1,024 research outputs found

    School students’ knowledge and understanding of the Global Solar Ultraviolet Index

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    Background. The Global Solar Ultraviolet Index (UVI) is a health communication tool used to inform the  public about the health risks of excess solar UV radiation and encourage appropriate sun-protection  behaviour. Knowledge and understanding of the UVI has been evaluated among adult populations but not  among school students.Objectives. To draw on previously unpublished data from two school-based studies, one in New Zealand (NZ) and the other in South Africa (SA), to investigate and compare students’ knowledge of the UVI and, where possible, report their understanding of UVI.Methods. Cross-sectional samples of schoolchildren in two countries answered questions on whether  they had seen or heard of the UVI and questions aimed at probing their understanding of this measure.Results. Self-report questionnaires were completed by 1 177 students, comprising 472 NZ (264 year 8  (Y8), 214 year 4 (Y4) students) and 705 SA grade 7 primary-school students aged 8 - 13 years. More than half of the NZ Y8 students answered that they had previously heard about or seen the UVI, whereas  significantly more SA students and NZ Y4 students replied that they had neither seen nor heard about the UVI. Among the NZ students who had seen or heard of the UVI, understanding of the tool was fairly good.Conclusion. The observed lack of awareness among many students in both countries provides an  opportunity to introduce an innovative and age-appropriate UVI communication method that combines  level of risk with behavioural responses to UVI categories and focus on personal relevance to the UVI message

    Highly efficient fullerene and non-fullerene based ternary organic solar cells incorporating a new tetrathiocin-cored semiconductor

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    A new dual-chain oligothiophene-based organic semiconductor, EH-5T-TTC, is presented. The molecule contains two conjugated chains linked by a fused tetrathiocin core. X-ray crystallography reveals a boat conformation within the 8-membered sulfur heterocycle core and extensive π–π and intermolecular sulfur–sulfur interactions in the bulk, leading to a 2-dimensional structure. This unusual molecule has been studied as a ternary component in organic solar cell blends containing the electron donor PTB7-Th and both fullerene (PC71BM) and non-fullerene acceptors ITIC and EH-IDTBR. By incorporating EH-5T-TTC as a ternary component, the power conversion efficiency of the binary blends containing non-fullerene acceptor increases by 17% (from 7.8% to 9.2%) and by 85% for the binary blend with fullerene acceptor (from 3.3% to 6.3%). Detailed characterisation of the ternary blend systems implies that the ternary small molecule EH-5T-TTC functions differently in polymer:fullerene and polymer:non-fullerene blends and has dual functions of morphology modification and complementary spectral absorption

    A peptide mimic of the chemotaxis inhibitory protein of Staphylococcus aureus: towards the development of novel anti-inflammatory compounds

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    Complement factor C5a is one of the most powerful pro-inflammatory agents involved in recruitment of leukocytes, activation of phagocytes and other inflammatory responses. C5a triggers inflammatory responses by binding to its G-protein-coupled C5a-receptor (C5aR). Excessive or erroneous activation of the C5aR has been implicated in numerous inflammatory diseases. The C5aR is therefore a key target in the development of specific anti-inflammatory compounds. A very potent natural inhibitor of the C5aR is the 121-residue chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS). Although CHIPS effectively blocks C5aR activation by binding tightly to its extra-cellular N terminus, it is not suitable as a potential anti-inflammatory drug due to its immunogenic properties. As a first step in the development of an improved CHIPS mimic, we designed and synthesized a substantially shorter 50-residue adapted peptide, designated CHOPS. This peptide included all residues important for receptor binding as based on the recent structure of CHIPS in complex with the C5aR N terminus. Using isothermal titration calorimetry we demonstrate that CHOPS has micromolar affinity for a model peptide comprising residues 7–28 of the C5aR N terminus including two O-sulfated tyrosine residues at positions 11 and 14. CD and NMR spectroscopy showed that CHOPS is unstructured free in solution. Upon addition of the doubly sulfated model peptide, however, the NMR and CD spectra reveal the formation of structural elements in CHOPS reminiscent of native CHIPS

    Protecting eyewitness evidence: Examining the efficacy of a self-administered interview tool

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    Given the crucial role of eyewitness evidence, statements should be obtained as soon as possible after an incident. This is not always achieved due to demands on police resources. Two studies trace the development of a new tool, the Self-Administered Interview (SAI), designed to elicit a comprehensive initial statement. In Study 1, SAI participants reported more correct details than participants who provided a free recall account, and performed at the same level as participants given a Cognitive Interview. In Study 2, participants viewed a simulated crime and half recorded their statement using the SAI. After a delay of 1 week, all participants completed a free recall test. SAI participants recalled more correct details in the delayed recall task than control participants

    Number crunching in the cancer stem cell market

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    Like their normal counterparts, many tumours are thought to have a hierarchical organization, albeit a disorganized one. Accordingly, the concept of cancer stem cells has emerged, and that these cells are responsible for perpetuating tumour existence. Operationally, cancer stem cells are regarded as prospectively purified cells that are the most effective at tumour initiation in an in vivo assay, usually after xenotransplantation to NOD/SCID mice. The conventional wisdom is that such tumour-initiating cells are rare based upon having to xenotransplant large numbers of human tumour cells into immunodeficient mice to propagate the tumour, but new evidence indicates that perhaps these cells are not so rare, at least in malignant melanoma, if a supportive soil is provided for the transplanted cells along with further restriction of the murine host's immune response

    Recombining Low Homology, Functionally Rich Regions of Bacterial Subtilisins by Combinatorial Fragment Exchange

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    Combinatorial fragment exchange was utilised to recombine key structural and functional low homology regions of bacilli subtilisins to generate new active hybrid proteases with altered substrate profiles. Up to six different regions comprising mostly of loop residues from the commercially important subtilisin Savinase were exchanged with the structurally equivalent regions of six other subtilisins. The six additional subtilisins derive from diverse origins and included thermophilic and intracellular subtilisins as well as other academically and commercially relevant subtilisins. Savinase was largely tolerant to fragment exchange; rational replacement of all six regions with 5 of 6 donating subtilisin sequences preserved activity, albeit reduced compared to Savinase. A combinatorial approach was used to generate hybrid Savinase variants in which the sequences derived from all seven subtilisins at each region were recombined to generate new region combinations. Variants with different substrate profiles and with greater apparent activity compared to Savinase and the rational fragment exchange variants were generated with the substrate profile exhibited by variants dependent on the sequence combination at each region
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