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Type 1 von Willebrand disease (VWD) is associated with a reduction in qualitatively normal von Willebrand factor (VWF). Current diagnostic guidelines only take into consideration the contribution of basal VWF levels, despite a lack of correlation with bleeding severity. Defects in stimulated VWF release, which occurs after hemostatic challenge, may contribute to bleeding in type 1 VWD, but the pathogenic mechanisms are poorly defined. In this study, a layered multiomic approach including messenger RNA (mRNA) and microRNA (miRNA) sequencing was used to evaluate transcriptome-wide differences between type 1 VWD- and control-derived endothelial colony forming cells (ECFCs) during basal and stimulated VWF release. ECFCs from 8 patients with type 1 VWD and 4 other patients were included in this study as controls. VWF protein analysis revealed heterogenous responses to stimulation among type 1 VWD and control ECFCs. During basal VWF release, 64 mRNAs and 7 miRNAs were differentially regulated between type 1 VWD and control ECFCs, and 65 putatively pathogenic miRNA-mRNA interactions were identified. During stimulated VWF release, 190 mRNAs and 5 mRNAs were differentially regulated between type 1 VWD and control ECFCs, and 110 putatively pathogenic miRNA-mRNA interactions were identified. Five gene ontology terms including coagulation, regulation of cell shape, and regulation of cell signaling were also differentially regulated in type 1 VWD ECFCs during stimulated release. To our knowledge, we have shown for the first time that transcriptome-wide differences exist between type 1 VWD and control ECFCs. These differences may contribute to bleeding in type 1 VWD, and further investigation may reveal novel biomarkers and therapeutic targets.

Medium-Chain Acyl-CoA Dehydrogenase Deficiency (MCADD) is the most common inherited metabolic disorder of β-oxidation. Patients with MCADD present with hypoketotic hypoglycemia, which may quickly progress to lethargy, coma, and death. Prognosis for MCADD patients is highly promising once a diagnosis has been established, though management strategies may vary depending on the severity of illness and the presence of comorbidities.Given the rapid developments in the world of gene therapy and implementation of newborn screening for inherited metabolic disorders, the provision of concise and contemporary knowledge of MCADD is essential for clinicians to effectively manage patients. Thus, this review aims to consolidate current information for physicians on the pathogenesis, diagnostic tools, and treatment options for MCADD patients.MCADD is a commonly inherited metabolic disease with serious implications for health outcomes, particularly in children, that may be successfully managed with proper intervention.

Type 1 von Willebrand disease (VWD) is associated with a reduction in qualitatively normal von Willebrand factor (VWF). Current diagnostic guidelines only take into consideration the contribution of basal VWF levels, despite a lack of correlation with bleeding severity. Defects in stimulated VWF release, which occurs following hemostatic challenge, may contribute to bleeding in Type 1 VWD, but the pathogenic mechanisms are poorly defined. In the present study, a layered multiomic approach including mRNA and miRNA sequencing was used to evaluate transcriptome-wide differences between Type 1 VWD- and control-derived endothelial colony forming cells (ECFCs) during basal and stimulated VWF release. ECFCs from eight Type 1 VWD patients and four controls were included in this study. VWF protein analysis revealed heterogenous responses to stimulation amongst Type 1 VWD and control ECFCs. During basal VWF release, 64 mRNAs and 7 miRNAs were differentially regulated between Type 1 VWD and control ECFCs and 65 putatively pathogenic miRNA-mRNA interactions were identified. During stimulated VWF release, 190 mRNAs and five mRNAs were differentially regulated between Type 1 VWD and control ECFCs and 110 putatively pathogenic miRNA-mRNA interactions were identified. Five gene ontology terms including coagulation, regulation of cell shape, and regulation of cell signalling were also differentially regulated in Type 1 VWD ECFCs during stimulated release. We have shown for the first time that transcriptome-wide differences exist between Type 1 VWD and control ECFCs. These differences may contribute to bleeding in Type 1 VWD, and further investigation may reveal novel biomarkers and therapeutic targets.

In prototype ferromagnet-antiferromagnet interfaces we demonstrate that surface acoustic waves can be used to identify complex magnetic phases arising upon evolution of exchange springs in an applied field. Applying sub-GHz surface acoustic waves to study the domain structure of the ferromagnetic layer in exchange-biased bilayers of Ir 20 Mn 80 − Co 60 Fe 20 B 20 , we are able to associate the magnetoelastic resonance with the presence of the exchange spin-spirals in both the ferromagnetic and antiferromagnetic layer. Our findings offer a complementary, integrative insight into emergent magnetic materials for applications of noncollinear spin textures in view of low-energy-consumption spintronic devices.

Imaging Mass Cytometry (IMC) is a powerful high-throughput technique enabling resolution of up to 37 markers in a single fixed tissue section while also preserving in situ spatial relationships. Currently, IMC processing and analysis necessitates the use of multiple different software, labour-intensive pipeline development, different operating systems and knowledge of bioinformatics, all of which are a barrier to many potential users. Here we present TITAN - an open-source, single environment, end-to-end pipeline that can be utilized for image visualization, segmentation, analysis and export of IMC data. TITAN is implemented as an extension within the publicly available 3D Slicer software. We demonstrate the utility, application, reliability and comparability of TITAN using publicly available IMC data from recently-published breast cancer and COVID-19 lung injury studies. Compared with current IMC analysis methods, TITAN provides a user-friendly, efficient single environment to accurately visualize, segment, and analyze IMC data for all users.

The HyperionTM Imaging System is a novel technology that uses imaging mass cytometry (IMC) to improve upon current methods of tissue imaging, enabling sub-cellular spatial resolution and acquisition of up to 37 proteins on a single tissue slide. The technology is fairly new, and thus we want to explore the types of analysis possible with these data. Here, we introduce an analysis pipeline to utilize machine learning-based analysis for IMC data using data from a muscle invasive bladder cancer patient cohort. We also propose a novel augmentation method to handle the challenge of low number of tissue samples from IMC studies. Our augmentation method was validated and shown to perform better than when only using the original data. Both our pipeline and augmentation method show promise for applications in future research studies and clinical evaluation of this technology. Our results indicate the feasibility of using the proposed framework with a more robust data set to identify prognostic features, which is an important foundation for further clinical research.

Spin current pumping from a ferromagnet through an insulating layer into a heavy metal was studied in a CoFeB/ SiO 2/Pt system in relation to the thickness and interfacial structure of the insulating layer. The propagation of spin current from the ferromagnet into the heavy metal falls rapidly with sub-nanometer thicknesses of SiO 2 and is suppressed beyond a nominal thickness of 2 nm. Structural analysis shows that SiO 2 only forms a complete barrier layer beyond around 2 nm, indicating that the presence of a discontinuous insulating barrier, and not tunneling or diffusion, explains the main observations of spin-pumping with thin insulating layers.Spin current pumping from a ferromagnet through an insulating layer into a heavy metal was studied in a CoFeB/ SiO 2/Pt system in relation to the thickness and interfacial structure of the insulating layer. The propagation of spin current from the ferromagnet into the heavy metal falls rapidly with sub-nanometer thicknesses of SiO 2 and is suppressed beyond a nominal thickness of 2 nm. Structural analysis shows that SiO 2 only forms a complete barrier layer beyond around 2 nm, indicating that the presence of a discontinuous insulating barrier, and not tunneling or diffusion, explains the main observations of spin-pumping with thin insulating layers.

Kinane, Christy/0000-0002-1185-0719; Tokac, Mustafa/0000-0001-5614-2292 WOS: 000496567800002 Proximity-induced magnetization (PIM) has broad implications across interface-driven spintronics applications employing spin currents. We directly determine the scaling between PIM in Pt and the temperature-dependent interface magnetization in an adjacent ferromagnet (FM) using depth-resolved magnetometry. The magnetization due to PIM does not follow the generally expected linear scaling with the FM interface magnetization, as a function of temperature. Instead, it vanishes while the FM interface magnetization remains. The effective magnetic susceptibilities of heavy-metal (HM) layers are shown to give rise to the previously unexplained asymmetric PIM found in HM/FM/HM trilayers. Nigerian government TET-Fund scheme; EPSRC DTPUK Research & Innovation (UKRI)Engineering & Physical Sciences Research Council (EPSRC); Republic of Turkey Ministry of National EducationMinistry of National Education - Turkey; EPSRCUK Research & Innovation (UKRI)Engineering & Physical Sciences Research Council (EPSRC) [EP/L000121/1]; HEFCE ODA; Royal SocietyRoyal Society of London; EPSRCUK Research & Innovation (UKRI)Engineering & Physical Sciences Research Council (EPSRC) We acknowledge support from Nigerian government TET-Fund scheme (OI), EPSRC DTP (BN and RMR-R), Republic of Turkey Ministry of National Education (MT), EPSRC Grant Ref. EP/L000121/1, HEFCE ODA, and the Royal Society (ATH). XMaS is a UK national facility supported by EPSRC. We thank STFC for ISIS beam time RB1620118 and access to ISIS R53 Materials Characterization Lab, and D. Atkinson, D. M. Burn, C. Cox, T. P. A. Hase, P. D. Hatton, and K. Morrison for stimulating discussions.

To realise the widespread implementation of future generations of lithium ion batteries (LIBs) in electric vehicles, significant improvements in the lifetime and power density are required. One of the most important aspects in achieving a long battery lifetime is the formation of an effective solid electrolyte interphase (SEI) layer on the anode. This layer forms mostly within the first few charge/discharge cycles by the decomposition of electrolyte components at the electrode/electrolyte interface. Although the importance of the SEI is well accepted, much dispute remains regarding its chemical composition, thickness, morphology and formation/decomposition mechanisms. This is largely due to a lack of characterisation techniques that can accurately probe the electrode-electrolyte interface with nm-scale surface sensitivity under realistic cycling conditions. As a result, most efforts to characterise the SEI have involved ex situ samples, the preparation of which may alter the SEI layer composition. Therefore, in order to gain the most accurate information, there has been a great drive to perform in situ and operando measurements. Neutron techniques offer several advantages for characterising the processes occurring in LIBs, particularly as the negative scattering length of Lithium gives a high sensitivity to changes in the lithium environment, which is not the case with X-ray techniques. Neutron reflectometry (NR) is one of the few techniques with which the nm-scale structure of buried electrode-electrolyte interfaces in a cell can be observed during electrochemical cycling.1 A number of previous studies have investigated thin film silicon or carbon electrodes, but these have typically been carried out across a limited potential range due to concerns about restructuring due to significant lithiation that could otherwise hinder interpretation of the neutron reflectivity data.2-4 To overcome this limitation we have recently used a nickel working electrode (anode) which, given its zero capacity for lithium insertion, does not alter in structure during electrochemical cycling. Here we directly observe the growth of the SEI layer on a nickel anode as a function of potential (2.00-0.05 V) during the first cycle by using our operando cell developed at ISIS Neutron and Muon Source. During the first lithiation cycle (decreasing potential), we observe the growth of a lithium-rich layer directly in contact with the nickel and another, more organic, layer on top of this lithium-rich layer. We are able to track the evolution of these layers with potential, and characterise their chemical composition using additional X-ray Photoelectron Spectroscopy measurements performed on both cycled nickel and commercial graphite electrodes for comparison. References 1. E. Owejan, J. P. Owejan, S. C. DeCaluwe, and J. A. Dura, Chem. Mater., 2012, 24, 2133−2140. 2. Jerliu, L. Dörrer, E. Hüger, G. Borchardt, R. Steitz, U. Geckle, V. Oberst, M. Bruns, O. Schneiderd and H. Schmidt, Phys. Chem. Chem. Phys., 2013, 15, 7777-7784. 3. M. Veith, M. Doucet, R. L. Sacci, B. Vacaliuc, J. K. Baldwin and J. F. Browning, Sci. Rep., 2017, 7, 6326. 4. Steinhauer, M. Stich, M. Kurniawan, B.-K. Seidlhofer, M. Trapp, A. Bund, N. Wagner, and K. A. Friedrich, ACS Appl. Mater. Interfaces, 2017, 9, 35794−35801.

The interfacial Dzyaloshinskii-Moriya interaction (IDMI) is investigated in Co2FeAl (CFA) ultrathin films of various thicknesses (0.8 nm ≤ tCFA ≤ 2nm) grown by sputtering on Si substrates, using Pt, W, Ir, and MgO buffer or/and capping layers. Vibrating sample magnetometry reveals that the magnetization at saturation (Ms) for the Pt- and Ir-buffered films is higher than the usual Ms of CFA due to the proximity-induced magnetization (PIM) in Ir and Pt estimated to be 19% and 27%, respectively. The presence of PIM in these materials is confirmed using x-ray resonant magnetic reflectivity. Moreover, while no PIM is induced in W, higher PIM is obtained with Pt when it is used as a buffer layer rather than a capping layer. Brillouin light scattering in the Damon-Eshbach geometry is used to investigate the thickness dependences of the IDMI constants from the spin-wave nonreciprocity and the perpendicular anisotropy field versus the annealing temperature. The IDMI sign is found to be negative for Pt / CFA and Ir / CFA, while it is positive for W / CFA. The thickness dependence of the effective IDMI constant for stacks involving Pt and W shows the existence of two regimes similar to that of the perpendicular anisotropy constant due to the degradation of the interfaces as the CFA thickness approaches a critical thickness. The surface IDMI and anisotropy constants of each stack are determined for the thickest samples where a linear thickness dependence of the effective IDMI constant and the effective magnetization are observed. The interface anisotropy and IDMI constants investigated for the Pt / CFA / MgO system show different trends with the annealing temperature. The decrease of the IDMI constant with increasing annealing temperature is probably due to the electronic structure changes at the interfaces, while the increase of the interface anisotropy constant is coherent with the interface quality and disorder enhancement.

The Dzyaloshinskii-Moriya interaction has been shown to stabilise Nèel domain walls in magnetic thin films, allowing high domain wall velocities driven by spin current effects. The interfacial Dzyaloshinskii-Moriya interaction (IDMI) occurs at the interface between ferromagnetic and heavy metal layers with strong spin-orbit coupling, but details of the interaction remain to be understood and the role of proximity induced magnetism (PIM) in the heavy metal is unknown. Here IDMI and PIM are reported in Pt determined as a function of Au and Ir spacer layers in Pt/Co/Au,Ir/Pt. Both interactions are found to be sensitive to sub-nanometre changes in the spacer thickness, correlating over sub-monolayer spacer thicknesses, but not for thicker spacers where IDMI continues to change even after PIM is lost.

Heavy metal layers, exemplified by Pt, are known to play a significant role in the magnetization behaviour of thin-film ferromagnets by three distinct mechanisms that can each contribute to the reversal process. These include modifying the local magnetization state via an interfacial Dzyaloshinskii-Moriya interaction (IDMI), enhancement of the damping, via d-d hybridisation and spin-pumping across the interface, and the mediation of the magnetization switching, with the flow of current through a system, via the spin-Hall effect. Here we show for a system with weak interfacial DMI (NiFe/Pt) that the measurement of magnetic field-driven magnetization reversal, mediated by domain wall (DW) motion, is dominated by the enhanced intrinsic damping contribution as a function of the Pt capping layer thickness. But, we also show micromagnetically that the IDMI and damping also combine to modify the domain wall velocity behaviour when the damping is larger. It is also noted that Walker breakdown occurs at lower fields and peak DW velocity decreases in the presence of IDMI. These results highlight the significance of the relative contributions of the damping and the IDMI from the heavy metal layer on the magnetization reversal and provide a route to controlling the DW behaviour in nanoscale device structures.

What is the topic of this review? We describe roles of crucial signalling molecules in the paraventricular nucleus of the hypothalamus and highlight recent data suggesting sex-specific changes in the expression of crucial signalling molecules and their receptors, which may underlie sex differences in both cardiovascular and metabolic function. What advances does it highlight? This review highlights the integrative capacity of the paraventricular nucleus in mediating cardiovascular and metabolic effects by integrating information from multiple signalling molecules. It also proposes that these signalling molecules have sex-specific differential gene expression, indicating the importance of considering these differences in our ongoing search to understand the female-male differences in the regulation of crucial autonomic systems. Many traditional cardiovascular hormones have been implicated in metabolic function. Conversely, many hormones traditionally involved in metabolic regulation have an effect on cardiovascular function. Many of these signalling molecules exert such effects through specific actions in the paraventricular nucleus, an integrative autonomic control centre located in the hypothalamus. Here, we focus on four cardiovascular/metabolic peptide hormones that signal within the paraventricular nucleus, namely angiotensin II, orexin, adiponectin and nesfatin-1. Each of these hormones has specific electrophysiological effects on paraventricular nucleus neurons that can be related to its physiological actions. In addition, we introduce preliminary transcriptomic data indicating that the genes for some of these hormones and their receptors have sex-specific differential expression.

The supraoptic nucleus (SON) is part of the central osmotic circuitry that synthesises the hormone vasopressin (Avp) and transports it to terminals in the posterior lobe of the pituitary. Following osmotic stress such as dehydration, this tissue undergoes morphological, electrical and transcriptional changes to facilitate the appropriate regulation and release of Avp into the circulation where it conserves water at the level of the kidney. Here, the organisation of the whole transcriptome following dehydration is modelled to fit Zipf's law, a natural power law that holds true for all natural languages, that states if the frequency of word usage is plotted against its rank, then the log linear regression of this is -1. We have applied this model to our previously published euhydrated and dehydrated SON data to observe this trend and how it changes following dehydration. In accordance with other studies, our whole transcriptome data fit well with this model in the euhydrated SON microarrays, but interestingly, fit better in the dehydrated arrays. This trend was observed in a subset of differentially regulated genes and also following network reconstruction using a third-party database that mines public data. We make use of language as a metaphor that helps us philosophise about the role of the whole transcriptome in providing a suitable environment for the delivery of Avp following a survival threat like dehydration.

Endothelial dysfunction caused by the combined action of disturbed flow, inflammatory mediators and oxidants derived from cigarette smoke is known to promote coronary atherosclerosis and increase the likelihood of myocardial infarctions and strokes. Conversely, laminar flow protects against endothelial dysfunction, at least in the initial phases of atherogenesis. We studied the effects of TNFα and cigarette smoke extract on human coronary artery endothelial cells under oscillatory, normal laminar and elevated laminar shear stress for a period of 72 hours. We found, firstly, that laminar flow fails to overcome the inflammatory effects of TNFα under these conditions but that cigarette smoke induces an anti-oxidant response that appears to reduce endothelial inflammation. Elevated laminar flow, TNFα and cigarette smoke extract synergise to induce expression of the transcriptional regulator activating transcription factor 3 (ATF3), which we show by adenovirus driven overexpression, decreases inflammatory gene expression independently of activation of nuclear factor-κB. Our results illustrate the importance of studying endothelial dysfunction in vitro over prolonged periods. They also identify ATF3 as an important protective factor against endothelial dysfunction. Modulation of ATF3 expression may represent a novel approach to modulate proinflammatory gene expression and open new therapeutic avenues to treat proinflammatory diseases.

Background Interferon-γ (IFN-γ) or interleukin-4 (IL-4) drives widely different transcriptional programs in macrophages. However, how IFN-γ and IL-4 alter expression of histone-modifying enzymes involved in epigenetic regulation and how this affects the resulting phenotypic polarization is incompletely understood. Methods and results We investigated steady-state messenger RNA levels of 84 histone-modifying enzymes and related regulators in colony-stimulating factor-1 differentiated primary human macrophages using quantitative polymerase chain reaction. IFN-γ or IL-4 treatment for 6–48 h changed 11 mRNAs significantly. IFN-γ increased CIITA, KDM6B, and NCOA1, and IL-4 also increased KDM6B by 6 h. However, either cytokine decreased AURKB, ESCO2, SETD6, SUV39H1, and WHSC1, whereas IFN-γ alone decreased KAT2A, PRMT7, and SMYD3 mRNAs only after 18 h, which coincided with decreased cell proliferation. Rendering macrophages quiescent by growth factor starvation or adenovirus-mediated overexpression of p27kip1 inhibited expression of AURKB, ESCO2, SUV39H1, and WHSC1, and mRNA levels were restored by overexpressing the S-phase transcription factor E2F1, implying their expression, at least partly, depended on proliferation. However, CIITA, KDM6B, NCOA1, KAT2A, PRMT7, SETD6, and SMYD3 were regulated independently of effects on proliferation. Silencing KDM6B, the only transcriptional activator upregulated by both IFN-γ and IL-4, pharmacologically or with short hairpin RNA, blunted a subset of responses to each cytokine. Conclusion These findings demonstrate that IFN-γ or IL-4 can regulate the expression of histone acetyl transferases and histone methyl transferases independently of effects on proliferation and that upregulation of the histone demethylase, KDM6B, assists phenotypic polarization by both cytokines.

The evolution of damping in Co/Pt, Co/Au, and Ni81Fe19/Pt bilayers was studied with increasing nonmagnetic (NM) heavy-metal layer thicknesses in the range 0.2nm≤tNM≤10nm, where tNM is the NM layer thickness. Magnetization precession was measured in the time domain using time-resolved magneto-optical Kerr effect magnetometry. Fitting of the data with a damped sinusoidal function was undertaken in order to extract the phenomenological Gilbert damping coefficient α. For Pt-capped Co and Ni81Fe19 layers a large and complex dependence of α on the Pt layer thickness was observed, while for Au capping no significant dependence was observed. It is suggested that this difference is related to the different localized spin-orbit interaction related to intermixing and to d−d hybridization of Pt and Au at the interface with Co or Ni81Fe19. Also it was shown that damping is affected by the crystal structure differences in FM thin films and at the interface, which can modify the spin-diffusion length and the effective spin-mixing conductance. In addition to the intrinsic damping an extrinsic contribution plays an important role in the enhancement of damping when the Pt capping layer is discontinuous. The dependence of damping on the nonmagnetic layer thickness is complex but shows qualitative agreement with recent theoretical predictions.

We demonstrate that a planar magnetron may be used as a source of ions for milling micro- and nanostructured devices. Reversing the polarity of the magnetron head, in combination with applying a voltage bias to the thin-film sample, allows acceleration of ions produced in the Ar glow-discharge to energies suitable for pattern transfer via etching. We have fabricated generic Hall-bar and nanowire L-bar structures from sputter deposited Ta/Ni/Ta trilayer films grown onto clean GaAs(001) surfaces. No degradation of the magnetic properties or contamination of the deposition chamber vacuum is observed, demonstrating that this method is effective for etching magnetic device structures patterned by both optical- and electron-beam lithography techniques.

Interface modification for control of ultrafast magnetic properties using low-dose focused ion beam irradiation is demonstrated for bilayers of two technologically important materials: Ni81Fe19 and Pt. Magnetization dynamics were studied using an all-optical time-resolved magneto-optical Kerr microscopy method. Magnetization relaxation, precession, damping and the spatial coherence of magnetization dynamics were studied. Magnetization precession was fitted with a single-mode damped sinusoid to extract the Gilbert damping parameter. A systematic study of the damping parameter and frequency as a function of irradiation dose varying from 0 to 3.3 pC/μm2 shows a complex dependence upon ion beam dose. This is interpreted in terms of both intrinsic effects and extrinsic two-magnon scattering effects resulting from the expansion of the interfacial region and the creation of a compositionally graded alloy. The results suggest a new direction for the control of precessional magnetization dynamics and open the opportunity to optimize high-speed magnetic devices.

Interfaces between dissimilar materials present a wide range of fascinating physical phenomena. When a nanoscale thin-film of a ferromagnetic metal is deposited in intimate contact with a compound semiconductor, the properties of the interface exhibit a wealth of novel behavior, having immense potential for technological application, and being of great interest from the perspective of fundamental physics. This article presents a review of recent advances in the field of interface magnetism in (001)-oriented ferromagnetic metal/III–V compound semiconductor hybrid structures. Until relatively recently, the majority of research in this area continued to concentrate almost exclusively on the prototypical epitaxial Fe / GaAs (001) system: now, a significant proportion of work has branched out from this theme, including ferromagnetic metal alloys, and other III–V compound semiconductors. After a general overview of the topic, and a review of the more recent literature, we discuss recent results where advances have been made in our understanding of the physics underpinning magnetic anisotropy in these systems: tailoring the terms contributing to the angular-dependent free-energy density by employing novel fabrication methods and ferromagnetic metal electrodes.

Cobalt nanoparticles have been embedded either within magnetic thin films of CuNi or Ni, or at their interface with an Al capping layer. Soft X-ray magnetic circular dichroism (XMCD) was used to measure element-specific hysteresis loops, allowing discrimination between the nanoparticles and the host film. The hysteresis shows coupling between the nanoparticles and the films and a reduction in coercivity is observed when positioning the nanoparticles within the film, as opposed to at its interface with the cap. Sum rule analysis of the XMCD spectra makes it possible to determine the orbital to spin moment ratios for Co and Ni in the samples. The difference in the calculated ratios is consistent with the differences in the coercivities, the films appearing more homogenous due to hybridization of the 3d bands of Co and Ni when the nanoparticles are embedded deeper within the films, creating less pinning sites and hence a lower coercivity.

We have used microarrays to comprehensively describe the transcriptomes of the supraoptic nucleus (SON), the paraventricular nucleus (PVN) and the neurointermediate lobe of adult male Sprague-Dawley (SD) and Wistar-Kyoto (WKY) rats, as well as the PVN of Wistar rats. Comparison of these gene lists has enabled us to identify surprisingly large differences in hypothalamic-neurohypophyseal system gene expression patterns in these three strains. We have also shown that different transcript populations are enriched in the PVN and the SON of SD and WKY rats. The transcriptome differences catalogued here may be molecular substrates for the neuro-humoral phenotypic differences exhibited by different strains of rats.

Electron-magnon spin-flip scattering in thin films was studied by investigating the thickness dependence of the anisotropic magnetoresistance (AMR) effect and spin-wave stiffness. The absolute resistivity change due to the AMR effect ($\ensuremath{\Delta}\ensuremath{\rho}$) in Ni, Ni:V, and Ni:Cr doped films reduced with film thickness. This loss of AMR is due to enhanced spin-flip scattering, dropping at the same thickness irrespective of dopant. The spin-wave stiffness reduced at the same thickness, confirming enhanced electron-magnon spin-flip scattering. The AMR ratio was fitted with a simple model, in which thickness dependence was included in a spin mixing resistivity term. This analysis gives insight into the fundamental contribution of magnon scattering to the resistivity in thin films, which ultimately has relevance to spin coherence in spintronic devices.

Interfaces between dissimilar materials present a wide range of fascinating physical phenomena. When a nanoscale thin-film of a ferromagnetic metal is deposited in intimate contact with a compound semiconductor, the properties of the interface exhibit a wealth of novel behavior, having immense potential for technological application, and being of great interest from the perspective of fundamental physics. This article presents a review of recent advances in the field of interface magnetism in (001)-oriented ferromagnetic metal/III–V compound semiconductor hybrid structures. Until relatively recently, the majority of research in this area continued to concentrate almost exclusively on the prototypical epitaxial Fe/GaAs(001) system: now, a significant proportion of work has branched out from this theme, including ferromagnetic metal alloys, and other III–V compound semiconductors. After a general overview of the topic, and a review of the more recent literature, we discuss recent results where advances have been made in our understanding of the physics underpinning magnetic anisotropy in these systems: tailoring the terms contributing to the angular-dependent free-energy density by employing novel fabrication methods and ferromagnetic metal electrodes.

Evidence of boron diffusion into the MgO barrier of a CoFeB/MgO based magnetic tunnel junction has been identified using analytical scanning transmission electron microscopy (STEM) and X-ray photoelectron spectroscopy. Structures were deposited by DC/RF-magnetron sputtering, where defective, sub-stoichiometric MgO barriers degrading device performance have been previously mitigated against by deposition of thin Mg layers prior to MgO deposition. We show that despite the protection offered by the Mg layer, disorder in the MgO barrier is still evident by STEM analysis and is a consequence of the oxidation of the Co40Fe40B20 surface during MgO deposition. Evidence of boron diffusion from CoFeB into the MgO barrier in the as-deposited and annealed structure is also presented, which in the as-deposited case we suggest results from the defective structures at the barrier interfaces. Annealing at 375 °C results in the presence of B in the trigonal coordination of [BO3]3− in the MgO barrier and partial crystallization of the top electrode (we presume there is also some boron diffusion into the Ta capping layer). The bottom electrode, however, fails to crystallize and much of the boron is retained in this thicker electrode. A higher annealing temperature or lower initial boron content is required to crystallize the bottom electrode.

We investigate the dependence of the magnetic and structural properties of (Ga,Mn)As/(Al,Ga,Mn)As bilayer films on the stoichiometry of the interface region. For films incorporating a thin As-deficient layer at the interface, the out-diffusion of interstitial Mn from the bottom layer is strongly suppressed, resulting in a large difference in T C and magnetic anisotropy between the two layers. X-ray reflectivity measurements show that the suppression of interstitial diffusion is correlated with an increased interface roughness. When the As-deficient interface layer is thicker than 2.5 nm, the in-plane uniaxial magnetic easy axis rotates from the [1-10] to the [110] crystalline axis.

Multiferroic composite materials, consisting of coupled ferromagnetic and piezoelectric phases, are of great importance in the drive towards creating faster, smaller and more energy efficient devices for information and communications technologies. Such devices require thin ferromagnetic films with large magnetostriction and narrow microwave resonance linewidths. Both properties are often degraded, compared to bulk materials, due to structural imperfections and interface effects in the thin films. We report the development of single crystal thin films of Galfenol (Fe81Ga19) with magnetostriction as large as the best reported values for bulk material. This allows the magnetic anisotropy and microwave resonant frequency to be tuned by voltage-induced strain, with a larger magnetoelectric response and a narrower linewidth than any previously reported Galfenol thin films. The combination of these properties make the single crystal thin films excellent candidates for developing tunable devices for magnetic information storage, processing and microwave communications.

We demonstrate reproducible voltage induced non-volatile switching of the magnetization in an epitaxial thin Fe81Ga19 film. Switching is induced at room temperature and without the aid of an external magnetic field. This is achieved by the modification of the magnetic anisotropy by mechanical strain induced by a piezoelectric transducer attached to the layer. Epitaxial Fe81Ga19 is shown to possess the favourable combination of cubic magnetic anisotropy and large magnetostriction necessary to achieve this functionality with experimentally accessible levels of strain. The switching of the magnetization proceeds by the motion of magnetic domain walls, also controlled by the voltage induced strain.

The transition between Kondo and Coulomb blockade effects in discontinuous double magnetic tunnel junctions is explored as a function of the size of the CoPt magnetic clusters embedded between AlO${}_{x}$ tunnel barriers. A gradual competition between cotunneling enhancement of the tunneling magnetoresistance (TMR) and the TMR suppression due to the Kondo effect has been found in these junctions, with both effects having been found to coexist even in the same sample. It is possible to tune between these two states with temperature (at a temperature far below the cluster blocking temperature). In addition, when further decreasing the size of the CoPt clusters, another gradual transition between the Kondo effect and direct tunneling between the electrodes takes place. This second transition shows that the spin-flip processes found in junctions with impurities in the barrier are in fact due to the Kondo effect. A simple theoretical model able to account for these experimental results is proposed.

We have used a transmission line deposited on a transparent substrate to deliver an optically triggered magnetic field pulse to a spin valve structure deposited upon an opaque substrate. The ensuing ferromagnetic resonance oscillations have been studied in optical pump-probe experiments in which the probe passes through the transmission line substrate. The resonance frequencies have been modeled by solving the Landau–Lifshitz equation and are used in determining the anisotropy, exchange bias, and interlayer coupling parameters of the sample.

Describing the origin of uniaxial magnetic anisotropy (UMA) is generally problematic in systems other than single crystals. We demonstrate an in-plane UMA in amorphous CoFeB films on GaAs(001) which has the expected symmetry of the interface anisotropy in ferromagnetic films on GaAs(001), but strength which is independent of, rather than in inverse proportion to, the film thickness. We show that this volume UMA is consistent with a bond-orientational anisotropy, which propagates the interface-induced UMA through the thickness of the amorphous film. It is explained how, in general, this mechanism may describe the origin of in-plane UMAs in amorphous ferromagnetic films., 4 pages, 4 figures

The area postrema (AP) is a sensory circumventricular organ characterized by extensive fenestrated vasculature and neurons which are capable of detecting circulating signals of osmotic, cardiovascular, immune and metabolic status. The AP can communicate these messages via efferent projections to brainstem and hypothalamic structures that are able to orchestrate an appropriate response. We have used microarrays to profile the transcriptome of the AP in the Sprague-Dawley (SD) and Wistar-Kyoto rat and present here a comprehensive catalogue of gene expression, focusing specifically on the population of ion channels, receptors and G protein-coupled receptors expressed in this sensory tissue; of the G protein-coupled receptors expressed in the rat AP, we identified ∼36% that are orphans, having no established ligand. We have also looked at the ways in which the AP transcriptome responds to the physiological stressors of 72 h dehydration (DSD) and 48 h fasting (FSD) and have performed microarrays in these conditions. Comparison between the DSD and SD or between FSD and SD revealed only a modest number of AP genes that are regulated by these homeostatic challenges. The expression levels of a much larger number of genes are altered in the spontaneously hypertensive rat AP compared with the normotensive Wistar-Kyoto control rat, however. Finally, analysis of these 'hypertension-related' elements revealed genes that are involved in the regulation of both blood pressure and immune function and as such are excellent targets for further study.

Temperature and bias voltage-dependent transport characteristics are presented for double magnetic tunnel junctions (DMTJs) with self-assembled NiFe nanoparticles embedded between insulating alumina barriers. The junctions with embedded nanoparticles are compared to junctions with a single barrier of comparable size and growth conditions. The embedded particles are characterized using x-ray absorption spectroscopy, transmission electron microscopy, and magnetometry techniques, showing that they are unoxidized and remain superparamagnetic to liquid helium temperatures. The tunneling magnetoresistance (TMR) for the DMTJs is lower than the control samples, however, for the DMTJs an enhancement in TMR is seen in the Coulomb blockade region. Fitting the transport data in this region supports the theory that cotunneling is the dominant electron transport process within the Coulomb blockade region, sequential tunneling being suppressed. We therefore see an enhanced TMR attributed to the change in the tunneling process due to the interplay of the Coulomb blockade and spin-dependent tunneling through superparamagnetic nanoparticles, and develop a simple model to quantify the effect, based on the fact that our nanoparticles will appear blocked when measured on femtosecond tunneling time scales.

We have addressed the question of how different rodent species cope with the life-threatening homeostatic challenge of dehydration at the level of transcriptome modulation in the supraoptic nucleus (SON), a specialised hypothalamic neurosecretory apparatus responsible for the production of the antidiuretic peptide hormone arginine vasopressin (AVP). AVP maintains water balance by promoting water conservation at the level of the kidney. Dehydration evokes a massive increase in the regulated release of AVP from SON axon terminals located in the posterior pituitary, and this is accompanied by a plethora of changes in the morphology, electrophysiological properties, biosynthetic and secretory activity of this structure. Microarray analysis was used to generate a definitive catalogue of the genes expressed in the mouse SON, and to describe how the gene expression profile changes in response to dehydration. Comparison of the genes differentially expressed in the mouse SON as a consequence of dehydration with those of the rat has revealed many similarities, pointing to common processes underlying the function-related plasticity in this nucleus. In addition, we have identified many genes that are differentially expressed in a species-specific manner. However, in many cases, we have found that the hyperosmotic cue can induce species-specific alterations in the expression of different genes in the same pathway. The same functional end can be served by different means, via differential modulation, in different species, of different molecules in the same pathway. We suggest that pathways, rather than specific genes, should be the focus of integrative physiological studies based on transcriptome data.

The effect of the application of a magnetic field during deposition of epitaxial Co{sub 70}Fe{sub 30} onto GaAs(001) is shown; we find an initially counterintuitive result. For field applied along the interfacial uniaxial hard axis the relative effective uniaxial magnetic anisotropy is increased by a factor of two in comparison to both field along the uniaxial easy axis, or no field; usually, application of a deposition field results in a uniaxial easy axis parallel to this field direction. We show that the deposition field changes the maximal projection of the atomic orbital magnetic moments onto the easy axis, which corresponds to a deposition field induced shift in the Helmholtz free-energy landscape of the system.

We determine the composition of intrinsic as well as extrinsic contributions to the anomalous Hall effect (AHE) in the isoelectronic L1_{0} FePd and FePt alloys. We show that the AHE signal in our 30 nm thick epitaxially deposited films of FePd is mainly due to an extrinsic side jump, while in the epitaxial FePt films of the same thickness and degree of order the intrinsic contribution is dominating over the extrinsic mechanisms of the AHE. We relate this crossover to the difference in spin-orbit strength of Pt and Pd atoms and suggest that this phenomenon can be used for tuning the origins of the AHE in complex alloys.