182 research outputs found

    Targeting late diagnosis of HIV in Kent, Medway and Picardy: evaluation of interventions in the Anglo-French IMPRESS Health 2 (Interreg IVA Channel Programme) project 4282

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    This report outlines the results and final stakeholder evaluations for the intervention phase (phase 3) of the Interreg IVA Channel Programme 4282 IMPRESSHealth 2 study. It describes how recommendations from the phase 1 report were implemented in Kent, Medway and Picardy in Northern France, the impact which these had on the uptake and timeliness of HIV testing in these areas; and analysis of the reasons for variance between the two countries (UK and France). The report contains examples of some of the public health and social media materials developed to increase the uptake and timeliness of HIV testing, and the results of the stakeholder assessment of its success. Overall, the impact of the interventions have been successful, with widespread increases in both the number and timeliness of HIV testing in the UK though less so in France. Reasons for these differences are discussed in the report. The report also highlights the huge contribution which social and broadcasting media can make to public health campaigns of this nature, and the value of multi-sector and inter-organisational team working

    A 16-Channel Wireless Neural Recording System-on-Chip with CHT Feature Extraction Processor in 65nm CMOS

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    Wireless implantable neural recording chips enable multichannel data acquisition with high spatiotemporal resolution in situ. Recently, the use of machine learning approaches on neural data for diagnosis and prosthesis control have renewed the interest in this field, and increased even more the demand for multichannel data. However, simultaneous data acquisition from many channels is a grand challenge due to data rate and power limitations on wireless transmission for implants. As a result, recent studies have focused on on-chip classifiers, despite the fact that only primitive classifiers can be placed on resource-constrained chips. Moreover, robustness of the chosen algorithm cannot be guaranteed pre-implantation due to the scarcity of patient-specific data; waveforms can change over time due to electrode micro migration or tissue reaction, highlighting the need for robust adaptive features

    The Multisensor Array Based on Grown-On-Chip Zinc Oxide Nanorod Network for Selective Discrimination of Alcohol Vapors at Sub-ppm Range

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    We discuss the fabrication of gas-analytical multisensor arrays based on ZnO nanorods grown via a hydrothermal route directly on a multielectrode chip. The protocol to deposit the nanorods over the chip includes the primary formation of ZnO nano-clusters over the surface and secondly the oxide hydrothermal growth in a solution that facilitates the appearance of ZnO nanorods in the high aspect ratio which comprise a network. We have tested the proof-of-concept prototype of the ZnO nanorod network-based chip heated up to 400 °C versus three alcohol vapors, ethanol, isopropanol and butanol, at approx. 0.2–5 ppm concentrations when mixed with dry air. The results indicate that the developed chip is highly sensitive to these analytes with a detection limit down to the sub-ppm range. Due to the pristine differences in ZnO nanorod network density the chip yields a vector signal which enables the discrimination of various alcohols at a reasonable degree via processing by linear discriminant analysis even at a sub-ppm concentration range suitable for practical applications

    Chemical vapor deposited polymer layer for efficient passivation of planar perovskite solar cells

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    Reducing non-radiative recombination losses by advanced passivation strategies is pivotal to maximize the power conversion efficiency (PCE) of perovskite solar cells (PSCs). Previously, polymers such as poly(methyl methacrylate), poly(ethylene oxide), and polystyrene were successfully applied in solution-processed passivation layers. However, controlling the thickness and homogeneity of these ultra-thin passivation layers on top of polycrystalline perovskite thin films is a major challenge. In response to this challenge, this work reports on chemical vapor deposition (CVD) polymerization of poly(p-xylylene) (PPX) layers at controlled substrate temperatures (14–16 °C) for efficient surface passivation of perovskite thin films. Prototype double-cation PSCs using a ∼1 nm PPX passivation layer exhibit an increase in open-circuit voltage (VOC_{OC}) of ∼40 mV along with an enhanced fill factor (FF) compared to a non-passivated PSC. These improvements result in a substantially enhanced PCE of 20.4% compared to 19.4% for the non-passivated PSC. Moreover, the power output measurements over 30 days under ambient atmosphere (relative humidity ∼40–50%) confirm that the passivated PSCs are more resilient towards humidity-induced degradation. Considering the urge to develop reliable, scalable and homogeneous deposition techniques for future large-area perovskite solar modules, this work establishes CVD polymerization as a novel approach for the passivation of perovskite thin films

    Activation of the hydrolytic polymerization of e-caprolactam by ester functions: straightforward route to aliphatic polyesteramides

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    peer reviewedThe hydrolytic polymerization of e-caprolactam (CLa) was carried out in bulk (in absence of solvent) at 250 °C in the presence of carboxylic esters and aqueous H3PO2. It turned out that by conducting the ring opening polymerization (ROP) of CLa in the presence of PEO-C(O)-O-C5H11, a selected model ester (PEO = poly(ethylene oxide)), a remarkable activating effect of the ester function on the hydrolytic polymerization of the lactam was observed yielding PEO-b-PCLa diblock copolymers. The comparison of the CLa monomer conversions obtained with or without the model ester activated by H3PO2, as determined by 1H NMR spectroscopy, has enabled to propose a multi-step mechanism in which three major reactions occurred: (i) ester and lactam hydrolysis, (ii) aminolysis of the carboxylic ester by the resulting primary amine of the hydrolyzed/opened lactam ring and (iii) condensation reactions between carboxylic acids and both amine/hydroxyl functions. The overall result of this multi-step mechanism can be assimilated as an 'insertion' of the opened lactam into the ester function. By conducting the hydrolytic polymerization of CLa in the presence of an aliphatic polyester chain, such as poly(e-caprolactone) (PCLo), polyesteramides were recovered with high yields and random distributions of the CLa and CLo repetitive units as determined by 13C NMR

    Zwitterion functionalized gold nanoclusters for multimodal near infrared fluorescence and photoacoustic imaging

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    Gold nanoclusters (Au NCs) are an emerging type of theranostic agents combining therapeutic and imaging features with reduced toxicity. Au NCs stabilized by a zwitterion ligand with a fine control of the metal core size and the ligand coverage were synthesized by wet chemistry. Intense fluorescence signal is reported for the highest ligand coverage, whereas photoacoustic signal is stronger for the largest metal core. The best Au NC candidate with an average molecular weight of 17 kDa could be detected with high sensitivity on a 2D-near-infrared imaging instrument (limit of detection (LOD) = 2.3 μM μM ) and by photoacoustic imaging. In vitro and in vivo experiments demonstrate an efficient cell uptake in U87 cell lines, a fast renal clearance (t 1/2α t1/2α = 6.5 ± 1.3 min), and a good correlation between near infrared fluorescence and photoacoustic measurements to follow the early uptake of Au NCs in liver

    Kcl Test:an open-source inspired asymptomatic SARS-CoV-2 surveillance programme in an academic institution

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    Rapid and accessible testing was paramount in the management of the COVID-19 pandemic. Our university established KCL TEST: a SARS-CoV-2 asymptomatic testing programme that enabled sensitive and accessible PCR testing of SARS-CoV-2 RNA in saliva. Here, we describe our learnings and provide our blueprint for launching diagnostic laboratories, particularly in low-resource settings. Between December 2020 and July 2022, we performed 158277 PCRs for our staff, students, and their household contacts, free of charge. Our average turnaround time was 16 h and 37 min from user registration to result delivery. KCL TEST combined open-source automation and in-house non-commercial reagents, which allows for rapid implementation and repurposing. Importantly, our data parallel those of the UK Office for National Statistics, though we detected a lower positive rate and virtually no delta wave. Our observations strongly support regular asymptomatic community testing as an important measure for decreasing outbreaks and providing safe working spaces. Universities can therefore provide agile, resilient, and accurate testing that reflects the infection rate and trend of the general population. Our findings call for the early integration of academic institutions in pandemic preparedness, with capabilities to rapidly deploy highly skilled staff, as well as develop, test, and accommodate efficient low-cost pipelines.</p

    B-RAF Mutant Alleles Associated with Langerhans Cell Histiocytosis, a Granulomatous Pediatric Disease

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    Langerhans cell histiocytosis (LCH) features inflammatory granuloma characterised by the presence of CD1a+ dendritic cells or 'LCH cells'. Badalian-Very et al. recently reported the presence of a canonical (V600E)B-RAF mutation in 57% of paraffin-embedded biopsies from LCH granuloma. Here we confirm their findings and report the identification of two novel B-RAF mutations detected in LCH patients.Mutations of B-RAF were observed in granuloma samples from 11 out of 16 patients using 'next generation' pyrosequencing. In 9 cases the mutation identified was (V600E)B-RAF. In 2 cases novel polymorphisms were identified. A somatic (600DLAT)B-RAF insertion mimicked the structural and functional consequences of the (V600E)B-RAF mutant. It destabilized the inactive conformation of the B-RAF kinase and resulted in increased ERK activation in 293 T cells. The (600DLAT)B-RAF and (V600E)B-RAF mutations were found enriched in DNA and mRNA from the CD1a+ fraction of granuloma. They were absent from the blood and monocytes of 58 LCH patients, with a lower threshold of sequencing sensitivity of 1%-2% relative mutation abundance. A novel germ line (T599A)B-RAF mutant allele was detected in one patient, at a relative mutation abundance close to 50% in the LCH granuloma, blood monocytes and lymphocytes. However, (T599A)B-RAF did not destabilize the inactive conformation of the B-RAF kinase, and did not induce increased ERK phosphorylation or C-RAF transactivation.Our data confirmed presence of the (V600E)B-RAF mutation in LCH granuloma of some patients, and identify two novel B-RAF mutations. They indicate that (V600E)B-RAF and (600DLAT)B-RAF mutations are somatic mutants enriched in LCH CD1a(+) cells and absent from the patient blood. Further studies are needed to assess the functional consequences of the germ-line (T599A)B-RAF allele
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