Spin and orbital moments of ultra-thin Fe films on various semiconductor surfaces

The magnetic moments of ultrathin Fe films on three different III-V semiconductor substrates, namely GaAs, InAs and In0.2Ga0.8As have been measured with X-ray magnetic circular dichroism at room temperature to assess their relative merits as combinations suitable for next-generation spintronic devices. The results revealed rather similar spin moments and orbital moments for the three systems, suggesting the relationship between film and semiconductor lattice parameters to be less critical to magnetic moments than magnetic anisotropy

Social media for physiotherapy clinics: considerations in creating a Facebook page

Social media websites play a prominent role in modern society, and the most popular of these websites is Facebook. Increasingly, physiotherapy clinics have begun to utilize Facebook in order to create pages to publicize their services. There are many factors to consider in the planning, implementing, and maintenance of Facebook pages for physiotherapy clinics, including ethical and privacy issues. The primary purpose of creating a page must be clearly defined, with dedicated clinicians given adequate time to manage the page. This technical article discusses these factors and summarizes the experiences at the University of Otago, New Zealand, in creating a Facebook page for the physiotherapy clinic and provides suggestions for physiotherapy clinicians in operating a Facebook page

The selectivity, voltage-dependence and acid sensitivity of the tandem pore potassium channel TASK-1 : contributions of the pore domains

We have investigated the contribution to ionic selectivity of residues in the selectivity filter and pore helices of the P1 and P2 domains in the acid sensitive potassium channel TASK-1. We used site directed mutagenesis and electrophysiological studies, assisted by structural models built through computational methods. We have measured selectivity in channels expressed in Xenopus oocytes, using voltage clamp to measure shifts in reversal potential and current amplitudes when Rb+ or Na+ replaced extracellular K+. Both P1 and P2 contribute to selectivity, and most mutations, including mutation of residues in the triplets GYG and GFG in P1 and P2, made channels nonselective. We interpret the effects of these—and of other mutations—in terms of the way the pore is likely to be stabilised structurally. We show also that residues in the outer pore mouth contribute to selectivity in TASK-1. Mutations resulting in loss of selectivity (e.g. I94S, G95A) were associated with slowing of the response of channels to depolarisation. More important physiologically, pH sensitivity is also lost or altered by such mutations. Mutations that retained selectivity (e.g. I94L, I94V) also retained their response to acidification. It is likely that responses both to voltage and pH changes involve gating at the selectivity filter

Spin-Dependent Transport in Fe/GaAs(100)/Fe Vertical Spin-Valves

The integration of magnetic materials with semiconductors will lead to the development of the next spintronics devices such as spin field effect transistor (SFET), which is capable of both data storage and processing. While the fabrication and transport studies of lateral SFET have attracted greatly attentions, there are only few studies of vertical devices, which may offer the opportunity for the future three-dimensional integration. Here, we provide evidence of two-terminal electrical spin injection and detection in Fe/GaAs/Fe vertical spin-valves (SVs) with the GaAs layer of 50 nanometers thick and top and bottom Fe electrodes deposited by molecular beam epitaxy. The spin-valve effect, which corresponds to the individual switching of the top and bottom Fe layers, is bias dependent and observed up to 20 K. We propose that the strongly bias-and temperature-dependent MR is associated with spin transport at the interfacial Fe/GaAs Schottky contacts and in the GaAs membranes, where balance between the barrier profiles as well as the dwell time to spin lifetime ratio are crucial factors for determining the device operations. The demonstration of the fabrication and spin injection in the vertical SV with a semiconductor interlayer is expected to open a new avenue in exploring the SFET

Polyunsaturated fatty acids inhibit k_v1.4 by interacting with positively charged extracellular pore residues

Polyunsaturated fatty acids (PUFAs) modulate voltage-gated K(+) channel inactivation by an unknown site and mechanism. The effects of ω-6 and ω-3 PUFAs were investigated on the heterologously expressed K(v)1.4 channel. PUFAs inhibited wild-type K(v)1.4 during repetitive pulsing as a result of slowing of recovery from inactivation. In a mutant K(v)1.4 channel lacking N-type inactivation, PUFAs reversibly enhanced C-type inactivation (K(d), 15–43 μM). C-type inactivation was affected by extracellular H(+) and K(+) as well as PUFAs and there was an interaction among the three: the effect of PUFAs was reversed during acidosis and abolished on raising K(+). Replacement of two positively charged residues in the extracellular pore (H508 and K532) abolished the effects of the PUFAs (and extracellular H(+) and K(+)) on C-type inactivation but had no effect on the lipoelectric modulation of voltage sensor activation, suggesting two separable interaction sites/mechanisms of action of PUFAs. Charge calculations suggest that the acidic head group of the PUFAs raises the pK(a) of H508 and this reduces the K(+) occupancy of the selectivity filter, stabilizing the C-type inactivated state

BSP implementation of European S3 - level evidence-based treatment guidelines for stage I-III periodontitis in UK clinical practice

OBJECTIVES: To adapt the supranational European Federation for Periodontology (EFP) S3-Level Clinical Practice Guideline for treatment of periodontitis (stage I-III) to a UK healthcare environment, taking into account the views of a broad range of stakeholders, and patients. SOURCES: This UK version is based on the supranational EFP guideline (Sanz et al., 2020) published in the Journal of Clinical Periodontology. The source guideline was developed using the S3-level methodology, which combined the assessment of formal evidence from 15 systematic reviews with a moderated consensus process of a representative group of stakeholders, and accounts for health equality, environmental factors and clinical effectiveness. It encompasses 62 clinical recommendations for the treatment of stage I-III periodontitis, based on a step-wise process mapped to the 2017 classification system. METHODOLOGY: The UK version was developed from the source guideline using a formal process called the GRADE ADOLOPMENT framework. This framework allows for the adoption (unmodified acceptance), adaptation (acceptance with modifications) and the de novo development of clinical recommendations. Using this framework and following the S3-process, the underlying systematic reviews were updated and a representative guideline group of 75 delegates from 17 stakeholder organisations was assembled into three working groups. Following the formal S3-process, all clinical recommendations were formally assessed for their applicability to the UK and adoloped accordingly. RESULTS AND CONCLUSION: Using the ADOLOPMENT protocol, a UK version of the EFP S3-level clinical practice guideline was developed. This guideline delivers evidence- and consensus-based clinical recommendations of direct relevance to the dental community in the UK. CLINICAL SIGNIFICANCE: The aim of S3-level guidelines is to combine the evaluation of formal evidence, grading and synthesis with the clinical expertise of a broad range of stakeholders to form clinical recommendations. Herein, the first major international S3-level guideline in dentistry, the EFP guideline, was implemented for direct clinical applicability in the UK healthcare system