Antiferromagnetism at T > 500 K in the layered hexagonal ruthenate SrRu2O6

Under the terms of the Creative Commons Attribution license.-- et al.We report an experimental and computational study of the magnetic and electronic properties of the layered Ru(V) oxide SrRu2O6 (hexagonal, P3¯1m), which shows antiferromagnetic order with a Néel temperature of 563(2) K, among the highest for 4d oxides. Magnetic order occurs both within edge-shared octahedral sheets and between layers and is accompanied by anisotropic thermal expansivity that implies strong magnetoelastic coupling of Ru(V) centers. Electrical transport measurements using focused-ion-beam¿induced deposited contacts on a micron-scale crystallite as a function of temperature show p-type semiconductivity. The calculated electronic structure using hybrid density functional theory successfully accounts for the experimentally observed magnetic and electronic structure, and Monte Carlo simulations reveal how strong intralayer as well as weaker interlayer interactions are a defining feature of the high-temperature magnetic order in the material.The work is funded by EPSRC through Grant No. EP/L000202.Peer Reviewe

Antiferromagnetism at T > 500 K in the Layered Hexagonal Ruthenate SrRu2O6

We report an experimental and computational study of magnetic and electronic properties of the layered Ru(V) oxide SrRu2O6 (hexagonal, P-3 1m), which shows antiferromagnetic order with a N\'eel temperature of 563(2) K, among the highest for 4d oxides. Magnetic order occurs both within edge-shared octahedral sheets and between layers and is accompanied by anisotropic thermal expansivity that implies strong magnetoelastic coupling of Ru(V) centers. Electrical transport measurements using focused ion beam induced deposited contacts on a micron-scale crystallite as a function of temperature show p-type semiconductivity. The calculated electronic structure using hybrid density functional theory successfully accounts for the experimentally observed magnetic and electronic structure and Monte Carlo simulations reveals how strong intralayer as well as weaker interlayer interactions are a defining feature of the high temperature magnetic order in the material.Comment: Physical Review B 2015 accepted for publicatio

Evidence of exactness of the mean field theory in the nonextensive regime of long-range spin models

The q-state Potts model with long-range interactions that decay as 1/r^alpha subjected to an uniform magnetic field on d-dimensional lattices is analized for different values of q in the nonextensive regime (alpha between 0 and d). We also consider the two dimensional antiferromagnetic Ising model with the same type of interactions. The mean field solution and Monte Carlo calculations for the equations of state for these models are compared. We show that, using a derived scaling which properly describes the nonextensive thermodynamic behaviour, both types of calculations show an excellent agreement in all the cases here considered, except for alpha=d. These results allow us to extend to nonextensive magnetic models a previous conjecture which states that the mean field theory is exact for the Ising one.Comment: 10 pages, 4 figure

Imprints of the Quantum World in Classical Mechanics

The imprints left by quantum mechanics in classical (Hamiltonian) mechanics are much more numerous than is usually believed. We show Using no physical hypotheses) that the Schroedinger equation for a nonrelativistic system of spinless particles is a classical equation which is equivalent to Hamilton's equations.Comment: Paper submitted to Foundations of Physic

Changes in the Management of Patients having Radical Radiotherapy for Lung Cancer during the First Wave of the COVID-19 Pandemic in the UK.

AIMS: In response to the COVID-19 pandemic, guidelines on reduced fractionation for patients treated with curative-intent radiotherapy were published, aimed at reducing the number of hospital attendances and potential exposure of vulnerable patients to minimise the risk of COVID-19 infection. We describe the changes that took place in the management of patients with stage I-III lung cancer from April to October 2020. MATERIALS AND METHODS: Lung Radiotherapy during the COVID-19 Pandemic (COVID-RT Lung) is a prospective multicentre UK cohort study. The inclusion criteria were: patients with stage I-III lung cancer referred for and/or treated with radical radiotherapy between 2nd April and 2nd October 2020. Patients who had had a change in their management and those who continued with standard management were included. Data on demographics, COVID-19 diagnosis, diagnostic work-up, radiotherapy and systemic treatment were collected and reported as counts and percentages. Patient characteristics associated with a change in treatment were analysed using multivariable binary logistic regression. RESULTS: In total, 1553 patients were included (median age 72 years, 49% female); 93 (12%) had a change to their diagnostic investigation and 528 (34%) had a change to their treatment from their centre's standard of care as a result of the COVID-19 pandemic. Age ≥70 years, male gender and stage III disease were associated with a change in treatment on multivariable analysis. Patients who had their treatment changed had a median of 15 fractions of radiotherapy compared with a median of 20 fractions in those who did not have their treatment changed. Low rates of COVID-19 infection were seen during or after radiotherapy, with only 21 patients (1.4%) developing the disease. CONCLUSIONS: The COVID-19 pandemic resulted in changes to patient treatment in line with national recommendations. The main change was an increase in hypofractionation. Further work is ongoing to analyse the impact of these changes on patient outcomes

Perturbation and Variational Methods in Nonextensive Tsallis Statistics

A unified presentation of the perturbation and variational methods for the generalized statistical mechanics based on Tsallis entropy is given here. In the case of the variational method, the Bogoliubov inequality is generalized in a very natural way following the Feynman proof for the usual statistical mechanics. The inequality turns out to be form-invariant with respect to the entropic index $q$. The method is illustrated with a simple example in classical mechanics. The formalisms developed here are expected to be useful in the discussion of nonextensive systems.Comment: revte

De Broglie-Bohm Guidance Equations for Arbitrary Hamiltonians

In a pilot-wave theory, an individual closed system is described by a wavefunction $\psi(q)$ and configuration $q$. The evolution of the wavefunction and configuration are respectively determined by the Schr\"odinger and guidance equations. The guidance equation states that the velocity field for the configuration is given by the quantum current divided by the density $|\psi(q)|^2$. We present the currents and associated guidance equations for any Hamiltonian given by a differential operator. These are derived directly from the Schr\"odinger equation, and also as Noether currents arising from a global phase symmetry associated with the wavefunction in configuration space.Comment: 22 pages, no figures, LaTex; v3 minor corrections; v2 minor correction

The cross on rings performed by an Olympic champion

The cross is a key skill in Male Artistic Gymnastics rings routines. However, few researches were found about this skill. There is knowledge about the forces needed to perform the cross, or about muscles activation, separately. The aim of this paper was to accomplish a comprehensive research about the biomechanics of cross on rings, in order to obtain a descriptive model about this skill. Therefore, the currently Olympic champion on rings event volunteered in this research. He performed three crosses with the usual apparatus in his training gym. The measurement methods were combined: One digital video camera, one strain gauge in each cable and surface electromyography of nine right shoulder muscles were used. Statistical analyses were performed by parametric and non parametric tests and descriptive statistics. Symmetry values were calculated for shoulder angles and cables of right and left side. Coefficient of variation of muscle activation and co contraction were verified. Within gymnast variability was calculated using biological coefficient of variation (BCV), discretely for kinematic measures. Low variability values of shoulder angles and cable forces were verified and low values of asymmetry as well. Muscle activation varied according to muscle function, while co-contraction values were different among trials. These results pointed out the characteristics of the cross performed by an elite gymnast. Knowledge about the characteristics of cross can inform coaches, practitioners and clinicians how a successful skill should be presented

Patients' independence of a nurse for the administration of subcutaneous anti-TNF therapy: A phenomenographic study

Rheumatology nursing supports patients to manage their lives and live as independently as possible without pain, stiffness and functional restrictions. When conventional drugs fail to delay the development of the rheumatic disease, the patient may require biological treatment such as self-administered subcutaneous anti-tumour necrosis factor (TNF) therapy. It is therefore important that the patient perspective focuses on the life-changing situation caused by the administration of regular subcutaneous injections. The aim of this study was to describe variations in how patients with rheumatic diseases experience their independence of a nurse for administration of subcutaneous anti-TNF therapy. The study had a descriptive, qualitative design with a phenomenographic approach and was carried out by means of 20 interviews. Four ways of understanding the patients' experience of their subcutaneous anti-TNF therapy and independence of a nurse emerged: the struggling patient; the learning patient; the participating patient; the independent patient. Achieving independence of a nurse for subcutaneous anti-TNF injections can be understood by the patients in different ways. In their strive for independence, patients progress by learning about and participating in drug treatment, after which they experience that the injections make them independent

A clonal expression biomarker associates with lung cancer mortality

An aim of molecular biomarkers is to stratify patients with cancer into disease subtypes predictive of outcome, improving diagnostic precision beyond clinical descriptors such as tumor stage1. Transcriptomic intratumor heterogeneity (RNA-ITH) has been shown to confound existing expression-based biomarkers across multiple cancer types2,3,4,5,6. Here, we analyze multi-region whole-exome and RNA sequencing data for 156 tumor regions from 48 patients enrolled in the TRACERx study to explore and control for RNA-ITH in non-small cell lung cancer. We find that chromosomal instability is a major driver of RNA-ITH, and existing prognostic gene expression signatures are vulnerable to tumor sampling bias. To address this, we identify genes expressed homogeneously within individual tumors that encode expression modules of cancer cell proliferation and are often driven by DNA copy-number gains selected early in tumor evolution. Clonal transcriptomic biomarkers overcome tumor sampling bias, associate with survival independent of clinicopathological risk factors, and may provide a general strategy to refine biomarker design across cancer types