results that higher optical darkness is correlated with increased X-ray absorption. For the 42 bursts for which it is possible, we have provided a measurement of the neutral hydrogen column density, increasing the total number of published HI column density measurements by similar to 33 per cent. This dataset provides a unique resource to study the ISM across cosmic time, from the local progenitor surroundings to the intervening Universe.
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| 4. |
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| 5. |
- Izzo, L., et al.
(författare)
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Signatures of a jet cocoon in early spectra of a supernova associated with a γ-ray burst
- 2019
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 565:7739, s. 324-
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Tidskriftsartikel (refereegranskat)abstract
- Long gamma-ray bursts are associated with energetic, broad-lined, stripped-envelope supernovae(1,2) and as such mark the death of massive stars. The scarcity of such events nearby and the brightness of the gamma-ray burst afterglow, which dominates the emission in the first few days after the burst, have so far prevented the study of the very early evolution of supernovae associated with gamma-ray bursts(3). In hydrogen-stripped supernovae that are not associated with gamma-ray bursts, an excess of high-velocity (roughly 30,000 kilometres per second) material has been interpreted as a signature of a choked jet, which did not emerge from the progenitor star and instead deposited all of its energy in a thermal cocoon(4). Here we report multi-epoch spectroscopic observations of the supernova SN 2017iuk, which is associated with the gamma-ray burst GRB 171205A. Our spectra display features at extremely high expansion velocities (around 115,000 kilometres per second) within the first day after the burst(5,6). Using spectral synthesis models developed for SN 2017iuk, we show that these features are characterized by chemical abundances that differ from those observed in the ejecta of SN 2017iuk at later times. We further show that the high-velocity features originate from the mildly relativistic hot cocoon that is generated by an ultra-relativistic jet within the gamma-ray burst expanding and decelerating into the medium that surrounds the progenitor star(7,8). This cocoon rapidly becomes transparent(9) and is outshone by the supernova emission, which starts to dominate the emission three days after the burst.
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| 6. |
- Lamb, G. P., et al.
(författare)
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Short GRB 160821B : A Reverse Shock, a Refreshed Shock, and a Well-sampled Kilonova
- 2019
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 883:1
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Tidskriftsartikel (refereegranskat)abstract
- We report our identification of the optical afterglow and host galaxy of the short-duration gamma-ray burst sGRB 160821B. The spectroscopic redshift of the host is z = 0.162, making it one of the lowest redshift short-duration gamma-ray bursts (sGRBs) identified by Swift. Our intensive follow-up campaign using a range of ground-based facilities as well as Hubble Space Telescope, XMM-Newton, and Swift, shows evidence for a late-time excess of optical and near-infrared emission in addition to a complex afterglow. The afterglow light curve at X-ray frequencies reveals a narrow jet, theta(j) similar to 1.9(-0.03)(+0.10) deg, that is refreshed at >1 day post-burst by a slower outflow with significantly more energy than the initial outflow that produced the main GRB. Observations of the 5 GHz radio afterglow shows a reverse shock into a mildly magnetized shell. The optical and near-infrared excess is fainter than AT2017gfo associated with GW170817, and is well explained by a kilonova with dynamic ejecta mass M-dyn = (1.0 +/- 0.6) x 10(-3) M-circle dot and a secular (post-merger) ejecta mass with M-pm = (1.0 +/- 0.6) x 10(-2) M-circle dot, consistent with a binary neutron star merger resulting in a short-lived massive neutron star. This optical and near-infrared data set provides the best-sampled kilonova light curve without a gravitational wave trigger to date.
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| 7. |
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| 8. |
- Melandri, A., et al.
(författare)
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GRB171010A/SN 2017htp : a GRB-SN at z=0.33
- 2019
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 490:4, s. 5366-5374
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Tidskriftsartikel (refereegranskat)abstract
- The number of supernovae known to be connected with long-duration gamma-ray bursts (GRBs) is increasing and the link between these events is no longer exclusively found at low redshift (z less than or similar to 0.3) but is well established also at larger distances. We present a new case of such a liaison at z = 0.33 between GRB171010A and SN 2017htp. It is the second closest GRB with an associated supernova of only three events detected by Fermi-LAT. The supernova is one of the few higher redshift cases where spectroscopic observations were possible and shows spectral similarities with the well-studied SN 1998bw, having produced a similar Ni mass (M-Ni = 0.33 +/- 0.02 M-circle dot) with slightly lower ejected mass (M-ej = 4.1 +/- 0.7 M-circle dot) and kinetic energy (E-K = 8.1 +/- 2.5 x 10(51) erg). The host-galaxy is bigger in size than typical GRB host galaxies, but the analysis of the region hosting the GRB revealed spectral properties typically observed in GRB hosts and showed that the progenitor of this event was located in a very bright H II region of its face-on host galaxy, at a projected distance of similar to 10 kpc from its galactic centre. The star-formation rate (SFRGRB similar to 0.2 M-circle dot yr(-1)) and metallicity (12 + log(O/H) similar to 8.15 +/- 0.10) of the GRB star-forming region are consistent with those of the host galaxies of previously studied GRB-SN systems.
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| 9. |
- Welearegay, T. G., et al.
(författare)
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Ultrapure Organically Modified Gold Nanoparticles for Breath Analysis
- 2016
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Ingår i: Procedia Engineering. - : Elsevier BV. - 1877-7058. ; 168, s. 133-136
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Tidskriftsartikel (refereegranskat)abstract
- In this study we present a new technological approach for the fabrication of ultrapure organically modified gold nanoparticles (AuNPs) for chemical sensing applied to exhaled breath analysis. To achieve a high purity level of the sensing films, we combined Advanced Gas Deposition (AGD) technique to deposit ultrapure monodispersed AuNPs, and dip coating process for functionalization of the AuNPs with thiolated organic ligands. Morphology and surface analysis revealed the deposition of ultrapure isolated AuNPs after the first processing step, and a network of nanoparticle–ligand nanoassemblies after the second processing step. Gas sensing measurements were performed with exhaled breath samples collected from a group of smokers, a group of non-smokers, and ambient air. Sensors responses towards these samples demonstrated characteristic responses for each study group. PCA analysis further revealed samples classification in three distinct characteristic clusters, which indicates the suitability of the molecularly modified AuNPs presented in this communication for breath analysis applications.
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| 10. |
- Cano, Z., et al.
(författare)
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GRB 161219B/SN 2016jca : A low-redshift gamma-ray burst supernova powered by radioactive heating
- 2017
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 605
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Tidskriftsartikel (refereegranskat)abstract
- Since the first discovery of a broad-lined type Ic supernova (SN) with a long-duration gamma-ray burst (GRB) in 1998, fewer than fifty GRB-supernovae (SNe) have been discovered. The intermediate-luminosity Swift GRB 161219B and its associated supernova SN 2016jca, which occurred at a redshift of z = 0.1475, represents only the seventh GRB-SN to have been discovered within 1 Gpc, and hence provides an excellent opportunity to investigate the observational and physical properties of these very elusive and rare type of SN. As such, we present optical to near-infrared photometry and optical spectroscopy of GRB 161219B and SN 2016jca, spanning the first three months since its discovery. GRB 161219B exploded in the disk of an edge-on spiral galaxy at a projected distance of 3.4 kpc from the galactic centre. GRB 161219B itself is an outlier in the E-p,E-i - E-gamma,E-iso plane, while SN 2016jca had a rest-frame, peak absolute V-band magnitude of M-V = -19.0 +/- 0.1, which it reached after 12.3 +/- 0.7 rest-frame days. We find that the bolometric properties of SN 2016jca are inconsistent with being powered solely by a magnetar central engine, and demonstrate that it was likely powered exclusively by energy deposited by the radioactive decay of nickel and cobalt into their daughter products, which were nucleosynthesised when its progenitor underwent core collapse. We find that 0.22 +/- 0.08 M-circle dot of nickel is required to reproduce the peak luminosity of SN 2016jca, and we constrain an ejecta mass of 5.8 +/- 0.3 M-circle dot and a kinetic energy of 5.1 +/- 0.8 x 10(52) erg. Finally, we report on a chromatic, pre-maximum bump in the g-band light curve, and discuss its possible origin.
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| 11. |
- Dunne, Jessica L., et al.
(författare)
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Rationale for enteroviral vaccination and antiviral therapies in human type 1 diabetes
- 2019
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 62:5, s. 744-753
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Tidskriftsartikel (refereegranskat)abstract
- In type 1 diabetes, pancreatic beta cells are destroyed by chronic autoimmune responses. The disease develops in genetically susceptible individuals, but a role for environmental factors has been postulated. Viral infections have long been considered as candidates for environmental triggers but, given the lack of evidence for an acute, widespread, cytopathic effect in the pancreas in type 1 diabetes or for a closely related temporal association of diabetes onset with such infections, a role for viruses in type 1 diabetes remains unproven. Moreover, viruses have rarely been isolated from the pancreas of individuals with type 1 diabetes, mainly (but not solely) due to the inaccessibility of the organ. Here, we review past and recent literature to evaluate the proposals that chronic, recurrent and, possibly, persistent enteroviral infections occur in pancreatic beta cells in type 1 diabetes. We also explore whether these infections may be sustained by different virus strains over time and whether multiple viral hits can occur during the natural history of type 1 diabetes. We emphasise that only a minority of beta cells appear to be infected at any given time and that enteroviruses may become replication defective, which could explain why they have been isolated from the pancreas only rarely. We argue that enteroviral infection of beta cells largely depends on the host innate and adaptive immune responses, including innate responses mounted by beta cells. Thus, we propose that viruses could play a role in type 1 diabetes on multiple levels, including in the triggering and chronic stimulation of autoimmunity and in the generation of inflammation and the promotion of beta cell dysfunction and stress, each of which might then contribute to autoimmunity, as part of a vicious circle. We conclude that studies into the effects of vaccinations and/or antiviral drugs (some of which are currently on-going) is the only means by which the role of viruses in type 1 diabetes can be finally proven or disproven.
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| 12. |
- Ferri, F., et al.
(författare)
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Donor small-droplet macrovesicular steatosis affects liver transplant outcome in HCV-negative recipients
- 2019
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Ingår i: Canadian Journal of Gastroenterology. - : Hindawi Limited. - 0835-7900 .- 2291-2789 .- 2291-2797. ; 2019
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Tidskriftsartikel (refereegranskat)abstract
- - Background. No data are available on liver transplantation (LT) outcome and donor liver steatosis, classified as large droplet macrovesicular (Ld-MaS), small-droplet macrovesicular (Sd-MaS), and true microvesicular (MiS), taking into account the recipient Hepatitis C virus (HCV) status. Aim. We investigate the impact of allograft steatosis reclassified according to the Brunt classification on early graft function and survival after LT. Methods. We retrospectively reviewed 204 consecutive preischemia biopsies of grafts transplanted in our center during the period 2001-2011 according to recipient HCV status. Results. The median follow-up after LT was 7.5 years (range: 0.0-16.7). In negative recipients (n=122), graft loss was independently associated with graft Sd-MaS, in multivariable Cox regression models comprehending only pre-/intraoperative variables (HR=1.03, 95%CI=1.01-1.05; P=0.003) and when including indexes of early postoperative graft function (HR=1.04, 95%CI=1.02-1.06; P=0.001). Graft Sd-MaS>15% showed a risk for graft loss > 2.5-folds in both the models. Graft Sd-MaS>15% was associated with reduced graft ATP content and, only in HCV-recipients, with higher early post-LT serum AST peaks. Conclusions. In HCV-negative recipients, allografts with >15% Sd-MaS have significantly reduced graft survival and show low ATP and higher AST peaks in the immediate posttransplant period. Donors with >15% Sd-MaS have significantly higher BMI, longer ICU stays, and lower PaO2. © 2019 Flaminia Ferri et al.
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| 13. |
- Laiho, Jutta E., et al.
(författare)
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Relative sensitivity of immunohistochemistry, multiple reaction monitoring mass spectrometry, in situ hybridization and PCR to detect Coxsackievirus B1 in A549 cells
- 2016
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Ingår i: Journal of Clinical Virology. - : Elsevier BV. - 1386-6532 .- 1873-5967. ; 77, s. 21-28
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Tidskriftsartikel (refereegranskat)abstract
- Background: Enteroviruses (EVs) have been linked to the pathogenesis of several diseases and there is a collective need to develop improved methods for the detection of these viruses in tissue samples. Objectives: This study evaluates the relative sensitivity of immunohistochemistry (IHC), proteomics, in situ hybridization (ISH) and RT-PCR to detect one common EV, Coxsackievirus B1 ( CVB1), in acutely infected human A549 cells in vitro. Study design: A549 cells were infected with CVB1 and diluted with uninfected A549 cells to produce a limited dilution series in which the proportion of infected cells ranged from 10-1 to 10-8. Analyses were carried out by several laboratories using IHC with different anti-EV antibodies, ISH with both ViewRNA and RNAScope systems, liquid chromatography multiple reaction monitoring mass spectrometry (LC/MRM/MS/MS), and two modifications of RT-PCR. Results: RT-PCR was the most sensitive method for EV detection yielding positive signals in the most diluted sample (10-8). LC/MRM/MS/MS detected viral peptides at dilutions as high as 10-7. The sensitivity of IHC depended on the antibody used, and the most sensitive antibody (Dako clone 5D8/1) detected virus proteins at a dilution of 10(-6), while ISH detected the virus at dilutions of 10(-4). Conclusions: All methods were able to detect CVB1 in infected A549 cells. RT-PCR was most sensitive followed by LC/MRM/MS/MS and then IHC. The results from this in vitro survey suggest that all methods are suitable tools for EV detection but that their differential sensitivities need to be considered when interpreting the results from such studies.
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| 14. |
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| 15. |
- van Hilst, Jony, et al.
(författare)
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Minimally Invasive versus Open Distal Pancreatectomy for Ductal Adenocarcinoma (DIPLOMA)
- 2019
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Ingår i: Annals of Surgery. - : Lippincott Williams & Wilkins. - 0003-4932 .- 1528-1140. ; 269:1, s. 10-17
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of this study was to compare oncological outcomes after minimally invasive distal pancreatectomy (MIDP) with open distal pancreatectomy (ODP) in patients with pancreatic ductal adenocarcinoma (PDAC).Background: Cohort studies have suggested superior short-term outcomes of MIDP vs. ODP. Recent international surveys, however, revealed that surgeons have concerns about the oncological outcomes of MIDP for PDAC.Methods: This is a pan-European propensity score matched study including patients who underwent MIDP (laparoscopic or robot-assisted) or ODP for PDAC between January 1, 2007 and July 1, 2015. MIDP patients were matched to ODP patients in a 1:1 ratio. Main outcomes were radical (R0) resection, lymph node retrieval, and survival.Results: In total, 1212 patients were included from 34 centers in 11 countries. Of 356 (29%) MIDP patients, 340 could be matched. After matching, the MIDP conversion rate was 19% (n = 62). Median blood loss [200 mL (60–400) vs 300 mL (150–500), P = 0.001] and hospital stay [8 (6–12) vs 9 (7–14) days, P < 0.001] were lower after MIDP. Clavien-Dindo grade ≥3 complications (18% vs 21%, P = 0.431) and 90-day mortality (2% vs 3%, P > 0.99) were comparable for MIDP and ODP, respectively. R0 resection rate was higher (67% vs 58%, P = 0.019), whereas Gerota's fascia resection (31% vs 60%, P < 0.001) and lymph node retrieval [14 (8–22) vs 22 (14–31), P< 0.001] were lower after MIDP. Median overall survival was 28 [95% confidence interval (CI), 22–34] versus 31 (95% CI, 26–36) months (P = 0.929).Conclusions: Comparable survival was seen after MIDP and ODP for PDAC, but the opposing differences in R0 resection rate, resection of Gerota's fascia, and lymph node retrieval strengthen the need for a randomized trial to confirm the oncological safety of MIDP.
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