1,202 research outputs found

    Directing cell migration using micropatterned and dynamically adhesive polymer brushes

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    This work was funded by the BBSRC, New Investigator Award (BB/J000914/1)

    Highly Stable RNA Capture by Dense Cationic Polymer Brushes for the Design of Cytocompatible, Serum-Stable SiRNA Delivery Vectors

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    The high density of polymer brushes confers to these coatings unique physicochemical properties, in particular for the regulation of biomolecular interaction and the design of highly selective coatings for biosensors and protein patterning. Here, we show that high density poly­(dimethylaminoethyl methacrylate) cationic polymer brushes enable the stable uptake of high levels of oligonucleotides. This is proposed to result from the high degree of crowding and associated increase in entropic driving force for the binding of polyelectrolytes such as nucleic acid molecules. We further demonstrate the ease with which such coatings allow the design of highly structured nanomaterials for siRNA delivery using block copolymer-brush-based nanoparticles that allow the protection of oligonucleotides by a protein-resistant outer block. In particular, these nanomaterials display a high serum stability and low cytotoxicity while retaining excellent knock down efficiencies. Polymer brush-based nanomaterials therefore appear particularly attractive for the rational design of a new generation of high performance theranostics and RNA delivery probes

    Contractile myosin rings and cofilin-mediated actin disassembly orchestrate ECM nanotopography sensing

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    The nanotopography and nanoscale geometry of the extra-cellular matrix (ECM) are important regulators of cell adhesion, motility and fate decision. However, unlike the sensing of matrix mechanics and ECM density, the molecular processes regulating the direct sensing of the ECM nanotopography and nanoscale geometry are not well understood. Here, we use nanotopographical patterns generated via electrospun nanofibre lithography (ENL) to investigate the mechanisms of nanotopography sensing by cells. We observe the dysregulation of actin dynamics, resulting in the surprising formation of actin foci. This alteration of actin organisation is regulated by myosin contractility but independent of adapter proteins such as vinculin. This process is highly dependent on differential integrin expression as β3 integrin expressing cells, more sensitive to nanopattern dimensions than β1 integrin expressing cells, also display increased perturbation of actin assembly and actin foci formation. We propose that, in β3 integrin expressing cells, contractility results in the destabilisation of nanopatterned actin networks, collapsing into foci and sequestering regulators of actin dynamics such as cofilin that orchestrate disassembly. Therefore, in contrast to the sensing of substrate mechanics and ECM ligand density, which are directly orchestrated by focal adhesion assembly, we propose that nanotopography sensing is regulated by a long-range sensing mechanism, remote from focal adhesions and mediated by the actin architecture

    Differential integrin expression regulates cell sensing of the matrix nanoscale geometry

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    Funding from Institute of Bioengineering (Queen Mary, University of London) and from the Engineering and Physical Sciences Research Council (EP/J501360/1) is gratefully acknowledged

    NF-κB, stem cells and breast cancer: the links get stronger

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    Self-renewing breast cancer stem cells are key actors in perpetuating tumour existence and in treatment resistance and relapse. The molecular pathways required for their maintenance are starting to be elucidated. Among them is the transcription factor NF-κB, which is known to play critical roles in cell survival, inflammation and immunity. Recent studies indicate that mammary epithelial NF-κB regulates the self-renewal of breast cancer stem cells in a model of Her2-dependent tumourigenesis. We will describe here the NF-κB-activating pathways that are involved in this process and in which progenitor cells this transcription factor is actually activated

    Personality, personnel selection, and job performance

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    Job Performance: The term job performance can either refer to the objective or subjective outcomes one achieves in a specific job (e.g., the profit of a sales persons, the number of publications of a scientist, the number of successful operations of a surgeon) or to work-related activities (e.g., writing an article, conducting specific surgical acts). In the majority of research on this topic, job performance as an outcome is used. Personnel selection: Personnel selection refers to the process of selecting the best employees for specific jobs. Introduction One major application of personality research is in the area of personnel selection. The key question in this area is to which extent personality can predict how well a candidate will perform on the job he or she is applying for. Most scholars in this area acknowledge that personality has predictive validity for job performance. In line with this, personality assessment is part of the selection procedure in many organizations

    Opposite poles: A comparison between two Spanish regions in health-related quality of life, with implications for health policy

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    <p>Abstract</p> <p>Background</p> <p>Although health is one of the main determinants of the welfare of societies, few studies have evaluated health related quality of life in representative samples of the population of a region or a country. Our aim is to describe the health-related quality of life of the inhabitants of two quite different Spanish regions (Canary Islands and Catalonia) and to compare the prevalence of health problems between age-sex groups.</p> <p>Methods</p> <p>We use data obtained from the 2006 Health Survey of Catalonia and the 2004 Canary Islands Health Survey. With an ordinal composite variable measuring HRQOL we identify the association of characteristics of individuals with self-reported quality of life and test for differences between the regions.</p> <p>Results</p> <p>The prevalence of problems in the five EQ-5 D dimensions increases with age and is generally higher for women than for men. The dimension with the highest prevalence of problems is "anxiety/depression", and there is noteworthy the extent of discomfort and pain among Canary Island women. Education, especially among the elderly, has an important effect on health-related quality of life.</p> <p>Conclusions</p> <p>There are substantial structural and compositional differences between the two regions. Regional context is a significant factor, independent of the compositional differences, and the effects of context are manifest above all in women. The findings show the importance of disease prevention and the need for improving the educational level of the population in order to reduce health inequalities.</p

    Can big data solve a big problem? Reporting the obesity data landscape in line with the Foresight obesity system map.

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    BACKGROUND: Obesity research at a population level is multifaceted and complex. This has been characterised in the UK by the Foresight obesity systems map, identifying over 100 variables, across seven domain areas which are thought to influence energy balance, and subsequent obesity. Availability of data to consider the whole obesity system is traditionally lacking. However, in an era of big data, new possibilities are emerging. Understanding what data are available can be the first challenge, followed by an inconsistency in data reporting to enable adequate use in the obesity context. In this study we map data sources against the Foresight obesity system map domains and nodes and develop a framework to report big data for obesity research. Opportunities and challenges associated with this new data approach to whole systems obesity research are discussed. METHODS: Expert opinion from the ESRC Strategic Network for Obesity was harnessed in order to develop a data source reporting framework for obesity research. The framework was then tested on a range of data sources. In order to assess availability of data sources relevant to obesity research, a data mapping exercise against the Foresight obesity systems map domains and nodes was carried out. RESULTS: A reporting framework was developed to recommend the reporting of key information in line with these headings: Background; Elements; Exemplars; Content; Ownership; Aggregation; Sharing; Temporality (BEE-COAST). The new BEE-COAST framework was successfully applied to eight exemplar data sources from the UK. 80% coverage of the Foresight obesity systems map is possible using a wide range of big data sources. The remaining 20% were primarily biological measurements often captured by more traditional laboratory based research. CONCLUSIONS: Big data offer great potential across many domains of obesity research and need to be leveraged in conjunction with traditional data for societal benefit and health promotion
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