We present a comprehensive simulation study of the Newtonian and quantum model of a Stern-Gerlach experiment with cold neutrons. By solving Newton's equation of motion and the time-dependent Pauli equation for a wide range of uniform magnetic field strengths, we scrutinize the role of the latter for drawing the conclusion that the magnetic moment of the neutron is quantized. We then demonstrate that a marginal modification of the Newtonian model suffices to construct, without invoking any concept of quantum theory, an event-based subquantum model that eliminates the shortcomings of the classical model and yields results that are in qualitative agreement with experiment and quantum theory.
View Article and Find Full Text PDFAim: To investigate the value of prospective in-hospital registry data and the impact of an infectious endocarditis heart team approach (IEHT) on improvement in quality of care and monitor outcomes in hospitalized patients with IE.
Methods: Between December 2014 and the end of 2019, 160 patients were hospitalized in one centre with the definite diagnosis of infectious endocarditis (IE) and entered in a prospective registry. From 2017, an IEHT was introduced.
The protection of quantum coherence is essential for building a practical quantum computer able to manipulate, store and read quantum information with a high degree of fidelity. Recently, it has been proposed to increase the operation time of a qubit by means of strong pulses to achieve a dynamical decoupling of the qubit from its environment. We propose and demonstrate a simple and highly efficient alternative route based on Floquet modes, which increases the Rabi decay time ([Formula: see text]) in a number of materials with different spin Hamiltonians and environments.
View Article and Find Full Text PDFBackground: Familial hypercholesterolaemia (FH) is underdiagnosed in most countries. We report our first experience from a national pilot project of cascade screening in relatives of FH patients.
Methodology: Participating specialists recruited consecutive index patients (IP) with Dutch Lipid Clinic Network (DLCN) score ≥6.
Eur Heart J Qual Care Clin Outcomes
October 2021
Aims: To assess the adherence to established quality indicators (QIs) for ST-elevation myocardial infarction (STEMI) at the hospital-network level and its relation to outcome.
Methods And Results: The data of 7774 STEMI patients admitted to 32 STEMI networks during the period 2014-18 were extracted from the Belgian STEMI database. Five QIs [primary percutaneous coronary intervention use, diagnosis-to-balloon time (DiaTB) <90 min, door-to-balloon time (DoTB) <60 min, P2Y12 inhibitor and statin prescription at discharge, and a composite QI score ranging from 0 to 10] were correlated with in-hospital mortality adjusted for differences in baseline risk profile (TIMI risk score).
Given a quantum many-body system and the expectation-value dynamics of some operator, we study how this reference dynamics is altered due to a perturbation of the system's Hamiltonian. Based on projection operator techniques, we unveil that if the perturbation exhibits a random-matrix structure in the eigenbasis of the unperturbed Hamiltonian, then this perturbation effectively leads to an exponential damping of the original dynamics. Employing a combination of dynamical quantum typicality and numerical linked cluster expansions, we demonstrate that our theoretical findings for random matrices can, in some cases, be relevant for the dynamics of realistic quantum many-body models as well.
View Article and Find Full Text PDFAim: Cardiac arrest is a common complication of ST elevation myocardial infarction and is associated with high mortality. We evaluated whether vulnerability to cardiac arrest follows a circadian rhythm and whether it is related to specific patient characteristics.
Methods: A total of 24,164 ST elevation myocardial infarction patients who were admitted to 60 Belgian hospitals between 2008-2017 were analysed.
Background: Compared to functional testing, coronary computed tomography angiography (CTA) improves clinical outcomes in patients with suspected coronary artery disease (CAD). This is thought to be the result of an increased prescription of preventive medical therapy (statins and aspirin) when relying on a CTA imaging strategy. We compared the rate of statins prescription in a patient cohort assessed either with coronary CTA or exercise testing, and evaluated the agreement on medication prescriptions.
View Article and Find Full Text PDFA correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
View Article and Find Full Text PDFWhen transmitting polarised light through histological brain sections, different types of diattenuation (polarisation-dependent attenuation of light) can be observed: In some brain regions, the light is minimally attenuated when it is polarised parallel to the nerve fibres (referred to as D), in others, it is maximally attenuated (referred to as D). The underlying mechanisms of these effects and their relationship to tissue properties were so far unknown. Here, we demonstrate in experimental studies that diattenuation of both types D and D can be observed in brain tissue samples from different species (rodent, monkey, and human) and that the strength and type of diattenuation depend on the nerve fibre orientations.
View Article and Find Full Text PDFBackground And Aims: Familial hypercholesterolaemia (FH) is an autosomal dominant lipoprotein disorder characterized by significant elevation of low-density lipoprotein cholesterol (LDL-C) and markedly increased risk of premature cardiovascular disease (CVD). Because of the very high coronary artery disease risk associated with this condition, the prevalence of FH among patients admitted for CVD outmatches many times the prevalence in the general population. Awareness of this disease is crucial for recognizing FH in the aftermath of a hospitalization of a patient with CVD, and also represents a unique opportunity to identify relatives of the index patient, who are unaware they have FH.
View Article and Find Full Text PDFIt is shown that by fitting a Markovian quantum master equation to the numerical solution of the time-dependent Schrödinger equation of a system of two spin-1/2 particles interacting with a bath of up to 34 spin-1/2 particles, the former can describe the dynamics of the two-spin system rather well. The fitting procedure that yields this Markovian quantum master equation accounts for all non-Markovian effects in as much the general structure of this equation allows and yields a description that is incompatible with the Lindblad equation.
View Article and Find Full Text PDFThe present report describes the quality of care, including in hospital mortality for more than 22.000 STEMI patients admitted in 60 Belgian hospitals for the period 2008-2016. We found a strong increase in the use of primary PCI over time, particularly for patients that were admitted first in a non-PCI capable hospital, reaching a penetration rate of >95%.
View Article and Find Full Text PDFWe study the real-time and real-space dynamics of charge in the one-dimensional Hubbard model in the limit of high temperatures. To this end, we prepare pure initial states with sharply peaked density profiles and calculate the time evolution of these nonequilibrium states, by using numerical forward-propagation approaches to chains as long as 20 sites. For a class of typical states, we find excellent agreement with linear-response theory and unveil the existence of remarkably clean charge diffusion in the regime of strong particle-particle interactions.
View Article and Find Full Text PDFA quartz-crystal-microbalance with dissipation (QCM-D) can measure molecular mass adsorption as well as register adhesion of colloidal particles. However, analysis of the QCM-D output to quantitatively analyze adhesion of (bio)colloids to obtain viscoelastic bond properties is still a subject of debate. Here, we analyze the QCM-D output to analyze the bond between two hydrophilic streptococcal strains 91 nm long and without fibrillar surface appendages and micron-sized hydrophobic polystyrene particles on QCM-D crystal surfaces with different hydrophobicities, using the Kelvin-Voigt model and the Maxwell model.
View Article and Find Full Text PDFThe quartz-crystal-microbalance-with-dissipation (QCM-D) has become a powerful tool for studying the bond viscoelasticity of biotic and abiotic colloidal particles adhering to substratum surfaces. A window-equipped QCM-D allows high-throughput analysis of the average bond viscoelasticity, measuring over 10 particles simultaneously in one single experiment. Other techniques require laborious analyses of individual particles.
View Article and Find Full Text PDFData of the numerical solution of the time-dependent Schrödinger equation of a system containing one spin-1/2 particle interacting with a bath of up to 32 spin-1/2 particles is used to construct a Markovian quantum master equation describing the dynamics of the system spin. The procedure of obtaining this quantum master equation, which takes the form of a Bloch equation with time-independent coefficients, accounts for all non-Markovian effects inasmuch the general structure of the quantum master equation allows. Our simulation results show that, with a few rather exotic exceptions, the Bloch-type equation with time-independent coefficients provides a simple and accurate description of the dynamics of a spin-1/2 particle in contact with a thermal bath.
View Article and Find Full Text PDFSince the first suggestion of the Jarzynski equality many derivations of this equality have been presented in both the classical and the quantum context. While the approaches and settings differ greatly from one another, they all appear to rely on the condition that the initial state is a thermal Gibbs state. Here, we present an investigation of work distributions in driven isolated quantum systems, starting from pure states that are close to energy eigenstates of the initial Hamiltonian.
View Article and Find Full Text PDFEur Heart J Acute Cardiovasc Care
September 2016
Objectives: Emergency medical services play a key role in the recognition and treatment of ST-segment elevation myocardial infarction (STEMI). This study evaluates the effect of emergency medical services use on adherence to reperfusion therapy guidelines in Belgian STEMI patients and on in-hospital mortality.
Methods: The mode of admission with against without emergency medical services was associated with baseline risk profile, reperfusion modalities and in-hospital mortality in 5692 consecutive STEMI patients from 2012 to 2014.
Philos Trans A Math Phys Eng Sci
May 2016
We review recent work that employs the framework of logical inference to establish a bridge between data gathered through experiments and their objective description in terms of human-made concepts. It is shown that logical inference applied to experiments for which the observed events are independent and for which the frequency distribution of these events is robust with respect to small changes of the conditions under which the experiments are carried out yields, without introducing any concept of quantum theory, the quantum theoretical description in terms of the Schrödinger or the Pauli equation, the Stern-Gerlach or Einstein-Podolsky-Rosen-Bohm experiments. The extraordinary descriptive power of quantum theory then follows from the fact that it is plausible reasoning, that is common sense, applied to reproducible and robust experimental data.
View Article and Find Full Text PDFThe neuroimaging technique three-dimensional polarized light imaging (3D-PLI) provides a high-resolution reconstruction of nerve fibres in human post-mortem brains. The orientations of the fibres are derived from birefringence measurements of histological brain sections assuming that the nerve fibres—consisting of an axon and a surrounding myelin sheath—are uniaxial birefringent and that the measured optic axis is oriented in the direction of the nerve fibres (macroscopic model). Although experimental studies support this assumption, the molecular structure of the myelin sheath suggests that the birefringence of a nerve fibre can be described more precisely by multiple optic axes oriented radially around the fibre axis (microscopic model).
View Article and Find Full Text PDFBirds-of-paradise are nature's prime examples of the evolution of color by sexual selection. Their brilliant, structurally colored feathers play a principal role in mating displays. The structural coloration of both the occipital and breast feathers of the bird-of-paradise Lawes' parotia is produced by melanin rodlets arranged in layers, together acting as interference reflectors.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
January 2014
A key feature of nonequilibrium thermodynamics is the Markovian, deterministic relaxation of coarse observables such as, for example, the temperature difference between two macroscopic objects which evolves independently of almost all details of the initial state. We demonstrate that the unitary dynamics for moderately sized spin-1/2 systems may yield the same type of relaxation dynamics for a given magnetization difference. This observation might contribute to the understanding of the emergence of thermodynamics within closed quantum systems.
View Article and Find Full Text PDFAims: The relationship between the predictive performance of the TIMI risk score for STEMI and gender has not been evaluated in the setting of primary PCI (pPCI). Here, we compared in-hospital mortality and predictive performance of the TIMI risk score between Belgian women and men undergoing pPCI.
Methods And Results: In-hospital mortality was analysed in 8,073 (1,920 [23.