297 research outputs found

    Surface Modulation Towards Next Generation Vascular Grafts

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    This Thesis is based on the surface modification of a platform-technology polymer, POSS-PCU. This POSS-PCU polymer has been primarily developed for use as a small diameter vascular bypass graft. The mechanical properties and compliance of this material is thought to be superior to current vascular graft materials in clinical use. However, the lack of endothelialisation of this polymer in preclinical evaluation is a cause for concern. The hydrophobic nature of the POSS-PCU polymer is thought to be the culprit and therefore the need to render the surface of the polymer suitable for endothelialisation forms the basis of this Thesis. It is possible to engineer the surface of the polymer without affecting the beneficial bulk properties of the polymer. Recent technological advances have made this possible. A combination of plasma treatment and surface topology modification on the micro- and nanoscale has been shown to encourage the growth of endothelial cells. However, nanofeatures show a subtle improvement in endothelial cell adherence. Two different nanopit topographies, SQ and NSQ, have formed the main focus of this Thesis to further investigate the effect of nanotopography on endothelial cells. These two topographies are different from each other only by an offset of 50nm and therefore are very similar. Despite this, they have shown to illicit different responses by the endothelial cells, especially in the up-regulation of different adhesion proteins. These topographies also have a strong effect on mesenchymal stem cells, by either directing them to maintenance or osteogenic differentiation, and unfortunately this effect can also be enhanced by the presence of endothelial cells, causing calcification. This can be detrimental in a vascular graft. The results of this Thesis highlight the potential of using a combination of plasma treatment and surface nanoengineering to create a new generation of vascular graft, that requires further investigation

    How do you define creativity? A qualitative study of undergraduate chemistry students’ perspectives.

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    As technology continues to become more sophisticated, human thought in a professional setting will become more dependent on creativity. Employers around Australia identify creativity as a highly sought after attribute of recent graduate. To better understand how universities can develop STEM students’ creativity, an open-ended questionnaire was administered to first, second and third year undergraduate chemistry students at Monash University in semester one of 2019. Over 900 students completed the questionnaire which was processed through via NVivo. When asked to define creativity, students commonly identified themes of “originality and innovation” which aligned with the existing literature. Additional themes uncommon to the literature, such as “expression” and “problem solving” were also expressed. Within their studies, students identified self-directed activities such as the laboratories, assignments, and “teamwork activities” where opinions and thoughts are discussed most developed their creativity. Finally, students most commonly associated creativity with performing or creative arts in their extracurricular activities and suggested that these activities helped develop their problem solving, team work and experimentation within a STEM context. Once this data is triangulated with educators and employer perspectives, we anticipate an undergraduate teaching intervention can be designed to improve STEM students’ learning outcomes in creativity

    Integrated Polyphenol-Based Hydrogel Templating Method for Functional and Structured Oxidic Nanomaterials

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    A straightforward fabrication method for tunable nanomaterials remains a key objective in the research areas of template chemistry, catalysis, and energy storage materials. A growing focus in materials chemistry is the development of structuring methods that are simple, scalable, and, at the same time, feasible with environmentally benign chemicals. We present a hydrogel-mediated templating method that yields customizable, porous transition-metal oxides. The protocol is extremely simple and includes predominately naturally occurring compounds. For example, the incorporation of sacrificial polymer latex into a polyphenolic hydrogel network produces xerogel composites with various filler contents. Voids are generated simultaneously during the pyrolysis of the dried gel, allowing for controlling the three-dimensional (3D) arrangement of titania nanocrystals. As a proof of concept, we use the produced macroporous titania as a negative electrode (anode) material in lithium-ion batteries. We demonstrate that the gel-derived macroporous anatase significantly reduces the capacity loss compared to its commercial or nonporous analogues. The modularity of this one-pot templating protocol is further demonstrated by the fabrication of titanate nanostructures and porous zirconia

    Reaction-kinetics of organo-clay hybrid films: in-situ IRRAS and AFM studies

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    In this paper we have reported the reaction kinetics of nano dimensional clay saponite and hectorite with an amphiphilic cation octadecyl rhodamine B (RhB) in hybrid Langmuir monolayer at the air-water interface. The surface pressure-molecular area (pi-A) isotherms were strongly influenced by the presence of clay with the lift-off area of the cationic amphiphile shifted to progressively larger area. In-situ infrared reflection absorption spectroscopy (IRRAS) was used to demonstrate the reaction kinetics. Time taken to complete the reaction kinetics for RhB-hectorite hybrid films is larger than RhB-saponite hybrid films. Atomic force microscopic images of hybrid Langmuir-Blodgett films give compelling visual evidence of the incorporation of clay platelets into the hybrid films and density of which increases with the progress of reaction kinetics.Comment: 11 pages, 5 figure

    The State of Altmetrics: A Tenth Anniversary Celebration

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    Altmetric’s mission is to help others understand the influence of research online.We collate what people are saying about published research in sources such as the mainstream media, policy documents, social networks, blogs, and other scholarly and non-scholarly forums to provide a more robust picture of the influence and reach of scholarly work. Altmetric works with some of the biggest publishers, funders, businesses and institutions around the world to deliver this data in an accessible and reliable format. Contents Altmetrics, Ten Years Later, Euan Adie (Altmetric (founder) & Overton) Reflections on Altmetrics, Gemma Derrick (University of Lancaster), Fereshteh Didegah (Karolinska Institutet & Simon Fraser University), Paul Groth (University of Amsterdam), Cameron Neylon (Curtin University), Jason Priem (Our Research), Shenmeng Xu (University of North Carolina at Chapel Hill), Zohreh Zahedi (Leiden University) Worldwide Awareness and Use of Altmetrics, Yin-Leng Theng (Nanyang Technological University) Leveraging Machine Learning on Altmetrics Big Data, Saeed-Ul Hassan (Information Technology University), Naif R. Aljohani (King Abdulaziz University), Timothy D. Bowman (Wayne State University) Altmetrics as Social-Spatial Sensors, Vanash M. Patel (West Hertfordshire Hospitals NHS Trust), Robin Haunschild (Max Planck Institute for Solid State Research), Lutz Bornmann (Administrative Headquarters of the Max Planck Society) Altmetric’s Fable of the Hare and the Tortoise, Mike Taylor (Digital Science) The Future of Altmetrics: A Community Vision, Liesa Ross (Altmetric), Stacy Konkiel (Altmetric

    Synergistic and competitive aspects of the adsorption of Poly(ethylene glycol) and Poly(vinyl alcohol) onto Na-Bentonite

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    Graph Presented) The competitive adsorption of poly(ethylene glycol) (PEG) and poly(vinyl alcohol) (PVOH) onto Na-bentonite has been assessed quantitatively. Particular emphasis was focused on the amount of organic located within the bentonite interlayer and any subsequent eff ects on the extent of layer expansion. The individual isotherms showed strong adsorption for both PVOH and PEG at amounts lower than the quantities required to produce a fully loaded bilayer (0.33 g of PVOH/g of clay) and single layered structures (0.10 g of PEG/g of clay), respectively. Above these concentrations, the incremental amounts adsorbed were smaller, and the concentration of adsorbates in solution gradually increased. Na-bentonite adsorbed more PVOH than PEG at any given concentration. In the competitive study, the amount of PVOH adsorbed was enhanced in the presence of PEG (0.10 and 0.30 g/g of clay), but less PEG was adsorbed. At low loadings of PVOH (0.02-0.10 g/g of clay), the amount of adsorbed PEG was increased but at higher PVOH levels PEG adsorption was reduced. The XRD data showed stepped changes in the d-spacing as the adsorbed amounts of both PEG and PVOH increased. The PEG-bentonite samples did not expand beyond a bilayer structure (18 A˚), but the XRD data for PVOH-treated samples indicated the formation of multilayer structures (d ≥ 44 A˚)

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    BRCA1 and BRCA2 Germline Mutations in Malaysian Women with Early-Onset Breast Cancer without a Family History

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    BACKGROUND: In Asia, breast cancer is characterised by an early age of onset: In Malaysia, approximately 50% of cases occur in women under the age of 50 years. A proportion of these cases may be attributable, at least in part, to genetic components, but to date, the contribution of genetic components to breast cancer in many of Malaysia's ethnic groups has not been well-characterised. METHODOLOGY: Given that hereditary breast carcinoma is primarily due to germline mutations in one of two breast cancer susceptibility genes, BRCA1 and BRCA2, we have characterised the spectrum of BRCA mutations in a cohort of 37 individuals with early-onset disease (<or=40 years) and no reported family history. Mutational analysis of BRCA1 and BRCA2 was conducted by full sequencing of all exons and intron-exon junctions. CONCLUSIONS: Here, we report a total of 14 BRCA1 and 17 BRCA2 sequence alterations, of which eight are novel (3 BRCA1 and 5 BRCA2). One deleterious BRCA1 mutation and 2 deleterious BRCA2 mutations, all of which are novel mutations, were identified in 3 of 37 individuals. This represents a prevalence of 2.7% and 5.4% respectively, which is consistent with other studies in other Asian ethnic groups (4-9%)

    Production of fiberboards from shives collected after continuous fiber mechanical extraction from oleaginous flax

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    In this study, fiberboards were produced from shives collected after continuous fiber mechanical extraction from oleaginous flax straw. Fiberboards were produced through thermo-pressing, and their mechanical and thermomechanical properties were studied, as well as their water resistance. The influence of two pretreatments for shives and lignin addition was investigated on the different properties. Boards obtained were all cohesive hardboards. The optimal board was obtained from fibers extruded from the shives and without addition of any supplementary lignin amount. Looking at its characteristics and standard NF EN 312, the latter perfectly complied with the requirements for type P1 boards, i.e., boards for general uses in dry conditions

    The serious games ecosystem: Interdisciplinary and intercontextual praxis

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    This chapter will situate academia in relation to serious games commercial production and contextual adoption, and vice-versa. As a researcher it is critical to recognize that academic research of serious games does not occur in a vaccum. Direct partnerships between universities and commercial organizations are increasingly common, as well as between research institutes and the contexts that their serious games are deployed in. Commercial production of serious games and their increased adoption in non-commercial contexts will influence academic research through emerging impact pathways and funding opportunities. Adding further complexity is the emergence of commercial organizations that undertake their own research, and research institutes that have inhouse commercial arms. To conclude, we explore how these issues affect the individual researcher, and offer considerations for future academic and industry serious games projects
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