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Catalyst-coated membranes (CCMs) for use in high temperature proton exchange membrane fuel cells (PEMFC) were successfully fabricated by a one-step jet-flame direct deposition process using reactive spray deposition technology (RSDT). The as-deposited catalyst layer (CL) was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA) and electrochemical measurements. Pt nanoparticles averaging 2.6 nm in diameter formed a good dispersion with a Pt content of 47.5 wt% on the carbon. The Pt/C catalyst had a specific activity and a mass activity of 277 µA/cmPt² and 0.155 A/mgPt, respectively. Polybenzimidazole (PBI) was employed as the membrane, and the membrane electrode assemblies (MEAs) were tested in temperatures ranging from 140°C to 160°C. Power densities of 375 mW/cm² in oxygen and 135 mW/cm² in air were achieved with a total Pt loading of 0.8 mg/cm². [ABSTRACT FROM AUTHOR]

Cancer incidence in 1990-92 among English south Asian (residents with ethnic origins in India, Pakistan or Bangladesh) and non-south Asian children is compared. Standardized incidence ratios show significant overall excesses in south Asians (131), largely due to higher rates in south Asian boys, and specific excesses for leukaemia (141), lymphoid leukaemia (141), lymphoma (172) and hepatic tumours (375). Aetiological investigation is required. [ABSTRACT FROM AUTHOR]

Cancer incidence among English south Asians (residents in England with ethnic origins in India, Pakistan or Bangladesh) is described and compared with non-south Asian and Indian subcontinent rates. The setting for the study was areas covered by Thames, Trent, West Midlands and Yorkshire cancer registries. The study identified 356 555 cases of incident cancer (ICD9:140-208) registered between 1990 and 1992, including 3845 classified as English south Asian. The main outcome measures were age specific and directly standardized incidence rates for all cancer sites (ICD9:140-208). English south Asian incidence rates for all sites combined were significantly lower than non-south Asian rates but higher than Indian subcontinent rates. English south Asian rates were substantially higher than Indian subcontinent rates for a number of common sites including lung cancer in males, breast cancer in females and lymphoma in both sexes. English south Asian rates for childhood and early adult cancer (0-29 years) were similar or higher than non-south Asian rates. English south Asian rates were significantly higher than non-south Asian rates for Hodgkin's disease in males, cancer of the tongue, mouth, oesophagus, thyroid gland and myeloid leukaemia in females, and cancer of the hypopharynx, liver and gall bladder in both sexes. The results are consistent with a transition from the lower cancer risk of the country of ethnic origin to that of the country of residence. They suggest that detrimental changes in lifestyle and other exposures have occurred in the migrant south Asian population. [ABSTRACT FROM AUTHOR]

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012. [ABSTRACT FROM PUBLISHER]

A letter to the editor is presented in response to the article "Influenza and COPD mortality protection as pleiotropic, dose-dependent effects of statins," by Floyd J. Frost, Hans Petersen and Kristine Tollestrup in the April 2007 issue.

The processing of advanced materials with luminescent properties (phosphors) emphasizes the importance of ultrafine powder synthesis. Aerosol synthesis is applied for the preparation of Eu-activated gadolinium oxide matrices, commonly used as red phosphors in cathodoluminescence. The process involves aerosol formation ultrasonically (1.7 MHz) from the precursor salt solutions and control over the aerosol decomposition in a high-temperature (1173 K) tubular flow reactor. During decomposition, the aerosol droplets undergo evaporation/drying, precipitation and thermolysis in a single-step process. Consequently, spherical, solid, agglomerate-free, submicronic particles with the mean particle size below 1000 nm are obtained. In order to control the particles crystal structure and establish the conditions for the stabilization of the low-temperature gadolinia cubic phase, the process parameters like temperature distribution, gas flow rate and annealing temperatures were adopted. The particle morphology, phase and chemical structure are revealed in accordance to various analysis methods (XRD, DSC, SEM-EMAX, particle stereology and size distribution) and discussed in terms of precursor chemistry and process parameters. The mechanisms of ultrafine phosphor particles generation are focused and correlated with the luminescence properties. [Copyright &y& Elsevier]

Unrecoverable and recoverable performance degradation is a major issue hindering commercialization of polymer electrolyte membrane fuel cells. The recoverable losses, caused for example by a contaminant adsorption, catalyst flooding, ionomer dehydration, and platinum oxidation, can be reversed, usually following an interruption in the cell operation. In order to elucidate the link between platinum oxidation and recoverable performance loss, three MEAs were characterized in this work. They involved catalysts with different nanoparticle sizes and loadings tested using a combination of the electrochemical impedance spectroscopy, constant-voltage, constant-current and potential controlled techniques, before and after electrocatalyst aging. Experimental results indicate that a decrease in specific activity over time is not affected by nanoparticle size or aging. Nevertheless, linear sweep voltammetry, which is adopted to reduce platinum oxide and as diagnostics for oxide composition, reveals that a change in composition is observed in correlation with catalyst morphology and catalyst aging. The formation of the platinum oxide associated with the peak at 0.61 V RHE in the voltammetry is found to decrease the catalyst's specific activity more than oxides associated with peaks at higher potentials. This indicates that the recoverable performance loss due to the platinum oxide formation depends on the oxide composition. • PtOx formation strongly contributes to the recoverable performance loss. • Evolution of ORR specific activity with time is substantially unaffected by aging. • The oxide-stripping peak at 0.61 V RHE is always observed before and after aging. • An increase in the peak at 0.61 V RHE strongly impacts ORR activity. [ABSTRACT FROM AUTHOR]

In recent years, sensitive, selective and accurate sensing techniques for ammonia gas detection have been highly demanded since ammonia is both a commonly utilized gas in various industrial sectors and a highly toxic and corrosive agent that can threat human health and environment. This review article discusses the widely used gas sensing techniques in ammonia detection. The fundamental working principles of the ammonia detection techniques relying on electronics, electrochemistry, tunable diode laser spectroscopy, surface acoustic wave, and field effect transistors are briefly described first, in conjunction with various sensing materials. Furthermore, recent progress in the development of advanced ammonia gas sensors was comprehensively reviewed and summarized. Finally, the outlook for future development of high-performance ammonia sensors was presented., (Copyright © 2019 Elsevier B.V. All rights reserved.)

A highly-sensitive ammonia (NH 3 ) gas sensor based on molybdenum trioxide nanoribbons was developed in this study. α-MoO 3 nanoribbons (MoO 3 NRs) were successfully synthesized via a hydrothermal method and systematically characterized using various advanced technologies. Following a simple drop-cast process, a high-performance chemiresistive NH 3 sensor was fabricated through the deposition of a MoO 3 NR sensing film onto Au interdigitated electrodes. At an optimal operation temperature of 450 °C, the MoO 3 nanoribbon-based sensor exhibited an excellent sensitivity (0.72) at NH 3 concentration as low as 50 ppb, a fast response time of 21 s, good stability and reproducibility, and impressive selectivity against the interfering gases such as H 2 , NO 2 , and O 2 . More importantly, the sensor represents a remarkable limit of detection of 280 ppt (calculated based on a signal-to-noise ratio of 3), which makes the as-prepared MoO 3 NR sensor the most sensitive NH 3 sensor in the literature. Moreover, density functional theory (DFT) simulations were employed to understand the adsorption energetics and electronic structures and thus shed light on the fundamentals of sensing performance. The enhanced sensitivity for NH 3 is explicitly discussed and explained by the remarkable band structure modification because of the NH 3 adsorption at the oxygen vacancy site on α-MoO 3 nanoribbons. These results verify that hydrothermally grown MoO 3 nanoribbons are a promising sensing material for enhanced NH 3 gas monitoring.

Nanostructured electrodes effectively enhance the kinetics of the charge/discharge process in lithium-ion (Li-ion) batteries. However, the fabrication of these electrodes often involves complex processing steps. This study demonstrates a one-step improved flame spray pyrolysis synthesis approach to directly deposit the most common Li-ion battery cathode material LiNi 1/3 Mn 1/3 Co 1/3 O 2 onto current collectors, which is identified as reactive spray deposition technology (RSDT). Because of the economical and continuous nature of RSDT, the industrial scale of manufacturing nanostructured electrodes for Li-ion batteries can be potentially developed. Morphologies of the electrodes are well controlled so that their electrochemical properties can be tailored to accommodate intended applications. In detail, by adjusting the precursor concentration in the solution feed during the operation of RSDT, the specific surface area of synthesized material can be fine-tuned accordingly. Although the electrodes prepared with low precursor concentration exhibit the highest surface area and deliver the highest initial discharge capacity of 192.1 mAh g -1 , the most stable cycling performance is demonstrated by the electrodes fabricated with high precursor concentration, retaining 93.6% of the initial capacity after 100 cycles in half-cell testing. This innovative direct deposition method considerably simplifies the manufacture process of high-performance nanostructured electrodes and enables effortless modification of their properties. Moreover, no hazardous waste is generated from this synthesis route., Competing Interests: The authors declare no competing financial interest.

We have investigated the role of human endogenous retroviruses in multiple sclerosis by analyzing the DNA of patients and controls in 4 cohorts for associations between multiple sclerosis and polymorphisms near viral restriction genes or near endogenous retroviral loci with one or more intact or almost-intact genes. We found that SNPs in the gene TRIM5 were inversely correlated with disease. Conversely, SNPs around one retroviral locus, HERV-Fc1, showed a highly significant association with disease. The latter association was limited to a narrow region that contains no other known genes. We conclude that HERV-Fc1 and TRIM5 play a role in the etiology of multiple sclerosis. If these results are confirmed, they point to new modes of treatment for multiple sclerosis.

Background and Aims: Mucosal flattening and epithelial cell apoptosis are typical features of T cell induced inflammatory diseases of the bowel, such as coeliac disease and graft versus host disease. Mice injected with a T cell activating anti-CD3 antibody develop a severe diarrhoeal illness. We describe the histological features of this enteropathy and define the effector mechanisms involved in T cell induced mucosal injury in this in vivo model., Methods: Wild-type and genetically modified mice were injected with the anti-CD3 antibody 3C11 (50 microg). Changes in the murine intestine were characterised by light microscopy analysis and terminal uridine nick-end labelling (TUNEL) assay. The role of perforin, Fas/Fas ligand (FasL), tumour necrosis factor alpha (TNF-alpha), and interferon gamma (IFN-gamma) in T cell induced mucosal damage was assessed using selected immunodeficient mouse strains., Results: T cell activation caused severe damage, including small intestinal mucosal flattening and apoptosis of crypt epithelial cells. Mucosal damage was unaltered in anti-CD3 treated mice lacking IFN-gamma, Fas, or TNF-alpha receptors. In mice lacking TNF-alpha receptors and Fas (TNF-R1xR2 lpr/lpr strain), enterocyte apoptosis was diminished but there was no significant reduction in tissue damage. Apoptosis and mucosal injury were significantly reduced in perforin knockout mice. Abrogation of both FasL and perforin (perforin KOxgld mice) further significantly reduced tissue damage and apoptotic bodies., Conclusions: T cell induced mucosal injury is mediated by the combined effect of multiple pathways but predominantly by perforin. The redundancy of the mechanisms of tissue damage will have significant impact on therapeutic strategies aimed at specific and targeted inhibition of inflammatory processes.

Background: An assessment was made of the usefulness and accuracy of a computer program for the identification of the south Asian population through the classification of names on a disease register., Methods: The computer program, Nam Pehchan, was used to classify names as either south Asian or non south Asian. The results were compared with a reference standard, which combined use of the program with visual inspection. The latter was facilitated by a computer-generated dictionary of common non south Asian names. The data set consisted of 356,555 cases of incident cancer (ICD9: 140-208) registered between 1990 and 1992 by Thames, Trent, West Midlands and Yorkshire cancer registries., Results: Nam Pehchan classified 5506 cases as south Asian. Visual inspection identified 2024 false positives (36.8 per cent of all cases identified as south Asian by Nam Pehchan) and 363 false negatives (9.5 per cent of those identified by the reference standard). Compared with the reference standard, Nam Pehchan had a sensitivity of 90.5 per cent and a positive predictive value of 63.2 per cent., Conclusion: The Nam Pehchan program quickly identified a high proportion of the names classified as south Asian by the reference standard, but the high false positive rate means that the program alone is not an adequate single strategy. The time-consuming process of inspection of program negatives for large data sets can be substantially reduced by comparison with dictionaries of common non south Asian names.