999 resultados para 1995_01300042 TM-63 4302803


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Medhurst, J. (2005). Mammon's Television?: ITV in Wales 1959-63. In C. Johnson and R. Turnock (Eds.), ITV Cultures: Independent Television over 50 Years (pp.88-107). Maidenhead: Open University Press. RAE2008

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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas

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Despite being exposed to the harsh sea-spray environment of the North Sea at Arbroath, Scotland, for over 63 years, many of the reinforced concrete precast beam elements of the 1.5 km long promenade railing are still in very good condition and show little evidence of reinforcement corrosion. In contrast, railing replacements constructed in about 1968 and in 1993 are almost all badly cracked as a result of extensive corrosion of the longitudinal reinforcement. This is despite the newer concrete appearing to be of better quality than the 1943 concrete. Statistics for maximum crack width for each of the three populations, based on measurements made in 2004 and in 2006, are presented. In situ and laboratory measurements show that the 1943 concrete appears to have high permeability but it also shows high electrical resistivity. Chloride penetration measurements show the 1943 and 1993 concretes to have similar chloride profiles and similar chloride concentrations at the reinforcement bars. This is inconsistent with the 1943 beams showing much less reinforcement corrosion than their later replacements and casts doubt on the conventional practice for durability design focusing on reducing concrete permeability through denser concretes or greater cover.

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The secondary structure of the trimeric protein 4-chlorobenzoyl coenzyme A dehalogenase from Arthrobacter sp. strain TM-1, the second of three enzymes involved in the dechlorination of 4-chlorobenzoate to form 4-hydroxybenzoate, has been examined. E(mM) for the enzyme was 12.59. Analysis by circular dichroism spectrometry in the far uv indicated that 4-chlorobenzoyl coenzyme A dehalogenase was composed mostly of alpha-helix (56%) with lesser amounts of random coil (21%), beta-turn (13%) and beta-sheet (9%). These data are in close agreement with a computational prediction of secondary structure from the primary amino acid sequence, which indicated 55.8% alpha-helix, 33.7% random coil and 10.5% beta-sheet; the enzyme is, therefore, similar to the 4-chlorobenzoyl coenzyme A dehalogenase from Pseudomonas sp. CBS-3. The three-dimensional structure, including that of the presumed active site, predicted by computational analysis, is also closely similar to that of the Pseudomonas dehalogenase. Study of the stability and physicochemical properties revealed that at room temperature, the enzyme was stable for 24 h but was completely inactivated by heating to 60 degrees C for 5 min; thereafter by cooling at 1 degrees C min(-1) to 45 degrees C, 20.6% of the activity could be recovered. Mildly acidic (pH 5.2) or alkaline (pH 10.1) conditions caused complete inactivation, but activity was fully recovered on returning the enzyme to pH 7.4. Circular dichroism studies also indicated that secondary structure was little altered by heating to 60 degrees C, or by changing the pH from 7.4 to 6.0 or 9.2. Complete, irreversible destruction of, and maximal decrease in the fluorescence yield of the protein at 330-350 nm were brought about by 4.5 M urea or 1.1 M guanidinium chloride. Evidence was obtained to support the hypothetical three-dimensional model, that residues W140 and W167 are buried in a non-polar environment, whereas W182 appears at or close to the surface of the protein. At least one of the enzymes of the dehalogenase system (the combined 4-chlorobenzoate:CoA ligase, the dehalogenase and 4-hydroxybenzoyl coenzyme A thioesterase) appears to be capable of association with the cell membrane.

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This paper describes the condition of a reinforced concrete balustrade consisting of some 1000 individual beam elements all exposed similarly to the hostile marine environment of the North Sea at Arbroath, Scotland since 1943. A comparison is made of the condition of the original construction with the condition of repairs carried out in 1968 and in 1993. It is shown that the 1943 construction shows very little corrosion-induced cracking and little rust staining even though it does not appear to be of high construction quality. Only a very low percentage of the balustrade beams have been replaced. In contrast the beam installed in 1968 and later in 1993 show very considerable and large concrete cracks directly attributable to the corrosion of the longitudinal reinforcement, even though the concrete is of a higher quality and density. A detailed condition survey and statistics of crack sizes are presented in the paper. It is found that the higher corrosion resistance of the 1943 concrete is generally consistent with the concrete electrical resistivity measurements but the degree of corrosion of the reinforcing bars is inconsistent with chloride penetration measurements. The results are compared with the very few observations available in the literature for ageing concrete structures in marine environments. The results cast doubt on the conventional wisdom that chloride content at the reinforcement correlates well with reinforcement corrosion.

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Invasive alien species (IAS) are considered one of the greatest threats to biodiversity, particularly through their interactions with other drivers of change. Horizon scanning, the systematic examination of future potential threats and opportunities, leading to prioritization of IAS threats is seen as an essential component of IAS management. Our aim was to consider IAS that were likely to impact on native biodiversity but were not yet established in the wild in Great Britain. To achieve this, we developed an approach which coupled consensus methods (which have previously been used for collaboratively identifying priorities in other contexts) with rapid risk assessment. The process involved two distinct phases: 1. Preliminary consultation with experts within five groups (plants, terrestrial invertebrates, freshwater invertebrates, vertebrates and marine species) to derive ranked lists of potential IAS. 2. Consensus-building across expert groups to compile and rank the entire list of potential IAS. Five hundred and ninety-one species not native to Great Britain were considered. Ninety-three of these species were agreed to constitute at least a medium risk (based on score and consensus) with respect to them arriving, establishing and posing a threat to native biodiversity. The quagga mussel, Dreissena rostriformis bugensis, received maximum scores for risk of arrival, establishment and impact; following discussions the unanimous consensus was to rank it in the top position. A further 29 species were considered to constitute a high risk and were grouped according to their ranked risk. The remaining 63 species were considered as medium risk, and included in an unranked long list. The information collated through this novel extension of the consensus method for horizon scanning provides evidence for underpinning and prioritizing management both for the species and, perhaps more importantly, their pathways of arrival. Although our study focused on Great Britain, we suggest that the methods adopted are applicable globally.

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We present the first detailed kinematical analysis of the planetary nebula Abell 63, which is known to contain the eclipsing close-binary nucleus UU Sge. Abell 63 provides an important test case in investigating the role of close-binary central stars on the evolution of planetary nebulae. Longslit observations were obtained using the Manchester echelle spectrometer combined with the 2.1-m San Pedro Martir Telescope. The spectra reveal that the central bright rim of Abell 63 has a tube-like structure. A deep image shows collimated lobes extending from the nebula, which are shown to be high-velocity outflows. The kinematic ages of the nebular rim and the extended lobes are calculated to be 8400 +/- 500 and 12900 +/- 2800 yr, respectively, which suggests that the lobes were formed at an earlier stage than the nebular rim. This is consistent with expectations that disc-generated jets form immediately after the common envelope phase. A morphological-kinematical model of the central nebula is presented and the best-fitting model is found to have the same inclination as the orbital plane of the central binary system; this is the first proof that a close-binary system directly affects the shaping of its nebula. A Hubble-type flow is well-established in the morphological-kinematical modelling of the observed line profiles and imagery. Two possible formation models for the elongated lobes of Abell 63 are considered, (i) a low-density, pressure-driven jet excavates a cavity in the remnant asymptotic giant branch (AGB) envelope; (ii) high-density bullets form the lobes in a single ballistic ejection event.

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Type 2 diabetes is a disease fast approaching epidemic proportions throughout the world. From insulin sensitizers to PPARg agonists, the lecture will outline the successful medicinal chem. and biol. strategy underpinning the discovery and selection of Avandia, an innovative new medicine for this disease.

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The Advanced JAX (TM) Bone Void Filler System (AJBVFS) is a novel bone graft material manufactured by Smith and Nephew Orthopaedics Ltd. and comprises beta tri-calcium phosphate granules with carboxymethylcellulose (CMC) gel as a handling agent. This study investigated the potential, in vitro, of the AJBVFS to function as a delivery system for cell therapy to enhance healing of bone defects. The attachment of rabbit bone marrow stromal cells (rbBMSCs), human BMSCs (hBMSCs) and human bone-derived cells (hBDCs) to JAX (TM) granules and the effect of CMC gel on cell proliferation and differentiation were investigated. There were slight species differences in the number and morphology of cells attached on the JAX (TM) granules with less rbBMSC attachment than human. All cells tolerated the presence of CMC gel and a reduction in cell number was only seen after longer exposure to higher gel concentrations. Low concentrations of CMC gel enhanced proliferation, alkaline phosphatase (ALP) expression and ALP activity in human cells but had no effect on rbBMSC. This study suggests that AJBVFS is an appropriate scaffold for the delivery of osteogenic cells and the addition of CMC gel as a handling agent promotes osteogenic proliferation and differentiation and is therefore likely to encourage bone healing.

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Pilkington Glass Activ(TM) represents a possible suitable successor to P25 TiO2, especially as a benchmark photocatalyst film for comparing other photocatalyst or PSH self-cleaning films. Activ(TM) is a glass product with a clear, colourless, effectively invisible, photocatalytic coating of titania that also exhibits PSH. Although not as active as a film of P25 TiO2, Activ(TM) vastly superior mechanical stability, very reproducible activity and widespread commercial availability makes it highly attractive as a reference photocatalytic film. The photocatalytic and photo-induced superhydrophilitic (PSH) properties of Activ(TM) are studied in some detail and the results reported. Thus, the kinetics of stearic acid destruction (a 104 electron process) are zero order over the stearic acid range 4-129 monolayers and exhibit formal quantum efficiencies (FQE) of 0.7 X 10(-5) and 10.2 x 10(-5) molecules per photon when irradiated with light of 365 +/- 20 and 254 nm, respectively; the latter appears also to be the quantum yield for Activ(TM) at 254 nm. The kinetics of stearic acid destruction exhibit Langmuir-Hinshelwood-like saturation type kinetics as a function of oxygen partial pressure, with no destruction occurring in the absence of oxygen and the rate of destruction appearing the same in air and oxygen atmospheres. Further kinetic work revealed a Langmuir adsorption type constant for oxygen of 0.45 +/- 0.16 kPa(-1) and an activation energy of 19 +/- 1 Kj mol(-1). A study of the PSH properties of Activ(TM) reveals a high water contact angle (67) before ultra-bandgap irradiation reduced to 0degrees after prolonged irradiation. The kinetics of PSH are similar to those reported by others for sol-gel films using a low level of UV light. The kinetics of contact angle recovery in the dark appear monophasic and different to the biphasic kinetics reported recently by others for sol-gel films [J. Phys. Chem. B 107 (2003) 1028]. Overall, Activ(TM) appears a very suitable reference material for semiconductor film photocatalysis. (C) 2003 Elsevier Science B.V All rights reserved.