A systematic study of the magnetic properties and both the temperature- and magnetic-field-induced structural transformations in the Ni50−xCoxMn39Sn11 (0⩽x⩽10) multifunctional alloys over a large ...temperature range from 500K down to 10K was performed. It is revealed that, with increasing x, the martensitic transformation temperatures first decrease slowly when 0⩽x⩽4 and then decrease rapidly when 5⩽x⩽8; no martensitic transformation was observed in the alloys with 9⩽x⩽10. The magnetic properties of these alloys are very sensitive to their chemical composition. The austenite in the alloys with 0⩽x⩽4 shows paramagnetic behavior and the martensite exhibits paramagnetic, superparamagnetic (SPM), and superspin glass (SSG) behaviors in different temperature ranges during cooling. In contrast, the austenite in the alloys with 5⩽x⩽8 is paramagnetic above its Curie temperature TC and ferromagnetic below TC, and the martensite shows SPM and SSG behaviors in different temperature ranges. The austenite in the alloys with 9⩽x⩽10, which remains stable down to 10K, shows paramagnetic and ferromagnetic behaviors above and below TC, respectively. The complete phase diagram for the Ni50−xCoxMn39Sn11 (0⩽x⩽10) alloy system, from high temperature down to 10K, is established. A significant magnetic-field-induced decrease of martensitic transformation temperatures and almost fully reversible magnetic-field-induced structural transformation are achieved across a broad temperature range in the alloys with 5⩽x⩽8. These results are important for understanding the composition and temperature-dependent functional properties, as well as their underlying mechanisms, in the Ni–(Co)–Mn–X (X=In, Sn, Sb) multifunctional alloys.
Neuroticism has been consistently correlated with the post-traumatic stress disorder (PTSD) response to traumatic events. Interpretation of these findings is limited by the retrospective nature of ...these findings: neuroticism was measured after the trauma had occurred. The prospective association of neuroticism with PTSD has not been examined (the relationship of neuroticism with PTSD symptoms was examined in a few prospective studies). We evaluate prospectively the relationship of neuroticism, measured at baseline, with the cumulative occurrence of PTSD during the subsequent 10 years, using data from a longitudinal epidemiological study of young adults.
A sample of 1007 young adults randomly selected from the membership of a large health maintenance organization in southeast Michigan was assessed at baseline and followed up at 3, 5 and 10 years later. We conducted a series of multinomial logistic regressions to estimate the relative risk (RR) of exposure to trauma and PTSD by neuroticism at baseline, adjusting for history of major depression (n = 990).
During the 10-year follow-up, 50.2% of the sample experienced traumatic events and 5.2% developed PTSD. Neuroticism score at baseline increased significantly the RR of PTSD response to trauma. Additional analysis revealed that, among persons with history of major depression at baseline, RR for PTSD associated with neuroticism was equal to the null value of 1, but was increased significantly among those with no history of major depression.
The results confirm the role of neuroticism as diathesis in the PTSD response to traumatic experiences.
We report on (1) direct measurements of ΔTad for binary Fe49Rh51 during field cycling and (2) maximum possible ΔTad measured under discontinuous protocol. Our results show that the ΔTad is 9.2 K on ...the first application of magnetic field of Δμ0H = 1.9 T and it remains as high as 6.2 K during the cycling in alternated field of the same magnitude. In addition, the adiabatic temperature change and magnetic entropy change under the first application of magnetic field and under cyclic conditions were determined indirectly using three different approaches: (1) from magnetic measurements (M(T)H dependences, Maxwell relations), (2) from calorimetry (C(T)p,H, S-T diagram) and (3) from H-T diagram. While the indirectly measured maximum possible ΔTad lies in the range of 10.5–12 K, the reduced value of ΔTad measured directly under cycling (6.2 K) is still extraordinarily high and is 15% higher than in Gd in similar magnetic field. This demonstrates the potential of materials with a first order metamagnetic transition for magnetocaloric applications despite the presence of hysteresis.
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Parkinson's disease (PD) is a common neurodegenerative disease that lacks therapies to prevent progressive neurodegeneration. Impaired energy metabolism and reduced ATP levels are common features of ...PD. Previous studies revealed that terazosin (TZ) enhances the activity of phosphoglycerate kinase 1 (PGK1), thereby stimulating glycolysis and increasing cellular ATP levels. Therefore, we asked whether enhancement of PGK1 activity would change the course of PD. In toxin-induced and genetic PD models in mice, rats, flies, and induced pluripotent stem cells, TZ increased brain ATP levels and slowed or prevented neuron loss. The drug increased dopamine levels and partially restored motor function. Because TZ is prescribed clinically, we also interrogated 2 distinct human databases. We found slower disease progression, decreased PD-related complications, and a reduced frequency of PD diagnoses in individuals taking TZ and related drugs. These findings suggest that enhancing PGK1 activity and increasing glycolysis may slow neurodegeneration in PD.
The magnetic microstructure and hysteresis properties of Fe84.3Cu0.7Si4B8P3 soft magnetic ribbons have been investigated by Kerr-microscopy, Kerr-magnetometry and inductive hysteresis measurements. ...Crystalline surface layers were already present after quenching, causing an out-of-plane anisotropy in the amorphous bulk. Annealing at elevated temperature leads to nanocrystallization in the inner part of the ribbon and to a gradual decline of the perpendicular anisotropy with increasing temperature. The surface magnetization process is determined by the coercive motion of 180° domain walls along the ribbon axis, while the bulk magnetization process is dominated by reversible rotation of magnetization.
Niemann-Pick type C disease is a fatal, progressive neurodegenerative disorder caused by loss-of-function mutations in NPC1, a multipass transmembrane glycoprotein essential for intracellular lipid ...trafficking. We sought to define the cellular machinery controlling degradation of the most common disease-causing mutant, I1061T NPC1. We show that this mutant is degraded, in part, by the proteasome following MARCH6-dependent ERAD. Unexpectedly, we demonstrate that I1061T NPC1 is also degraded by a recently described autophagic pathway called selective ER autophagy (ER-phagy). We establish the importance of ER-phagy both in vitro and in vivo, and identify I1061T as a misfolded endogenous substrate for this FAM134B-dependent process. Subcellular fractionation of I1061T Npc1 mouse tissues and analysis of human samples show alterations of key components of ER-phagy, including FAM134B. Our data establish that I1061T NPC1 is recognized in the ER and degraded by two different pathways that function in a complementary fashion to regulate protein turnover.
The issue of whether viruses are subject to restriction by endogenous microRNAs (miRNAs) and/or by virus-induced small interfering RNAs (siRNAs) in infected human somatic cells has been ...controversial. Here, we address this question in two ways. First, using deep sequencing, we demonstrate that infection of human cells by the RNA virus dengue virus (DENV) or West Nile virus (WNV) does not result in the production of any virus-derived siRNAs or viral miRNAs. Second, to more globally assess the potential of small regulatory RNAs to inhibit virus replication, we used gene editing to derive human cell lines that lack a functional Dicer enzyme and that therefore are unable to produce miRNAs or siRNAs. Infection of these cells with a wide range of viruses, including DENV, WNV, yellow fever virus, Sindbis virus, Venezuelan equine encephalitis virus, measles virus, influenza A virus, reovirus, vesicular stomatitis virus, human immunodeficiency virus type 1, or herpes simplex virus 1 (HSV-1), failed to reveal any enhancement in the replication of any of these viruses, although HSV-1, which encodes at least eight Dicer-dependent viral miRNAs, did replicate somewhat more slowly in the absence of Dicer. We conclude that most, and perhaps all, human viruses have evolved to be resistant to inhibition by endogenous human miRNAs during productive replication and that dependence on a cellular miRNA, as seen with hepatitis C virus, is rare. How viruses have evolved to avoid inhibition by endogenous cellular miRNAs, which are generally highly conserved during metazoan evolution, remains to be determined. Importance: Eukaryotic cells express a wide range of small regulatory RNAs, including miRNAs, that have the potential to inhibit the expression of mRNAs that show sequence complementarity. Indeed, previous work has suggested that endogenous miRNAs have the potential to inhibit viral gene expression and replication. Here, we demonstrate that the replication of a wide range of pathogenic viruses is not enhanced in human cells engineered to be unable to produce miRNAs, indicating that viruses have evolved to be resistant to inhibition by miRNAs. This result is important, as it implies that manipulation of miRNA levels is not likely to prove useful in inhibiting virus replication. It also focuses attention on the question of how viruses have evolved to resist inhibition by miRNAs and whether virus mutants that have lost this resistance might prove useful, for example, in the development of attenuated virus vaccines.
Two different transformation routes, quenching followed by heat treatment (route 1), and cooling at intermediate rate (route 2), were used to obtain the L10 phase in Mn-Al alloys. The resulting ...materials showed remarkable differences in microstructure and magnetic properties. In addition, fully transformed material was cold-worked and then recovered by heat treatment. The microstructure of both cold-worked and recovered samples appeared similar in backscattered electron images, however, the magnetic properties differed greatly. Large numbers of electron backscatter diffraction (EBSD) patterns were recorded from all the materials and the pattern quality was quantified, yielding a measure of the dislocation density. The results indicated that both the dislocation density and the coercivity of the cold-worked sample were much higher than in the recovered sample. In addition to other microstructural changes, the route 1 sample had higher dislocation density and coercivity compared to the route 2 sample. For the as-transformed materials, the results were supported by EBSD misorientation mapping and strain analysis of x-ray diffraction data. The continuum theory of dislocations was used to show that the local stress fields of dislocations will cause distortions in the crystal structure leading to local changes in the intrinsic magnetic properties. Such features are likely to act as pinning centres for magnetic domain walls and therefore a higher dislocation density implies a higher coercivity. This conclusion was additionally supported by initial magnetisation curves, which showed evidence for an active pinning mechanism in the cold-worked sample but not for the recovered sample.
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•Dislocation density of τ-MnAl depends on transformation route or mechanical working.•High coercivity after cold working is attributed to increased dislocation density.•Initial magnetisation curve indicates pinning of domain walls.•Domain walls pinned by dislocations due to locally changed intrinsic properties.
We present a method that allows for a quantitative measurement of the surface self-diffusion on nanostructures, such as nanoparticles, at the atomic scale using aberration-corrected high-resolution ...transmission electron microscopy (HRTEM). The diffusion coefficient can be estimated by measuring the fluctuation of the atom column occupation at the surface of Au nanoparticles, which is directly observable in temporal sequences of HRTEM images. Both a Au icosahedron and a truncated Au octahedron are investigated, and their diffusion coefficients are found to be in the same order of magnitude, D = 10–17 to 10–16 cm2/s. It is to be assumed that the measured surface diffusion is affected by the imaging electron beam. This assumption is supported by the observed instability of a (5 × 1) surface reconstruction on a {100} Au facet.
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