Measurement of the energy barrier distribution in the antiferromagnetic layer of exchange-biased materials

The value of exchange field of two FeMn–NiFeCobased spin valves with varying thickness of the pinned ferromagnetic layer has been determined as a function of temperature. The complexities caused by thermal activation of the antiferromagnet during measurement have been overcome by the development of a measurement protocol. The values of the exchange field obtained provide a measure of the degree of order in the antiferromagnet. Thus it is possible to determine the distribution of energy barriers to reversal for the system. We find that for a 110-A -thick pinned NiFeCo layer a broad distribution exists, whereas for an 80-A layer, the distribution is bimodal and has a component subject to thermal activation at temperatures down to 260 K

Approach to lymphoma diagnosis and management in South Africa

Lymphoma is a cancer of the lymphoid cells, with a hugely variable mode of clinical presentation, which includes constitutional symptoms, lymphadenopathy, superficial or deep-seated masses, effusions, and full blood count abnormalities such as anaemia and lymphocytosis. Lymphoma can infiltrate any organ of the body, although it typically involves lymphoid tissue or bone marrow, or both. In this article an overview is given of the diagnostic pathway and clinical diagnostic subsets that determine treatment. The treatment approach according to these subsets is best understood as: indolent lymphoma, where treatment is not urgent and the disease is not curable; aggressive lymphoma, where rapid diagnosis and treatment are of the utmost importance, with the majority of cases curable; and very aggressive lymphoma, where patients are at high risk of death at presentation, but with rapid diagnosis and treatment there is an excellent chance of long-term cure. The past decade has seen an explosion of targeted (as opposed to classic chemotherapeutic) treatments for lymphoma. These drugs target certain molecules or receptors in the tumour pathway, often with spectacularly beneficial effects that open up new horizons for cure

{\it Ab initio} calculations of magnetic structure and lattice dynamics of Fe/Pt multilayers

The magnetization distribution, its energetic characterization by the interlayer coupling constants and lattice dynamics of (001)-oriented Fe/Pt multilayers are investigated using density functional theory combined with the direct method to determine phonon frequencies. It is found that ferromagnetic order between consecutive Fe layers is favoured, with the enhanced magnetic moments at the interface. The bilinear and biquadratic coupling coefficients between Fe layers are shown to saturate fast with increasing thickness of nonmagnetic Pt layers which separate them. The phonon calculations demonstrate a rather strong dependence of partial iron phonon densities of states on the actual position of Fe monolayer in the multilayer structure.Comment: 7 pages, 8 figure

Suggestive Evidence for an Antidepressant Effect of Metreleptin Treatment in Patients with Lipodystrophy

Introduction: Lipodystrophy (LD) syndromes are rare heterogeneous disorders characterized by reduction or absence of subcutaneous fat, low or nondetectable leptin concentrations in blood and impaired hunger/satiety regulation. Metreleptin treatment reverses metabolic complications and improves eating behavior in LD. Because depression in anorexia nervosa (AN), which is also characterized by hypoleptinemia, improves substantially upon treatment with metreleptin, we hypothesized that metreleptin substitution may be associated with an antidepressant effect in patients with LD, too. Methods: In this ancillary study, 10 adult patients with LD were treated with metreleptin. To assess depressive symptoms, the self-rating questionnaire Beck's Depression Inventory (BDI) was filled in at preestablished time points prior (T1) and after initiation of metreleptin (T2: 1 week; T3: 4 weeks; T4: 12 weeks) dosing. The differences between time points were tested with nonparametric Friedman's analysis of variance. Sensitivity analyses were performed upon exclusion of the BDI items addressing appetite and weight changes. Results: According to their BDI scores, 4 patients had mild depression and 2 had moderate depression at baseline. Friedman's test revealed significant differences in BDI scores between the four time points. Post hoc analyses revealed that the difference between T1 and T3 was significant upon Bonferroni correction (p = 0.034, effect size r = 0.88). The sensitivity analyses upon exclusion of the appetite and weight change items again revealed a significant Friedman's test and significant Bonferroni corrected differences in the revised BDI scores between T1 versus T2 (p = 0.002, r = 0.99) and T1 versus T3 (p = 0.007, r = 0.79). Discussion/conclusion: Our study for the first time revealed suggestive evidence for an antidepressant effect of metreleptin in patients with LD. Metreleptin caused a rapid drop in depression scores within 1 week of treatment. A reduction of the depression score was also observed in 2 of the 3 LD patients whose BDI scores were in the normal range before start of the treatment. The reduction in total scores of BDI was still apparent after 3 months (T4) of dosing. This observation matches findings obtained in clinical case studies of AN patients, in whom depression scores also dropped during the first week of metreleptin treatment. It needs to be noted that by the nature of this observational study without a placebo group, nonspecific treatment expectation affecting mood cannot fully be ruled out.info:eu-repo/semantics/publishedVersio

Measurement of Azimuthal Anisotropy of Muons from Charm and Bottom Hadrons in pp Collisions at sqrt[s]=13 TeV with the ATLAS Detector.

The elliptic flow of muons from the decay of charm and bottom hadrons is measured in pp collisions at sqrt[s]=13  TeV using a data sample with an integrated luminosity of 150  pb^{-1} recorded by the ATLAS detector at the LHC. The muons from heavy-flavor decay are separated from light-hadron decay muons using momentum imbalance between the tracking and muon spectrometers. The heavy-flavor decay muons are further separated into those from charm decay and those from bottom decay using the distance-of-closest-approach to the collision vertex. The measurement is performed for muons in the transverse momentum range 4-7 GeV and pseudorapidity range |η|<2.4. A significant nonzero elliptic anisotropy coefficient v_{2} is observed for muons from charm decays, while the v_{2} value for muons from bottom decays is consistent with zero within uncertainties

Z boson production in Pb+Pb collisions at √Snn = 5.02 TeV measured by the ATLAS experiment

The production yield of Z bosons is measured in the electron and muon decay channels in Pb+Pb collisions at √S = 5.02 TeV with the ATLAS detector. Data from the 2015 LHC run corresponding to an integrated luminosity of 0.49 nb are used for the analysis. The Z boson yield, normalised by the total number of minimum-bias events and the mean nuclear thickness function, is measured as a function of dilepton rapidity and event centrality. The measurements in Pb+Pb collisions are compared with similar measurements made in proton-proton collisions at the same centre-of-mass energy. The nuclear modification factor is found to be consistent with unity for all centrality intervals. The results are compared with theoretical predictions obtained at next-to-leading order using nucleon and nuclear parton distribution functions. The normalised Z boson yields in Pb+Pb collisions lie 1-3σ above the predictions. The nuclear modification factor measured as a function of rapidity agrees with unity and is consistent with a next-to-leading-order QCD calculation including the isospin effect. nn -

Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb−1 of pp collisions at s=13TeV with the ATLAS experiment

A search for flavour-changing neutral current (FCNC) events via the coupling of a top quark, a photon, and an up or charm quark is presented using 81 fb−1 of proton–proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Events with a photon, an electron or muon, a b-tagged jet, and missing transverse momentum are selected. A neural network based on kinematic variables differentiates between events from signal and background processes. The data are consistent with the background-only hypothesis, and limits are set on the strength of the tqγ coupling in an effective field theory. These are also interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tuγ coupling of 36 fb (78 fb) and on the branching ratio for t→γu of 2.8×10−5 (6.1×10−5). In addition, they are interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tcγ coupling of 40 fb (33 fb) and on the branching ratio for t→γc of 22×10−5 (18×10−5)