114 research outputs found
Quantum quenches to the attractive one-dimensional Bose gas: exact results
We study quantum quenches to the one-dimensional Bose gas with attractive interactions in the case when the initial state is an ideal one-dimensional Bose condensate. We focus on properties of the stationary state reached at late times after the quench. This displays a finite density of multi-particle bound states, whose rapidity distribution is determined exactly by means of the quench action method. We discuss the relevance of the multi-particle bound states for the physical properties of the system, computing in particular the stationary value of the local pair correlation function g2. Copyright L. Piroli et al
Percutaneous coronary intervention of unprotected left main and bifurcation in octogenarians: Subanalysis from RAIN (veRy thin stents for patients with left mAIn or bifurcatioN in real life)
Quantification of Information Transmission in Signal Play-calling for NCAA Division 1 College Football: A Comprehensive Literature Review
Background: To gain a competitive advantage in National Collegiate Athletic Association (NCAA) Division 1 American college football, teams often use a coded, hand/body gesture-based play-calling system to communicate calls to student-athletes on the field. Objective: The purpose of this study is to apply cognitive engineering concepts toward the improvement of signal transmission such that a realistic amount of data signaled will be received and understood by the student-athlete. Methods: Partnering with an NCAA coaching staff, information transmitted via signal-based communication pathways were quantified to inform the design of their signal system. Quality control coaches, practitioners of football signalling characterization and design, used an autoethnographic frame to train researchers on the communication protocol standards. A comprehensive literature review of sources from 1900 to 2019 was conducted to examine information transmission, signal-gesture taxonomies, sign-language recognition, and code design. Findings were applied to the signal system to quantify the information contained in the transmission between the signalling coaches and the student-athletes. Results: Results found that the observed signal system transmits an average of 12.62 bits of information on offense and 12.92 bits on defense with 23% and 12% redundancy, respectively. Conclusion: Recommendations were provided to the coaching staff regarding code optimization and gesture design to improve student-athlete performance
Does the inflow velocity profile influence physiologically relevant flow patterns in computational hemodynamic models of left anterior descending coronary artery?
Patient-specific computational fluid dynamics is a powerful tool for investigating the hemodynamic risk in coronary arteries. Proper setting of flow boundary conditions in computational hemodynamic models of coronary arteries is one of the sources of uncertainty weakening the findings of in silico experiments, in consequence of the challenging task of obtaining in vivo 3D flow measurements within the clinical framework. Accordingly, in this study we evaluated the influence of assumptions on inflow velocity profile shape on coronary artery hemodynamics. To do that, (1) ten left anterior descending coronary artery (LAD) geometries were reconstructed from clinical angiography, and (2) eleven velocity profiles with realistic 3D features such as eccentricity and differently shaped (single- and double-vortex) secondary flows were generated analytically and imposed as inflow boundary conditions. Wall shear stress and helicity-based descriptors obtained prescribing the commonly used parabolic velocity profile were compared with those obtained with the other velocity profiles. Our findings indicated that the imposition of idealized velocity profiles as inflow boundary condition is acceptable as long the results of the proximal vessel segment are not considered, in LAD coronary arteries. As a pragmatic rule of thumb, a conservative estimation of the length of influence of the shape of the inflow velocity profile on LAD local hemodynamics can be given by the theoretical entrance length for cylindrical conduits in laminar flow conditions
Economic impact of remote monitoring on ordinary follow-up of implantable cardioverter defibrillators as compared with conventional in-hospital visits: a single-center prospective and randomized study
Few data are available on actual follow-up
costs of remote monitoring (RM) of implantable defibrillators
(ICD). Our study aimed at assessing current direct costs
of 1-year ICD follow-up based on RM compared with
conventional quarterly in-hospital follow-ups.
Methods and results Patients (N=233) with indications for
ICD were consecutively recruited and randomized at implant
to be followed up for 1 year with standard quarterly inhospital
visits or by RM with one in-hospital visit at 12
months, unless additional in-hospital visits were required
due to specific patient conditions or RM alarms. Costs were
calculated distinguishing between provider and patient
costs, excluding RM device and service cost. The frequency
of scheduled in-hospital visits was lower in the RM group
than in the control arm. Follow-up required 47 min per
patient/year in the RM arm versus 86 min in the control
arm (p=0.03) for involved physicians, generating cost estimates
for the provider of USD 45 and USD 83 per patient/-
year, respectively. Costs for nurses were comparable.
Overall, the costs associated with RM and standard
follow-up were USD 103±27 and 154±21 per patient/year,
respectively (p=0.01). RM was cost-saving for the patients:
USD 97±121 per patient/year in the RM group versus 287±
160 per patient/year (p=0.0001).
Conclusion The time spent by the hospital staff was significantly
reduced in the RM group. If the costs for the device
and service are not charged to patients or the provider,
patients could save about USD 190 per patient/year while
the hospital could save USD 51 per patient/year
Single-Center-Single-Blinded Clinical Trial to Evaluate the Efficacy of a Nutraceutical Containing Boswellia Serrata, Bromelain, Zinc, Magnesium, Honey, Tyndallized Lactobacillus Acidophilus and Casei to Fight Upper Respiratory Tract Infection and Otitis Media
Some nutraceuticals have been studied as supportive treatment for fighting upper respiratory tract infection and middle ear disease. Our study aims at evaluating the effect of a specific oral supplementation in the treatment of pediatric otits media. The subjects were randomly assigned by the physician (single-blinded study) to one of three groups: Control Group (CG), Treatment Group 1 (TG1), or Treatment Group 2 (TG2). Both TG were treated with Flogostop Duo (for 20 daysâTG1 or 30 daysâTG2) in combination with the standard treatment, while CG underwent standard treatment only. The standard treatment was nasal aerosol with Fluticasone and Mucolytic, and nasal washing with hypertonic solution. All patients were analyzed by otoscopy, impedance, fibroscopy, and pure auditory test at the baseline (T0), after 20 days (T1) and 35 days (T2). 120 children were included in the study, 40 in the CG, 40 in the TG1, and 40 in the TG2. Both TG1 and TG2 presented statistically significant differences with respect to controls in otoscopy, impedance, fibroscopy, and PTA at T2. The otoscopy improved at T2 with statistically significant value only in TG2. The impedance and fibroscopy improved at T1 both in TG1 and TG2 compared to CG. A statistically significant improvement was observed in TG2 at T2 in comparison to both CG and TG1. Statistically significant differences were observed in PTA at T2 only compared with controls. This study confirmed the efficacy of nutraceutical as supporting therapy in the upper respiratory tract infection in children. In particular, the supplement containing Boswellia serrata and Bromelain, which are molecules with strong anti-inflammatory and pain-control capacities, could add the benefit without the adverse effects which are related to NSAID us
Transport in out-of-equilibrium XXZ chains: Nonballistic behavior and correlation functions
We consider the nonequilibrium protocol where two semi-infinite gapped XXZ chains, initially prepared in different equilibrium states, are suddenly joint together. At large times, a generalized hydrodynamic description applies, according to which the system can locally be represented by space- and time- dependent stationary states. The magnetization displays an unusual behavior: depending on the initial state, its profile may exhibit abrupt jumps that can not be predicted directly from the standard hydrodynamic equations and which signal non-ballistic spin transport. We ascribe this phenomenon to the structure of the local conservation laws and make a prediction for the exact location of the jumps. We find that the jumps propagate at the velocities of the heaviest quasiparticles. By means of tDMRG simulations we show that our theory yields a complete description of the long-time steady profiles of conserved charges, currents, and local correlations
From the quantum transfer matrix to the quench action: the Loschmidt echo in XXZ Heisenberg spin chains
We consider the computation of the Loschmidt echo after quantum quenches in the interacting XXZ Heisenberg spin chain both for real and imaginary times. We study two-site product initial states, focusing in particular on the N\ue9el and tilted N\ue9el states. We apply the Quantum Transfer Matrix (QTM) approach to derive generalized TBA equations, which follow from the fusion hierarchy of the appropriate QTM's. Our formulas are valid for arbitrary imaginary time and for real times at least up to a time t0, after which the integral equations have to be modified. In some regimes, t0 is seen to be either very large or infinite, allowing to explore in detail the post-quench dynamics of the system. As an important part of our work, we show that for the N\ue9el state our imaginary time results can be recovered by means of the quench action approach, unveiling a direct connection with the quantum transfer matrix formalism. In particular, we show that in the zero-time limit, the study of our TBA equations allows for a simple alternative derivation of the recently obtained Bethe ansatz distribution functions for the N\ue9el, tilted N\ue9el and tilted ferromagnet states
Entanglement Dynamics after a Quench in Ising Field Theory: A Branch Point Twist Field Approach
We extend the branch point twist field approach for the calculation of entanglement entropies to time-dependent problems in 1+1-dimensional massive quantum field theories. We focus on the simplest example: a mass quench in the Ising field theory from initial mass m0 to final mass m. The main analytical results are obtained from a perturbative expansion of the twist field one-point function in the post-quench quasi-particle basis. The expected linear growth of the RĂ©nyi entropies at large times mt â« 1 emerges from a perturbative calculation at second order. We also show that the RĂ©nyi and von Neumann entropies, in infinite volume, contain subleading oscillatory contributions of frequency 2m and amplitude proportional to (mt)â3/2. The oscillatory terms are correctly predicted by an alternative perturbation series, in the pre-quench quasi-particle basis, which we also discuss. A comparison to lattice numerical calculations carried out on an Ising chain in the scaling limit shows very good agreement with the quantum field theory predictions. We also find evidence of clustering of twist field correlators which implies that the entanglement entropies are proportional to the number of subsystem boundary points
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