A psychometric investigation of health-related quality of life measures for paediatric neurodevelopment assessment: Reliability and concurrent validity of the PEDS-QL, CHU-9D, and the EQ-5D-Y.

There is a need for tools that can provide a brief assessment of functioning for children with neurodevelopmental conditions, including health-related quality of life (HR-QoL). This study evaluated the psychometric properties of three commonly used and well known HR-QoL measures in a cohort of children presenting to clinical developmental assessment services. The most common diagnoses received in these assessment services were autism spectrum disorders. Findings showed good internal consistency for the PedsQL and the CHU-9D, but not the EQ-5D-Y. This research also found that the CHU-9D, EQ-5D-Y, and PedsQL correlated with relevant functioning domains assessed by the VABS-III. Overall, the measures showed that children with neurodevelopmental conditions experienced poor HR-QoL. The majority of children (>86%) met cut-off criteria for significant health concerns on the PedsQL. On the EQ-5D-Y and CHU-9D, they showed reduced HR-QoL particularly on domains relating to school and homework, being able to join in activities, looking after self, and doing usual activities. This study supports the use of the CHU-9D and PedsQL in this population to assess and potentially track HR-QoL in a broad neurodevelopment paediatric population.

Chemical Bonding Induces One-Dimensional Physics in Bulk Crystal BiIr4Se8.

One-dimensional (1D) systems persist as some of the most interesting because of the rich physics that emerges from constrained degrees of freedom. A desirable route to harness the properties therein is to grow bulk single crystals of a physically three-dimensional (3D) but electronically 1D compound. Most bulk compounds which approach the electronic 1D limit still field interactions across the other two crystallographic directions and, consequently, deviate from the 1D models. In this paper, we lay out chemical concepts to realize the physics of 1D models in 3D crystals. These are based on both structural and electronic arguments. We present BiIr4Se8, a bulk crystal consisting of linear Bi2+ chains within a scaffolding of IrSe6 octahedra, as a prime example. Through crystal structure analysis, density functional theory calculations, X-ray diffraction, and physical property measurements, we demonstrate the unique 1D electronic configuration in BiIr4Se8. This configuration at ambient temperature is a gapped Su-Schriefer-Heeger system, generated by way of a canonical Peierls distortion involving Bi dimerization that relieves instabilities in a 1D metallic state. At 190 K, an additional 1D charge density wave distortion emerges, which affects the Peierls distortion. The experimental evidence validates our design principles and distinguishes BiIr4Se8 among other quasi-1D bulk compounds. We thus show that it is possible to realize unique electronically 1D materials applying chemical concepts.

Anisotropic resistance with a 90° twist in a ferromagnetic Weyl semimetal, Co2MnGa.

Weyl semimetals exhibit exotic magnetotransport phenomena such as the chiral anomaly and surface-to-bulk quantum oscillations (Weyl orbits) due to chiral bulk states and topologically protected surface states. Here we report a unique transport property in crystals of the ferromagnetic nodal-line Weyl semimetal Co2MnGa that have been polished to micron thicknesses using a focused ion beam. These thin crystals exhibit a large planar resistance anisotropy (10 × ) with axes that rotate by 90 degrees between opposite faces of the crystal. We use symmetry arguments and electrostatic simulations to show that the observed anisotropy resembles that of an isotropic conductor with surface states that are impeded from hybridization with bulk states. The origin of these states awaits further experiments that can correlate the surface bands with the observed 90° twist.

Colossal magnetoresistance in the multiple wave vector charge density wave regime of an antiferromagnetic Dirac semimetal.

Colossal negative magnetoresistance is a well-known phenomenon, notably observed in hole-doped ferromagnetic manganites. It remains a major research topic due to its potential in technological applications. In contrast, topological semimetals show large but positive magnetoresistance, originated from the high-mobility charge carriers. Here, we show that in the highly electron-doped region, the Dirac semimetal CeSbTe demonstrates similar properties as the manganites. CeSb0.11Te1.90 hosts multiple charge density wave modulation vectors and has a complex magnetic phase diagram. We confirm that this compound is an antiferromagnetic Dirac semimetal. Despite having a metallic Fermi surface, the electronic transport properties are semiconductor-like and deviate from known theoretical models. An external magnetic field induces a semiconductor metal-like transition, which results in a colossal negative magnetoresistance. Moreover, signatures of the coupling between the charge density wave and a spin modulation are observed in resistivity. This spin modulation also produces a giant anomalous Hall response.

Increase in hospitalisation-associated methadone intoxication in France following first COVID-19 lockdown.

OBJECTIVES: At the beginning of the COVID-19 pandemic, the French Addictovigilance Network drew attention to the need to facilitate access to methadone while ensuring its safe use, in order to avoid the occurrence of overdoses and deaths. The objectives of the study were to assess the impact of the lockdowns on the incidence of methadone-use-related hospitalisations (MUHs) and describe the characteristics of patients and hospitalisations. STUDY DESIGN: An interrupted time series using the unobserved components model was performed to predict the monthly incidence of MUHs in 2020 on the basis of previous years' data and compared with MUHs observed. Data were presented with prediction intervals (PI95%). METHODS: This retrospective study was conducted on patients hospitalised in France for methadone between 2014 and 2020, using the French national database hospital discharge database. Patients' characteristics and hospitalisations were described over four periods: before lockdown, first lockdown, after first lockdown, and second lockdown. RESULTS: Compared to the predictions, a higher incidence of MUH was found during the first lockdown, especially in March 2020 (66 cases vs. 51.3; PI95%: 34-65), and there was a large increase during the month following the end of the first lockdown (79 cases vs. 61; PI95%: 46-75). Coconsumptions (alcohol, cannabis, cocaine) were more frequent during the first lockdown, whereas patients aged over 30 years were more concerned thereafter. The second lockdown did not present any particularity. CONCLUSIONS: The first lockdown had a significant impact on the incidence of MUHs. These results confirm the data from the reinforced national monitoring during first lockdown published in 2020, where methadone was the primary substance involved in overdoses and deaths.

General hospital admissions in young and middle-aged people who use psychoactive substances: Impact of Covid-19 lockdowns.

BACKGROUNDS: The Covid-19 pandemic offered a unique opportunity to investigate trends in hospitalizations related to psychoactive substance intoxication, since the usual health burden of social use at parties and gatherings was likely to be decreased during lockdowns and curfew periods. Since young adults are the main users of psychoactive substances for experimental and recreational purposes, this study identified and compared hospitalization trends in young adults and adults over 30 years old. METHODS: This national cohort study was conducted using the French hospital discharge database. An interrupted time-series analysis for the period between 2014 and 2020 was performed in two groups: young (age 18-29) and other adults (30+) to ascertain the trends in the monthly incidence of hospitalization related to psychoactive substance intoxication (opiates, cocaine, benzodiazepines, psychostimulants, alcohol and cannabis). Hospitalization characteristics during the first and second lockdown and the period between them were compared to the reference period (from 01/01/2014 to 29/02/2020). RESULTS: Among 1,358,007 stays associated with psychoactive substance intoxication, 215,430 concerned young adults. Compared with adults 30+, hospitalization trends in young adults showed a greater decrease in the number of stays during lockdown, with a maximum decrease of -39% during the first lockdown (1,566 vs. 2,576; CI95%: 2,285-2,868) versus -20% (10,212 vs. 12,894; CI95%: 12,001-13,787) in the second lockdown. Presentations for alcohol intoxication decreased throughout the pandemic, particularly during the second lockdown, while admissions for benzodiazepine intoxication increased during both lockdowns. Admissions for cannabis intoxication increased throughout the entire period. CONCLUSIONS: Lockdowns were associated with fewer hospitalizations related to psychoactive substance intoxication in both age groups, especially among young adults, which might reflect a decrease in social use. Recreational use might therefore be an important target for prevention and risk minimization.

Planar thermal Hall effect of topological bosons in the Kitaev magnet α-RuCl3.

The honeycomb magnet α-RuCl3 has attracted considerable interest because it is proximate to the Kitaev Hamiltonian whose excitations are Majoranas and vortices. The thermal Hall conductivity κxy of Majorana fermions is predicted to be half-quantized. Half-quantization of κxy/T (T, temperature) was recently reported, but this observation has proven difficult to reproduce. Here, we report detailed measurements of κxy on α-RuCl3 with the magnetic field B ∥ a (zigzag axis). In our experiment, κxy/T is observed to be strongly temperature dependent between 0.5 and 10 K. We show that its temperature profile matches the distinct form expected for topological bosonic modes in a Chern-insulator-like model. Our analysis yields magnon band energies in agreement with spectroscopic experiments. At high B, the spin excitations evolve into magnon-like modes with a Chern number of ~1. The bosonic character is incompatible with half-quantization of κxy/T.

Phase tuning of multiple Andreev reflections of Dirac fermions and the Josephson supercurrent in Al-MoTe2-Al junctions.

When an electron is incident on a superconductor from a metal, it is reflected as a hole in a process called Andreev reflection. If the metal N is sandwiched between two superconductors S in an SNS junction, multiple Andreev reflections (MARs) occur. We have found that, in SNS junctions with high transparency ([Formula: see text]) based on the Dirac semimetal MoTe2, the MAR features are observed with exceptional resolution. By tuning the phase difference [Formula: see text] between the bracketing Al superconductors, we establish that the MARs coexist with a Josephson supercurrent [Formula: see text]. As we vary the junction voltage V, the supercurrent amplitude [Formula: see text] varies in step with the MAR order n, revealing a direct relation between them. Two successive Andreev reflections serve to shuttle a Cooper pair across the junction. If the pair is shuttled coherently, it contributes to [Formula: see text]. The experiment measures the fraction of pairs shuttled coherently vs. V. Surprisingly, superconductivity in MoTe2 does not affect the MAR features.

Catalogue of flat-band stoichiometric materials.

Topological electronic flattened bands near or at the Fermi level are a promising route towards unconventional superconductivity and correlated insulating states. However, the related experiments are mostly limited to engineered materials, such as moiré systems1-3. Here we present a catalogue of the naturally occuring three-dimensional stoichiometric materials with flat bands around the Fermi level. We consider 55,206 materials from the Inorganic Crystal Structure Database catalogued using the Topological Quantum Chemistry website4,5, which provides their structural parameters, space group, band structure, density of states and topological characterization. We combine several direct signatures and properties of band flatness with a high-throughput analysis of all crystal structures. In particular, we identify materials hosting line-graph or bipartite sublattices-in either two or three dimensions-that probably lead to flat bands. From this trove of information, we create the Materials Flatband Database website, a powerful search engine for future theoretical and experimental studies. We use the database to extract a curated list of 2,379 high-quality flat-band materials, from which we identify 345 promising candidates that potentially host flat bands with charge centres that are not strongly localized on the atomic sites. We showcase five representative materials and provide a theoretical explanation for the origin of their flat bands close to the Fermi energy using the S-matrix method introduced in a parallel work6.

Evolving Devil's Staircase Magnetization from Tunable Charge Density Waves in Nonsymmorphic Dirac Semimetals.

While several magnetic topological semimetals have been discovered in recent years, their band structures are far from ideal, often obscured by trivial bands at the Fermi energy. Square-net materials with clean, linearly dispersing bands show potential to circumvent this issue. CeSbTe, a square-net material, features multiple magnetic-field-controllable topological phases. Here, it is shown that in this material, even higher degrees of tunability can be achieved by changing the electron count at the square-net motif. Increased electron filling results in structural distortion and formation of charge density waves (CDWs). The modulation wave-vector evolves continuously leading to a region of multiple discrete CDWs and a corresponding complex "Devil's staircase" magnetic ground state. A series of fractionally quantized magnetization plateaus is observed, which implies direct coupling between CDW and a collective spin-excitation. It is further shown that the CDW creates a robust idealized nonsymmorphic Dirac semimetal, thus providing access to topological systems with rich magnetism.

Band Engineering of Dirac Semimetals Using Charge Density Waves.

New developments in the field of topological matter are often driven by materials discovery, including novel topological insulators, Dirac semimetals, and Weyl semimetals. In the last few years, large efforts have been made to classify all known inorganic materials with respect to their topology. Unfortunately, a large number of topological materials suffer from non-ideal band structures. For example, topological bands are frequently convoluted with trivial ones, and band structure features of interest can appear far below the Fermi level. This leaves just a handful of materials that are intensively studied. Finding strategies to design new topological materials is a solution. Here, a new mechanism is introduced, which is based on charge density waves and non-symmorphic symmetry, to design an idealized Dirac semimetal. It is then shown experimentally that the antiferromagnetic compound GdSb0.46 Te1.48 is a nearly ideal Dirac semimetal based on the proposed mechanism, meaning that most interfering bands at the Fermi level are suppressed. Its highly unusual transport behavior points to a thus far unknown regime, in which Dirac carriers with Fermi energy very close to the node seem to gradually localize in the presence of lattice and magnetic disorder.

Publisher's Note: Time-Reversal-Breaking Weyl Fermions in Magnetic Heusler Alloys [Phys. Rev. Lett. 117, 236401 (2016)].

This corrects the article DOI: 10.1103/PhysRevLett.117.236401.

Evidence for an edge supercurrent in the Weyl superconductor MoTe2.

Edge supercurrents in superconductors have long been an elusive target. Interest in them has reappeared in the context of topological superconductivity. We report evidence for the existence of a robust edge supercurrent in the Weyl superconductor molybdenum ditelluride (MoTe2). In a magnetic field B, fluxoid quantization generates a periodic modulation of the edge condensate observable as a "fast-mode" oscillation of the critical current I c versus B The fast-mode frequency is distinct from the conventional Fraunhofer oscillation displayed by the bulk supercurrent. We confirm that the fast-mode frequency increases with crystal area as expected for an edge supercurrent. In addition, weak excitation branches are resolved that display an unusual broken symmetry.

Feasibility of a school-based exercise intervention for children with intellectual disability to reduce cardio-metabolic risk.

BACKGROUND: People with intellectual disabilities (ID) are at increased risk of secondary health conditions, reduced quality of life and life expectancy. Children with ID demonstrate low levels of physical activity in association with a higher prevalence of obesity, a modifiable risk factor associated with secondary health conditions including type 2 diabetes and cardiovascular disease. Despite this, physical activity interventions addressing weight and weight-related complications in this population are limited. This study aimed to establish the feasibility of a school-based group exercise intervention for children with moderate to severe ID. METHODS: A single-arm intervention study was used to establish the feasibility of a 16-week exercise intervention. Children attending a School for Specific Purposes in Sydney, Australia, participated in two 30-min exercise sessions per week across the intervention period in addition to their regular physical education class. Each exercise session was 60% aerobically based, 20% strength based and 20% targeted towards fundamental movement skill development. We used two facilitation strategies to assist the delivery of the intervention, including the implementation of a variety of communication resources and promotion of social interaction. Feasibility was assessed through recruitment rates, program retention, adverse effects, attendance, group size feasibility and non-compliance. Anthropometric measures included height (m), weight (kg) and waist circumference (cm; umbilicus), with body mass index (BMI) and waist-to-height ratios (WtHR) used to determine cardio-metabolic risk. Aerobic capacity was assessed using the submaximal 6-min walk test (6-MWT). Intensity of physical activity sessions was measured through the use of tri-axial accelerometers and compared to physical activity recommendations. RESULTS: Ten children aged between 9 and 13 years completed the 16-week intervention, with a 55% recruitment rate, 91% program retention, 86% attendance and with no adverse effects reported. Sessions commenced as 1:1 supervisor to child ratios before progressing to established small groups of 2:7 (supervisor : child). Children spent 38.4% (11.5 min) of each session in moderate to vigorous physical activity (MVPA), equating to 20% of their MVPA recommended daily physical activity levels (twice per week). There was a significant change in weight across the intervention period, with a trend towards increased weight between mid-intervention and 3-month follow-up time points. There were no significant changes in child BMI, WtHR or aerobic capacity. CONCLUSIONS: A school-based group exercise intervention for children with moderate to severe ID is feasible and safe, with high retention rates and physical activity participation. No significant improvements in body composition or aerobic capacity were determined. The present study demonstrates that engaging children with moderate-severe ID in school-based group exercise is feasible to assist in physical activity participation.

A gap-protected zero-Hall effect state in the quantum limit of the non-symmorphic metal KHgSb.

A recurring theme in topological matter is the protection of unusual electronic states by symmetry, for example, protection of the surface states in Z2 topological insulators by time-reversal symmetry1-3. Recently, interest has turned to unusual surface states in the large class of non-symmorphic materials4-12. In particular, KHgSb is predicted to exhibit double quantum spin Hall states10. Here we report measurements of the Hall conductivity in KHgSb in a strong magnetic field B. In the quantum limit, the Hall conductivity is observed to fall exponentially to zero, but the diagonal conductivity is finite. A large gap protects this unusual zero-Hall state. We theoretically propose that, in this quantum limit, the chemical potential drops into the bulk gap, intersecting equal numbers of right- and left-moving quantum spin Hall surface modes to produce the zero-Hall state. The zero-Hall state illustrates how topological protection in a non-symmorphic material with glide symmetry may lead to highly unusual transport phenomena.

CT imaging features of skeletal muscle metastasis.

AIM: To define the computed tomography (CT) features common in skeletal muscle metastases and their prevalence and to identify the most commonly associated primary malignancy and the most common muscle groups in which skeletal muscle metastases are found. METHODS AND MATERIALS: Institutional review board (IRB) waiver for informed consent was obtained. A retrospective review was conducted of CT examinations from a single, large, academic centre picture archiving and communication system (PACS) database, performed from August 2009 to July 2013. All 10,426 examinations and 8,524 unique patients reviewed had a confirmed diagnosis of malignancy. The CT reports were screened manually to identify disease involving the skeletal muscles. Images of the 60 initial studies identified were then reviewed. Cases that showed direct invasion of the tumour into the skeletal muscles, and follow-up studies of the same patient were excluded. The 27 included cases were classified under five distinct patterns. RESULTS: In the present study, the prevalence for skeletal muscle metastasis was 0.33% across all malignancies. The most common primary involved was breast cancer (25%). The most common pattern was focal intramuscular mass with homogeneous contrast enhancement. The most common sites of skeletal muscle metastasis were in the abdomen (43%) and thorax (33%) musculature. CONCLUSION: Breast cancer was the most commonly associated primary malignancy and a focal, homogeneously enhancing intramuscular mass was the most common presentation. Although skeletal muscle metastasis remains a rare entity, its incidence rate should increase with the increased usage of whole-body PET CT for cancer staging.

A pressure-induced topological phase with large Berry curvature in Pb1-x Sn x Te.

The picture of how a gap closes in a semiconductor has been radically transformed by topological concepts. Instead of the gap closing and immediately reopening, topological arguments predict that, in the absence of inversion symmetry, a metallic phase protected by Weyl nodes persists over a finite interval of the tuning parameter (for example, pressure P). The gap reappears when the Weyl nodes mutually annihilate. We report evidence that Pb1-x Sn x Te exhibits this topological metallic phase. Using pressure to tune the gap, we have tracked the nucleation of a Fermi surface droplet that rapidly grows in volume with P. In the metallic state, we observe a large Berry curvature, which dominates the Hall effect. Moreover, a giant negative magnetoresistance is observed in the insulating side of phase boundaries, in accord with ab initio calculations. The results confirm the existence of a topological metallic phase over a finite pressure interval.