| 1. |
- Aoyama, T., et al.
(författare)
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The anomalous magnetic moment of the muon in the Standard Model
- 2020
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Ingår i: Physics reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 887, s. 1-166
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Forskningsöversikt (refereegranskat)abstract
- We review the present status of the Standard Model calculation of the anomalous magnetic moment of the muon. This is performed in a perturbative expansion in the fine-structure constant α and is broken down into pure QED, electroweak, and hadronic contributions. The pure QED contribution is by far the largest and has been evaluated up to and including O(α5) with negligible numerical uncertainty. The electroweak contribution is suppressed by (mμ/MW)2 and only shows up at the level of the seventh significant digit. It has been evaluated up to two loops and is known to better than one percent. Hadronic contributions are the most difficult to calculate and are responsible for almost all of the theoretical uncertainty. The leading hadronic contribution appears at O(α2) and is due to hadronic vacuum polarization, whereas at O(α3) the hadronic light-by-light scattering contribution appears. Given the low characteristic scale of this observable, these contributions have to be calculated with nonperturbative methods, in particular, dispersion relations and the lattice approach to QCD. The largest part of this review is dedicated to a detailed account of recent efforts to improve the calculation of these two contributions with either a data-driven, dispersive approach, or a first-principle, lattice-QCD approach. The final result reads aμSM = 116 591 810(43) x 10-11 and is smaller than the Brookhaven measurement by 3.7 σ. The experimental uncertainty will soon be reduced by up to a factor four by the new experiment currently running at Fermilab, and also by the future J-PARC experiment. This and the prospects to further reduce the theoretical uncertainty in the near future - which are also discussed here - make this quantity one of the most promising places to look for evidence of new physics.
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| 2. |
- Marinković, Goran, et al.
(författare)
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Inhibition of pro-inflammatory myeloid cell responses by short-term S100A9 blockade improves cardiac function after myocardial infarction
- 2019
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 1522-9645 .- 0195-668X. ; 40:32, s. 2713-2723
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Neutrophils have both detrimental and beneficial effects in myocardial infarction (MI), but little is known about the underlying pathways. S100A8/A9 is a pro-inflammatory alarmin abundantly expressed in neutrophils that is rapidly released in the myocardium and circulation after myocardial ischaemia. We investigated the role of S100A8/A9 in the innate immune response to MI. METHODS AND RESULTS: In 524 patients with acute coronary syndrome (ACS), we found that high plasma S100A8/A9 at the time of the acute event was associated with lower left ventricular ejection fraction (EF) at 1-year and increased hospitalization for heart failure (HF) during follow-up. In wild-type C57BL/6 mice with MI induced by permanent coronary artery ligation, treatment with the S100A9 blocker ABR-238901 during the inflammatory phase of the immune response inhibited haematopoietic stem cell proliferation and myeloid cell egression from the bone marrow. The treatment reduced the numbers of neutrophils and monocytes/macrophages in the myocardium, promoted an anti-inflammatory environment, and significantly improved cardiac function compared with MI controls. To mimic the clinical scenario, we further confirmed the effects of the treatment in a mouse model of ischaemia/reperfusion. Compared with untreated mice, 3-day ABR-238901 treatment significantly improved left ventricular EF (48% vs. 35%, P = 0.002) and cardiac output (15.7 vs. 11.1 mL/min, P = 0.002) by Day 21 post-MI. CONCLUSION: Short-term S100A9 blockade inhibits inflammation and improves cardiac function in murine models of MI. As an excessive S100A8/A9 release is linked to incident HF, S100A9 blockade might represent a feasible strategy to improve prognosis in ACS patients.
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| 3. |
- Marinković, Goran, et al.
(författare)
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S100A9 Links Inflammation and Repair in Myocardial Infarction
- 2020
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Ingår i: Circulation Research. - 0009-7330. ; 127:5, s. 664-676
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Tidskriftsartikel (refereegranskat)abstract
- RATIONALE: The alarmin S100A9 has been identified as a potential therapeutic target in myocardial infarction. Short-term S100A9 blockade during the inflammatory phase post-myocardial infarction inhibits systemic and cardiac inflammation and improves cardiac function long term. OBJECTIVE: To evaluate the impact of S100A9 blockade on postischemic cardiac repair. METHODS AND RESULTS: We assessed cardiac function, hematopoietic response, and myeloid phagocyte dynamics in WT (wild type) C57BL/6 mice with permanent coronary artery ligation, treated with the specific S100A9 blocker ABR-238901 for 7 or 21 days. In contrast to the beneficial effects of short-term therapy, extended S100A9 blockade led to progressive deterioration of cardiac function and left ventricle dilation. The treatment reduced the proliferation of Lin-Sca-1+c-Kit+ hematopoietic stem and progenitor cells in the bone marrow and the production of proreparatory CD150+CD48-CCR2+ hematopoietic stem cells. Monocyte trafficking from the spleen to the myocardium and subsequent phenotype switching to reparatory Ly6CloMerTKhi macrophages was also impaired, leading to inefficient efferocytosis, accumulation of apoptotic cardiomyocytes, and a larger myocardial scar. The transcription factor Nur77 (Nr4a1 [nuclear receptor subfamily 4 group A member 1]) mediates the transition from inflammatory Ly6Chi monocytes to reparatory Ly6Clo macrophages. S100A9 upregulated the levels and activity of Nur77 in monocytes and macrophages in vitro and in Ly6Chi/int monocytes in vivo, and S100A9 blockade antagonized these effects. Finally, the presence of reparatory macrophages in the myocardium was also impaired in S100A9-/- mice with permanent myocardial ischemia, leading to depressed cardiac function long term. CONCLUSIONS: We show that S100A9 plays an important role in both the inflammatory and the reparatory immune responses to myocardial infarction. Long-term S100A9 blockade negatively impacts cardiac recovery and counterbalances the beneficial effects of short-term therapy. These results define a therapeutic window targeting the inflammatory phase for optimal effects of S100A9 blockade as potential immunomodulatory treatment in acute myocardial infarction.
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| 4. |
- Marinković, Stefan, et al.
(författare)
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Oxygen ordering in untwinned YBa2Cu3 O7-δ films driven by electrothermal stress
- 2023
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Ingår i: Physical Review B. - 2469-9969 .- 2469-9950. ; 107:1
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally investigate the displacement of oxygen vacancies at high current densities in highly untwinned YBa2Cu3O7-δ films grown on top of MgO substrates. Transport bridges oriented along the YBa2Cu3O7-δ crystallographic directions [100] (a axis), [010] (b axis), and [110] (45∘ from principal axes) reveal that the onset of vacancy migration is mainly determined by the local temperature (or equivalently by the dissipated power) rather than the associated activation energy. Exceeding this threshold value, a clear directional migration proceeds as evidenced by optical microscopy. Concomitant electrotransport measurements show that an intermediate phase, characterized by a decrease in resistivity, precedes long-range migration of vacancies. We numerically demonstrate that this intermediate phase consists of a homogenization of the oxygen distribution along the transport bridge, a phenomenon strongly dependent on the activation energy and the initial degree of disorder. These findings provide some important clues to determine the level of order/disorder in YBa2Cu3O7-δ films based on electric transport measurements.
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| 5. |
- Nulens, Lukas, et al.
(författare)
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Catastrophic magnetic flux avalanches in NbTiN superconducting resonators
- 2023
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Ingår i: Communications Physics. - 2399-3650. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Macroscopic superconducting components are an important building block of various quantum circuits. Since several of the envisioned applications require exposure to magnetic fields, it is of utmost importance to explore the impact of magnetic fields on their performance. Here we explore the complex pattern of magnetic field penetration and identify its impact on the resonance frequency of NbTiN superconducting resonators by combining magneto-optical imaging and high-frequency measurements. At temperatures below approximately half of the superconducting critical temperature, the development of magnetic flux avalanches manifests itself as a noisy response in the field-dependent resonance frequency. Magneto-optical imaging reveals different regimes and distinguishes the impact of avalanches in the ground plane and resonator. Our findings demonstrate that superconducting resonators represent a valuable tool to investigate magnetic flux dynamics. Moreover, the current blooming of niobium-based superconducting radio-frequency devices makes this report timely by unveiling the severe implications of magnetic flux dynamics.
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