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Fast radio bursts (FRBs) are millisecond-duration radio transients 1 , 2 of unknown origin. Two possible mechanisms that could generate extremely coherent emission from FRBs invoke neutron star magnetospheres 3 – 5 or relativistic shocks far from the central energy source 6 – 8 . Detailed polarization observations may help us to understand the emission mechanism. However, the available FRB polarization data have been perplexing, because they show a host of polarimetric properties, including either a constant polarization angle during each burst for some repeaters 9 , 10 or variable polarization angles in some other apparently one-off events 11 , 12 . Here we report observations of 15 bursts from FRB 180301 and find various polarization angle swings in seven of them. The diversity of the polarization angle features of these bursts is consistent with a magnetospheric origin of the radio emission, and disfavours the radiation models invoking relativistic shocks. Polarization observations of the fast radio burst FRB 180301 with the FAST radio telescope show diverse polarization angle swings, consistent with a magnetospheric origin of the emission.

The nitrogen-vacancy (NV) center in diamond is a promising quantum system for magnetometry applications exhibiting optical readout of minute energy shifts in its spin sub-levels. Key material requirements for NV ensembles are a high NV − concentration, a long spin coherence time and a stable charge state. However, these are interdependent and can be difficult to optimize during diamond growth and subsequent NV creation. In this work, we systematically investigate the NV center formation and properties in bulk chemical vapor deposition (CVD) diamond. The nitrogen flow during growth is varied by over four orders of magnitude, resulting in a broad range of single substitutional nitrogen concentrations of 0.2–20 parts per million. For a fixed nitrogen concentration, we optimize electron-irradiation fluences with two different accelerated electron energies, and we study defect formation via optical characterizations. We discuss a general approach to determine the optimal irradiation conditions, for which an enhanced NV concentration and an optimum of NV charge states can both be satisfied. We achieve spin–spin coherence times T 2 ranging from 45.5 to 549 μ s for CVD diamonds containing 168 to 1 parts per billion NV − centers, respectively. This study shows a pathway to engineer properties of NV-doped CVD diamonds for improved sensitivity.

Fast radio bursts (FRBs) are immensely energetic millisecond-duration radio pulses. Observations indicate that nearby FRBs can be produced by old stellar populations, as suggested by the localization of the repeating source FRB 20200120E in a globular cluster of M81. Nevertheless, the burst energies of FRB 20200120E are significantly smaller than those of other cosmological FRBs. Here, we report the detection of a bright burst from FRB 20200120E in 1.1 – 1.7 GHz, with a fluence of approximately 30 Jy ms, which is more than 42 times larger than the previously detected bursts near 1.4 GHz frequency. It reaches one-third of the energy of the weakest burst from FRB 20121102A and is detectable at a distance exceeding 200 Mpc. Our finding bridges the gap between nearby and cosmological FRBs and indicates that FRBs hosted in globular clusters can be bright enough to be observable at cosmological distances. Repeating fast radio burst, FRB 20200120E, has been localized to a globular cluster M81. Here, the authors show detection of a burst from FRB 20200120E that is 42 times stronger than the previously detected bursts.

The characteristics of ion-scale turbulence in the presence of a magnetic island are numerically investigated using a gyrokinetic model in fusion plasma. We observe that in the absence of the usual ion temperature gradient (ITG) drive gradient, a magnetic island and its flatten effect could drive ITG instability. The magnetic island (MI) not only drives high- n modes of ITG instability but also induces low- n modes of vortex flow. Moreover, as the magnetic island width increases, the width of the vortex flow also increases. This implies that wider islands may more easily induce vortex flows. The study further indicates that the saturated amplitude and transport level of MI-induced ITG turbulence vary with different magnetic island widths. In general, larger magnetic islands enhance both particle and heat transport. When the magnetic island width reaches to 21 ρ i , the turbulence-driven transport becomes the same level with the cases that ITG is driven by pressure gradients. Our findings indicate the presence of intricate nonlinear effects in the modulation of plasma turbulence by MIs. These effects are of significant importance for comprehending the phenomenon of nonlinear coupling in forthcoming tokamaks such as ITER.

Introduction A sinus tract, an abnormal channel between the skin and joint, is a major criterion that proves the presence of an underlying periprosthetic joint infection. Its presence not only increases failure rates but also leads to poor outcomes. Despite its clinical relevance, little is known about risk factors and underlying microorganism profiles. The aim of this study was to investigate PJIs of the hip with a sinus tract, identifying risk factors and microorganism profiles. Materials and methods This was a retrospective case control study of all PJI cases of the hip treated at our institution. A total of 4,368 cases with a PJI of the hip were identified of which 653 patients (14.95%), displayed a sinus tract. Univariate and multivariate analysis was performed. Odds ratio (OR) and 95% confidence interval (CI) were presented. Results Multivariate analysis identified diabetes mellitus ( p  = 0.004; OR = 1.62; 95% CI 1.17–2.44), history of ileus ( p  < 0.001; OR = 4.65; 95% CI 2.38–9.08), osteomyelitis ( p  < 0.001; OR = 2.35; 95% CI 1.65–3.35) and prior revisions ( p  = 0–014; OR = 1.36; 95% CI 1.07–1.74) as risk factors for a sinus tract. Polymicrobial infections ( p  < 0.001; OR = 2.35; 95% CI 1.86–2.96), Staphylococcus aureus ( p  < 0.001; OR = 3.67; 95% CI 2.86–4.71) and Escherichia coli ( p  = 0.014; OR = 1.65; 95% CI 1.11–2.46) were associated with a sinus tract in PJIs of the hip. Conclusions Microorganism profiles and risk factors differ significantly in patients with PJI of a THA with a sinus tract. These insights can help surgeons in planning and selecting appropriate antibiotics for cement loading and empiric antibiotic treatment, as well as in risk stratification of patients, who may develop a sinus tract following THA.

Coal seam gas will seriously threaten the safety of mining. The stability of drainage borehole determines the safety of both mining and utilization of coal seam gas. However, the borehole will collapse, leading to the failure of gas drainage. A porous and firm low-cost aerated concrete-based material for borehole protection is proposed as a solution. Under high confining pressure, the mechanism of pore distribution of aerated concrete-based material on its properties is still unclear. In this work, the experiment and molecular dynamics simulation are combined to analyze how pore distribution determines its permeability and compressive strength. The effect of water-to-cement ratio on aerated concrete is first investigated by pore distribution, compressive strength, and permeability measures. The experimental results of optimal water-to-cement ratio of 0.6 agree with the existing experimental results of 0.54–0.64. Further, the orthogonal experiment is used to investigate the relationship between pore distribution and its permeability by doping fly-ash. It is found that under the same water-to-cement ratio, the doped fly-ash shows a limited effect on the permeability of aerated concrete. The pore in the range from 500 to 1500  μ m mainly contributes to the flow rate. The optimal mixture of doped aerated concrete is water-to-cement ratio of 0.6 and mass fraction of doped fly-ash of 40%. Moreover, the absorption/desorption effects of methane molecules are illustrated by molecular dynamics simulation. It is found that the flow rate of aerated concrete will be enhanced by hydrophobic fly-ash nanoparticles. The present work can inspire further mixture design and pave the way for the development of aerated concrete-based material with high porosity and compressive strength at high confining pressure.

Introduction The purpose of this study was to evaluate the association between the Soft Tissue Radiological Knee (SToRK) Index and the risk of developing a superficial surgical site infection (SSSI) following primary total knee arthroplasty (TKA). Methods The SToRK Index was measured using calibrated long leg radiographs (LLR) in 174 patients undergoing TKA. Results A moderate correlation was found between the SToRK Index and body mass index (BMI) (r s =0.574; p  < 0.001). The SToRK Index was a better predictor of SSSI in females than males. In females, a SToRK Index cutoff of 2.01 had a sensitivity and specificity of 41.3% and 74.6% for developing SSSI, respectively, with a positive likelihood ratio of 1.63. Conclusion The SToRK Index can be used as an additional tool in assessing the risk for SSSI after TKA. It might be more predictive in females due to the different fat distribution compared to males.

Quantum metrology with non-classical states offers a promising route to improved precision in physical measurements. The quantum effects of Schrödinger-cat superpositions or entanglements enable measurement uncertainties to reach below the standard quantum limit. However, the challenge of maintaining a long coherence time for such non-classical states often prevents full exploitation of the quantum advantage in metrology. Here we demonstrate a long-lived Schrödinger-cat state of optically trapped 173 Yb ( I  = 5/2) atoms. The cat state, a superposition of two oppositely directed and furthest-apart spin states, is generated by a nonlinear spin rotation. Protected in a decoherence-free subspace against inhomogeneous light shifts of an optical lattice, the cat state persists for a coherence time of 1.4(1) × 10 3  s. A magnetic field is measured using Ramsey interferometry, demonstrating a scheme of Heisenberg-limited metrology for atomic magnetometry, quantum information processing and searching for new physics beyond the Standard Model. Using spin-5/2 nuclei of 173 Yb atoms trapped in an optical lattice, a Schrödinger-cat state persists for a coherence time of 1.4 × 10 3  s. In measuring external magnetic fields, the cat state exhibits a sensitivity approaching the Heisenberg limit.

Purpose Cutibacterium species, formerly known as Propionibacterium , are gram-positive, anaerobic bacilli increasingly recognized as a cause of periprosthetic joint infection (PJI) following total hip arthroplasty (THA). This study aimed to compare the incidence of Cutibacterium -associated PJI among different surgical approaches for THA. Methods A retrospective review was conducted on patients treated for Cutibacterium -associated PJI following THA between 2011 and 2021. Patients were categorized based on the surgical approach: direct anterior (DAA), lateral, or posterior. A total of 211 patients met inclusion criteria, comprising 153 men (72.5%) and 58 women (27.5%). Results Among the 211 cases of Cutibacterium -associated PJI, 102 (48.3%) underwent THA via DAA, 63 (29.9%) via a lateral approach, and 46 (21.8%) via a posterior approach. There were no significant differences between groups in age, sex, laterality, BMI or fistula formation. The incidence of Cutibacterium PJI was significantly higher with DAA compared to the lateral ( P  < 0.001) and posterior approaches ( P  < 0.001), while no significant difference was observed between lateral and posterior approaches ( P  = 0.059). The rate of Cutibacterium -associated PJI has increased since 2016. Conclusion Nearly half of all Cutibacterium PJIs were associated with the DAA. Surgeons should be aware of this increased risk and implement appropriate preventive measures when performing THA via DAA.