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Tricuspid atresia: Where are we now?
Tricuspid atresia (TA) is a complex congenital heart disease that presents with cyanosis in the neonatal period. It is invariably fatal if left untreated and requires multiple stages of palliation. Early recognition and timely surgical intervention are therefore pivotal in the management of these infants. This literature review considers the pathophysiology, presentation, investigations, and classification of TA. Moreover, it discusses the evidence upon which the latest medical and surgical treatments are based, as well as numerous recent case reports. Further work is needed to elucidate the etiology of TA, clarify the role of pharmacotherapy, and optimize the surgical management that these patients receive.None
Evolution of flame displacement speed within flame front in different regimes of premixed turbulent combustion
A transport equation for the flame displacement speed evolution in premixed flames is derived from first principles, and the mean behaviours of the terms of this equation are analysed based on a Direct Numerical Simulation database of statistically planar turbulent premixed flames with a range of different Karlovitz numbers. It is found that the regime of combustion (or Karlovitz number) affects the statistical behaviour of the mean contributions of the terms of the displacement speed transport equation which are associated with the normal strain rate and curvature dependence of displacement speed. The contributions arising from molecular diffusion and flame curvature play leading order roles in all combustion regimes, whereas the terms arising from the flame normal straining and reactive scalar gradient become leading order contributors only for the flames with high Karlovitz number values representing the thin reaction zones regime. The mean behaviours of the terms of the displacement speed transport equation indicate that the effects arising from fluid-dynamic normal straining, reactive scalar gradient and flame curvature play key roles in the evolution of displacement speed. The mean characteristics of the various terms of the displacement speed transport equation are explained in detail and their qualitative behaviours can be expounded based on the behaviours of the corresponding terms in the case of 1D steady laminar premixed flames. This implies that the flamelet assumption has the potential to be utilised for the purpose of any future modelling of the unclosed terms of the displacement speed transport equation even in the thin reaction zones regime for moderate values of Karlovitz number
Probing many-body dynamics on a 51-atom quantum simulator
Controllable, coherent many-body systems can provide insights into the
fundamental properties of quantum matter, enable the realization of new quantum
phases and could ultimately lead to computational systems that outperform
existing computers based on classical approaches. Here we demonstrate a method
for creating controlled many-body quantum matter that combines
deterministically prepared, reconfigurable arrays of individually trapped cold
atoms with strong, coherent interactions enabled by excitation to Rydberg
states. We realize a programmable Ising-type quantum spin model with tunable
interactions and system sizes of up to 51 qubits. Within this model, we observe
phase transitions into spatially ordered states that break various discrete
symmetries, verify the high-fidelity preparation of these states and
investigate the dynamics across the phase transition in large arrays of atoms.
In particular, we observe robust manybody dynamics corresponding to persistent
oscillations of the order after a rapid quantum quench that results from a
sudden transition across the phase boundary. Our method provides a way of
exploring many-body phenomena on a programmable quantum simulator and could
enable realizations of new quantum algorithms.Comment: 17 pages, 13 figure
Integrating Neural Networks with a Quantum Simulator for State Reconstruction
We demonstrate quantum many-body state reconstruction from experimental data
generated by a programmable quantum simulator, by means of a neural network
model incorporating known experimental errors. Specifically, we extract
restricted Boltzmann machine (RBM) wavefunctions from data produced by a
Rydberg quantum simulator with eight and nine atoms in a single measurement
basis, and apply a novel regularization technique to mitigate the effects of
measurement errors in the training data. Reconstructions of modest complexity
are able to capture one- and two-body observables not accessible to
experimentalists, as well as more sophisticated observables such as the R\'enyi
mutual information. Our results open the door to integration of machine
learning architectures with intermediate-scale quantum hardware.Comment: 15 pages, 13 figure
Quantum Kibble-Zurek mechanism and critical dynamics on a programmable Rydberg simulator
Quantum phase transitions (QPTs) involve transformations between different
states of matter that are driven by quantum fluctuations. These fluctuations
play a dominant role in the quantum critical region surrounding the transition
point, where the dynamics are governed by the universal properties associated
with the QPT. While time-dependent phenomena associated with classical,
thermally driven phase transitions have been extensively studied in systems
ranging from the early universe to Bose Einstein Condensates, understanding
critical real-time dynamics in isolated, non-equilibrium quantum systems is an
outstanding challenge. Here, we use a Rydberg atom quantum simulator with
programmable interactions to study the quantum critical dynamics associated
with several distinct QPTs. By studying the growth of spatial correlations
while crossing the QPT, we experimentally verify the quantum Kibble-Zurek
mechanism (QKZM) for an Ising-type QPT, explore scaling universality, and
observe corrections beyond QKZM predictions. This approach is subsequently used
to measure the critical exponents associated with chiral clock models,
providing new insights into exotic systems that have not been understood
previously, and opening the door for precision studies of critical phenomena,
simulations of lattice gauge theories and applications to quantum optimization
Managing pneumonia through facility-based Integrated Management of Childhood Management (IMCI) Services:An analysis of the service availability and readiness among public health facilities in Bangladesh
Long-term ocular and visual outcomes following symptomatic and asymptomatic congenital CMV infection: a systematic review protocol
Introduction: Cytomegalovirus (CMV) is one of the most common congenitally acquired infections worldwide. Visual impairment is a common outcome for symptomatic infants, with long-term ophthalmic surveillance often recommended. However, there are no clear guidelines for ophthalmic surveillance in infants with asymptomatic disease. We aim to conduct a systematic review to establish the overall prevalence and incidence of eye and vision related disorders following congenital CMV infection (cCMV). // Methods and analysis: A systematic review and meta-analysis (pending appropriate data for analysis) of cross-sectional and longitudinal studies will be conducted. The PubMed, Embase and CINAHL databases will be searched up to 29 March 2022 without date or language restrictions. Studies will be screened by at least two independent reviewers. Methodological quality of included studies will be assessed using the Joanna Briggs Institute tool. The primary outcome measures will be incidence and/or prevalence of vision impairment or ophthalmic disorders in patients with symptomatic and asymptomatic cCMV infection. A narrative synthesis will be conducted for all included studies. The overall prevalence will be estimated by pooling data using a random-effects model. Heterogeneity between studies will be estimated using Cochran’s Q and the I2 statistics. Egger’s test will be used to assess for publication bias. // Ethics and dissemination: Ethical approval is not required as there is no primary data collection. Study findings will be disseminated at scientific meetings and through publication in peer-reviewed journals
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