Radiological lung sequelae, functional status and symptoms in older patients 3 and 6 months after hospitalization for COVID-19 pneumonia.

The aim of our study was to assess the lung sequelae and clinical consequences 3 and 6 months after hospitalization for COVID-19 pneumonia in older patients. An observational study was conducted on 55 patients aged 65 years and older. Activities of daily living (ADL) and clinical frailty scale (CFS) were assessed at baseline and after 3 months. Both quantitative assessment at chest high-resolution computed tomography (CT) and semi-quantitative severity score (CTSS) were performed at baseline and after 3 and 6 months. Mean age: 82.3 ± 7.1 years. Male prevalence: 56.4%. After 6 months, ground-glass opacities (GGO) were still detectable in 22% of subjects, while consolidations were no longer appreciable. During follow-up, CTSS reached an overall median score of zero after 6 months. Fibrotic-like changes were found in 40% of subjects with an overall median score of 0 (0-5) points, being more prevalent in males. Patients reporting worsening ADL and CFS were 10.9% and 45.5%, respectively. They were associated with the burden of comorbidities, especially history of heart failure and chronic obstructive pulmonary disease at baseline. Amnesic disorders, exertional dyspnea, and fatigue were the most relevant symptoms reported. No association emerged between persistent or new-onset symptoms and evidence of fibrotic-like changes. The typical chest CT abnormalities of the COVID-19 pneumonia acute phase resolved in most of our older patients. Mild fibrotic-like changes persisted in less than half of the patients, especially males, without significantly affecting the functional status and frailty condition, which instead were more likely associated with pre-existing comorbidities.

Transverse-Momentum-Dependent Distributions with Jets.

We investigate the use of jets to measure transverse-momentum-dependent distributions (TMDs). The example we use to present our framework is the dijet momentum decorrelation at lepton colliders. Translating this momentum decorrelation into an angle θ≪1, we analyze the factorization of the cross section for the cases θ≫R, θ∼R, and θ≪R, where R is the jet radius. Critically, for the winner-take-all axis, the jet TMD has the same double-scale renormalization group evolution as TMD fragmentation functions for all radii R. TMD fragmentation functions in factorization theorems may then simply be replaced by the jet TMDs we calculate, and all ingredients to perform the resummation to next-to-next-to-leading logarithmic accuracy are available. Our approach also applies to semi-inclusive deep inelastic scattering, where a jet instead of a hadron is measured in the final state, and we find a clean method to probe the intrinsic transverse momentum of quarks and gluons in the proton that is less sensitive to final-state nonperturbative effects.