Magnetic flux density and the critical field in the intermediate state of type-I superconductors

To address unsolved fundamental problems of the intermediate state (IS), the equilibrium magnetic flux structure and the critical field in a high purity type-I superconductor (indium film) are investigated using magneto-optical imaging with a 3D vector magnet and electrical transport measurements. The least expected observation is that the critical field in the IS can be as small as nearly 40% of the thermodynamic critical field $H_c$. This indicates that the flux density in the \textit{bulk} of normal domains can be \textit{considerably} less than $H_c$, in apparent contradiction with the long established paradigm, stating that the normal phase is unstable below $H_c$. Here we present a novel theoretical model consistently describing this and \textit{all} other properties of the IS. Moreover, our model, based the rigorous thermodynamic treatment of observed laminar flux structure in a tilted field, allows for a \textit{quantitative} determination of the domain-wall parameter and the coherence length, and provides new insight into the properties of all superconductors.Comment: 5 pages, 5 figure

Numerical and asymptotic solutions of generalised Burgers’ equation

The generalised Burgers’ equation has been subject to a considerable amount of research on how the equation should behave according to asymptotic analysis, however there has been limited research verifying the asymptotic analysis. In order to verify the asymptotic analysis, this paper aims to run long time and detailed numerical simulations of Burgers’ equation by employing suitable rescalings of Burgers’ equation. It is hoped that this technique will make it possible to notice subtle changes in the shock structure which would otherwise be impossible to observe. The main aim of this paper is to validate the numerical methods used in order to allow further research into shock evolution where further relaxation effects will be included

E1-E1 damping interference in the electric field quenching of spin-polarized He+2s12 ions

When a beam of spin-polarized metastable He+2s12 ions is quenched by an electric field E, the emitted radiation intensity contains an asymmetry term proportional to (kE)(P\u27k×E) where P\u27 is the spin-polarization vector and k is the direction of observation. The resulting asymmetry is nearly proportional to the level width of the 2p12 state in He+. The experiment provides the first observation of the asymmetry. The measured asymmetry is (0.007 69±0.000 10) in agreement with the theoretical value 0.007 618 and corresponds to a lifetime 2p=(0.988±0.013)×10-10 sec. © 1982 The American Physical Society

The ConCom Safety Management Scale:Developing and testing a measurement instrument for control-based and commitment-based safety management approaches in hospitals

Background Nursing management is considered important for patient safety. Prior research has predominantly focused on charismatic leadership styles, although it is questionable whether these best characterise the role of nurse managers. Managerial control is also relevant. Therefore, we aimed to develop and test a measurement instrument for control-based and commitment-based safety management of nurse managers in clinical hospital departments. Methods A cross-sectional survey design was used to test the newly developed questionnaire in a sample of 2378 nurses working in clinical departments. The nurses were asked about their perceptions of the leadership behaviour and management practices of their direct supervisors. Psychometric properties were evaluated using confirmatory factor analysis and reliability estimates. Results The final 33-item questionnaire showed acceptable goodness-of-fit indices and internal consistency (Cronbach’s α of the subscales range: 0.59–0.90). The factor structure revealed three subdimensions for control-based safety management: (1) stressing the importance of safety rules and regulations; (2) monitoring compliance; and (3) providing employees with feedback. Commitment-based management consisted of four subdimensions: (1) showing role modelling behaviour; (2) creating safety awareness; (3) showing safety commitment; and (4) encouraging participation. Construct validity of the scale was supported by high factor loadings and provided preliminary evidence that control-based and commitment-based safety management are two distinct yet related constructs. The findings were reconfirmed in a cross-validation procedure. Conclusion The results provide initial support for the construct validity and reliability of our ConCom Safety Management Scale. Both management approaches were found to be relevant for managing patient safety in clinical hospital departments. The scale can be used to deepen our understanding of the influence of patient safety management on healthcare professionals’ safety behaviour as well as patient safety outcomes

Diabetic retinopathy: a complex pathophysiology requiring novel therapeutic strategies.

INTRODUCTION: Diabetic retinopathy (DR) is the leading cause of vision loss in the working age population of the developed world. DR encompasses a complex pathology, and one that is reflected in the variety of currently available treatments, which include laser photocoagulation, glucocorticoids, vitrectomy and agents which neutralize vascular endothelial growth factor (VEGF). Whilst these options demonstrate modest clinical benefits, none is yet to fully attenuate clinical progression or reverse damage to the retina. This has led to an interest in developing novel therapies for the condition, such as mediators of angiopoietin signaling axes, immunosuppressants, nonsteroidal anti-inflammatory drugs (NSAIDs), oxidative stress inhibitors and vitriol viscosity inhibitors. Further, preclinical research suggests that gene therapy treatment for DR could provide significant benefits over existing treatments options. AREAS COVERED: Here we review the pathophysiology of DR and provide an overview of currently available treatments. We then outline recent advances made towards improved patient outcomes and highlight the potential of the gene therapy paradigm to revolutionize DR management. EXPERT OPINION: Whilst significant progress has been made towards our understanding of DR, further research is required to enable the development of a detailed spatiotemporal model of the disease. In addition, we hope that improvements in our knowledge of the condition facilitate therapeutic innovations that continue to address unmet medical need and improve patient outcomes, with a focus on the development of targeted medicines.Cambridge Eye Trust Research Councils UK - Medical Research Council the Wellcome Trus

Lifetimes and polarizabilities of low lying lithium S, P and D states

Abstract The radiative lifetimes, scalar and tensor polarizabilities of low lying S, P and D states of lithium are obtained using a Coulomb approximation. The calculated lifetimes agree very well with the handful of experimental values listed in the literature. The ground state polarizability is also close to the measured result. This method requires substantially less computational time than ab initio theory, thereby permitting the study of nearly 40 states.

The S0_0(0) structure in highly compressed hydrogen and the orientational transition

A calculation of the rotational S$_0$(0) frequencies in high pressure solid para-hydrogen is performed. Convergence of the perturbative series at high density is demonstrated by the calculation of second and third order terms. The results of the theory are compared with the available experimental data to derive the density behaviour of structural parameters. In particular, a strong increase of the value of the lattice constant ratio $c/a$ and of the internuclear distance is determined. Also a decrease of the anisotropic intermolecular potential is observed which is attributed to charge transfer effects. The structural parameters determined at the phase transition may be used to calculate quantum properties of the rotationally ordered phase.Comment: accepted Europhysics Letter