Magnetic interactions in EuTe epitaxial layers and EuTe/PbTe superlattices

The magnetic properties of antiferromagnetic (AFM) EuTe epitaxial layers and short period EuTe/PbTe superlattices (SLs), grown by molecular beam epitaxy on (111) BaF$_2$ substrates, were studied by magnetization and neutron diffraction measurements. Considerable changes of the N\'eel temperature as a function of the EuTe layer thickness as well as of the strain state were found. A mean field model, taking into account the variation of the exchange constants with the strain-induced lattice distortions, and the nearest neighbor environment of a Eu atoms, was developed to explain the observed $T_{\text N}$ changes in wide range of samples. Pronounced interlayer magnetic correlations have been revealed by neutron diffraction in EuTe/PbTe SLs with PbTe spacer thickness up to 60 \AA. The observed diffraction spectra were analyzed, in a kinematical approximation, assuming partial interlayer correlations characterized by an appropriate correlation parameter. The formation of interlayer correlations between the AFM EuTe layers across the nonmagnetic PbTe spacer was explained within a framework of a tight-binding model. In this model, the interlayer coupling stems from the dependence of the total electronic energy of the EuTe/PbTe SL on the spin configurations in adjacent EuTe layers. The influence of the EuTe and PbTe layer thickness fluctuations, inherent in the epitaxial growth process, on magnetic properties and interlayer coupling is discussed.Comment: 17 pages, 19 figures, accepted to PR

Dexamethasone therapy versus surgery for chronic subdural haematoma (DECSA trial): study protocol for a randomised controlled trial

Paroxysmal Cerebral Disorder

Dexamethasone therapy versus surgery for chronic subdural haematoma (DECSA trial): study protocol for a randomised controlled trial

BACKGROUND: Chronic subdural haematoma (CSDH) is a common neurological disease with a rapidly rising incidence due to increasing age and widespread use of anticoagulants. Surgical intervention by burr-hole craniotomy (BHC) is the current standard practice for symptomatic patients, but associated with complications, a recurrence rate of up to 30% and increased mortality. Dexamethasone (DXM) therapy is, therefore, used as a non-surgical alternative but considered to achieve a lower success rate. Furthermore, the benefit of DXM therapy appears much more deliberate than the immediate relief from BHC. Lack of evidence and clinical equipoise among caregivers prompts the need for a head-to-head randomised controlled trial. The objective of this study is to compare the effect of primary DXM therapy versus primary BHC on functional outcome and cost-effectiveness in symptomatic patients with CSDH.METHODS/DESIGN: This study is a prospective, multicentre, randomised controlled trial (RCT). Consecutive patients with a CSDH with a Markwalder Grading Scale (MGS) grade 1 to 3 will be randomised to treatment with DXM or BHC. The DXM treatment scheme will be 16 mg DXM per day (8 mg twice daily, days 1 to 4) which is then halved every 3 days until a dosage of 0.5 mg a day on day 19 and stopped on day 20. If the treatment response is insufficient (i.e. persistent or progressive symptomatology due to insufficient haematoma resolution), additional surgery can be performed. The primary outcomes are the functional outcome by means of the modified Rankin Scale (mRS) score at 3 months and cost-effectiveness at 12 months. Secondary outcomes are quality of life at 3 and 12 months using the Short Form Health Survey (SF-36) and Quality of Life after Brain Injury Overall Scale (QOLIBRI), haematoma thickness after 2 weeks on follow-up computed tomography (CT), haematoma recurrence during the first 12 months, complications and drug-related adverse events, failure of therapy within 12 months after randomisation and requiring intervention, mortality during the first 3 and 12 months, duration of hospital stay and overall healthcare and productivity costs. To test non-inferiority of DXM therapy compared to BHC, 210 patients in each treatment arm are required (assumed adjusted common odds ratio DXM compared to BHC 1.15, limit for inferiority < 0.9). The aim is to include a total of 420 patients in 3 years with an enrolment rate of 60%.DISCUSSION: The present study should demonstrate whether treatment with DXM is as effective as BHC on functional outcome, at lower costs.TRIAL REGISTRATION: EUCTR 2015-001563-39 . Date of registration: 29 March 2015

Gaia Early Data Release 3: Gaia photometric science alerts

Context. Since July 2014, the Gaia mission has been engaged in a high-spatial-resolution, time-resolved, precise, accurate astrometric, and photometric survey of the entire sky. Aims. We present the Gaia Science Alerts project, which has been in operation since 1 June 2016. We describe the system which has been developed to enable the discovery and publication of transient photometric events as seen by Gaia. Methods. We outline the data handling, timings, and performances, and we describe the transient detection algorithms and filtering procedures needed to manage the high false alarm rate. We identify two classes of events: (1) sources which are new to Gaia and (2) Gaia sources which have undergone a significant brightening or fading. Validation of the Gaia transit astrometry and photometry was performed, followed by testing of the source environment to minimise contamination from Solar System objects, bright stars, and fainter near-neighbours. Results. We show that the Gaia Science Alerts project suffers from very low contamination, that is there are very few false-positives. We find that the external completeness for supernovae, CE = 0.46, is dominated by the Gaia scanning law and the requirement of detections from both fields-of-view. Where we have two or more scans the internal completeness is CI = 0.79 at 3 arcsec or larger from the centres of galaxies, but it drops closer in, especially within 1 arcsec. Conclusions. The per-Transit photometry for Gaia transients is precise to 1% at G = 13, and 3% at G = 19. The per-Transit astrometry is accurate to 55 mas when compared to Gaia DR2. The Gaia Science Alerts project is one of the most homogeneous and productive transient surveys in operation, and it is the only survey which covers the whole sky at high spatial resolution (subarcsecond), including the Galactic plane and bulge. © S. T. Hodgkin et al. 2021

TRY plant trait database – enhanced coverage and open access

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Markedly reduced rate of diabetic ketoacidosis at onset of type 1 diabetes in relatives screened for islet autoantibodies.

OBJECTIVE: To determine whether screening for islet autoantibodies in children prevents ketoacidosis and other metabolic complications at diabetes onset and improves the clinical course after diagnosis. SUBJECTS AND METHODS: The German BABYDIAB and the Munich Family Study follow children with a first-degree family history of type 1 diabetes for the development of islet autoantibodies and type 1 diabetes. The Diabetes Prospective Documentation (DPV) Initiative registers and collects information on pediatric patients with type 1 diabetes throughout Germany. Here, clinical characteristics at diabetes onset [ketoacidosis, mean hemoglobin A1c (HbA1c), and length of hospitalization] and the 5-yr clinical course (HbA1c and insulin dose) of screened and followed islet autoantibody-positive children (n = 101) and 49 883 non-screened children within the DPV registry were compared. RESULTS: At diabetes onset, children who were followed after screening and were positive for islet autoantibodies had lower HbA1c (8.6 vs. 11%, p &lt; 0.001) and a lower prevalence of diabetic ketoacidosis (3.3 vs. 29.1%, p &lt; 0.001). Screened children also had a shorter hospitalization period at onset (11.4 vs. 14.9 d, p = 0.005). Similar results were observed when the analysis was restricted to 759 non-screened DPV children with a first-degree family history of type 1 diabetes. No differences between screened and non-screened children were observed with respect to HbA1c and insulin dose during the first 5 yr after diagnosis. CONCLUSIONS: Screening for islet autoantibodies in children likely leads to earlier diabetes diagnosis resulting in less complications at diagnosis. However, no substantial benefit in the clinical outcome during the first 5 yr after diagnosis was observed

Diabetic retinopathy in type 1 diabetes-a contemporary analysis of 8,784 patients

AIMS/HYPOTHESIS: The aim of this study was to analyse the risk profile for diabetic retinopathy under real-life conditions in a large cohort of patients with type 1 diabetes. METHODS: Patients (n = 18,891) with childhood, adolescent or adult onset of type 1 diabetes from the prospective German Diabetes Documentation System survey were analysed. A total of 8,784 patients fulfilled the inclusion criterion, which was availability of retinopathy status. Retinopathy grading (any retinopathy, advanced retinopathy), treatment regimens and risk factors were prospectively recorded and tested as covariates by Kaplan-Meier analysis and logistic regression. RESULTS: Any retinopathy was present in 27.4% and advanced retinopathy (severe non-proliferative or proliferative diabetic retinopathy) in 8.0% of the cohort. After 40 years of diabetes, the cumulative proportion of patients with any retinopathy and advanced retinopathy was 84.1% and 50.2%, respectively. In multiple regression analysis, risk factors for any retinopathy were diabetes duration (OR 1.167 per year), HbA(1c) >7.0% (53 mmol/mol) (OR 2.225), smoking (OR 1.295) and male sex (OR 1.187) (p 7.0% (53 mmol/mol) (1.499, p 1.7 mmol/l (1.398, p = 0.0013) and blood pressure >140/90 mmHg (1.911, p < 0.0001). CONCLUSIONS/INTERPRETATION: The prevalence of retinopathy remains significant in type 1 diabetes. Any improvement of metabolic control and non-smoking is protective, while hypertension affects progression to severe levels under real-life conditions. These data reinforce the validity of multifactorial concepts for morbidity protection in type 1 diabetes