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The development of quantum computing across several technologies and platforms has reached the point of having an advantage over classical computers for an artificial problem, a point known as ‘quantum advantage’. As a next step along the development of this technology, it is now important to discuss ‘practical quantum advantage’, the point at which quantum devices will solve problems of practical interest that are not tractable for traditional supercomputers. Many of the most promising short-term applications of quantum computers fall under the umbrella of quantum simulation: modelling the quantum properties of microscopic particles that are directly relevant to modern materials science, high-energy physics and quantum chemistry. This would impact several important real-world applications, such as developing materials for batteries, industrial catalysis or nitrogen fixing. Much as aerodynamics can be studied either through simulations on a digital computer or in a wind tunnel, quantum simulation can be performed not only on future fault-tolerant digital quantum computers but also already today through special-purpose analogue quantum simulators. Here we overview the state of the art and future perspectives for quantum simulation, arguing that a first practical quantum advantage already exists in the case of specialized applications of analogue devices, and that fully digital devices open a full range of applications but require further development of fault-tolerant hardware. Hybrid digital–analogue devices that exist today already promise substantial flexibility in near-term applications.

Semiconductor heterostructures1and ultracold neutral atomic lattices2capture many of the essential properties of one-dimensional electronic systems. However, fully one-dimensional superlattices are highly challenging to fabricate in the solid state due to the inherently small length scales involved. Conductive atomic force microscope lithography applied to an oxide interface can create ballistic few-mode electron waveguides with highly quantized conductance and strongly attractive electron–electron interactions3. Here we show that artificial Kronig–Penney-like superlattice potentials can be imposed on such waveguides, introducing a new superlattice spacing that can be made comparable to the mean separation between electrons. The imposed superlattice potential fractures the electronic subbands into a manifold of new subbands with magnetically tunable fractional conductance. The lowest plateau, associated with ballistic transport of spin-singlet electron pairs3, shows enhanced electron pairing, in some cases up to the highest magnetic fields explored. A one-dimensional model of the system suggests that an engineered spin–orbit interaction in the superlattice contributes to the enhanced pairing observed in the devices. These findings are an advance in the ability to design new families of quantum materials with emergent properties and the development of solid-state one-dimensional quantum simulation platforms.

IMPORTANCE: Gynecological laparoscopies are one of the most common surgical procedures worldwide. Limited evidence exists on rates of surgical site infections in patients undergoing gynecological laparoscopies and strategies to prevent these infections. OBJECTIVE: To compare rates of port-site infections, organ or space infections, and any type of surgical site infections among patients who underwent gynecological laparoscopies and received 1 of 3 types of skin preparation solutions. DESIGN, SETTING, AND PARTICIPANTS: A double-blind randomized clinical trial was conducted between February 28, 2017, and November 26, 2018, at a tertiary university-affiliated referral center. A total of 661 patients 18 years or older who underwent an elective operative laparoscopy for treatment of nonmalignant gynecological disorders were randomly assigned in a 1:1:1 ratio to have their skin cleaned before surgery with alcohol-based chlorhexidine, alcohol-based povidone-iodine, or water-based povidone-iodine. Statistical analysis was performed from February 28, 2017, to November 26, 2018. Analyses were performed on a modified intention-to-treat basis. INTERVENTIONS: A total of 221 patients were randomized to have their skin prepared preoperatively with water-based povidone-iodine, 220 were randomized to alcohol-based povidone-iodine, and 220 were randomized to alcohol-based chlorhexidine. The patients were blinded to the solution used to clean their skin. Patients were followed up 1 and 4 weeks after surgery by a physician who was blinded to the skin preparation solution used at surgery. Evidence of infection according to Centers for Disease Control and Prevention criteria were documented. MAIN OUTCOMES AND MEASURES: The primary outcome of this study was port-site infection 30 days after surgery. Secondary outcomes were organ or space infections and any type of surgical site infections; the study also aimed to prospectively describe rates of surgical site infections in gynecological laparoscopies. RESULTS: Of the 661 patients, 640 (96.8%; mean [SD] age, 36.2 [10.6] years) were examined after surgery by a physician at the study site and were included in the modified intention-to-treat analysis. The overall rate of port-site infection was 10.2% (65 of 640), rate of organ or space infection was 6.6% (42 of 640), and rate of any surgical site infection was 16.3% (104 of 640). The odds ratio for port-site infection for alcohol-based chlorhexidine vs water-based povidone-iodine was 1.13 (95% CI, 0.61-2.08), for alcohol-based chlorhexidine vs alcohol-based povidone-iodine was 1.34 (95% CI, 0.71-2.52), and for water-based povidone-iodine vs alcohol-based povidone-iodine was 1.19 (95% 0.62-2.27). CONCLUSIONS AND RELEVANCE: Surgical site infections were more common than expected among patients who underwent gynecological laparoscopies. No skin preparation solution provided an advantage compared with the other solutions in reducing infection rates. TRIAL REGISTRATION: http://anzctr.org.au Identifier: ACTRN12617000475347

ObjectiveChildren with moderate/severe cellulitis requiring intravenous antibiotics are usually admitted to hospital. Admission avoidance is attractive but there are few data in children. We implemented a new pathway for children to be treated with intravenous antibiotics at home and aimed to describe the characteristics of patients treated on this pathway and in hospital and to evaluate the outcomes.MethodsThis is a prospective, observational cohort study of children aged 6 months–18 years attending the ED with uncomplicated moderate/severe cellulitis in March 2014–January 2015. Patients received either intravenous ceftriaxone at home or intravenous flucloxacillin in hospital based on physician discretion. Primary outcome was treatment failure defined as antibiotic change within 48 hours due to inadequate clinical improvement or serious adverse events. Secondary outcomes include duration of intravenous antibiotics and complications.Results115 children were included: 47 (41%) in the home group and 68 (59%) in the hospital group (59 hospital-only, 9 transferred home during treatment). The groups had similar clinical features. 2/47 (4%) of the children in the home group compared with 8/59 (14%) in the hospital group had treatment failure (P=0.10). Duration of intravenous antibiotics (median 1.9 vs 1.8 days, P=0.31) and complications (6% vs 10%, P=0.49) were no different between groups. Home treatment costs less, averaging $A1166 (£705) per episode compared with $A2594 (£1570) in hospital.ConclusionsChildren with uncomplicated cellulitis may be able to avoid hospital admission via a home intravenous pathway. This approach has the potential to provide cost and other benefits of home treatment.

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To describe trends in aetiology and resistance patterns and patient outcomes of bacteraemia and pneumonia in a PICU over an 11-year period. We also describe interventions aimed at reducing multi-resistant infections and other serious bacterial infections in the PICU.

Continuous infusions of vancomycin over 24 hours have been shown in adults to reduce drug toxicity, lower treatment costs and require fewer blood samples for therapeutic drug monitoring. They may also improve clinical outcome through earlier attainment of target drug concentrations. In neonates, there is no consensus on vancomycin dosing. We reviewed the literature to assess the evidence for vancomycin dosing regimens for continuous infusion in neonates.

We present a simple, experimentally realizable method to make coherent three-body interactions dominate the physics of an ultracold lattice gas. Our scheme employs either lattice modulation or laser-induced tunneling to reduce or tum off two-body interactions in a rotating frame, promoting three-body interactions arising from multiorbital physics to leading-order processes. This approach provides a route to strongly correlated phases of lattice gases that are beyond the reach of previously proposed dissipative three-body interactions. In particular, we study the mean-field phase diagram for spinless bosons with three- and two- body interactions and provide a roadmap to dimer states of varying character in one dimension. This toolkit should be immediately applicable in state-of-the-art cold-atom experiments. [ABSTRACT FROM AUTHOR]

Infection with antibiotic-resistant (AR) Gram-negative (GN) bacteria is associated with increased morbidity and mortality. The aim of this study was to determine risk factors and outcomes associated with GN bacteremia with acquired resistance to antibiotics used in the empiric treatment of febrile neutropenia in pediatric oncology patients at our institution.

ABSTRACTCoagulase-negative staphylococci have been identified as major causes of late-onset neonatal bacteremia in neonatal intensive care units. Sixty isolates of Staphylococcus capitisobtained from blood cultures of neonates between 2000 and 2005 were examined in this study. Biochemical analysis confirmed that 52 of these isolates belonged to the subsp. urealyticus, and the remaining 8 belonged to the subsp. capitis.Isolates of the predominant subsp. urealyticusclones were characterized by their resistance to penicillin, erythromycin, and oxacillin and their biofilm formation ability, whereas subsp. capitisisolates were generally antibiotic susceptible and biofilm negative. Pulsed-field gel electrophoresis (PFGE) after SacII digestion separated the 60 isolates into five major clusters. Sequence analysis showed that, in S. capitis, the icaoperon plus the negative regulator icaRwas 4,160 bp in length. PCRs demonstrated the presence of the icaoperon in all isolates. Further analysis of five isolates (two biofilm-positive subsp. urealyticus, one biofilm-negative subsp. urealyticus, and two biofilm-negative subsp. capitis) revealed that the icaoperons were identical in all of the biofilm-positive subsp. urealyticusstrains; however, the biofilm-negative isolates showed variations. The distinctive phenotypic and genotypic characteristics revealed by this study may affect the epidemiology of the two subspecies of S. capitisin the clinical setting. These results may provide a better understanding of the contribution of these two species to bloodstream infections in neonates.

Term newborns commonly undergo evaluations to ‘rule out sepsis’, although the frequency of this practice is unknown. Consequences may include increased duration of hospitalisation, admission to the neonatal unit and mother-infant separation, with interrupted breastfeeding.

Novel swine-origin influenza A pandemic 2009 (H1N1) virus (S-OIV) infection in the context of other respiratory viruses circulating in winter has not been studied.

The epidemiology and management of nontuberculous mycobacterial (NTM) infection in Australian children is unknown.

Intrapartum antibiotics have reduced the incidence of neonatal early onset (EO) group B streptococcal (GBS) disease. Some surveillance data suggest that this success may be at the cost of increasing rates of non-GBS infection, especially in premature neonates.

Health care personnel, including laboratory workers, are at risk of contracting vaccine-preventable diseases from patients, their blood or other body fluids. Health care workers may also transmit infection to their patients. These workers should be appropriately vaccinated against the hepatitis B virus, the influenza viruses and the measles, mumps, rubella and varicella zoster viruses. Vaccination against these agents is discussed, including issues regarding the vaccination of immunocompromised health care workers and factors that influence the uptake of vaccines amongst health care workers.

The benefits of breast feeding are numerous. However, breast milk is implicated in the transmission of many infectious agents to the newborn infant. Human immunodeficiency virus and, in certain populations, human T-cell leukaemia virus type I are the most important. Transmission of hepatitis B and C viruses is controversial, although recent data suggests that the risk of transmission is low. The use of banked expressed breast milk, still popular in some countries, as well as management of the accidental exposure of a baby to another mother's breast milk, will also be discussed.

ABSTRACTNine Staphylococcus capitisisolates from blood cultures of newborns were examined for resistance to vancomycin. MICs were within the susceptible range, but population profiling revealed a resistant subpopulation. Only isolates with the largest subpopulation were identified as heteroresistant to vancomycin by Etest. This finding may have therapeutic implications.

A chemical autonomous agent is defined as a reproducing molecular system that carries out a thermodynamic work cycle, reminiscent of the earliest prebiotic replicators that harnessed free energy. The efficiency with which free energy is utilized to promote replication is a measure of the selective fitness of such a system. Simulations of the operation of a typical autonomous agent over a wide range of possible parameter settings reveals a fitness landscape with a well-defined maximum and a variety of features that are amenable to interpretation in terms of evolutionary concepts.

We study the driven-dissipative dynamics of a network of spin-1/2 systems coupled to one or more chiral ID bosonic waveguides within the framework of a Markovian master equation. We determine how the interplay between a coherent drive and collective decay processes can lead to the formation of pure multipartite entangled steady states. The key ingredient for the emergence of these many-body dark states is an asymmetric coupling of the spins to left and right propagating guided modes. Such systems are motivated by experimental possibilities with internal states of atoms coupled to optical fibers, or motional states of trapped atoms coupled to a spin-orbit coupled Bose-Einstein condensate. We discuss the characterization of the emerging multipartite entanglement in this system in terms of the Fisher information. [ABSTRACT FROM AUTHOR]

We analyze the heating of interacting bosonic atoms in an optical lattice due to intensity fluctuations of the lasers forming the lattice. We focus in particular on fluctuations at low frequencies below the band-gap frequency, such that the dynamics is restricted to the lowest band. We derive stochastic equations of motion, and analyze the effects on different many-body states, characterizing heating processes in both strongly and weakly interacting regimes. In the limit where the noise spectrum is flat at low frequencies, we can derive an effective master equation describing the dynamics. We compute heating rates and changes to characteristic correlation functions both in the perturbation theory limit and using a full time-dependent calculation of the stochastic many-body dynamics in one dimension based on time-dependent density-matrix-renormalization-group methods. [ABSTRACT FROM AUTHOR]

We suggest and analyze a scheme to adiabatically cool bosonic atoms to picokelvin temperatures which should allow the observation of magnetic ordering via superexchange in optical lattices. The starting point is a gapped phase called the spin Mott phase, where each site is occupied by one spin-up and one spin-down atom. An adiabatic ramp leads to an xy-ferromagnetic phase. We show that the combination of time-dependent density matrix renormalization group methods with quantum trajectories can be used to fully address possible experimental limitations due to decoherence, and demonstrate that the magnetic correlations are robust for experimentally realizable ramp speeds. Using a microscopic master equation treatment of light scattering in the many-particle system, we test the robustness of adiabatic state preparation against decoherence. Due to different ground-state symmetries, we alsofind a metastable state with xy-ferromagnetic order if the ramp crosses to regimes where the ground state is a z ferromagnet. The bosonic spin Mott phase as the initial gapped state for adiabatic cooling has many features in common with a fermionic band insulator, but the use of bosons should enable experiments with substantially lower initial entropies. [ABSTRACT FROM AUTHOR]

We show how a dressed lattice scheme can provide control over certain types of noise for atomic quantum gases in the lowest band of an optical lattice, removing the effects of global lattice amplitude noise to first order for particular choices of the dressing field parameters. We investigate the nonequilibrium many-body dynamics of bosons and fermions induced by noise away from this parameter regime, and show how the same technique can reduce spatial disorder in projected lattice potentials. [ABSTRACT FROM AUTHOR]

We investigate the dynamics following a global parameter quench for two one-dimensional models with variable-range power-law interactions: a long-range transverse Ising model, which has recently been realized in chains of trapped ions, and a long-range lattice model for spinless fermions with long-range tunneling. For the transverse Ising model, the spreading of correlations and growth of entanglement are computed using numerical matrix product state techniques, and are compared with exact solutions for the fermionic tunneling model. We identify transitions between regimes with and without an apparent linear light cone for correlations, which correspond closely between the two models. For long-range interactions (in terms of separation distance r, decaying slower than 1/r), we find that despite the lack of a light cone, correlations grow slowly as a power law at short times, and that--depending on the structure of the initial state--the growth of entanglement can also be sublinear. These results are understood through analytical calculations, and should be measurable in experiments with trapped ions. [ABSTRACT FROM AUTHOR]