Abstract
There is a scarcity of follow-up data on post-COVID syndrome and its physical, psychological, and quality of life attributes, particularly from South Asian populations. This study was ...conducted to assess the prevalence, associations, and impact of the post-COVID syndrome among patients treated at a dedicated COVID-19 treatment unit. A prospective cohort study was conducted to follow-up patients with moderate to severe disease or mild disease with co-morbidities at 2 and 6 weeks, 3 and 6 months and 1 year from discharge. Clinical notes, an interviewer-administered questionnaire and six-item cognitive impairment, Montreal Cognitive Assessment, Fatigue (11-item Chalder) and EQ5D5L questionnaires were used for data collection. All patients had follow-up echocardiograms and symptomatic patients had biochemical and haematological investigations, chest x-rays, high-resolution computed tomography of chest and lung function tests. Among 153 patients {mean age 57.2 ± 16.3 years (83 (54.2% males)}, 92 (60.1%) got the severe disease. At least a single post-COVID symptom was reported by 119 (77.3%), 92 (60.1%), 54 (35.3%) and 25 (16.3%) at 6 weeks, 3 months, 6 months and 1 year respectively. Post-COVID symptoms were significantly associated with disease severity (
p
= 0.004). Fatigue was found in 139 (90.3%), 97 (63.4%) and 66 (43.1%) patients at 2, 6 and 12 weeks respectively. Dyspnoea {OR 1.136 (CI 95% 0.525–2.455)}, arthralgia {OR 1.83(CI 95% 0.96–3.503)} and unsteadiness {OR 1.34 (CI 95% 0.607–2.957)}were strongly associated with age above 60 years. Both genders were equally affected. In multivariable logistic regression, fatigue and anxiety/depression were associated with poor quality of life (QoL) (
p
= 0.014,
p
≤ 0.001) in 6 weeks. In cardiac assessments, diastolic dysfunction (DD) was detected in 110 (72%) patients at 2 weeks and this number reduced to 64 (41.8%) at 12 weeks. The decline in diastolic dysfunction in elderly patients was significantly higher compared to young patients (
p
= 0.012). Most post-COVID symptoms, QoL and cognition improve during the first few months. The severity of the disease and older age are associated with post-COVID symptoms. Transient DD may contribute to cardiac symptoms of post-COVID syndrome, especially in elderly patients.
In this work, the modification of hard jets in an extended static medium held at a fixed temperature is studied using three different Monte Carlo event generators: linear Boltzmann transport (LBT), ...modular all twist transverse-scattering elastic-drag and radiation (MATTER), and modular algorithm for relativistic treatment of heavy-ion interactions (MARTINI). Each event generator contains a different set of assumptions regarding the energy and virtuality of the partons within a jet versus the energy scale of the medium and, hence, applies to a different epoch in the space-time history of the jet evolution. Here modeling is developed where a jet may sequentially transition from one generator to the next, on a parton-by-parton level, providing a detailed simulation of the space-time evolution of medium modified jets over a much broader dynamic range than has been attempted previously in a single calculation. Comparisons are carried out for different observables sensitive to jet quenching, including the parton fragmentation function and the azimuthal distribution of jet energy around the jet axis. The effect of varying the boundary between different generators is studied and a theoretically motivated criterion for the location of this boundary is proposed. Lastly, the importance of such an approach with coupled generators to the modeling of jet quenching is discussed.
We present a new study of jet interactions in the quark-gluon plasma created in high-energy heavy-ion collisions, using a multistage event generator within the jetscape framework. We focus on ...medium-induced modifications in the rate of inclusive jets and high transverse momentum (high-pT) hadrons. Scattering-induced jet energy loss is calculated in two stages: a high virtuality stage based on the matter model, in which scattering of highly virtual partons modifies the vacuum radiation pattern, and a second stage at lower jet virtuality based on the lbt model, in which leading partons gain and lose virtuality by scattering and radiation. Coherence effects that reduce the medium-induced emission rate in the matter phase are also included. The trento model is used for initial conditions, and the (2 + 1)dimensional vishnu model is used for viscous hydrodynamic evolution. Jet interactions with the medium are modeled via 2-to-2 scattering with Debye screened potentials, in which the recoiling partons are tracked, hadronized, and included in the jet clustering. Holes left in the medium are also tracked and subtracted to conserve transverse momentum. Calculations of the nuclear modification factor (RAA) for inclusive jets and high-pT hadrons are compared to experimental measurements at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC). Within this framework, we find that with one extra parameter which codifies the transition between stages of jet modification—along with the typical parameters such as the coupling in the medium, the start and stop criteria, etc.—we can describe these data at all energies for central and semicentral collisions without a rescaling of the jet transport coefficient qˆ.
Parton energy-momentum exchange with the quark gluon plasma (QGP) is a multiscale problem. In this work, we calculate the interaction of charm quarks with the QGP within the higher twist formalism at ...high virtuality and high energy using the Modular All Twist Transverse-scattering Elastic-drag and Radiation (MATTER) model, while the low-virtuality and high-energy portion is treated via a linearized Boltzmann transport formalism. Coherence effect that reduces the medium-induced emission rate in the MATTER model is also taken into account through a virtuality-dependent qˆ, leaving the simultaneous dependence of qˆ on heavy quark mass and virtuality for future studies. The interplay between these two formalisms is studied phenomenologically and used to produce a first description of the D-meson and charged hadron nuclear modification factor RAA across multiple centralities. As a result, all calculations were carried out utilizing the Jet Energy-loss Tomography with a Statistically and Computationally Advanced Program Envelope framework.
We study parton energy-momentum exchange with the quark gluon plasma (QGP) within a multistage approach composed of in-medium Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution at high virtuality, ...and (linearized) Boltzmann transport formalism at lower virtuality. This multistage simulation is then calibrated in comparison with high- p T charged hadrons, D mesons, and the inclusive jet nuclear modification factors, using Bayesian model-to-data comparison, to extract the virtuality-dependent transverse momentum broadening transport coefficient q ̂ . To facilitate this undertaking, we develop a quantitative metric for validating the Bayesian workflow, which is used to analyze the sensitivity of various model parameters to individual observables. The usefulness of this new metric in improving Bayesian model emulation is shown to be highly beneficial for future such analyses. Published by the American Physical Society 2024
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