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Russell P.J.,Colworth Science Park | Swindells C.,Phytopharm plc
Food and Chemical Toxicology | Year: 2012

The chemical composition of a solvent extract of Hoodia gordonii termed '. H. gordonii extract' has been characterised by hyphenated chromatographic methods and traditional analytical techniques. The extract consists of a mixture of steroid glycosides, fatty acids, plant sterols and polar organic material. High performance liquid chromatography (HPLC) with ultra violet (UV) and mass spectrometric (MS) detection was used to quantify and confirm the identity of a number of steroid glycosides (73.7% w/w) present in the extract. Gas chromatography (GC) with MS and flame ionisation detection (FID) was applied to determine the fatty acid (3.12% w/w) sterol (0.39% w/w) and alcohol (0.03% w/w) content of a saponified sample of the extract. Polar organic material was quantified by gravimetric methodology using C 18 SPE separation and was determined to be a minimum of 3% w/w. Moisture content was measured by Karl Fischer coulometric titration (0.81% w/w).The protein content was investigated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) with SYPRO Ruby staining and a negative result was determined with a limit of detection of <0.001%w/w of protein per band. The chemical composition of the extract remained stable for 19. months when stored in re-sealable plastic bags at ambient (21-24 °C) temperature and <60% relative humidity. © 2011 Elsevier Ltd. Source

Soureti A.,Colworth Science Park
Journal of medical Internet research | Year: 2011

A healthy diet, low in saturated fat and high in fiber, is a popular medical recommendation in preventing cardiovascular disease (CVD). One approach to motivating healthier eating is to raise individuals' awareness of their CVD risk and then help them form specific plans to change. The aim was to explore the combined impact of a Web-based CVD risk message and a fully automated planning tool on risk perceptions, intentions, and saturated fat intake changes over 4 weeks. Of the 1187 men and women recruited online, 781 were randomly allocated to one of four conditions: a CVD risk message, the same CVD risk message paired with planning, planning on its own, and a control group. All outcome measures were assessed by online self-reports. Generalized linear modeling was used to analyze the data. Self-perceived consumption of low saturated fat foods (odds ratio 11.40, 95% CI 1.86-69.68) and intentions to change diet (odds ratio 21.20, 95% CI 2.6-172.4) increased more in participants allocated to the planning than the control group. No difference was observed between the four conditions with regard to percentage saturated fat intake changes. Contrary to our expectations, there was no difference in perceived and percentage saturated fat intake change between the CVD risk message plus planning group and the control group. Risk perceptions among those receiving the CVD risk message changed to be more in line with their age (change in slope(individual) = 0.075, P = .01; change in slope(comparative) = 0.100, P = .001), whereas there was no change among those who did not receive the CVD risk message. There was no evidence that combining a CVD risk message with a planning tool reduces saturated fat intake more than either alone. Further research is required to identify ways in which matching motivational and volitional strategies can lead to greater behavior changes. Source

Brandao M.,European Commission - Joint Research Center Ispra | I Canals L.M.,Colworth Science Park
International Journal of Life Cycle Assessment | Year: 2013

Purpose: The inclusion of land-use activities in life cycle assessment (LCA) has been subject to much debate in the LCA community. Despite the recent methodological developments in this area, the impacts of land occupation and transformation on its long-term ability to produce biomass (referred to here as biotic production potential [BPP]) - an important endpoint for the Area of Protection (AoP) Natural Resources - have been largely excluded from LCAs partly due to the lack of life cycle impact assessment methods. Materials and methods: Several possible methods/indicators for BPP associated with biomass, carbon balance, soil erosion, salinisation, energy, soil biota and soil organic matter (SOM) were evaluated. The latter indicator was considered the most appropriate for LCA, and characterisation factors for eight land use types at the climate region level were developed. Results and discussion: Most of the indicators assessed address land-use impacts satisfactorily for land uses that include biotic production of some kind (agriculture or silviculture). However, some fail to address potentially important land use impacts from other life cycle stages, such as those arising from transport. It is shown that the change in soil organic carbon (SOC) can be used as an indicator for impacts on BPP, because SOC relates to a range of soil properties responsible for soil resilience and fertility. Conclusions: The characterisation factors developed suggest that the proposed approach to characterize land use impacts on BBP, despite its limitations, is both possible and robust. The availability of land-use-specific and biogeographically differentiated data on SOC makes BPP impact assessments operational. The characterisation factors provided allow for the assessment of land-use impacts on BPP, regardless of where they occur thus enabling more complete LCAs of products and services. Existing databases on every country's terrestrial carbon stocks and land use enable the operability of this method. Furthermore, BPP impacts will be better assessed by this approach as increasingly spatially specific data are available for all geographical regions of the world at a large scale. The characterisation factors developed are applied to the case studies (Part D of this special issue), which show the practical issues related to their implementation. © 2012 Springer-Verlag. Source

Martin J.E.,University of Bristol | Patil A.J.,University of Bristol | Butler M.F.,Colworth Science Park | Mann S.,University of Bristol
Advanced Functional Materials | Year: 2011

Given the urgent need for soft materials with high functional value, hydrogels based on the integrative assembly of organic polymers and nanoscale inorganic building blocksa-so-called nanocomposite polymer hydrogelsa-offer a generic approach to swollen hybrid networks with tuneable and synergistic properties. Here, we report a new approach to assembling nanocomposite polymer hydrogels with multiple levels of structural complexity and enhanced functionality by using nanoscale integration of mesostructured inorganic building blocks capable of sequestering and releasing drugs (ibuprofen, aspirin, naproxen) and enzymes (glucose oxidase). The viscoelastic materials are produced by noncovalent crosslinking of poly(vinylpyrrolidone) in the presence of low amounts (1-5 wt%) of an exfoliated synthetic organoclay that undergoes in situ guest-molecule-directed self-assembly. The hydrogels can be moulded into shape-persistent, free-standing objects that are stable between pH values of 4 to 11 and self-heal when damaged. Significantly, the mesostructured nanocomposite polymer hydrogels, which can be reversibly dried and reconstituted in the form of highly swollen materials, exhibit sustained drug release and can be recharged and reused. The results provide important guidelines for developing new multifunctional nanocomposite polymer hydrogels based on the concerted self-assembly of inorganic building blocks with mesostructured interiors. New multifunctional nanocomposite polymer hydrogels with mesostructured crosslinking units are prepared by in situ self-assembly of organoclay sheets and guest-drug or protein molecules within a poly(vinylpyrrolidone) matrix. The mesostructured hydrogels are mouldable, swellable, and self-adhesive, and exhibit sustained drug release compared with their exfoliated counterparts. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Blake K.L.,University of Leeds | Blake K.L.,Colworth Science Park | O'Neill A.J.,University of Leeds
Journal of Antimicrobial Chemotherapy | Year: 2013

Objectives: To establish an experimental platform in Staphylococcus aureus for identifying genetic loci that determine intrinsic antibiotic susceptibility and/or that have the potential to contribute to acquired antibiotic resistance. A near-saturation S. aureus transposon (Tn) library was screened for mutants exhibiting altered susceptibility to the antistaphylococcal agents daptomycin, vancomycin and nisin. Methods: S. aureus SH1000 was mutagenized with Tn InsTetG+2Cm by electroporation of transposomes. Approximately 20500 transposants were screened for increased or reduced susceptibility to the three antistaphylococcal agents and Tn insertion sites were mapped by DNA sequencing in mutants of interest. Results: Transposants exhibiting hypersusceptibility or reduced susceptibility were identified for all three antibacterial agents; mapping of Tn insertion sites in these mutants identified genetic determinants of intrinsic susceptibility and potential contributors to acquired resistance, respectively. Tn insertions in the dlt operon caused cross-hypersusceptibility to vancomycin, daptomycin and nisin. Daptomycin hypersusceptibility was also associated with disruption of genes directing lipoteichoic acid and riboflavin biosynthesis, apparent inactivation of a putative membrane protein encoded by SAOUHSC_00957 and truncation of the cell-division gene ezrA. Tn-mediated disruption of the vraDE- and SAOUHSC_02953/4-encoded ABC transporters conferred hypersusceptibility to nisin. Reduced susceptibility to both daptomycin and vancomycin was associated with Tn insertions in rpsU and upstream of yycFG. Several loci were associated with reduced susceptibility to nisin, including two genes encoding putative glycosyltransferases. Conclusions: Tn library screening identified both known and novel modulators of antibacterial susceptibility in S. aureus and therefore represents a useful approach towards delineating the staphylococcal resistome. © The Author 2012. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. Source

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