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| 2. |
- Algaba, Juan-Carlos, et al.
(författare)
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Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
- 2021
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 911:1
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Forskningsöversikt (refereegranskat)abstract
- In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M o˙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded.
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| 3. |
- Berg, Kirsti, et al.
(författare)
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Acetylsalicylic acid treatment until surgery reduces oxidative stress and inflammation in patients undergoing coronary artery bypass grafting
- 2013
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Ingår i: European Journal of Cardio-Thoracic Surgery. - : Oxford University Press (OUP). - 1010-7940 .- 1873-734X. ; 43:6, s. 1154-1163
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Acetylsalicylic acid (ASA) is a cornerstone in the treatment of coronary artery disease (CAD) due to its antiplatelet effect. Cessation of aspirin before coronary artery bypass grafting (CABG) is often recommended to avoid bleeding, but the practice is controversial because it is suggested to worsen the underlying CAD. The aims of the present prospective, randomized study were to assess if ASA administration until the day before CABG decreases the oxidative load through a reduction of inflammation and myocardial damage, compared with patients with preoperative discontinuation of ASA. METHODS: Twenty patients scheduled for CABG were randomly assigned to either routine ASA-treatment (160 mg daily) until the time of surgery (ASA), or to ASA-withdrawal 7 days before surgery (No-ASA). Blood-samples were taken from a radial artery and coronary sinus, during and after surgery and analysed for 8-iso-prostaglandin (PG) F(2α); a major F(2)-isoprostane, high-sensitivity C-reactive protein (hs-CRP), cytokines and troponin T. Left ventricle Tru-Cut biopsies were taken from viable myocardium close to the left anterior descending artery just after connection to cardiopulmonary bypass, and before cardioplegia were established for gene analysis (Illumina HT-12) and immunohistochemistry (CD45). RESULTS: 8-Iso-PGF(2α) at baseline (t(1)) were 111 (277) pmol/l and 221 (490) pmol/l for ASA and No-ASA, respectively (P = 0.065). Area under the curve showed a significantly lower level in plasma concentration of 8-iso-PGF(2α) and hsCRP in the ASA group compared with the No-ASA group with (158 pM vs 297 pM, P = 0.035) and hsCRP (8.4 mg/l vs 10.1 mg/l, P = 0.013). All cytokines increased during surgery, but no significant differences between the two groups were observed. Nine genes (10 transcripts) were found with a false discovery rate (FDR) <0.1 between the ASA and No-ASA groups. CONCLUSIONS: Continued ASA treatment until the time of CABG reduced oxidative and inflammatory responses. Also, a likely beneficial effect upon myocardial injury was noticed. Although none of the genes known to be involved in oxidative stress or inflammation took a different expression in myocardial tissue, the genetic analysis showed interesting differences in the mRNA level. Further research in this field is necessary to understand the role of the genes.
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| 4. |
- Devito, Fiorella, et al.
(författare)
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Evaluation of endothelial function and cardiovascular risk in non-obese patients with slight degree of obstructive sleep apnea syndrome
- 2017
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Ingår i: Monaldi Archives for Chest Disease. - : Fondazione Salvatore Maugeri. - 1122-0643 .- 2532-5264. ; 87:3, s. 112-118
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Tidskriftsartikel (refereegranskat)abstract
- Recently, it has been clearly described an independent relationship between obstructive sleep apnea syndrome (OSAS) and cardiovascular risk, with underlying mechanisms also including endothelial dysfunction. We enrolled 32 consecutive non-obese patients (mean age of 39.5 +/- 11.5 years), of which 16 with mild OSAS and 16 snoring without OSAS. Mild OSAS is defined by an AHI index between 5 and 15. We have investigated if whether there was a relationship between mild OSAS, endothelial function and carotid intima-media thickness (C-IMT). The population was divided into two groups: Group 1 (16 simple snorer patients with an average age of 39.4 +/- 12.1 years) and Group 2 (16 subjects with mild OSAS with an average age of 39.6 +/- 11.2 years). Each group underwent cardiovascular investigation including measurement of flow-mediated dilation (FMD) of the brachial artery and C-IMT. Both groups comprised non-obese subjects. Patients with mild OSAS had serum total cholesterol values statistically significantly higher than simple snores patients (178.6 +/- 24.9 vs 159.2 +/- 25.3; p=0.038). OSAS patients had also a trend towards higher values of maximum C-IMT compared to simple snorer patients (0.70 +/- 0.15 vs 0.65 +/- 0.16), although below the level of significance. Between the two groups, no difference was found for FMD values. The present results on mild OSAS strengthen the importance of a diagnosis of OSAS as soon as possible, in order to encourage all primary prevention interventions to correct risk factors responsible for disease progression and the occurrence of cardiovascular diseases, not excluding the use of therapies of non-invasive ventilation even in the early stages of the disease.
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| 5. |
- Nordgaard, Håvard B., et al.
(författare)
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Pulsatility index variations using two different transit-time flowmeters in coronary artery bypass surgery
- 2010
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Ingår i: European Journal of Cardio-Thoracic Surgery. - : Oxford University Press (OUP). - 1010-7940 .- 1873-734X. ; 37:5, s. 1063-1067
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Tidskriftsartikel (refereegranskat)abstract
- The MediStim flowmeter displayed a lower PI than the Transonic, due to a lower filter setting. In the Transonic, flow signals are filtered at a lower level, rendering a 'smoother' pattern of flow curves. Because different filter settings determine different PIs, caution must be taken when flow values and flowmeters are compared. The type of flowmeter should be indicated whenever graft flow measurements and derived indexes are provided.
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