RKKY interaction between extended magnetic defect lines in graphene

Of fundamental interest in the field of spintronics is the mechanism of indirect exchange coupling between magnetic impurities embedded in metallic hosts. A range of physical features, such as magnetotransport and overall magnetic moment formation, are predicated upon this magnetic coupling, often referred to as the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. Recent theoretical studies on the RKKY in graphene have been motivated by possible spintronic applications of magnetically doped graphene systems. In this work a combination of analytic and numerical techniques are used to examine the effects of defect dimensionality on such an interaction. We show, in a mathematically transparent manner, that moving from single magnetic impurities to extended lines of impurities effectively reduces the dimensionality of the system and increases the range of the interaction. This has important consequences for the spintronic application of magnetically-doped and we illustrate this with a simple magnetoresistance device.Comment: 6 pages, 5 figure

Convective Fingering of an Autocatalytic Reaction Front

We report experimental observations of the convection-driven fingering instability of an iodate-arsenous acid chemical reaction front. The front propagated upward in a vertical slab; the thickness of the slab was varied to control the degree of instability. We observed the onset and subsequent nonlinear evolution of the fingers, which were made visible by a {\it p}H indicator. We measured the spacing of the fingers during their initial stages and compared this to the wavelength of the fastest growing linear mode predicted by the stability analysis of Huang {\it et. al.} [{\it Phys. Rev. E}, {\bf 48}, 4378 (1993), and unpublished]. We find agreement with the thickness dependence predicted by the theory.Comment: 11 pages, RevTex with 3 eps figures. To be published in Phys Rev E, [email protected], [email protected], [email protected]

'Relieved to be seen'-patient and carer experiences of psychosocial assessment in the emergency department following self-harm: qualitative analysis of 102 free-text survey responses.

From Europe PMC via Jisc Publications RouterHistory: ppub 2021-05-01, epub 2021-05-23Publication status: PublishedObjectivesWe sought to explore patient and carer experiences of psychosocial assessments following presentations to hospital after self-harm.DesignThematic analysis of free-text responses to an open-ended online survey.SettingBetween March and November 2019, we recruited 88 patients (82% women) and 14 carers aged ≥18 years from 16 English mental health trusts, community organisations, and via social media.ResultsPsychosocial assessments were experienced as helpful on some occasions but harmful on others. Participants felt better, less suicidal and less likely to repeat self-harm after good-quality compassionate and supportive assessments. However, negative experiences during the assessment pathway were common and, in some cases, contributed to greater distress, less engagement and further self-harm. Participants reported receiving negative and stigmatising comments about their injuries. Others reported that they were refused medical care or an anaesthetic. Stigmatising attitudes among some mental health staff centred on preconceived ideas over self-harm as a 'behavioural issue', inappropriate use of services and psychiatric diagnosis.ConclusionOur findings highlight important patient experiences that can inform service provision and they demonstrate the value of involving patients/carers throughout the research process. Psychosocial assessments can be beneficial when empathetic and collaborative but less helpful when overly standardised, lacking in compassion and waiting times are unduly long. Patient views are essential to inform practice, particularly given the rapidly changing service context during and after the COVID-19 emergency

Using Radiological Data to Estimate Ischemic Stroke Severity

Background Risk-adjusted poststroke mortality has been proposed for use as a measure of stroke care quality. Although valid measures of stroke severity (e.g., the National Institutes of Health Stroke Scale [NIHSS]) are not typically available in administrative datasets, radiology reports are often available within electronic health records. We sought to examine whether admission head computed tomography data could be used to estimate stroke severity. Materials and Methods Using chart review data from a cohort of acute ischemic stroke patients (1998-2003), we developed a radiographic measure ([BIS]) of stroke severity in a two-third development set and assessed in a one-third validation set. The retrospective NIHSS was dichotomized as mild/moderate (<10) and severe (≥10). We compared the association of this radiographic score with NIHSS and in-hospital mortality at the patient level. Results Among 1348 stroke patients, 86.5% had abnormal findings on initial head computed tomography. The c-statistic for the BIS for modeling severe stroke (development, .581; validation, .579) and in-hospital mortality (development, .623; validation, .678) were generated. Conclusions Although the c-statistics were only moderate, the BIS provided significant risk stratification information with a 2-variable score. Until administrative data routinely includes a valid measure of stroke severity, radiographic data may provide information for use in risk adjustment

IL-25 regulates Th17 function in autoimmune inflammation

Interleukin (IL)-25 is a member of the IL-17 family of cytokines. However, unlike the other members of this family, IL-25 promotes T helper (Th) 2 responses. We now show that IL-25 also regulates the development of autoimmune inflammation mediated by IL-17–producing T cells. We have generated IL-25–deficient (il25−/−) mice and found that they are highly susceptible to experimental autoimmune encephalomyelitis (EAE). The accelerated disease in the il25−/− mice is associated with an increase of IL-23 in the periphery and a subsequent increase in the number of inflammatory IL-17–, IFNγ-, and TNF-producing T cells that invade the central nervous system. Neutralization of IL-17 but not IFNγ in il25−/− mice prevented EAE, suggesting that IL-17 is a major disease-promoting factor. IL-25 treatment at several time points during a relapse-remitting model or chronic model of EAE completely suppressed disease. IL-25 treatment induced elevated production of IL-13, which is required for suppression of Th17 responses by direct inhibition of IL-23, IL-1β, and IL-6 expression in activated dendritic cells. Thus, IL-25 and IL-17, being members of the same cytokine family, play opposing roles in the pathogenesis of organ-specific autoimmunity

Coronary revascularization after intravenous tissue plasminogen activator for unstable angina pectoris: Results of a randomized, double-blind, placebo-controlled trial

To determine the role of intravenous tissue plasminogen activator (t-PA) in unstable angina, it was compared with placebo in a randomized, double-blind trial. Forty patients with angina at rest and provocable ischemia (pacing induced) had baseline coronary angiography, study drug infusion and then repeat angiography at 20 +/- 9 hours. All patients received diltiazem, nitrates, [beta] blockers, aspirin and intravenous heparin. During study drug infusion (150 mg over 8 hours), refractory ischemia necessitating emergency bypass surgery (CABG) or coronary angioplasty (PTCA) occurred in 4 of 20 t-PA patients compared with 1 of 20 placebo patients (p = 0.21). Before discharge, revascularization for persistent, provocable ischemia and a residual stenosis &gt;= 60% was as follows: t-PA patients, 8 PTCA and 7 CABG; placebo patients, 11 PTCA and 8 CABG (p = 0.39). Quantitative angiographic percent diameter stenosis of the culprit artery at baseline and follow-up was: t-PA 71 +/- 17 and 63 +/- 22; placebo 70 +/- 19 and 67 +/- 22 (difference not significant). However, 3 t-PA patients compared with no placebo patients demonstrated an insignificant (&lt; 60% diameter) residual stenosis and averted PTCA (p = 0.14). There were no complications of PTCA in the 8 t-PA patients; in contrast, 3 of 11 placebo patients had abrupt closure, necessitating emergency CABG in 2 (p = 0.23). Thus, intravenous t-PA in unstable angina can eliminate the need for PTCA in a few patients, does not appear to decrease the overall or emergency rate of revascularization procedures and may facilitate the safety of PTCA.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27162/1/0000157.pd

Pan-viral serology implicates enteroviruses in acute flaccid myelitis.

Since 2012, the United States of America has experienced a biennial spike in pediatric acute flaccid myelitis (AFM)1-6. Epidemiologic evidence suggests non-polio enteroviruses (EVs) are a potential etiology, yet EV RNA is rarely detected in cerebrospinal fluid (CSF)2. CSF from children with AFM (n = 42) and other pediatric neurologic disease controls (n = 58) were investigated for intrathecal antiviral antibodies, using a phage display library expressing 481,966 overlapping peptides derived from all known vertebrate and arboviruses (VirScan). Metagenomic next-generation sequencing (mNGS) of AFM CSF RNA (n = 20 cases) was also performed, both unbiased sequencing and with targeted enrichment for EVs. Using VirScan, the viral family significantly enriched by the CSF of AFM cases relative to controls was Picornaviridae, with the most enriched Picornaviridae peptides belonging to the genus Enterovirus (n = 29/42 cases versus 4/58 controls). EV VP1 ELISA confirmed this finding (n = 22/26 cases versus 7/50 controls). mNGS did not detect additional EV RNA. Despite rare detection of EV RNA, pan-viral serology frequently identified high levels of CSF EV-specific antibodies in AFM compared with controls, providing further evidence for a causal role of non-polio EVs in AFM

Design and Status of the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII): An Interferometer at the Edge of Space

The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter baseline far-infraredinterferometer designed to fly on a high altitude balloon. BETTII uses a double-Fourier Michelson interferometer tosimultaneously obtain spatial and spectral information on science targets; the long baseline permits subarcsecond angular resolution, a capability unmatched by other far-infrared facilities. Here, we present key aspects of the overall design of the mission and provide an overview of the current status of the project. We also discuss briefly the implications of this experiment for future space-based far-infrared interferometers