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Purpose During a follow-up program of patients admitted for COVID-19 at our non-ICU Unit, we found that 37% of them had decreased diffusing lung capacity for carbon monoxide (DLCO) 3–6 months after discharge. This prospective observational study aimed to evaluate the evolution of changes in DLCO and respiratory symptoms at the 1-year follow-up visit. Methods Seventeen (mean age 71 years; 8 males) of 19 eligible patients (DLCO 80% of predicted) in 6 (35%); in the other 6 (35%) it remained unchanged. The prevalence of exertional dyspnea (65–35%, P = 0.17), cough (24–18%, P = 1), and fatigue (76–35%, P = 0.04) decreased at the 1-year visit. Conclusion These results suggest that DLCO and respiratory symptoms tend to normalize or improve 1 year after hospitalization for COVID-19 in most patients. However, there is also a non-negligible number of patients (about one-third) in whom respiratory changes persist and will need prolonged follow-up.

The nanoscopic mutual diffusion coefficient, DMn, of a methanol/water mixture is smaller than the single particle diffusion coefficient of either methanol or water, indicating the existence of dynamic associates of water and methanol molecules.

Background Nursing home (NH) residents have been dramatically affected by COVID-19, with extremely high rates of hospitalization and mortality. Aims To describe the features and impact of an assistance model involving an intermediate care mobile medical specialist team (GIROT, Gruppo Intervento Rapido Ospedale Territorio) aimed at delivering “hospital-at-nursing home” care to NH residents with COVID-19 in Florence, Italy. Methods The GIROT activity was set-up during the first wave of the pandemic (W1, March–April 2020) and became a structured healthcare model during the second (W2, October 2020–January 2021). The activity involved (1) infection transmission control among NHs residents and staff, (2) comprehensive geriatric assessment including prognostication and geriatric syndromes management, (3) on-site diagnostic assessment and protocol-based treatment of COVID-19, (4) supply of nursing personnel to understaffed NHs. To estimate the impact of the GIROT intervention, we reported hospitalization and infection lethality rates recorded in SARS-CoV-2-positive NH residents during W1 and W2. Results The GIROT activity involved 21 NHs (1159 residents) and 43 NHs (2448 residents) during W1 and W2, respectively. The percentage of infected residents was higher in W2 than in W1 (64.5% vs. 38.8%), while both hospitalization and lethality rates significantly decreased in W2 compared to W1 (10.1% vs 58.2% and 23.4% vs 31.1%, respectively). Discussion Potentiating on-site care in the NHs paralleled a decrease of hospital admissions with no increase of lethality. Conclusions An innovative “hospital-at-nursing home” patient-centred care model based on comprehensive geriatric assessment may provide a valuable contribution in fighting COVID-19 in NH residents.

Background The COVID‐19 pandemic has put a strain on health systems. Predictors of adverse outcomes need to be investigated to properly manage COVID‐19 patients. The Braden Scale (BS), commonly used for the assessment of pressure ulcer risk, has recently been proposed to identify frailty. Objective To investigate the predictive utility of the BS for prediction of in‐hospital mortality in a cohort of COVID‐19 patients admitted to non‐ICU wards. Methods We conducted a retrospective single‐center cohort study evaluating all patients with SARS‐CoV‐2 infection consecutively admitted over a 2‐month period (from March 6 to May 7, 2020) to the COVID‐19 general wards of our institution. Demographic, clinical, and nursing assessment data, including admission BS, were extracted from electronic medical records. Univariable and multivariable logistic regression models were used to explore the association between the BS score and in‐hospital death. Results Braden Scale was assessed in 146 patients (mean age 74.7 years; 52% males). On admission, 46 had a BS ≤ 15, and 100 patients had a BS > 15. Mortality among patients with BS ≤ 15 was significantly higher than in patients with BS > 15 (45.7% vs. 16%; p

Calprotectin (S100A8/A9) has been identified as a biomarker that can aid in predicting the severity of disease in COVID-19 patients. This study aims to evaluate the correlation between levels of circulating calprotectin (cCP) and the severity of COVID-19.Sera from 245 COVID-19 patients and 110 apparently healthy individuals were tested for calprotectin levels using a chemiluminescent immunoassay (Inova Diagnostics). Intensive care unit (ICU) admission and type of respiratory support administered were used as indicators of disease severity, and their correlation with calprotectin levels was assessed.Samples from patients in the ICU had a median calprotectin concentration of 11.6 µg/ml as compared to 3.5 µg/ml from COVID-19 patients who were not in the ICU. The median calprotectin concentration in a cohort of healthy individuals collected before the COVID-19 pandemic was 3.0 µg/ml (95% CI: 2.820-2.969 µg/ml). Patients requiring a Venturi mask, continuous positive airway pressure, or orotracheal intubation all had significantly higher values of calprotectin than controls, with the increase of cCP levels proportional to the increasing need of respiratory support.Calprotectin levels in serum correlate well with disease severity and represent a promising serological biomarker for the risk assessment of COVID-19 patients.

2-Propanol was investigated, in both the liquid and supercooled states, as a model system to study how hydrogen bonds affect the structural relaxation and the dynamics of mesoscale structures, of approximately several Ångstroms, employing static and quasi-elastic neutron scattering and molecular dynamics simulation. Dynamic neutron scattering measurements were performed over an exchanged wave-vector range encompassing the pre-peak, indicative of the presence of H-bonding associates, and the main peak. The dynamics observed at the pre-peak is associated with the formation and disaggregation of the H-bonded associates and is measured to be at least one order of magnitude slower than the dynamics at the main peak, which is identified as the structural relaxation. The measurements indicate that the macroscopic shear viscosity has a similar temperature dependence as the dynamics of the H-bonded associates, which highlights the important role played by these structures, together with the structural relaxation, in defining the macroscopic rheological properties of the system. Importantly, the characteristic relaxation time at the pre-peak follows an Arrhenius temperature dependence whereas at the main peak it exhibits a non-Arrhenius behavior on approaching the supercooled state. The origin of this differing behavior is attributed to an increased structuring of the hydrophobic domains of 2-propanol accommodating a more and more encompassing H-bond network, and a consequent set in of dynamic cooperativity.

Introduction: Inflammatory response plays a key role in coronavirus disease 2019 (COVID-19) as it has been shown that the resulting cytokine storm increases its severity. Aim: To investigate the role of procalcitonin (PCT) as a predictor of in-hospital mortality in patients with severe to critical COVID-19. Design and methods: Retrospective cohort study. For the purpose of this research, 150 patients with severe to critical COVID-19 consecutively admitted to the intensive care unit (ICU) were investigated. Patients’ demographics, clinical and laboratory findings, and PCT level were collected upon their admission to the hospital and from the disease outcome data. Findings: Of the 150 patients who entered the study, 77 were discharged alive from the hospital. The mean age of the patients was 60.9 ±16.3 years and 51.3% of them were male. The mean PCT level was significantly higher in the deceased patients than in survivors (2.4 ±3.4 vs 0.7±1.3, pConclusion: Serum PCT levels are associated with in-hospital mortality in COVID-19 patients admitted to ICU and could be used as a simple tool to predict adverse outcomes and expedite timely and appropriate interventions.

Understanding the dynamics of soft colloids, such as star polymers, dendrimers, and microgels, is of scientific and practical importance. It is known that the excluded volume effect plays a key role in colloidal dynamics. Here, we propose a condition of compressibility equivalence that provides a simple method to experimentally evaluate the excluded volume of soft colloids from a thermodynamic view. We apply this condition to survey the dynamics of a series of star polymer dispersions. It is found that as the concentration increases, the slowing of the long-time self-diffusivity of the star polymer, normalized by the short-time self-diffusivity, can be mapped onto the hard-sphere behavior. This phenomenon reveals the dynamic equivalence between soft colloids and hard spheres, despite the apparent complexity of the interparticle interaction of the soft colloids. The methods for measuring the osmotic compressibility and the self-diffusivities of soft colloidal dispersions are also presented., 18 pages, 4 figures

When grafted to spherical nanoparticles at high grafting densities, polymers adopt a variety of conformations. Because of strong confinement by neighboring chains, portions of the polymer near the nanoparticle core are highly stretched in the concentrated polymer brush region (CPB) of the polymer layer. Farther away from the core, where the polymer is less confined, the conformation becomes more ideal in the semidilute polymer brush (SDPB) region. Using a combination of small-angle neutron scattering (SANS) and neutron spin echo (NSE) spectroscopy, we directly characterized both the structure and dynamics of the CPB and SDPB on poly(methyl acrylate) (PMA) grafted SiO2 nanoparticles (NPs). Analysis of SANS measurements using a new core-chain-chain (CCC) model confirmed that the portion of the chain in the CPB region is highly stretched, and transitions to a more random conformation. Dynamics in the CPB region were found to be much slower than the SDPB region.

Polymer mobility near nanoparticle surfaces has been extensively discussed; however, direct experimental observation in the nanocomposite melts has been a difficult task. Here, by taking advantage of large dynamical asymmetry between the miscible matrix and surface-bound polymers, we highlighted their interphases and studied the resulting effect on the nanoparticle relaxation using X-ray photon correlation spectroscopy. The local mobility gradient is signified by an unprecedented increase in the relaxation time at length scales on the order of polymer radius of gyration. The effect is accompanied by a transition from simple diffusive to subdiffusive behavior in accord with viscous and entangled dynamics of polymers in the matrix and in the interphase, respectively. Our results demonstrate that the nanoparticle-induced polymer mobility changes in the interphases of nanocomposite melts can be extracted from the length-scale-dependent slow particle motion.

Particle-polymer attractions in nanocomposites can cause significant heterogeneities in the polymer dynamics and remarkably impact the material properties. Dynamical perturbations are generally expected to be limited to interfacial polymer segments. However, composites with highly anisotropic nanoparticles usually exhibit very low percolation thresholds. In such systems, the overlapping interfacial regions could result in a complex polymer relaxation behavior that is unanticipated from dilute nanoparticle dispersions in polymer matrices. To understand this behavior, we examine a system of percolated single-wall carbon nanotubes (SWNT) in a polymer matrix, PMMA, which is known to have strong interfacial binding. Neutron spectroscopy measurements on the composites reveal not only an interfacial polymer layer that is transiently pinned to the SWNT surface, but suggest that the percolated network forms a kinetic cage that dramatically restricts both local and cooperative relaxations of noninterfacial polymer segments. These findings should help guide theories and simulations of hierarchical polymer dynamics in nanocomposites.

Inpatients with hospital-acquired (HA) COVID-19 have mortality rates above 30%. Subjects with early diagnosis of COVID-19 and risk factors for disease progression are suitable for treatment with anti-SARS-CoV-2 neutralizing monoclonal antibodies (mAbs). We retrospectively assessed the outcome of a cohort of hospitalized patients with laboratory confirmed SARS-CoV-2 nosocomial infection who were admitted to the COVID-19 general ward of an acute-care Italian hospital between October 25, 2020 and April 30, 2021. Patients receiving the REGEN-COV mAb cocktail (casirivimab/imdevimab) were compared with those receiving standard care. Of 34 patients, 11 (mean age, 73.1; 9 males) underwent treatment with REGEN-COV and 23 received standard care. The 2 study groups were well balanced regarding age, sex, comorbidities, acute illness severity at diagnosis of SARS-CoV-2 infection, and all participants had at least 2 risk factors for disease progression. Five of 11 patients in the REGEN-COV group and 16 of 23 in the standard care group were asymptomatic at diagnosis; the remaining had symptoms of mild COVID-19. All patients received REGEN-COV within 3 days of infection confirmation. Treatment with REGEN-COV was inversely associated with oxygen requirement for COVID-19 during hospital stay (OR 0.02, CI 0–0.52, p=0.0174). No 28-day deaths were registered in the REGEN-COV group, compared to 8 (34.8%) in the standard care group (p=0.0339). Kaplan-Meier analysis confirmed the survival advantage of REGEN-COV group (log-rank p=0.00324). No serious adverse events related to REGEN-COV administration were recorded. Based on these findings, REGEN-COV appears safe and might prevent disease progression in high-risk inpatients with early diagnosis of HA-COVID-19.

Using neutron spin-echo spectroscopy, we studied the microscopic structural relaxation of a prototypical network ionic liquid ZnCl2 at the structure factor primary peak and prepeak. The results show that the relaxation at the primary peak is faster than the prepeak and that the activation energy is ∼33% higher. A stretched exponential relaxation is observed even at temperatures well-above the melting point Tm. Surprisingly, the stretching exponent shows a rapid increase upon cooling, especially at the primary peak, where it changes from a stretched exponential to a simple exponential on approaching the Tm. These results suggest that the appearance of glassy dynamics typical of the supercooled state even in the equilibrium liquid state of ZnCl2 as well as the difference of activation energy at the two investigated length scales are related to the formation of a network structure on cooling.

Carbapenem consumption is a major driver for selection and spread of carbapenem-resistant Enterobacterales (CRE). We assessed the impact of a carbapenem-focused multimodal antimicrobial stewardship program (ASP) in the internal medicine unit of a medium-size acute-care hospital.We compared the percentage of inappropriate carbapenem prescriptions and the proportion of carbapenem treated patients registered in a 12-month pre-intervention and in a 24-month post-intervention period by using an interrupted time series analysis. The consumption of carbapenems, expressed in defined daily doses (DDD), was also assessed. As a secondary objective, the incidence of infections by carbapenem-resistant Klebsiella pneumoniae (CRKP) and the percentage of CRKP invasive isolates in the same time periods were compared.After the ASP intervention, the mean monthly percentage of inappropriate carbapenem prescriptions dropped from 59% to 25%, and the mean monthly proportion of carbapenem treated patients decreased from 3% to 1%. The interrupted time series analysis confirmed a significant decrease in the percentage of inappropriate carbapenem prescriptions (-41.6%, p = 0.0262) and in the proportion of carbapenem treated patients (-2.1%, p 0.0001). Carbapenem consumption decreased from 5.2 to 1.6 DDD x 100 patient-days. The incidence of CRKP infections remained unchanged (29.1 × 100,000 patient-days vs 28.9 × 100,000 patient-days, p = 0.9864) and the percentage of CRKP invasive isolates decreased, though not significantly, from 36.4% to 13.3% (p = 0.3478).The implementation of a carbapenem-focused ASP was effective at limiting the inappropriate use of carbapenems and was associated with a significant decrease in carbapenem consumption. Such effects were sustained during a 24-month post-intervention period.

We investigate single chain dynamics of an entangled linear poly(ethylene oxide) melt in the presence of well-dispersed attractive nanoparticles using high-resolution neutron spectroscopy at partic...

Polymer chain dynamics of a nanostructured block copolymer electrolyte, polystyrene-block-poly(ethylene oxide) (SEO) mixed with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt, are investigated by neutron spin echo (NSE) spectroscopy on the 0.1-100 ns time scale and analyzed using the Rouse model at short times (t ≤ 10 ns) and the reptation tube model at long times (t ≥ 50 ns). In the Rouse regime, the monomeric friction coefficient increases with increasing salt concentration, as seen previously in homopolymer electrolytes. In the reptation regime, the tube diameters, which represent entanglement constraints, decrease with increasing salt concentration. The normalized longest molecular relaxation time, calculated from the NSE results, increases with increasing salt concentration. We argue that quantifying chain motion in the presence of ions is essential for predicting the behavior of polymer-electrolyte-based batteries operating at large currents.

The instruments best suited to performing high-energy-resolution neutron spectroscopy are spin-echo spectrometers and backscattering spectrometers. The development of these experimental techniques dates back almost half a century, and most major neutron scattering facilities operate mature spectrometers of one or both classes. Recent advances in instrumentation and neutron sources are enhancing their performance and expanding their capabilities, with the objective of enabling researchers to tackle new and more complex problems. In this Technical Review, we assess the current state of the art in high-energy-resolution neutron spectrometers, showcasing their role in the study of nanoscale dynamics in soft and biological materials, as well as disordered magnets. Neutron spectroscopy is a powerful probe to study the dynamics in materials. This Technical Review assesses the state-of-the-art experimental spectroscopic methods, which are optimized to provide high energy resolution and can reveal dynamic processes on the picosecond and nanosecond timescales.

The incomplete Hankel functions (IHFs) are employed to evaluate the scattered field from thin truncated cylinders excited by uniform plane waves or by arbitrarily oriented elemental current sources. Metallic and dielectric lossy structures are modeled by means of impedance boundary conditions (IBCs) including surface curvature effects. The scattering currents, expanded in triangular basis functions, are determined upon solving electrical field integral equations (EFIEs) by means of the point-matching method of moments (MoM). The scattered field is then expressed in closed analytical form in terms of IHFs, thus yielding highly accurate numerical results. Furthermore, accurate IHFs approximants are also derived to reduce the computational burden in the analysis of large electrical structures. The proposed approach is demonstrated in practical applications involving cylindrical dielectric structures used in planar lenses, lossy dielectric cylinders suitable to model cane-like vegetation, as well as polarization rotators featuring multiple stages composed of thin metallic wire arrays.

Evidence on the effectiveness of SARS-CoV-2 vaccines in nursing home (NHs) residents is limited. We examined the impact of the BNT162b2 mRNA SARS-CoV-2 vaccine on the course of the epidemic in NHs in the Florence Health District, Italy, before and after vaccination. Moreover, we assessed survival and hospitalization by vaccination status in SARS-CoV-2-positive cases occurring during the post-vaccination period. We calculated the weekly infection rates during the pre-vaccination (1 October–26 December 2020) and post-vaccination period (27 December 2020–31 March 2021). Cox analysis was used to analyze survival by vaccination status. The study involved 3730 residents (mean age 84, 69% female). Weekly infection rates fluctuated during the pre-vaccination period (1.8%–6.5%) and dropped to zero during the post-vaccination period. Nine unvaccinated (UN), 56 partially vaccinated (PV) and 35 fully vaccinated (FV) residents tested SARS-CoV-2+ during the post-vaccination period. FV showed significantly lower hospitalization and mortality rates than PV and UV (hospitalization: FV 3%, PV 14%, UV 33%; mortality: FV 6%, PV 18%, UV 56%). The death risk was 84% and 96% lower in PV (HR 0.157, 95%CI 0.049–0.491) and FV (HR 0.037, 95%CI 0.006–0.223) versus UV. SARS-CoV-2 vaccination was followed by a marked decline in infection rates and was associated with lower morbidity and mortality among infected NH residents.

The relaxation behavior of glass formers exhibits spatial heterogeneity and dramatically changes upon cooling towards the glass transition. However, the underlying mechanisms of the dynamics at different microscopic length scales are not fully understood. Employing the recently developed wide-angle neutron spin-echo spectroscopy technique, we measured the Q-dependent coherent intermediate scattering function of a prototypical ionic glass former Ca

Polymers assembled using computationally designed coiled coil bundlemers display tunable stiffness via control of interbundlemer covalent connectivity as confirmed using small-angle neutron scattering. Neutron spin echo spectroscopy reveals that rigid rod polymers show a decay rate $\mathrm{\ensuremath{\Gamma}}\ensuremath{\sim}{Q}^{2}$ ($Q$ is the scattering vector) expected of straight cylinders. Semirigid polymers assembled using bundlemers linked via 4-armed organic linker show flexible segmental dynamics at mid-$Q$ and $\mathrm{\ensuremath{\Gamma}}\ensuremath{\sim}{Q}^{2}$ behavior at high Q. The results give insight into linker flexibility-dependent interbundlemer dynamics in the hybrid polymers.

We have measured the effect of added salt on the chain dimensions of mixtures of poly(ethylene oxide) (PEO) and lithium bis(trifluoromethanesulfonyl)imide salt (LiTFSI) in the melt state through small-angle neutron scattering (SANS) experiments. Scattering profiles from blends of hydrogenated and deuterated PEO mixed with LiTFSI were measured as a function of salt concentration. Scattering profiles from pure deuterated PEO/LiTFSI mixtures were used for background-subtraction purposes. The densities of PEO/LiTFSI mixtures of varying salt concentrations were measured to calculate partial molar monomer volumes of PEO and LiTFSI to account for nonideal mixing. Kratky plots of the scattering profiles were used to calculate the salt concentration dependence of statistical segment length. At low salt concentrations, segment length decreases with increasing salt concentration, before increasing with increasing salt concentration in the high salt concentration regime. The random phase approximation was used to predict theoretical scattering profiles from the calculated segment lengths and partial molar volumes; there is excellent agreement between the theoretical and measured scattering profiles at all salt concentrations. There appears to be a correlation between chain dimensions and coordination between lithium ions and EO monomers. The scattering profiles of the pure deuterated PEO/LiTFSI mixtures suggested the presence of ion clusters of characteristic size of 0.6 nm at high salt concentrations.

The cross-linker nature and water content may impact the microscopic dynamics of hydrogels components and thus their properties in applications such as drug delivery and water confinement. To inves...

Neutron polarization analysis capability with a large scattering angle and momentum transfer coverage has not been widely implemented for the separation of coherent and incoherent quasi-elastic neutron scattering (QENS) spectra. A feasibility test for soft condensed matter applications was performed on the Multi-Axis Crystal Spectrometer (MACS) at the NIST Center for Neutron Research (NCNR). This capability benefitted from the high flux wide angle polarization analysis capability recently developed on MACS for hard condensed matter investigations. The experimental procedure is thoroughly described on how to take data and perform polarization efficiency correction before further data analysis is done. This capability was employed to unambiguously separate the coherent and incoherent signal from the QENS spectra for the investigation of both the collective and the single particle dynamics in partially deuterated (CH3OD, D 99.5% purity) methanol. By studying a Q range encompassing the prepeak position, it was possible to directly measure the dynamics of the h-bonding associates which originate the prepeak signal, without contamination from the incoherent scattering, in spite of the relative weakness of the coherent scattering.

While ionomer nanocomposites show promise for advancing the viability of energy storage technologies, such as the vanadium redox flow battery, the improvements in ion selectivity are appreciable on...

The single particle dynamics of water confined within two ordered mesoporous carbon matrices was investigated in the temperature range from 290 K to 170 K by quasielastic neutron scattering using three high resolution neutron spectrometers. Thus, it was possible to investigate the mobility of water confined in model hydrophobic cavities at the nanoscale. Models developed for the nanoscale dynamics of supercooled water and water confined within hydrophilic matrices were able to describe the collected data but remarkable differences with analogous silica confined matrices were observed in these carbon samples. A significant fraction of the water molecules was immobile on the nanosecond timescale, even at room temperature. As the temperature was lowered, the mobility of the water molecules slowed down, but the strongly non-Arrhenius behavior observed in bulk water and for fully hydrated hydrophilic confinement was absent, which indicates frustration of the hydrogen bond network formation. The obtained results were relevant for applications of mesoporous carbon materials.

EXPANSE, an EXPanded Angle Neutron Spin Echo instrument, has been proposed and selected as one of the first suite of instruments to be built at the Second Target Station of the Spallation Neutron Source at the Oak Ridge National Laboratory. This instrument is designed to address scientific problems that involve high-energy resolution (neV– μeV) of dynamic processes in a wide range of materials. The wide-angle detector banks of EXPANSE provide coverage of nearly two orders of magnitude in scattering wavenumbers, and the wide wavelength band affords approximately four orders of magnitude in Fourier times. This instrument will offer unique capabilities that are not available in the currently existing neutron scattering instruments in the United States. Specifically, EXPANSE will enable direct measurements of slow dynamics in the time domain over wide Q-ranges simultaneously and will also enable time-resolved spectroscopic studies. The instrument is expected to contribute to a diverse range of science areas, including soft matter, polymers, biological materials, liquids and glasses, energy materials, unconventional magnets, and quantum materials.