We present a lattice calculation of the leading-order electromagnetic and strong isospin-breaking corrections to the hadronic vacuum polarization (HVP) contribution to the anomalous magnetic moment ...of the muon. We employ the gauge configurations generated by the European Twisted Mass Collaboration with Nf = 2 + 1 + 1 dynamical quarks at three values of the lattice spacing (a≃0.062,0.082,0.089 fm) with pion masses between ≃210 and ≃450 MeV. The results are obtained by adopting the RM123 approach in the quenched-QED approximation, which neglects the charges of the sea quarks. Quark disconnected diagrams are not included. After the extrapolations to the physical pion mass and to the continuum and infinite-volume limits the contributions of the light, strange, and charm quarks are, respectively, equal to δaμHVP(ud)=7.1(2.5)×10−10, δaμHVP(s)=−0.0053(33)×10−10, and δaμHVP(c)=0.0182(36)×10−10. At leading order in αem and (md−mu)/ΛQCD we obtain δaμHVP(udsc)=7.1(2.9)×10−10, which is currently the most accurate determination of the isospin-breaking corrections to aμHVP.
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We present a lattice calculation of the leading hadronic vacuum polarization (HVP) contribution of the light u- and d-quarks to the anomalous magnetic moment of the muon, aHVPμ (ud), adopting the ...gauge configurations generated by the European Twisted Mass Collaboration (ETMC) with Nf = 2 + 1 + 1 dynamical quarks at three values of the lattice spacing (a ≃ 0.062, 0.082, 0.089 fm) with pion masses in the range Mπ ≃ 210–450 MeV. Thanks to several lattices at fixed values of the light-quark mass and scale but with different sizes we perform a careful investigation of finite-volume effects (FVEs), which represent one of main source of uncertainty in modern lattice calculations of aHVPμ (ud). In order to remove FVEs we develop an analytic representation of the vector correlator, which describes the lattice data for time distances larger than ≃ 0.2 fm. The representation is based on quark-hadron duality at small and intermediate time distances and on the two-pion contributions in a finite box at larger time distances. After removing FVEs we extrapolate the corrected lattice data to the physical pion point and to the continuum limit taking into account the chiral logs predicted by Chiral Perturbation Theory (ChPT). We obtain aHVPμ (ud) = 619.0 (17.8) × 10−10. Adding the contribution of strange and charm quarks, obtained by ETMC, and an estimate of the isospin-breaking corrections and quark-disconnected diagrams from the literature we get aHVPμ (udsc) = 683 (19) × 10−10, which is consistent with recent results based on dispersive analyses of the experimental cross section data for e+e− annihilation into hadrons. Using our analytic representation of the vector correlator, taken at the physical pion mass in the continuum and infinite volume limits, we provide the first eleven moments of the polarization function and we compare them with recent results of the dispersive analysis of the π+π− channels. We estimate also the light-quark contribution to the missing part of aHVPμ not covered in the MUonE experiment.
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The leading-order electromagnetic and strong isospin-breaking corrections to the ratio of K_{μ2} and π_{μ2} decay rates are evaluated for the first time on the lattice, following a method recently ...proposed. The lattice results are obtained using the gauge ensembles produced by the European Twisted Mass Collaboration with N_{f}=2+1+1 dynamical quarks. Systematic effects are evaluated and the impact of the quenched QED approximation is estimated. Our result for the correction to the tree-level K_{μ2}/π_{μ2} decay ratio is -1.22(16)%, to be compared to the estimate of -1.12(21)% based on chiral perturbation theory and adopted by the Particle Data Group.
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Introduction
This narrative review focusing on critical care echocardiography (CCE) has been written by a group of experts in the field, with the aim of outlining the state of the art in CCE in the ...10 years after its official recognition and definition.
Results
In the last 10 years, CCE has become an essential branch of critical care ultrasonography and has gained general acceptance. Its use, both as a diagnostic tool and for hemodynamic monitoring, has increased markedly, influencing contemporary cardiorespiratory management. Recent studies suggest that the use of CCE may have a positive impact on outcomes. CCE may be used in critically ill patients in many different clinical situations, both in their early evaluation of in the emergency department and during intensive care unit (ICU) admission and stay. CCE has also proven its utility in perioperative settings, as well as in the management of mechanical circulatory support. CCE may be performed with very simple diagnostic objectives. This application, referred to as basic CCE, does not require a high level of training. Advanced CCE, on the other hand, uses ultrasonography for full evaluation of cardiac function and hemodynamics, and requires extensive training, with formal certification now available. Indeed, recent years have seen the creation of worldwide certification in advanced CCE. While transthoracic CCE remains the most commonly used method, the transesophageal route has gained importance, particularly for intubated and ventilated patients.
Conclusion
CCE is now widely accepted by the critical care community as a valuable tool in the ICU and emergency department, and in perioperative settings.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Sepsis-induced myocardial dysfunction is associated with poor outcomes, but traditional measurements of systolic function such as left ventricular ejection fraction (LVEF) do not directly correlate ...with prognosis. Global longitudinal strain (GLS) utilizing speckle-tracking echocardiography (STE) could be a better marker of intrinsic left ventricular (LV) function, reflecting myocardial deformation rather than displacement and volume changes. We sought to investigate the prognostic value of GLS in patients with sepsis and/or septic shock.
We conducted a systematic review (PubMed and Embase up to 26 October 2017) and meta-analysis to investigate the association between GLS and mortality at longest follow up in patients with severe sepsis and/or septic shock. In the primary analysis, we included studies reporting transthoracic echocardiography data on GLS according to mortality. A secondary analysis evaluated the association between LVEF and mortality including data from studies reporting GLS.
We included eight studies in the primary analysis with a total of 794 patients (survival 68%, n = 540). We found a significant association between worse LV function and GLS values and mortality: standard mean difference (SMD) - 0.26; 95% confidence interval (CI) - 0.47, - 0.04; p = 0.02 (low heterogeneity, I
= 43%). No significant association was found between LVEF and mortality in the same population of patients (eight studies; SMD, 0.02; 95% CI - 0.14, 0.17; p = 0.83; no heterogeneity, I
= 3%).
Worse GLS (less negative) values are associated with higher mortality in patients with severe sepsis or septic shock, while such association is not valid for LVEF. More critical care research is warranted to confirm the better ability of STE in demonstrating underlying intrinsic myocardial disease compared to LVEF.
We present a nonperturbative lattice calculation of the form factors which contribute to the amplitudes for the radiative decays P → ℓνℓγ, where P is a pseudoscalar meson and ℓ is a charged lepton. ...Together with the nonperturbative determination of the corrections to the processes P → ℓνℓ due to the exchange of a virtual photon, this allows accurate predictions at O(αem) to be made for leptonic decay rates for pseudoscalar mesons ranging from the pion to the Ds meson. We are able to separate unambiguously and nonpertubatively the pointlike contribution, from the structure-dependent, infrared-safe, terms in the amplitude. The fully nonperturbative O(a) improved calculation of the inclusive leptonic decay rates will lead to the determination of the corresponding Cabibbo-Kobayashi-Maskawa matrix elements also at O(αem). Prospects for a precise evaluation of leptonic decay rates with emission of a hard photon are also very interesting, especially for the decays of heavy D and B mesons for which currently only model-dependent predictions are available to compare with existing experimental data.
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A
bstract
We present a lattice calculation of the Hadronic Vacuum Polarization (HVP) contribution of the strange and charm quarks to the anomalous magnetic moment of the muon including leading-order ...electromagnetic corrections. We employ the gauge configurations generated by the European Twisted Mass Collaboration (ETMC) with
N
f
= 2 + 1 + 1 dynamical quarks at three values of the lattice spacing (
a
≃ 0
.
062
,
0
.
082
,
0
.
089 fm) with pion masses in the range
M
π
≃ 210-450 MeV. The strange and charm quark masses are tuned at their physical values. Neglecting disconnected diagrams and after the extrapolations to the physical pion mass and to the continuum limit we obtain:
a
μ
s
(
α
em
2
) = (53.1 ± 2.5) · 10
− 10
,
a
μ
s
(
α
em
3
) = (−0.018 ± 0.011) · 10
− 10
and
a
μ
c
(
α
em
2
) = (14.75 ± 0.56) · 10
− 10
,
a
μ
c
(
α
em
3
) = (−0.030 ± 0.013) · 10
− 10
for the strange and charm contributions, respectively.
The leading electromagnetic (e.m.) and strong isospin-breaking corrections to the π+→μ+νγ and K+→μ+νγ leptonic decay rates are evaluated for the first time on the lattice. The results are obtained ...using gauge ensembles produced by the European Twisted Mass Collaboration with Nf=2+1+1 dynamical quarks. The relative leading-order e.m. and strong isospin-breaking corrections to the decay rates are 1.53(19)% for πμ2 decays and 0.24(10)% for Kμ2 decays. Using the experimental values of the πμ2 and Kμ2 decay rates and updated lattice QCD results for the pion and kaon decay constants in isosymmetric QCD, we find that the Cabibbo-Kobayashi-Maskawa matrix element |Vus|=0.22538(46), reducing by a factor of about 1.8 the corresponding uncertainty in the particle data group review. Our calculation of |Vus| allows also an accurate determination of the first-row Cabibbo-Kobayashi-Maskawa unitarity relation |Vud|2+|Vus|2+|Vub|2=0.99988(46). Theoretical developments in this paper include a detailed discussion of how QCD can be defined in the full QCD+QED theory and an improved renormalization procedure in which the bare lattice operators are renormalized nonperturbatively into the regularization independent momentum subtraction (RI'-MOM) scheme and subsequently matched perturbatively at O(αemαs(MW)) into the W-regularization scheme appropriate for these calculations.
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We present a lattice computation of the isospin-breaking corrections to pseudoscalar meson masses using the gauge configurations produced by the European Twisted Mass Collaboration with Nf=2+1+1 ...dynamical quarks at three values of the lattice spacing (a≃0.062, 0.082, and 0.089 fm) with pion masses in the range Mπ≃210–450 MeV. The strange and charm quark masses are tuned at their physical values. We adopt the RM123 method based on the combined expansion of the path integral in powers of the d- and u-quark mass difference (m^d−m^u) and of the electromagnetic coupling αem. Within the quenched QED approximation, which neglects the effects of the sea-quark charges, and after the extrapolations to the physical pion mass and to the continuum and infinite volume limits, we provide results for the pion, kaon, and (for the first time) charmed-meson mass splittings, for the prescription-dependent parameters επ0, εγ(MS¯,2 GeV), εK0(MS¯,2 GeV), related to the violations of the Dashen’s theorem, and for the light quark mass difference (m^d−m^u)(MS¯,2 GeV).
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The authors describe safety issues associated with the administration of convalescent plasma, reporting both non-specific (infection, circulatory overload, lung injury) and disease-specific (viral ...enhancement) side effects of plasma transfusions. ...it is crucial to ascertain which (if) treatments during the preparation of convalescent plasma have been performed to reduce the amount of coagulation factors. ...we believe that plasma transfusions should be administered thoughtfully in COVID-19 patients to avoid an unnecessary potentiation of their already existing pro-thrombotic state.
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