Electrochemical Characterization of Precious Metal Braze Alloys Using Potentiodynamic Polarization

This study aimed to characterize the electrochemical behavior of six precious metal braze alloys by performing potentiodynamic polarization tests (ParStat 2273) based on ASTM Specifications G5 and G59. To determine the extent to which the alloys will contribute to galvanic corrosion in a marine environment (3.5 wt% NaCl), corrosion analysis software was used to produce fitted Tafel lines to determine the open circuit potential, Voc, for each alloy. The Voc values for the alloys were found to be -66.58 mV for Gold ABA, 13.01 mV for Nicoro®, -39.00 mV for Nioro®, 23.4 mV for Palniro-1®, -47.91 mV for Palniro-7®, and -205.16 mV for Silver ABA. These values were compared to industry-standard base materials typically used in brazing processes to determine their compatibility as galvanic couples. Differences in Voc greater than 250 mV within the couple are considered unsuitable for joining without additional galvanic protection. To provide coupling recommendations, 95% confidence intervals were made to estimate each alloy’s Voc

Colocalization of neurons in optical coherence microscopy and Nissl-stained histology in Brodmann’s area 32 and area 21

Published in final edited form as: Brain Struct Funct. 2019 January ; 224(1): 351–362. doi:10.1007/s00429-018-1777-z.Optical coherence tomography is an optical technique that uses backscattered light to highlight intrinsic structure, and when applied to brain tissue, it can resolve cortical layers and fiber bundles. Optical coherence microscopy (OCM) is higher resolution (i.e., 1.25 µm) and is capable of detecting neurons. In a previous report, we compared the correspondence of OCM acquired imaging of neurons with traditional Nissl stained histology in entorhinal cortex layer II. In the current method-oriented study, we aimed to determine the colocalization success rate between OCM and Nissl in other brain cortical areas with different laminar arrangements and cell packing density. We focused on two additional cortical areas: medial prefrontal, pre-genual Brodmann area (BA) 32 and lateral temporal BA 21. We present the data as colocalization matrices and as quantitative percentages. The overall average colocalization in OCM compared to Nissl was 67% for BA 32 (47% for Nissl colocalization) and 60% for BA 21 (52% for Nissl colocalization), but with a large variability across cases and layers. One source of variability and confounds could be ascribed to an obscuring effect from large and dense intracortical fiber bundles. Other technical challenges, including obstacles inherent to human brain tissue, are discussed. Despite limitations, OCM is a promising semi-high throughput tool for demonstrating detail at the neuronal level, and, with further development, has distinct potential for the automatic acquisition of large databases as are required for the human brain.Accepted manuscrip

The Most Powerful Lenses in the Universe: Quasar Microlensing as a Probe of the Lensing Galaxy

Optical and X-ray observations of strongly gravitationally lensed quasars (especially when four separate images of the quasar are produced) determine not only the amount of matter in the lensing galaxy but also how much is in a smooth component and how much is composed of compact masses (e.g., stars, stellar remnants, primordial black holes, CDM sub-halos, and planets). Future optical surveys will discover hundreds to thousands of quadruply lensed quasars, and sensitive X-ray observations will unambiguously determine the ratio of smooth to clumpy matter at specific locations in the lensing galaxies and calibrate the stellar mass fundamental plane, providing a determination of the stellar $M/L$. A modest observing program with a sensitive, sub-arcsecond X-ray imager, combined with the planned optical observations, can make those determinations for a large number (hundreds) of the lensing galaxies, which will span a redshift range of $\sim$$0.25<z<1.5$Comment: Astro2020 Science White Pape

A highly specific Escherichia coli qPCR and its comparison with existing methods for environmental waters

The presence of Escherichia coli in environmental waters is considered as evidence of faecal contamination and is therefore commonly used as an indicator in both water quality and food safety analysis. The long period of time between sample collection and obtaining results from existing culture based methods means that contamination events may already impact public health by the time they are detected. The adoption of molecular based methods for E. coli could significantly reduce the time to detection. A new quantitative real-time PCR (qPCR) assay was developed to detect the ybbW gene sequence, which was found to be 100% exclusive and inclusive (specific and sensitive) for E. coli and directly compared for its ability to quantify E. coli in environmental waters against colony counts, quantitative real-time NASBA (qNASBA) targeting clpB and qPCR targeting uidA. Of the 87 E. coli strains tested, 100% were found to be ybbW positive, 94.2% were culture positive, 100% were clpB positive and 98.9% were uidA positive. The qPCR assays had a linear range of quantification over several orders of magnitude, and had high amplification efficiencies when using single isolates as a template. This compared favourably with qNASBA which showed poor linearity and amplification efficiency. When the assays were applied to environmental water samples, qNASBA was unable to reliably quantify E. coli while both qPCR assays were capable of predicting E. coli concentrations in environmental waters. This study highlights the inability of qNASBA targeting mRNA to quantify E. coli in environmental waters, and presents the first E. coli qPCR assay with 100% target exclusivity. The application of a highly exclusive and inclusive qPCR assay has the potential to allow water quality managers to reliably and rapidly detect and quantify E. coli and therefore take appropriate measures to reduce the risk to public health posed by faecal contamination

The deposition of metal nanoparticles on carbon surfaces: the role of specific functional groups

The enormous complexity of a typical heterogeneous catalyst makes understanding the development and properties of any active nanoparticles present extremely challenging. In the case of carbon based catalysts that difficulty is compounded by the variability of the carbon powders used. We have previously developed a strategy that addresses these problems by mimicking the catalyst preparation conditions very closely but using highly ordered pyrolytic graphite crystals (HOPG) as a model surface. This enables us to examine the effects of specific functional groups on nanoparticle formation. We report here an extension of our work characterising functional groups on the HOPG surface, using XPS and AFM to explore the deposition of gold from aqueous solution onto HOPG surfaces treated in a variety of ways to alter the surface functionality. The structure and oxidation state of the resulting nanoparticles depend critically on the nature of the functional groups present and offers some insight into the development of catalysts based on these materials. Hydroxyls are identified as key functional species, reducing gold ions to their metallic state whilst being oxidised themselves to carbonyls. Carbonyls meanwhile promote the nucleation of Au3+, creating a network of islands at the HOPG surface. The results have relevance not only to catalysts using activated carbons but also the new generation of materials based on graphene and carbon nanotubes

Geotechnical laboratory testing of glacial deposits from Aldbrough, phase 2 boreholes

This report is a published product of an ongoing study by the British Geological Survey (BGS) of the coastal change at Aldbrough on the Holderness coast, East Riding of Yorkshire, UK. The test site at Aldbrough has been selected as one of the BGS Landslide Observatories because it is representative of the high rates of coastal recession along this stretch of the east coast. The Aldbrough Landslide Observatory is operated under the BGS ‘Slope Dynamics’ task within the BGS’s ‘Landslide’ project of the ‘Shallow Geohazards and Risk’ team. As well as providing new insights with respect to the volumetric rates of recession and the near surface processes, it is a focus for the trialling of new surface and subsurface monitoring technologies. The establishment of the Aldbrough observatory and the initial research findings are reported in a series of reports in addition to this report. These are: Hobbs, P.R.N., Jones, L.D. and Kirkham, M.P. (2015) Slope Dynamics project report: Holderness Coast – Aldbrough: Drilling & Instrumentation, 2012-2015. British Geological Survey, Internal Report No IR/15/001. Hobbs, P. R. N., Jones, L. D., Kirkham, M. P., Pennington, C. V. L., Jenkins, G. O., Dashwood, C., Haslam, E. P., Freeborough, K. A. and Lawley, R. S. (2013) Slope Dynamics Project Report: Holderness Coast – Aldbrough: Survey & Monitoring, 2001 - 2013 British Geological Survey, Open Report No. OR/11/063. Whilst this report is focused on the geotechnical laboratory testing programme, it should be read in conjunction with the reports listed above, which provide further details on drilling and instrumentation and on survey and monitoring. A series of reports will follow presenting the updated survey and monitoring reports, and their publication will be announced through the BGS project web page. Readers of these reports will probably also be interested in the context for this research, which can be found in: Hobbs, P.R.N., Pennington, C.V.L., Pearson, S.G., Jones, L.D., Foster, C., Lee, J.R., Gibson, A. (2008) Slope Dynamics Project Report: the Norfolk Coast (2000-2006). British Geological Survey, Open Report No. OR/08/018

How does the outcome of research training fellowships funded via the NHS compare with that from competitively funded fellowships from the MRC and other charities::a cross-sectional retrospective survey of trainees undertaking research training in the West Midlands

ObjectivesThis study aimed to investigate the impact of research training funded via the National Health Service (NHS) on medical trainees compared with traditional clinical research training fellowships (CRTFs).Design, setting and participantsOnline survey of 221 clinical trainees who had completed a period of research during their clinical training between 2009 and 2015 in the West Midlands.Main outcome measuresResearch outcomes.ResultsOverall response rate was 59%, of whom 72 participants were funded by CRTFs and 51 funded by the NHS. Although participants with CRTFs were more likely to be awarded a higher degree compared with those on NHS-administered funding (66/72 CRTFs and 37/51 NHS, P=0.005), similar proportions of NHS-funded and CRTF-funded participants entered clinical lecturer posts on completing initial research training (8/51 NHS and 16/72 CRTF, P=0.37). 77% of participants had three or more publications (CRTF 57 and NHS 39, P=0.72). 57 participants had completed clinical training; similar proportions of CRTF-funded and NHS-funded trainees had research included in their consultant contract (12/22 NHS and 14/26 CRTF, P=0.96) or were appointed to academic posts (3 of 25 NHS funded and 6 of 32 CRTF, P&gt;0.05). 95% of participants would recommend to colleagues and 82% of participants felt the research experience improved their provision of clinical care with no difference between CRTF-funded and NHS-funded participants (P=0.49). Continuing to participate in clinical work during the research reduced reports of trainee difficulty on returning to clinical work (23/108 continued clinical work vs 12/22 no clinical work, P=0.001).ConclusionResearch training funded by the NHS provides a quality experience and contributes to the clinical academic capacity within the UK. More needs to be done to support NHS participants to successfully achieve a higher degree.</jats:sec

BikeNet: Preventing theft, building community

This report discusses the Save the Bike Project and the BikeNet App, and the ways it helps prevent and recover stolen bikes.Ope