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| 2. |
- Abe, H., et al.
(författare)
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Gamma-ray observations of MAXI J1820+070 during the 2018 outburst
- 2022
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press. - 0035-8711 .- 1365-2966. ; 517:4, s. 4736-4751
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Tidskriftsartikel (refereegranskat)abstract
- MAXIJ1820+070 is a low-mass X-ray binary with a black hole (BH) as a compact object. This binary underwent an exceptionally bright X-ray outburst from 2018 March to October, showing evidence of a non-thermal particle population through its radio emission during this whole period. The combined results of 59.5 h of observations of the MAXI J1820+070 outburst with the H.E.S.S., MAGIC and VERITAS experiments at energies above 200 GeV are presented, together with Fermi-LAT data between 0.1 and 500 GeV, and multiwavelength observations from radio to X-rays. Gamma-ray emission is not detected from MAXI J1820+070, but the obtained upper limits and the multiwavelength data allow us to put meaningful constraints on the source properties under reasonable assumptions regarding the non-thermal particle population and the jet synchrotron spectrum. In particular, it is possible to show that, if a high-energy (HE) gamma-ray emitting region is present during the hard state of the source, its predicted flux should be at most a factor of 20 below the obtained Fermi-LAT upper limits, and closer to them for magnetic fields significantly below equipartition. During the state transitions, under the plausible assumption that electrons are accelerated up to similar to 500 GeV, the multiwavelength data and the gamma-ray upper limits lead consistently to the conclusion that a potential HE and very-HE gamma-ray emitting region should be located at a distance from the BH ranging between 10(11) and 10(13) cm. Similar outbursts from low-mass X-ray binaries might be detectable in the near future with upcoming instruments such as CTA.
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| 3. |
- Adams, C. B., et al.
(författare)
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Observation of the Gamma-Ray Binary HESS J0632+057 with the HESS, MAGIC, and VERITAS Telescopes
- 2021
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Ingår i: Astrophysical Journal. - : Institute of Physics Publishing (IOPP). - 0004-637X .- 1538-4357. ; 923:2
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Tidskriftsartikel (refereegranskat)abstract
- The results of gamma-ray observations of the binary system HESS J0632 + 057 collected during 450 hr over 15 yr, between 2004 and 2019, are presented. Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and VERITAS at energies above 350 GeV were used together with observations at X-ray energies obtained with Swift-XRT, Chandra, XMM-Newton, NuSTAR, and Suzaku. Some of these observations were accompanied by measurements of the H alpha emission line. A significant detection of the modulation of the very high-energy gamma-ray fluxes with a period of 316.7 +/- 4.4 days is reported, consistent with the period of 317.3 +/- 0.7 days obtained with a refined analysis of X-ray data. The analysis of data from four orbital cycles with dense observational coverage reveals short-timescale variability, with flux-decay timescales of less than 20 days at very high energies. Flux variations observed over a timescale of several years indicate orbit-to-orbit variability. The analysis confirms the previously reported correlation of X-ray and gamma-ray emission from the system at very high significance, but cannot find any correlation of optical H alpha parameters with fluxes at X-ray or gamma-ray energies in simultaneous observations. The key finding is that the emission of HESS J0632 + 057 in the X-ray and gamma-ray energy bands is highly variable on different timescales. The ratio of gamma-ray to X-ray flux shows the equality or even dominance of the gamma-ray energy range. This wealth of new data is interpreted taking into account the insufficient knowledge of the ephemeris of the system, and discussed in the context of results reported on other gamma-ray binary systems.
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| 4. |
- Bouyoucef, S E, et al.
(författare)
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Poster Session 2 : Monday 4 May 2015, 08
- 2015
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Ingår i: European Heart Journal Cardiovascular Imaging. - : Oxford University Press (OUP). - 2047-2404 .- 2047-2412. ; 16 Suppl 1
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Tidskriftsartikel (refereegranskat)
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| 5. |
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| 6. |
- Aimo, Alberto, et al.
(författare)
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High-sensitivity troponin T, NT-proBNP and glomerular filtration rate : A multimarker strategy for risk stratification in chronic heart failure
- 2019
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Ingår i: International Journal of Cardiology. - : Elsevier BV. - 0167-5273 .- 1874-1754. ; 277, s. 166-172
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Tidskriftsartikel (refereegranskat)abstract
- Background: In a recent individual patient data meta-analysis, high-sensitivity troponin T (hs-TnT) emerged as robust predictor of prognosis in stable chronic heart failure (HF). In the same population, we compared the relative predictive performances of hs-TnT, N-terminal fraction of pro-B-type natriuretic peptide (NT-proBNP), hs-C-reactive protein (hs-CRP), and estimated glomerular filtration rate (eGFR) for prognosis.Methods and results: 9289 patients (66 ± 12 years, 77% men, 85% LVEF <40%, 60% ischemic HF) were evaluated over a 2.4-year median follow-up. Median eGFR was 58 mL/min/1.73 m2 (interquartile interval 46–70; n = 9220), hs-TnT 16 ng/L (8–20; n = 9289), NT-proBNP 1067 ng/L (433–2470; n = 8845), and hs-CRP 3.3 mg/L (1.4–7.8; n = 7083). In a model including all 3 biomarkers, only hs-TnT and NT-proBNP were independent predictors of all-cause and cardiovascular mortality and cardiovascular hospitalization. hs-TnT was a stronger predictor than NT-proBNP: for example, the risk for all-cause death increased by 54% per doubling of hs-TnT vs. 24% per doubling of NT-proBNP. eGFR showed independent prognostic value from both hs-TnT and NT-proBNP. The best hs-TnT and NT-proBNP cut-offs for the prediction of all-cause death increased progressively with declining renal function (eGFR ≥ 90: hs-TnT 13 ng/L and NT-proBNP 825 ng/L; eGFR < 30: hs-TnT 40 ng/L and NT-proBNP 4608 ng/L). Patient categorization according to these cut-offs effectively stratified patient prognosis across all eGFR classes.Conclusions: hs-TnT conveys independent prognostic information from NT-proBNP, while hs-CRP does not. Concomitant assessment of eGFR may further refine risk stratification. Patient classification according to hs-TnT and NT-proBNP cut-offs specific for the eGFR classes holds prognostic significance.
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| 7. |
- Aimo, Alberto, et al.
(författare)
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Prognostic Value of High-Sensitivity Troponin T in Chronic Heart Failure : An Individual Patient Data Meta-Analysis
- 2018
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Ingår i: Circulation. - 0009-7322 .- 1524-4539. ; 137:3, s. 286-297
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Tidskriftsartikel (refereegranskat)abstract
- Background: Most patients with chronic heart failure have detectable troponin concentrations when evaluated by high-sensitivity assays. The prognostic relevance of this finding has not been clearly established so far. We aimed to assess high-sensitivity troponin assay for risk stratification in chronic heart failure through a meta-analysis approach.Methods: Medline, EMBASE, Cochrane Library, and Scopus were searched in April 2017 by 2 independent authors. The terms were “troponin” AND “heart failure” OR “cardiac failure” OR “cardiac dysfunction” OR “cardiac insufficiency” OR “left ventricular dysfunction.” Inclusion criteria were English language, clinical stability, use of a high-sensitivity troponin assay, follow-up studies, and availability of individual patient data after request to authors. Data retrieved from articles and provided by authors were used in agreement with the PRISMA statement. The end points were all-cause death, cardiovascular death, and hospitalization for cardiovascular cause.Results: Ten studies were included, reporting data on 11 cohorts and 9289 patients (age 66±12 years, 77% men, 60% ischemic heart failure, 85% with left ventricular ejection fraction <40%). High-sensitivity troponin T data were available for all patients, whereas only 209 patients also had high-sensitivity troponin I assayed. When added to a prognostic model including established risk markers (sex, age, ischemic versus nonischemic etiology, left ventricular ejection fraction, estimated glomerular filtration rate, and N-terminal fraction of pro-B-type natriuretic peptide), high-sensitivity troponin T remained independently associated with all-cause mortality (hazard ratio, 1.48; 95% confidence interval, 1.41–1.55), cardiovascular mortality (hazard ratio, 1.40; 95% confidence interval, 1.33–1.48), and cardiovascular hospitalization (hazard ratio, 1.42; 95% confidence interval, 1.36–1.49), over a median 2.4-year follow-up (all P<0.001). High-sensitivity troponin T significantly improved risk prediction when added to a prognostic model including the variables above. It also displayed an independent prognostic value for all outcomes in almost all population subgroups. The area under the curve–derived 18 ng/L cutoff yielded independent prognostic value for the 3 end points in both men and women, patients with either ischemic or nonischemic etiology, and across categories of renal dysfunction.Conclusions: In chronic heart failure, high-sensitivity troponin T is a strong and independent predictor of all-cause and cardiovascular mortality, and of hospitalization for cardiovascular causes, as well. This biomarker then represents an additional tool for prognostic stratification.
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| 8. |
- Aimo, Alberto, et al.
(författare)
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Revisiting the obesity paradox in heart failure : Per cent body fat as predictor of biomarkers and outcome
- 2019
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Ingår i: European Journal of Preventive Cardiology. - : Sage Publications. - 2047-4873 .- 2047-4881. ; 26:16, s. 1751-1759
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Tidskriftsartikel (refereegranskat)abstract
- Aims Obesity defined by body mass index (BMI) is characterized by better prognosis and lower plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) in heart failure. We assessed whether another anthropometric measure, per cent body fat (PBF), reveals different associations with outcome and heart failure biomarkers (NT-proBNP, high-sensitivity troponin T (hs-TnT), soluble suppression of tumorigenesis-2 (sST2)). Methods In an individual patient dataset, BMI was calculated as weight (kg)/height (m) (2) , and PBF through the Jackson-Pollock and Gallagher equations. Results Out of 6468 patients (median 68 years, 78% men, 76% ischaemic heart failure, 90% reduced ejection fraction), 24% died over 2.2 years (1.5-2.9), 17% from cardiovascular death. Median PBF was 26.9% (22.4-33.0%) with the Jackson-Pollock equation, and 28.0% (23.8-33.5%) with the Gallagher equation, with an extremely strong correlation (r = 0.996, p < 0.001). Patients in the first PBF tertile had the worst prognosis, while patients in the second and third tertile had similar survival. The risks of all-cause and cardiovascular death decreased by up to 36% and 27%, respectively, per each doubling of PBF. Furthermore, prognosis was better in the second or third PBF tertiles than in the first tertile regardless of model variables. Both BMI and PBF were inverse predictors of NT-proBNP, but not hs-TnT. In obese patients (BMI >= 30 kg/m(2), third PBF tertile), hs-TnT and sST2, but not NT-proBNP, independently predicted outcome. Conclusion In parallel with increasing BMI or PBF there is an improvement in patient prognosis and a decrease in NT-proBNP, but not hs-TnT or sST2. hs-TnT or sST2 are stronger predictors of outcome than NT-proBNP among obese patients.
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| 9. |
- Marcks, Nick, et al.
(författare)
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Re-appraisal of the obesity paradox in heart failure : a meta-analysis of individual data
- 2021
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Ingår i: Clinical Research in Cardiology. - : Springer Nature. - 1861-0684 .- 1861-0692. ; 110:8, s. 1280-1291
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Tidskriftsartikel (refereegranskat)abstract
- Background Higher body mass index (BMI) is associated with better outcome compared with normal weight in patients with HF and other chronic diseases. It remains uncertain whether the apparent protective role of obesity relates to the absence of comorbidities. Therefore, we investigated the effect of BMI on outcome in younger patients without co-morbidities as compared to older patients with co-morbidities in a large heart failure (HF) population. Methods In an individual patient data analysis from pooled cohorts, 5,819 patients with chronic HF and data available on BMI, co-morbidities and outcome were analysed. Patients were divided into four groups based on BMI (i.e. <= 18.5 kg/m(2), 18.5-25.0 kg/m(2); 25.0-30.0 kg/m(2); 30.0 kg/m(2)). Primary endpoints included all-cause mortality and HF hospitalization-free survival. Results Mean age was 65 +/- 12 years, with a majority of males (78%), ischaemic HF and HF with reduced ejection fraction. Frequency of all-cause mortality or HF hospitalization was significantly worse in the lowest two BMI groups as compared to the other two groups; however, this effect was only seen in patients older than 75 years or having at least one relevant co-morbidity, and not in younger patients with HF only. After including medications and N-terminal pro-B-type natriuretic peptide and high-sensitivity cardiac troponin concentrations into the model, the prognostic impact of BMI was largely absent even in the elderly group with co-morbidity. Conclusions The present study suggests that obesity is a marker of less advanced disease, but does not have an independent protective effect in patients with chronic HF. [GRAPHICS] .
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| 10. |
- Pham, M. K., et al.
(författare)
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A new reference material for radionuclides in the mussel sample from the Mediterranean Sea (IAEA-437)
- 2010
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 283:3, s. 851-859
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Tidskriftsartikel (refereegranskat)abstract
- A new Reference Material (RM) for radionuclides in mussel (Mytilus galloprovincialis) from the Mediterranean Sea (IAEA-437) is described and the results of the certification process are presented. Four radionuclides (K-40, U-234, U-238, and Pu239+240) have been certified, and information values on massic activities with 95% confidence intervals are given for nine radionuclides (Cs-137, Pb-210(Po-210), Ra-226, Ra-228, Th-228, Th-230, Th-232, U-235, and Am-241). Results for less frequently reported radionuclides (Sr-90, I-129, Pu-238, Pu-239, and Pu-240) are also reported. The RM can be used for quality assurance/quality control of the analysis of radionuclides in mussel samples, for the development and validation of analytical methods and for training purposes. The material is available in 200 g units.
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