Anisotropic Absorption of Pure Spin Currents

Spin transfer in magnetic multilayers offers the possibility of ultrafast, low-power device operation. We report a study of spin pumping in spin valves, demonstrating that a strong anisotropy of spin pumping from the source layer can be induced by an angular dependence of the total Gilbert damping parameter, α, in the spin sink layer. Using lab- and synchrotron-based ferromagnetic resonance, we show that an in-plane variation of damping in a crystalline Co_{50}Fe_{50} layer leads to an anisotropic α in a polycrystalline Ni_{81}Fe_{19} layer. This anisotropy is suppressed above the spin diffusion length in Cr, which is found to be 8 nm, and is independent of static exchange coupling in the spin valve. These results offer a valuable insight into the transmission and absorption of spin currents, and a mechanism by which enhanced spin torques and angular control may be realized for next-generation spintronic devices.

Non-Saccharomyces yeasts protect against epithelial cell barrier disruption induced by Salmonella enterica subsp. enterica serovar Typhimurium

The human gastrointestinal epithelium makes up the largest barrier separating the body from the external environment. Whereas invasive pathogens cause epithelial barrier disruption, probiotic micro-organisms modulate tight junction regulation and improve epithelial barrier function. In addition, probiotic strains may be able to reduce epithelial barrier disruption caused by pathogenic species. The aim of this study was to explore non-Saccharomyces yeast modulation of epithelial cell barrier function in vitro. Benchmarking against established probiotic strains, we evaluated the ability of four nonpathogenic yeast species to modulate transepithelial electrical resistance (TER) across a monolayer of differentiated human colonocytes (Caco-2 cells). Further, we assessed yeast modulation of a Salmonella Typhimurium-induced epithelial cell barrier function insult. Our findings demonstrate distinct patterns of non-Saccharomyces yeast modulation of epithelial cell barrier function. While the established probiotic yeast Saccharomyces boulardii increased TER across a Caco-2 monolayer by 30%, Kluyveromyces marxianus exhibited significantly stronger properties of TER enhancement (50% TER increase). In addition, our data demonstrate significant yeast-mediated modulation of Salmonella-induced epithelial cell barrier disruption and identify K. marxianus and Metschnikowia gruessii as two non-Saccharomyces yeasts capable of protecting human epithelial cells from pathogen invasion.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates distinct patterns of non-Saccharomyces yeast modulation of epithelial cell barrier function in vitro. Further, our data demonstrate significant yeast-mediated modulation of Salmonella Typhimurium-induced epithelial cell barrier disruption and identify Kluyveromyces marxianus and Metschnikowia gruessii as two non-Saccharomyces yeasts capable of protecting human epithelial cells from pathogen invasion. This study is the first to demonstrate significant non-Saccharomyces yeast-mediated epithelial cell barrier protection from Salmonella invasion, thus encouraging future efforts aimed at confirming the observed effects in vivo and driving further strain development towards novel yeast probiotics.

Portable LED fluorescence instrumentation for the rapid assessment of potable water quality

Characterising the organic and microbial matrix of water are key issues in ensuring a safe potable water supply. Current techniques only confirm water quality retrospectively via laboratory analysis of discrete samples. Whilst such analysis is required for regulatory purposes, it would be highly beneficial to monitor water quality in-situ in real time, enabling rapid water quality assessment and facilitating proactive management of water supply systems. A novel LED-based instrument, detecting fluorescence peaks C and T (surrogates for organic and microbial matter, respectively), was constructed and performance assessed. Results from over 200 samples taken from source waters through to customer tap from three UK water companies are presented. Excellent correlation was observed between the new device and a research grade spectrophotometer (r(2)=0.98 and 0.77 for peak C and peak T respectively), demonstrating the potential of providing a low cost, portable alternative fluorimeter. The peak C/TOC correlation was very good (r(2)=0.75) at low TOC levels found in drinking water. However, correlations between peak T and regulatory measures of microbial matter (2 day/3 day heterotrophic plate counts (HPC), E. coli, and total coliforms) were poor, due to the specific nature of these regulatory measures and the general measure of peak T. A more promising correlation was obtained between peak T and total bacteria using flow cytometry. Assessment of the fluorescence of four individual bacteria isolated from drinking water was also considered and excellent correlations found with peak T (Sphingobium sp. (r(2)=0.83); Methylobacterium sp. (r(2)=1.0); Rhodococcus sp. (r(2)=0.86); Xenophilus sp. (r(2)=0.96)). It is notable that each of the bacteria studied exhibited different levels of fluorescence as a function of their number. The scope for LED based instrumentation for in-situ, real time assessment of the organic and microbial matrix of potable water is clearly demonstrated.

Study of Dy-doped Bi₂Te₃: thin film growth and magnetic properties

Breaking the time-reversal symmetry (TRS) in topological insulators (TIs) through ferromagnetic doping is an essential prerequisite for unlocking novel physical phenomena and exploring potential device applications. Here, we report the successful growth of high-quality (Dy(x)Bi(1-x))2Te3 thin films with Dy concentrations up to x = 0.355 by molecular beam epitaxy. Bulk-sensitive magnetisation studies using superconducting quantum interference device magnetometry find paramagnetic behaviour down to 2 K for the entire doping series. The effective magnetic moment, μeff, is strongly doping concentration-dependent and reduces from ∼12.6 μ(B) Dy(-1) for x = 0.023 to ∼4.3 μ(B) Dy(-1) for x = 0.355. X-ray absorption spectra and x-ray magnetic circular dichroism (XMCD) at the Dy M4,5 edge are employed to provide a deeper insight into the magnetic nature of the Dy(3+)-doped films. XMCD, measured in surface-sensitive total-electron-yield detection, gives μ(eff )= 4.2 μ(B) Dy(-1). The large measured moments make Dy-doped films interesting TI systems in which the TRS may be broken via the proximity effect due to an adjacent ferromagnetic insulator.

Acute paraspinal compartment syndrome as a rare cause of loin pain

A significant proportion of emergency urological admissions are comprised of ureteric colic presenting as loin pain. A variety of alternative pathologies present in this manner and should be considered during systematic assessment. We report the case of a patient admitted with severe unilateral back and flank pain after strenuous deadlift exercise. Clinical examination and subsequent investigation following a significant delay demonstrated acute paraspinal compartment syndrome (PCS) after an initial misdiagnosis of ureteric colic. The patient was managed conservatively. We review the current literature surrounding the rare diagnosis of PCS and discuss the management options.

An ultra-compact, high-throughput molecular beam epitaxy growth system

We present a miniaturized molecular beam epitaxy (miniMBE) system with an outer diameter of 206 mm, optimized for flexible and high-throughput operation. The three-chamber system, used here for oxide growth, consists of a sample loading chamber, a storage chamber, and a growth chamber. The growth chamber is equipped with eight identical effusion cell ports with linear shutters, one larger port for either a multi-pocket electron beam evaporator or an oxygen plasma source, an integrated cryoshroud, retractable beam-flux monitor or quartz-crystal microbalance, reflection high energy electron diffraction, substrate manipulator, main shutter, and quadrupole mass spectrometer. The system can be combined with ultrahigh vacuum (UHV) end stations on synchrotron and neutron beamlines, or equivalently with other complex surface analysis systems, including low-temperature scanning probe microscopy systems. Substrate handling is compatible with most UHV surface characterization systems, as the miniMBE can accommodate standard surface science sample holders. We introduce the design of the system, and its specific capabilities and operational parameters, and we demonstrate the epitaxial thin film growth of magnetoelectric Cr2O3 on c-plane sapphire and ferrimagnetic Fe3O4 on MgO (001).

Omental Torsion in a Child – a Case Report

Omental torsion, a very rare cause of acute abdominal pain, mimicking acute appendicitis .A boy of 11 years, presented to us with the symptoms and signs suggestive of acute appendicitis clinically, was admitted through OPD of Apollo Hospitals. His laboratory reports were also in favor of clinical diagnosis. Laparoscopic appendicectomy was planned. But on laparoscopic intra-abdominal inspection it was found to be a case of Omental torsion, distal part was closely adherent to the ascending colon and blackish in color. So, procedure was converted into laparotomy and resection of the tensioned and gangrenous part of the omentum including appendicectomy was done. His post operative period was uneventful. Although torsion of the omentum is a rare clinical entity, but accurate pre-operative clinical assessment and relevant study including imaging and CT abdomen may reduce the diagnostic dilemma between omental torsion and acute appendicitis. DOI: http://dx.doi.org/10.3329/pulse.v6i1-2.20360 Pulse Vol.6 January-December 2013 p.75-77

'Trochars no more': Teaching chest drain insertion to remote and rural practitioners using a mobile skills unit

BACKGROUND

There are a number of approaches to teaching high-risk clinical skills, such as a large bore chest drain insertion, although effectiveness is limited and realism is only achieved at great expense. Summary of work: In response to a training needs' analysis of practitioners in remote and rural areas in Scotland, training in chest drains was identified as an urgent priority need. Subsequently, the Clinical Skills Managed Educational Network (CSMEN) developed an evidence-based multi-professional clinical skills pack. This e-learning resource encompasses all aspects of chest drain management, both pre and in-hospital. The pack and an interactive workshop is used to deliver 'blended' chest drain training on a mobile clinical skills unit. Evaluation confirms that the chest drain training is a valuable resource and has been widely used to deliver skills training in remote and rural areas. Feedback from all professional groups is positive.

CONCLUSIONS

Developing shared national resources, with standardised workshops taught in local contexts via a mobile skills unit is one approach to the challenges associated with delivering high-risk clinical skills education.

Mortality, survival and residual injury burden of Royal Navy and Royal Marine combat casualties sustained in 11-years of operations in Iraq and Afghanistan

We present eleven years of prospectively-gathered data defining the full spectrum of the United Kingdom’s (UK) Naval Service (Royal Navy and Royal Marines) casualties, and characterise the injury patterns, recovery and residual functional burden from the conflicts of the last decade. The UK Military Trauma Registry was searched for all Naval Service personnel injured between March 2003 and April 2013. These records were then cross-referenced with the records of the Naval Service Medical Board of Survey (NSMBOS), which evaluates injured Naval Service personnel for medical discharge, continued service in a reduced capacity or Return to Full Duty (RTD). Population at risk data was calculated from service records.

There were 277 casualties in the study period: 63 (23%) of these were fatalities. Of the 214 survivors, 63 or 29% (23% of total) were medically discharged; 24 or 11% (9% of total) were placed in a reduced fitness category with medical restrictions placed on their continued military service. A total of 127 individuals (46% of the total and 59% of survivors) RTD without any restriction. The greatest number of casualties was sustained in 2007. There was a 3% casualty risk per year of operational service for Naval Service personnel. The most common reason cited by Naval Service Medical Board of Survey (NSMBOS) for medical downgrading or discharge was injury to the lower limb, with upper limb trauma the next most frequent.

This study characterises the spectrum of injuries sustained by the Naval Service during recent conflicts with a very high rate of follow-up. Extremity injuries pose the biggest challenge to reconstructive and rehabilitative services striving to maximise the functional outcomes of injured service personnel.