Correlation Between ECT Quality Measures and Likelihood to Transition From Acute to Continuation and Maintenance ECT.

OBJECTIVES: To evaluate the association between 3 ECT quality measures (seizure duration, Postictal Suppression Index [PSI], and heart rate response) and therapeutic compliance as indicated by transitioning from acute to continuation to maintenance phases of ECT. METHODS: This was a retrospective chart review of patients who received ECT between July 2016 and July 2019. ECT quality measures were lagged by 1 ECT session to examine the effect of the prior session's quality measure on progressing to a higher ECT phase at the subsequent ECT session. Associations with therapeutic compliance were analyzed using mixed-effects ordinal regression and mixed-effects partial proportional odds models. RESULTS: Seizure duration was associated with 8% higher adjusted odds of progressing to out of the acute phase (95% confidence interval [CI]: 2% to 15%, P = 0.007) and 18% higher adjusted odds of progressing to the maintenance phase (95% CI: 10% to 28%, P < 0.001); PSI was associated with 9% higher adjusted odds of progressing out of the acute phase (95% CI: 3% to 16%, P = 0.005), whereas heart rate response was not statistically associated with therapeutic compliance. Greater therapeutic compliance was also associated with bilateral electrode placement and older age. CONCLUSIONS: Longer seizure duration was associated with greater therapeutic compliance across all ECT phases, PSI was associated with progressing out of the acute phase, and heart rate response was not associated with therapeutic compliance. Our findings assist ECT psychiatrists in optimizing ECT quality measures to promote better compliance with ECT.

Erratum: Oriented Active Solids [Phys. Rev. Lett. 123, 238001 (2019)].

This corrects the article DOI: 10.1103/PhysRevLett.123.238001.

Impact of delirium on mortality in patients hospitalized for heart failure.

OBJECTIVE: Heart Failure (HF) is one of the leading causes of hospitalization in the United States accounting for ≈800,000 hospital discharges and $11 billion in annual costs. Delirium occurs in approximately 30% of elderly hospitalized patients and its incidence is significantly higher among those admitted to the critical care units. Despite this, there has been limited exploration of the clinical and economic impact of delirium in patients hospitalized with acute HF. We hypothesized that delirium in HF is associated with excess mortality and hospital costs. METHODS: We queried the 2001-2014 Nationwide Inpatient Sample to identify hospitalizations that included a primary discharge diagnosis of HF (ICD-9-CM: 428.xx) and stratified them by presence or absence of delirium (ICD-9-CM: 239.0, 290.41, 293.0, 293.1, 348.31). Differences in in-hospital mortality, length of stay (LOS), and hospital costs were assessed using propensity-score matched cohorts. RESULTS: Major predictors of delirium included advanced age, Caucasian race, underlying dementia or psychiatric diagnoses, higher Elixhauser Comorbidity Index, renal failure, cardiogenic shock, and coronary artery bypass surgery. In the propensity-score matched analysis of 76,411 hospitalization with delirium compared to 76,612 without delirium, in-hospital mortality (odds ratio: 1.67, 95% CI: 1.51-1.77), LOS (rate ratio [RR]: 1.47, 95% CI: 1.45-1.51), and hospital costs (RR: 1.44, 95% CI: 1.41-1.48) were all statistically higher in the presence of delirium (all p < 0.001). CONCLUSION: In patients hospitalized with HF, delirium is an independent predictor of increased in-hospital mortality, longer LOS, and excess hospital costs despite adjustment for baseline characteristics.

Layered Chiral Active Matter: Beyond Odd Elasticity.

In equilibrium liquid crystals, chirality leads to a variety of spectacular three-dimensional structures, but chiral and achiral phases with the same broken continuous symmetries have identical long-time, large-scale dynamics. In this Letter, starting from active model H^{*}, the general hydrodynamics of a pseudoscalar in a momentum-conserving fluid, we demonstrate that chirality qualitatively modifies the dynamics of layered liquid crystals in active systems in both two and three dimensions due to an active "odder" elasticity. In three dimensions, we demonstrate that the hydrodynamics of active cholesterics differs fundamentally from smectic-A liquid crystals, unlike their equilibrium counterpart. This distinction can be used to engineer a columnar array of vortices, with an antiferromagnetic vorticity alignment, that can be switched on and off by external strain. A two-dimensional chiral layered state-an array of lines on an incompressible, freestanding film of chiral active fluid with a preferred normal direction-is generically unstable. However, this instability can be tuned in easily realizable experimental settings when the film is either on a substrate or in an ambient fluid.

A nonequilibrium force can stabilize 2D active nematics.

Suspensions of actively driven anisotropic objects exhibit distinctively nonequilibrium behaviors, and current theories predict that they are incapable of sustaining orientational order at high activity. By contrast, here we show that nematic suspensions on a substrate can display order at arbitrarily high activity due to a previously unreported, potentially stabilizing active force. This force moreover emerges inevitably in theories of active orientable fluids under geometric confinement. The resulting nonequilibrium ordered phase displays robust giant number fluctuations that cannot be suppressed even by an incompressible solvent. Our results apply to virtually all experimental assays used to investigate the active nematic ordering of self-propelled colloids, bacterial suspensions, and the cytoskeleton and have testable implications in interpreting their nonequilibrium behaviors.

Swimmer Suspensions on Substrates: Anomalous Stability and Long-Range Order.

We present a comprehensive theory of the dynamics and fluctuations of a two-dimensional suspension of polar active particles in an incompressible fluid confined to a substrate. We show that, depending on the sign of a single parameter, a state with polar orientational order is anomalously stable (or anomalously unstable), with a nonzero relaxation (or growth) rate for angular fluctuations, not parallel to the ordering direction, at zero wave number. This screening of the broken-symmetry mode in the stable state does lead to conventional rather than giant number fluctuations as argued by Bricard et al., Nature 503, 95 (2013), but their bend instability in a splay-stable flock does not exist and the polar phase has long-range order in two dimensions. Our theory also describes confined three-dimensional thin-film suspensions of active polar particles as well as dense compressible active polar rods, and predicts a flocking transition without a banding instability.

Phases and excitations of active rod-bead mixtures: simulations and experiments.

We present a large-scale numerical study, supplemented by experimental observations, on a quasi-two-dimensional active system of polar rods and spherical beads confined between two horizontal plates and energised by vertical vibration. For a low rod concentration Φr, our observations are consistent with a direct phase transition, as bead concentration Φb is increased, from the isotropic phase to a homogeneous flock. For Φr above a threshold value, an ordered band dense in both rods and beads occurs between the disordered phase and the homogeneous flock, in both experiments and simulations. Within the size ranges accessible, we observe only a single band, whose width increases with Φr. Deep in the ordered state, we observe broken-symmetry "sound" modes and giant number fluctuations. The direction-dependent sound speeds and the scaling of fluctuations are consistent with the predictions of field theories of flocking; sound damping rates show departures from such theories, but the range of wavenumbers explored is modest. At very high densities, we see phase separation into rod-rich and bead-rich regions, both of which move coherently.

Oriented Active Solids.

We present a complete analysis of the linearized dynamics of active solids with uniaxial orientational order, taking into account a hitherto overlooked consequence of rotation invariance. Our predictions include a purely active response of two-dimensional orientationally ordered solids to shear, the possibility of stable active solids with quasi-long-range order in two dimensions and long-range order in three dimensions, generic instability of the solid for one sign of active forcing, and the instability of the uniaxially ordered phase in momentum-conserved systems for large active forcing irrespective of its sign.

Kepler Orbits in Pairs of Disks Settling in a Viscous Fluid.

We show experimentally that a pair of disks settling at negligible Reynolds number (∼10^{-4}) displays two classes of bound periodic orbits, each with transitions to scattering states. We account for these dynamics, at leading far-field order, through an effective Hamiltonian in which gravitational driving endows orientation with the properties of momentum. This treatment is successfully compared against the measured properties of orbits and critical parameters of transitions between types of orbits. We demonstrate a precise correspondence with the Kepler problem of planetary motion for a wide range of initial conditions, find and account for a family of orbits with no Keplerian analog, and highlight the role of orientation as momentum in the many-disk problem.

Stress fluctuations in transient active networks.

Inspired by experiments on dynamic extensile gels of biofilaments and motors, we propose a model of a network of linear springs with kinetics consisting of growth at a prescribed rate, death after a lifetime drawn from a distribution, and birth at a randomly chosen node. The model captures features such as the build-up of self-stress, that are not easily incorporated into hydrodynamic theories. We study the model numerically and show that our observations can largely be understood through a stochastic effective-medium model. The resulting dynamically extending force-dipole network displays many features of yielded plastic solids, and offers a way to incorporate strongly non-affine effects into theories of active solids. A rather distinctive form for the stress distribution, and a Herschel-Bulkley dependence of stress on activity, are our major predictions.