Diffusion tensor imaging of the uncinate fasciculus in mood and psychotic disorders

Background: The uncinate fasciculus (UF) is the largest white matter association tract connecting the prefrontal cortex and the medial temporal lobe, and is the final major association tract to mature with myelination extending into the third decade of life. The UF is typically described as having a temporal stem, a body, and two prefrontal stems extending to the lateral and fronto-polar prefrontal cortex respectively. However, there is increasing evidence of fibers extending from the subgenual cingulate gyrus (Brodmann Area 25: BA25) to the amygdala, along the expected course of the UF. If these fibers are continuous with the UF, they may represent a separate medial subgenual stem. BA25 is implicated in mood disorder pathophysiology, whilst the lateral prefrontal cortex is implicated in the negative symptoms of psychosis. Hypotheses: Given that the UF as a whole has reduced integrity in both mood and psychotic disorders, it is feasible that the lateral stem of the UF is more markedly affected in psychosis and the potential subgenual stem more markedly affected in depression. In addition, since the UF matures during the typical clinical onset age of these disorders, we hypothesize that such changes are present from first onset. Methods: In a series of four manuscripts utilizing diffusion tensor imaging (DTI), the anatomy, anatomical variability, and stem-by-stem microstructural changes in depression and first-onset psychosis patients were investigated within the UF. The use of a stem-by-stem analysis within the UF was a common link across the four articles. Results: A subgenual stem of the UF was consistently demonstrated. Significantly reduced integrity was shown in the subgenual and polar stems of the UF in depressed patients (in both the first-onset and chronic depression cohorts), and in the lateral and polar stems in first-onset psychosis patients. Conclusion: We have demonstrated anatomically distinct patterns of white matter changes within the uncinate fasciculus in mood vs. psychotic disorders, present from the time of first clinical onset

Unconventional domain wall magnetoresistance of patterned Ni/Nb bilayer structures below superconducting transition temperature of Nb

Scattering of spin-up and spin-down electrons while passing through a ferromagnetic domain wall leads to an additional resistance for transport current, usually observed prominently in constricted magnetic structures. In this report, we use the resistance of the domain wall as a probe to find indirect signatures of the theoretically predicted spin-singlet supercurrent to spin-triplet supercurrent conversion effect of ferromagnetic domain walls. Here we examine the domain wall induced resistance in Ni stripe in a bilayer Ni/Nb geometry in the normal state and in the superconducting state of Nb. By making a 6um wide gap in the top Nb layer we routed the transport current through the Ni layer in the normal state and in the superconducting state of Nb. In the normal state of Nb, in-field transport measurements showed a clear domain wall magneto-resistance (DWMR) peak near the coercive field, where the domain wall density is expected to be maximum. Interestingly, however, below the superconducting transition temperature of Nb, the DWMR peak of the Ni layer showed a sharp drop in the field range where the number of domain walls becomes maximum. This observation may be a possible signature of magnetic domain wall induced spin-triplet correlations in the Ni layer due to the direct injection of spin-singlet Cooper pairs from Nb into the magnetic domain walls

Anatomical variations in the branches of the human aortic arch: a recent study of a South Australian population

Variations of the branches of the aortic arch are likely to occur as a result of the altered development of certain branchial arch arteries during the embryonic period of gestation. In the present investigation the pattern of branches of the aortic arch was studied in 81 cadavers from a recent South Australian population of European descent, who have migrated to (n = 38) or were born and lived in (n = 43) South Australia during the twentieth century. Two principal variations were noted in the present study. Firstly, in 6 cadavers, the left vertebral artery originated directly from the arch of the aorta, between the left common carotid and the left subclavian arteries. The 6 subjects were among the subgroup born in South Australia, giving an incidence of 13.95%, which is much higher than in previous reports. The overall incidence of 7.41%, when related to the whole group, is also higher than incidences reported in other populations. The presence of this variation suggests that in some individuals part of the aortic arch is formed from the left 7th inter-segmental artery. Secondly, none of the cadavers examined had the thyroidea ima artery, contrasting with previously reported incidences that varied between 4% and 10%. Since all 6 cadavers with the left vertebral artery variant were born in South Australia, it is suggested that environmental factors may have contributed to this variation. Significant environmental changes in South Australia around the turn of the twentieth century are discussed. This study represents the first systematic investigation of the branches of the aortic arch in a South Australian population and provides data relevant to the practice of medicine

Study of magnetization reversal in Neel and Bloch regime of Ni and Py stripes using Kerr microscopy

We present a systematic study of the magnetization reversal of nickel and permalloy micro-stripes with Neel and Bloch domain walls using Kerr microscopy. Magnetic field driven domain propagation was observed from higher width to lower width stripes for magnetic fields applied along the length of micro-stripes. Stripe like domains were observed with nucleation starting in lower width region followed by their propagation to higher width regions for magnetic fields applied along the width of micro-stripes. The comparison of magnetization reversal in Bloch and N\'eel domain wall regime showed higher domain wall density in Bloch regime for both nickel and permalloy stripes.Comment: 13 pages, 5 figure

Prevention of heart failure events with sodium-glucose co-transporter 2 inhibitors across a spectrum of cardio-renal-metabolic risk

Aims Trials have tested the safety and efficacy of sodium-glucose co-transporter 2 inhibitors (SGLT2i) across various disease states. We performed a meta-analysis of randomized controlled trials (RCTs) to estimate the relative and absolute effects of SGLT2i in the prevention of heart failure (HF) events across different risk groups. Methods and results We conducted a systematic review and meta-analysis of large, placebo-controlled RCTs with >1000 participants evaluating HF hospitalization and the composite of cardiovascular (CV) death or HF hospitalization. Due to varying durations of therapeutic exposure and follow-up, absolute risk reductions and number needed to treat were calculated based on incidence rates (per 100 patient-years). Across 71 553 patients enrolled in 10 late-phase RCTs, SGLT2i reduced the risk of HF hospitalization by 31% [hazard ratio (HR) 0.69, 95% confidence interval (CI) 0.64-0.74; I-2 = 0%] and the composite outcome of CV death or HF hospitalization by 24% (HR 0.76, 95% CI 0.72-0.80; I-2 = 1.4%) compared with placebo. The number of patient-years of treatment exposure needed to prevent one CV death or HF hospitalization ranged from 19-26 (established HF) to 72-125 (chronic kidney disease) to 96-400 (high-risk type 2 diabetes). In mixed-effects meta-regression analyses, the benefits of SGLT2i on HF hospitalizations or the composite outcome (CV death or HF hospitalization) were not influenced by age, sex, or change in intermediate markers (glycated haemoglobin, systolic blood pressure, and body weight) (all P >= 0.10). Conclusion Despite wide variation in baseline risks and disease states evaluated, SGLT2i demonstrated comparable relative risk reductions in preventing HF events. Patients at highest baseline risk derived the greatest absolute benefits in preventing HF events. These composite estimates may help guide targeted implementation of SGLT2i for the prevention of HF events in type 2 diabetes and chronic kidney disease and in the treatment of HF

Domain wall induced modulation of low field H-T phase diagram in patterned superconductor-ferromagnet stripes

We present a systematic study of the magnetic domain wall induced modulation of superconducting transition temperature (Tc) in Nb/Ni bilayer stripes. By varying the thickness of the Ni layer from 20 nm to 100 nm we have been able to measure the low field Tc-H phase diagram spanning the N´eel domain wall and Bloch domain wall range of thicknesses. Micromagnetic simulations and magnetic force microscopy measurements confirmed a stronger out-of-plane stray field in the Bloch domain walls compared to the N´eel walls. A suppression in Tc was observed in the magnetization reversal region of the Ni film, the magnitude of which followed linearly to the strength of the out-of-plane stray field due to the domain walls. The magnitude of the stray field was quantified by comparing the Tc of the suppressed region of H-Tc phase diagrams with the unaffected part of the H-Tc curve. With Bloch domain walls a change in Tc of more than 60 mK was observed which is much more compared to the earlier reports. We believe that the narrow stripe geometry of the bilayers and the transverse external field maximized the effect of the domain walls in the Ni layer on the overlying superconducting film, leading to a larger change in Tc. This observation may be useful for domain wall controlled switching devices in superconducting spintronics

Expression of paramyxovirus V proteins promotes replication and spread of hepatitis C virus in cultures of primary human fetal liver cells

Here we demonstrate that primary cultures of human fetal liver cells (HFLC) reliably support infection with laboratory strains of hepatitis C virus (HCV), although levels of virus replication vary significantly between different donor cell preparations and frequently decline in a manner suggestive of active viral clearance. To investigate possible contributions of the interferon (IFN) system to control HCV infection in HFLC, we exploited the well-characterized ability of paramyxovirus (PMV) V proteins to counteract both IFN induction and antiviral signaling. The V proteins of measles virus (MV) and parainfluenza virus 5 (PIV5) were introduced into HFLC using lentiviral vectors encoding a fluorescent reporter for visualization of HCV-infected cells. V protein-transduced HFLC supported enhanced (10 to 100-fold) levels of HCV infection relative to untransduced or control vector-transduced HFLC. Infection was assessed by measurement of virus-driven luciferase, by assays for infectious HCV and viral RNA, and by direct visualization of HCV-infected hepatocytes. Live cell imaging between 48 and 119 hours postinfection demonstrated little or no spread of infection in the absence of PMV V protein expression. In contrast, V protein-transduced HFLC showed numerous HCV infection events. V protein expression efficiently antagonized the HCV-inhibitory effects of added IFNs in HFLC. In addition, induction of the type III IFN, IL29, following acute HCV infection was inhibited in V protein-transduced cultures. Conclusion: These studies suggest that the cellular IFN response plays a significant role in limiting the spread of HCV infection in primary hepatocyte cultures. Strategies aimed at dampening this response may be key to further development of robust HCV culture systems, enabling studies of virus pathogenicity and the mechanisms by which HCV spreads in its natural host cell population.National Institutes of Health (U.S.) (NIH Roadmap for Medical Research Grant 1 R01 DK085713-01)Greenberg Institute for Medical ResearchStarr Foundatio

Superconductivity, Kondo effect, and observation of self-organized pattern formation in intermetallic NiBi 3 thin films

The superconducting properties of the intermetallic compound NiBi3 have been studied mostly in bulk crystals. In this report we have studied several aspects of NiBi3 thin films, spontaneously formed at the interface of Ni and Bi multilayers. We have observed superconducting transition around 3.9 K, close to the bulk transition temperature of 4.1 K. Due to the diffusive mechanism of formation of NiBi3, additional phenomena such as magnetic (Nickel) impurity induced Kondo effect and self organized Turing pattern formation also come into picture. From X-ray diffraction and Magneto-resistance measurements we have established the presence of atomic Ni impurities in the films. Kondo minima were found to scale with varied concentration of Ni impurities in a series of Ni-Bi multilayer films (with fixed Ni thickness and varied Bi thickness). Similarly, saturation magnetization and superconducting transition temperature were also found to follow the concentration of Ni impurities. In addition, we have also observed signatures of Turing patterns, from magnetic force microscopy, naturally formed with time without any external heat treatment

Domain wall induced modulation of low field H-T phase diagram in patterned superconductor-ferromagnet stripes

We present a systematic study of the magnetic domain wall induced modulation of superconducting transition temperature (Tc) in Nb/Ni bilayer stripes. By varying the thickness of the Ni layer from 20 nm to 100 nm we have been able to measure the low field Tc-H phase diagram spanning the Néel domain wall and Bloch domain wall range of thicknesses. Micromagnetic simulations confirmed a stronger out-of-plane stray field in the Bloch domain walls compared to the Néel walls. A suppression in Tc was observed in the magnetization reversal region of the Ni film, the magnitude of which followed linearly to the strength of the out-of-plane stray field due to the domain walls. The upper limit of the magnitude of domain wall stray field was roughly estimated by comparing the Tc of the suppressed region of H-Tc phase diagrams with the unaffected part of the H-Tc curve. With Bloch domain walls a change in Tc of more than 60 mK was observed which is much more compared to the earlier reports. We believe that the narrow stripe geometry of the bilayers and the transverse external field maximized the effect of the domain walls in the Ni layer on the overlying superconducting film, leading to a larger change in Tc. This observation may be useful for domain wall controlled switching devices in superconducting spintronics.peerReviewe