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Seasonal respiratory illnesses present a major burden on primary care services. We assessed the burden of respiratory illness on a national telehealth system in England and investigated the potential for providing early warning of respiratory infection. We compared weekly laboratory reports for respiratory pathogens with telehealth calls (NHS 111) between week 40 in 2013 and week 29 in 2015. Multiple linear regression was used to identify which pathogens had a significant association with respiratory calls. Children aged <5 and 5–14 years, and adults over 65 years were modelled separately as were time lags of up to 4 weeks between calls and laboratory specimen dates. Associations with respiratory pathogens explained over 83% of the variation in cold/flu, cough and difficulty breathing calls. Based on the first two seasons available, the greatest burden was associated with respiratory syncytial virus (RSV) and influenza, with associations found in all age bands. The most sensitive signal for influenza was calls for ‘cold/flu’, whilst for RSV it was calls for cough. The best-fitting models showed calls increasing a week before laboratory specimen dates. Daily surveillance of these calls can provide early warning of seasonal rises in influenza and RSV, contributing to the national respiratory surveillance programme.
Water degradation of glass waste forms has been studied extensively under a
variety of conditions including of bulk glass immersed completely in static or
dynamic water. In practice, the vitrified nuclear waste cracks as soon as poured
into a container because of differences in thermal expansion coefficients. In
addition, in repository the canisters may be only partially immersed in water.
Later, water condenses on the surface of glass which corrodes releasing ions. In
this work experiments have been performed to understand these effects on the
degradation of International Simple Glass (ISG). Simulated cracks were found to
develop pitting corrosion in the crack openings when tested by immersing ISG in
water. Under load, these pits concentrated stress and grew as large planar
cracks inside the glass. The condensation of water on glass surfaces leads to
formation of pits and growth of calcium silicate crystals.
A large area nanogap electrode fabrication method combinig conventional lithography patterning with the of focused ion beam (FIB) is presented. Lithography and a lift-off process were used to pattern 50 nm thick platinum pads having an area of 300 μm × 300 μm. A range of 30-300 nm wide nanogaps (length from 300 μm to 10 mm ) were then etched using an FIB of Ga+ at an acceleration voltage of 30 kV at various beam currents. An investigation of Ga+ beam current ranging between 1-50 pA was undertaken to optimise the process for the current fabrication method. In this study, we used Monte Carlo simulation to calculate the damage depth in various materials by the Ga+. Calculation of the recoil cascades of the substrate atoms are also presented. The nanogap electrodes fabricated in this study were found to have empty gap resistances exceeding several hundred MΩ. A comparison of the gap length versus electrical resistance on glass substrates is presented. The results thus outline some important issues in low-conductance measurements. The proposed nanogap fabrication method can be extended to various sensor applications, such as chemical sensing, that employ the nanogap platform. This method may be used as a prototype technique for large-scale fabrication due to its simple, fast and reliable features.
In the present paper regular systems of silicon and platinum assemblies have been fabricated in a three-dimensional (3D) void sublattice of synthetic opal. The detailed TEM and HREM structure study of ‘opal-Si’ and ‘opal-Pt-Si’ composites was carried out. It was found that in regular composites ‘opal-Si’ the silica spheres were covered uniformly with a nanocrystalline silicon layer of up to 25-30 nm in thickness. To form the Pt-Si contact the silica spheres were coated with platinum layer before embedding silicon. The results obtained demonstrate a possibility of creating 3D multilayer semiconductor structure (p-n junctions, Schottky barriers etc.) on the inner surface of opal voids.
Ni/Ti multilayered thin films can be efficient neutron guides and are therefore of great interest in neutron optics. Ni/Ti and NiC/Ti multilayers with various layer thicknesses were fabricated by magnetron sputtering and characterized by high resolution transmission electron microscopy (TEM). The TEM studies, performed on cross-sectional specimens, revealed that both kinds of layers were textured and snowed coherence in the growth direction. The presence of a 2 nra thick amorphous zone at the Ni/Ti interface in the carbon free thin films was also confirmed. On the contrary, sharp interfaces were obtained in NiC/Ti multilayers. The fine structure of the different layers will also be reported.
The metamict transformation under electron irradiation has been studied in α-quartz using transmission electron microscopy (TEM) and convergent-beam electron diffraction (CBD). The transformation occurs in two stages: heterogeneous nucleation of discrete disordered inclusions and a slower homogeneous loss of crystalline order in the surrounding matrix. Both features are attributable to solidstate radiolysis, a mechanism for which is proposed. Ultrahigh resolution TEM structure images and information from zeroth and high order Laue zones in CBD confirm that shortrange correlations are the first to be lost and that longerrange correlations persist well into the metamict transformation. A transformation model is advanced in which progressive disorder evolves from small displacements of individual [SiO4] coordination units, made possible by lowered connectivity, within a framework of long-range ordered material.
Nanocomposites of poly(bis-(2(2-memoxyethoxy)ethoxy)phosphazene) (MEEP) or cryptand[2.2.2] with the aluminosilicate Na-montmorillonite (NaMont) were studied to develop new solid electrolytes with high conductivity and a unity cation transport number. An aluminosilicate was chosen because the low basicity of the Si-0-Al framework should minimize ion pairing. To further reduce ion pairing, solvating molecules or polymers such as cryptand[2.2.2] or MEEP were introduced into the aluminosilicate. When compared to pristine Na-montmorillonite, impedance spectroscopy indicates an increase in conductivity of up to 100 for MEEP-NaMont intercalates, and of 50 for cryptand[2.2.2]·NaMont intercalates. The MEEP·NaMont intercalate exhibits high ionic conductivity anisotropy with respect to the montmorillonite layers (σpara./σperp. = 100), which is consistent with increased tortuosity of the cation diffusion path perpendicular to the structure layers. The temperature dependance of the conductivity suggests that cation transport is coupled to segmental motion of the intercalated polymer, as observed previously for simple polymer-salt complexes. Nanocomposites of solvating polymers or molecules with aluminosilicates provide a promising new direction in solid-state electrolytes.
A point source outbreak of haemorrhagic colitis due to Escherichia coli O 157. H7 producing verocytotoxin (VT), took place following a christening party in Birmingham in June 1987. Twenty-six people were affected, six were admitted to hospital and one developed haemolytic uraemic syndrome: there were no deaths. VT + E. coli O 157. H7 was isolated from 13 (57%) of 23 faecal specimens from affected people and from 3 (9%) of 33 specimens from asymptomatic people. Free VT was detected in the faeces of one further asymptomatic person. Illness was associated with eating turkey-roll sandwiches (P < 0·001) suggesting that cold meats might be an important source of infection.
A large outbreak of Legionnaires’ disease was associated with Stafford District General Hospital. A total of 68 confirmed cases was treated in hospital and 22 of these patients died. A further 35 patients, 14 of whom were treated at home, were suspected cases of Legionnaires’ disease. All these patients had visited the hospital during April 1985. Epidemiological investigations demonstrated that there had been a high risk of acquiring the disease in the out patient department (OPD), but no risk in other parts of the hospital. The epidemic strain of Legionella pneumophila, serogroup 1, subgroup Pontiac la was isolated from the cooling water system of one of the air conditioning plants. This plant served several departments of the hospital including the OPD. The water in the cooling tower and a chiller unit which cooled the air entering the OPD were contaminated with legionellae. Bacteriological and engineering investigations showed how the chiller unit could have been contaminated and how an aerosol containing legionellae could have been generated in the U–trap below the chiller unit. These results, together with the epidemiological evidence, suggest that the chiller unit was most likely to have been the major source of the outbreak.
Nearly one third of hospital staff had legionella antibodies. These staff were likely to have worked in areas of the hospital ventilated by the contaminated air conditioning plant, but not necessarily the OPD. There was evidence that a small proportion of these staff had a mild legionellosis and that these ‘influenza–like’ illnesses had been spread over a 5–month period. A possible explanation of this finding is that small amounts of aerosol from cooling tower sources could have entered the air–intake and been distributed throughout the areas of the hospital served by this ventilation system. Legionellae, subsequently found to be of the epidemic strain, had been found in the cooling tower pond in November 1984 and thus it is possible that staff were exposed to low doses of contaminated aerosol over several months.
Control measures are described, but it was later apparent that the outbreak had ended before these interventions were introduced. The investigations revealed faults in the design of the ventilation system.
Indirect high resolution electron microscopy using one of several
possible data-set geometries offers advantages over conventional
high-resolution imaging in enabling the recovery of the complex
wavefunction at the specimen exit plane and simultaneously eliminating the
aberrations present in the objective lens. This article discusses results
obtained using this method from structures formed by inorganic materials
confined within the bores of carbon nanotubes. Such materials are shown to
be atomically regulated due to their confinement, leading to integral
layer architectures that we have termed “Feynman crystals.”
These one-dimensional (1D) crystals also show a wide range of structural
deviations from the bulk, including unexpected lattice distortions, and in
some cases entirely new forms have been observed.
Extended abstract of a paper presented at the Pre-Meeting Congress: Materials Research in an Aberration-Free Environment, at Microscopy and Microanalysis 2004 in Savannah, Georgia, USA, July 31 and August 1, 2004.
A monoclonal antibody (MAb), UB31, is described that binds to the extracellular matrix (ECM) surrounding germ-tubes and appressoria, but not conidia, of the bean anthracnose fungus, Colletotrichum lindemuthianum. Comparative localisation studies with MAb UB26, which has the same cell type specificity, suggest that the ECM is heterogeneous in composition. Immunofluorescence showed that UB31 labelled appressoria more intensely than germ-tubes, whereas UB26 labelled these structures to a similar extent. Immunofluorescence and TEM-immunogold labelling showed that UB31 antigens were located close to the appressorial wall, while UB26 antigens extended further away from the wall. MAb UB31 bound to the ECMs of all six Colletotrichum species tested. Western blotting and ELISA indicated that the antibody recognises a high Mr glycoprotein (>200000) that may be linked to melanin. The glycoprotein recognised by UB31 was not removed from substrata by ultrasonication, suggesting it may contribute to germling adhesion.