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Optically-pumped magnetometers (OPMs) are an established alternative to superconducting sensors for magnetoencephalography (MEG), offering significant advantages including flexibility to accommodate any head size, uniform coverage, free movement during scanning, better data quality and lower cost. However, OPM sensor technology remains under development; there is flexibility regarding OPM design and it is not yet clear which variant will prove most effective for MEG. Most OPM-MEG implementations have either used single-axis (equivalent to conventional MEG) or dual-axis magnetic field measurements. Here we demonstrate use of a triaxial OPM formulation, able to characterise the full 3D neuromagnetic field vector. We show that this novel sensor is able to characterise magnetic fields with high accuracy and sensitivity that matches conventional (dual-axis) OPMs. We show practicality via measurement of biomagnetic fields from both the heart and the brain. Using simulations, we demonstrate how triaxial measurement offers improved cortical coverage, especially in infants. Finally, we introduce a new 3D-printed child-friendly OPM-helmet and demonstrate feasibility of triaxial measurement in a five-year-old. In sum, the data presented demonstrate that triaxial OPMs offer a significant improvement over dual-axis variants and are likely to become the sensor of choice for future MEG systems, particularly for deployment in paediatric populations.

The role of plasma membrane transporters in the nephrotoxicity of two antiretroviral drugs, cidofovir and tenofovir, was studied in primary cultures of human proximal tubular (hPT) cells. Cells were grown on Transwell filter inserts to maintain epithelial polarity and access to either the apical or basolateral plasma membrane. The function of relevant membrane transporters, organic anion transporter 1 and 3 (OAT1/3), P-glycoprotein (multidrug resistance protein-1; P-gp or MDR1), and organic cation transporter 2 (OCT2), was validated by measurements of apical-to-basolateral and basolateral-to-apical fluxes of furosemide, digoxin, and metformin, respectively. Acute cytotoxicity of cidofovir (0, 10, 50, 150, or 300 μM) in the absence or presence of 500 μM probenecid, tenofovir disoproxil fumarate (0, 20, 90, 180, or 360 μM) in the absence or presence of 500 μM probenecid, or cisplatin (0, 20, 90, 180, or 360 μM) as a positive control in the absence or presence of 500 μM cimetidine, was assessed after 4-h incubations by determinations of release of lactate dehydrogenase (LDH), γ-glutamyltransferase (GGT), N-acetyl-β-d-glucosaminidase (NAG), or Kidney Injury Molecule-1 (KIM-1). Cell death generally agreed with each of the four biomarkers, was generally greater when cidofovir or tenofovir was added to the upper compartment, and was markedly diminished in the presence of the appropriate transport inhibitor. Additionally, the extent of cytotoxicity caused by the two antiviral drugs was similar to that caused by cisplatin. The results demonstrate the importance of plasma membrane transport of antiviral drugs to elicit cytotoxicity in the hPT cell.

Fetal magnetocardiography (fMCG) is an emerging technology that has provided invaluable insight into the mechanisms of fetal arrhythmia. Its efficacy for diagnosis and management of serious fetal arrhythmia has been acknowledged in the recent American Heart Association Statement on Diagnosis and

The alloy silicon carbon (Si1-yCy) has various strain engineering applications. It is often implemented as a dopant diffusion barrier and has been identified as a potential buffer layer for cubic silicon carbide (3C-SiC) heteroepitaxy. While suspended membranes formed from thin films of semiconductor (Ge and 3C-SiC) and dielectric (Si3N4) materials have been well studied, pseudomorphic, defect-free epilayers under high levels of tensile strain have received little attention. Often, tensile strain is a desired quality of semiconductors and enhancing this property can lead to various benefits of subsequent device applications. The strain state and crystalline tilt of suspended Si1-yCy epilayers have been investigated through micro-X-ray diffraction techniques. The in-plane tensile strain of the alloy was found to increase from 0.67% to 0.82%. This strain increase could reduce the C content required to achieve suitable levels of strain in such alloys and further strain enhancement could be externally induced. The source of this strain increase was found to stem from slight tilts at the edges of the membranes, however, the bulk of the suspended films remained flat. The novel process utilised to fabricate suspended Si1-yCy thin-films is applicable to many other materials that are typically not resistant to anisotropic Si wet etchants.

The optically pumped magnetometer (OPM) is a viable means to detect magnetic fields generated by human brain activity. Compared to conventional detectors (superconducting quantum interference devices) OPMs are small, lightweight, flexible, and operate without cryogenics. This has led to a step change in instrumentation for magnetoencephalography (MEG), enabling a “wearable” scanner platform, adaptable to fit any head size, able to acquire data whilst subjects move, and offering improved data quality. Although many studies have shown the efficacy of ‘OPM-MEG’, one relatively untapped advantage relates to improved array design. Specifically, OPMs enable the simultaneous measurement of magnetic field components along multiple axes (distinct from a single radial orientation, as used in most conventional MEG systems). This enables characterisation of the magnetic field vector at all sensors, affording extra information which has the potential to improve source reconstruction. Here, we conduct a theoretical analysis of the critical parameters that should be optimised for effective source reconstruction. We show that these parameters can be optimised by judicious array design incorporating triaxial MEG measurements. Using simulations, we demonstrate how a triaxial array offers a dramatic improvement on our ability to differentiate real brain activity from sources of magnetic interference (external to the brain). Further, a triaxial system is shown to offer a marked improvement in the elimination of artefact caused by head movement. Theoretical results are supplemented by an experimental recording demonstrating improved interference reduction. These findings offer new insights into how future OPM-MEG arrays can be designed with improved performance.

Micro X-ray diffraction (μ-XRD) has been used to map the strain profile of a suspended crystalline cubic Silicon Carbide (3C-SiC) square membrane. While the presence of crystal defects in the 3C-SiC epilayer induces significant errors on the position of the 3C-SiC Bragg peaks, relaxation from residual tensile strain can be observed and directly quantified from the XRD measurements. The advantage of μ-XRD over other strain mapping techniques is that the tilt of the crystalline layers can be measured simultaneously with the lattice parameters. Significant tilt variations have been observed at the corner of the 3C-SiC membrane, implying that the undercut from chemical etching induces distortions in the crystal structure. These distortions are likely to be the cause of the increase in strain commonly observed at the edges of suspended structures using the micro-Raman shift strain mapping technique. Keywords: 3C-SiC, Membrane, Strain, Tilt, XRD

Germanium membranes and microstructures of 50-1000 nm thickness have been fabricated by a combination of epitaxial growth on a Si substrate and simple etching processes. The strain in these structures has been measured by high-resolution micro-X-ray diffraction and micro-Raman spectroscopy. The strain in these membranes is extremely isotropic and the surface is observed to be very smooth, with an RMS roughness below 2 nm. The process of membrane fabrication also serves to remove the misfit dislocation network that originally forms at the Si/Ge interface, with benefits for the mechanical, optical and electrical properties of the crystalline membranes., This work was supported by the EPSRC, Projects. EP/F040784/1, and EP/J001074/1; ERC grant #202735, “NonContactUltrasonic”; NANOFUNCTION Network of Excellence, funded by the European Commission 7th Framework Programme (ICT-FP7, #228464).

The hole-phonon energy loss rate in silicon is measured at phonon temperatures ranging from 300 mK to 700 mK. We demonstrate that it is approximately an order of magnitude higher than the corresponding electron-phonon energy loss rate over an identical temperature range.

A thin, flat and single crystal membrane on which to mount sensors is generally required for integration with electronics through standard silicon processing technology. We present an approach to producing single crystal membranes of germanium with in-built tensile strain, which serves to keep the membrane flat and ripple free, and demonstrate a 600 nm thick, free-standing 1 mm2 Ge membrane. We convert the fabrication technique into an integrated-circuit compatible wafer scale process to produce 60 nm thin membranes with large areas of 3.5 mm2. The single crystal Ge membrane provides an excellent platform for further epitaxial growth or deposition of materials.

The increasing use of engineered nanoparticles (NPs) in industrial and household applications will very likely lead to the increased release of such materials into the public sewer systems. During the wastewater treatment process, some fraction of NPs would always be concentrated in the biosolids. When biosolids is applied on the agricultural land, NPs are introduced into the soil matrix. In the current study we investigate the influence of five different metal nanoparticles present in biosolids on soil microbial community as a function of time. Results indicate that ZnO and Zero Valent Cu NPs were not toxic to soil bacterial community. Biosolids mixed with Ag NPs and TiO2 (both anatase and rutile phase) in contrast changed the bacterial richness and composition in wavering pattern as a function of time. Based on the observations made in the study, we suggest caution when interpreting the toxicity of NPs based on single time point study.

One of the most severe limitations of functional neuroimaging techniques, such as magnetoencephalography (MEG), is that participants must maintain a fixed head position during data acquisition. This imposes restrictions on the characteristics of the experimental cohorts that can be scanned and the experimental questions that can be addressed. For these reasons, the use of 'wearable' neuroimaging, in which participants can move freely during scanning, is attractive. The most successful example of wearable neuroimaging is electroencephalography (EEG), which employs lightweight and flexible instrumentation that makes it useable in almost any experimental setting. However, EEG has major technical limitations compared to MEG, and therefore the development of wearable MEG, or hybrid MEG/EEG systems, is a compelling prospect. In this paper, we combine and compare EEG and MEG measurements, the latter made using a new generation of optically-pumped magnetometers (OPMs). We show that these new second generation commercial OPMs, can be mounted on the scalp in an 'EEG-like' cap, enabling the acquisition of high fidelity electrophysiological measurements. We show that these sensors can be used in conjunction with conventional EEG electrodes, offering the potential for the development of hybrid MEG/EEG systems. We compare concurrently measured signals, showing that, whilst both modalities offer high quality data in stationary subjects, OPM-MEG measurements are less sensitive to artefacts produced when subjects move. Finally, we show using simulations that OPM-MEG offers a fundamentally better spatial specificity than EEG. The demonstrated technology holds the potential to revolutionise the utility of functional brain imaging, exploiting the flexibility of wearable systems to facilitate hitherto impractical experimental paradigms.

Reverse terrace graded buffers are proposed for high quality high Ge content Si0.23Ge0.77 buffers. The buffer structure allows the effects of applied thermal budget and grading rate to be separated and compared to previously reported reverse linearly graded virtual substrates. A reduction in threading dislocation density to 2.1 × 106 cm− 2 and an enhanced relaxation is found for these terrace graded structures of almost identical thickness and twice the strain gradient of the linear graded structures, whilst a smooth surface is retained with an rms roughness of just 1.9 nm.

A study of Ge epilayer growth directly on a Si(001) substrate is presented, following the two temperature Ge layer method. In an attempt to minimize the overall thickness while maintaining a good quality Ge epilayer, we have investigated the effect of varying the thickness of both the low and high temperature Ge layers, grown at 400 °C and 670 °C, respectively, by reduced pressure chemical vapor deposition. We find that the surface of the low temperature (LT) seed layer has a threading dislocation density (TDD) to the order of 10 11 cm − 2 . On increasing the LT layer thickness from 30 nm to 150 nm this TDD decreases by a factor of 2, while its roughness doubles and degree of relaxation increases from 82% to 96%. Growth of the high temperature (HT) layer reduces the TDD level to around 10 8 cm − 2 , which is also shown to decrease with increasing layer thickness. Both the surface roughness and degree of relaxation reach stable values for which increasing the thickness beyond about 700 nm has no effect. Finally, annealing the HT layer is shown to reduce the TDD, without affecting the degree of relaxation. However, unless a thick structure is used the surface roughness increases significantly on annealing.

After a long period of developing integrated circuit technology through simple scaling of silicon devices, the semiconductor industry is now embracing technology boosters such as strain for higher mobility channel material. Germanium is the logical supplement to enhance existing technologies, as its material behaviour is very close to silicon, and to create new functional devices that cannot be fabricated from silicon alone (Hartmann et al. (2004) [1]). Germanium wafers are, however, both expensive and less durable than their silicon counterparts. Hence it is highly desirable to create a relaxed high quality Ge layer on a Si substrate, with the provision that this does not unduly compromise the planarity of the system. The two temperature method, proposed by Colace et al. (1997) [2], can give smooth (RMS surface roughness below 1 nm) and low threading dislocation density (TDD

The excess molar volume VmE, viscosity deviation Δη, and excess Gibbs energy of activation ΔG⁎E of viscous flow have been investigated from the density ρ and viscosity η measurements of binary mixtures of methanol with n-butylamine and di-n-butylamine over the entire range of mole fractions at 303.15, 313.15, and 323.15 K. The systems studied exhibit very strong cross association through strong O–H…N bonding between –OH and –NH– groups. As a consequence of this strong intermolecular association, both the systems have very large negative VmE and positive Δη and ΔG⁎E over entire range of composition and at all the temperatures of investigation. VmE of the studied mixtures is consistently described by the ERAS model. The values of cross association constants KAB illustrate that cross-associates are more pronounced in primary amine mixtures than that in secondary amine.

The physical and electrical properties of heavily doped silicon (5x10^1^9cm^-^3) deposited by molecular beam epitaxy (MBE) on 4H-SiC are investigated in this paper. Silicon layers on silicon carbide have a broad number of potential applications including device fabrication or passivation when oxidised. In particular, Si/SiC contacts present several atractive material advantages for the semiconductor industry and especially for SiC processing procedures for avoiding stages such as high temperature contact annealing or SiC etching. Si films of 100nm thickness have been grown using a MBE system after different cleaning procedures on n-type (0001) Si face 8^o off 4H-SiC substrates. Isotype (n-n) and an-isotype (p-n) devices were fabricated at both 500 and 900^oC using antimonium (Sb) or boron (B), respectively. X-ray diffraction analysis (XRD) and scanning electronic mircorscope (SEM) have been used to investigate the crystal composition and morphology of the deposited layers. The electrical mesurements were performed to determine the rectifiying contact characteristics and band offsets.

Introduction. Sophorolipids, a family of natural and easily chemo-enzymatically modified microbial glycolipids, are promising modulators of the immune response. We have previously demonstrated that sophorolipids mediate anti-inflammatory effects, including decreasing sepsis-related mortality at 36 h in vivo in a rat model of septic peritonitis and in vitro by decreasing nitric oxide and inflammatory cytokine production. Here we assessed the effect of sophorolipids on sepsis-related mortality when administered as a (1) single bolus versus sequential dosing and (2) natural mixture versus individual derivatives compared with vehicle alone. Methods. Intra-abdominal sepsis was induced in male, Sprague Dawley rats, 200 to 240 g, via cecal ligation and puncture. Sophorolipids (5‐750 mg/kg) or vehicle (ethanol/sucrose/physiological saline) were injected intravenously (i.v.) via tail vein or inferior vena cava at the end of the operation either as a single dose or sequentially (q24 h 3 doses); natural mixture was compared with select sophorolipid derivatives (n 10‐15 per group). Sham-operated animals served as nonsepsis controls. Survival rates were compared at 1 through 6 d post sepsis induction and tissue was analyzed by histopathology. Significance was determined by Kruskal-Wallis analysis with Bonferroni adjustment and Student’s t-test. Results. Sophorolipid treatment at 5 mg/kg body weight improved survival in rats with cecal ligation and puncture-induced septic shock by 28% at 24 h and 42% at 72 h for single dose, 39% at 24 h and 26% at 72 h for sequential doses, and 23% overall survival for select sophorolipid derivatives when compared with vehicle control (P < 0.05 for sequential dosing). Toxicity was evident and dose-dependent with very high doses of sophorolipid (375‐750 mg/kg body weight) with histopathology demonstrating interstitial and intraalveolar edema with areas of microhemorrhage in pulmonary tissue when compared with vehicle controls (P < 0.05). No mortality was observed in sham operated controls at all doses tested. Conclusions. Administration of sophorolipids after induction of intra-abdominal sepsis improves survival. The demonstration that sophorolipids can reduce sepsis-related mortality with different dosing regimens and derivatives provides continuing evidence toward a promising new therapy. Toxicity is evident at 75 to 150 the therapeutic dose in septic

Yeast Candida bombicola is known to produce sophorolipids from a variety of saccharic and lipidic feed-stocks. In the current study, the influence of fatty acid carbon chain length, unsaturation, source of low-cost industrial lipid feed-stocks, and nickel content in lipid feed-stocks on sophorolipid production by C. bombicola were investigated. Saturated and monounsaturated C18 fatty acid gave the highest levels of sophorolipid production while fatty acids with more than one site of unsaturation gave much lower yields. Sophorolipid production was reduced when shorter (≤C16) and longer (≥C20) fatty acids were fed. The possibility of exploiting low-cost industrial wastes or by-products for sophorolipid production by batch or fed-batch processes was investigated. Tallow fatty acid residue was the best lipid feed-stock for sophorolipid production (120 g/L, fed-batch cultures), while coconut fatty acid residue resulted in the lowest production (40 g/L, fed-batch cultures). Co-feeding coconut fatty acid residue with other feed-stocks improved its substrate value in batch cultures. C. bombicola was tolerant to nickel contamination of up to 112.5 mg/L during sophorolipid production. Nickel contaminated stearic fatty acid residue was transformed to value added sophorolipid product while nickel was sequestered primarily in biomass for safe removal and recovery. Sophorolipid product obtained from nickel contaminated lipid wastes had low nickel levels (

An ultra-fast liquid chromatographic method combined with atmospheric pressure chemical ionization mass detection (UHPLC/APCI-MS) has been developed for the separation and quantification of sophorolipid analogs produced by the yeast Candida bombicola. The sophorolipid mixture was produced by growing the yeast in the presence of glucose and oleic acid under higher aeration. It was found that more than 95% of the analogs are lactonic sophorolipids and all the produced sophorolipids produced were either mono- or di-acetylated. Also observed was a sophorolipid analog with a tri-unsaturated fatty acid, which has not been reported previously.