450 research outputs found

    The cellular interactions of PEGylated gold nanoparticles : effect of PEGylation on cellular uptake and cytotoxicity

    Get PDF
    Poly(ethylene glycol) (PEG) is frequently used to coat various medical nanoparticles (NPs). As PEG is known to minimize NP interactions with biological specimens, the question remains whether PEGylated NPs are intrinsically less toxic or whether this is caused by reduced NP uptake. In the present work, the effect of gold NP PEGylation on uptake by three cell types is compared and evaluated the effect on cell viability, oxidative stress, cell morphology, and functionality using a multiparametric methodology. The data reveal that PEGylation affects cellular NP uptake in a cell-type-dependent manner and influences toxicity by different mechanisms. At similar intracellular NP numbers, PEGylated NPs are found to yield higher levels of cell death, mostly by induction of oxidative stress. These findings reveal that PEGylation significantly reduces NP uptake, but that at similar functional (= cell-associated) NP levels, non-PEGylated NPs are better tolerated by the cells

    Crucial Ignored Parameters on Nanotoxicology: The Importance of Toxicity Assay Modifications and “Cell Vision”

    Get PDF
    Until now, the results of nanotoxicology research have shown that the interactions between nanoparticles (NPs) and cells are remarkably complex. In order to get a deep understanding of the NP-cell interactions, scientists have focused on the physicochemical effects. However, there are still considerable debates about the regulation of nanomaterials and the reported results are usually in contradictions. Here, we are going to introduce the potential key reasons for these conflicts. In this case, modification of conventional in vitro toxicity assays, is one of the crucial ignored matter in nanotoxicological sciences. More specifically, the conventional methods neglect important factors such as the sedimentation of NPs and absorption of proteins and other essential biomolecules onto the surface of NPs. Another ignored matter in nanotoxicological sciences is the effect of cell “vision” (i.e., cell type). In order to show the effects of these ignored subjects, we probed the effect of superparamagnetic iron oxide NPs (SPIONs), with various surface chemistries, on various cell lines. We found thatthe modification of conventional toxicity assays and the consideration of the “cell vision” concept are crucial matters to obtain reliable, and reproducible nanotoxicology data. These new concepts offer a suitable way to obtain a deep understanding on the cell-NP interactions. In addition, by consideration of these ignored factors, the conflict of future toxicological reports would be significantly decreased

    A cross-sectional study of nutrient intake and health status among older adults in Yogyakarta Indonesia

    Get PDF
    Many communities around the world, particularly developing countries including Indonesia, are experiencing population ageing. There is little knowledge regarding the impact of malnutrition, or its prevalence within rural compared to urban areas, on the nutritional, functional and mental status of community-living older residents in these countries. Hence, a cross-sectional study was conducted to determine socio-demographic and anthropometric characteristics, nutritional, mental and functional status, and energy and nutrient intake of community-dwelling Indonesians from both rural and urban areas of Yogyakarta. Older individuals were included in the study if they had been living in Yogyakarta for the last year and were aged ≄65 years (n = 527; mean ± SD age of 74 ± 7 years). Rural compared with urban participants had a lower level of education and income, more hospital admissions, less dietary protein intake, lower cognitive function, poorer nutritional status and grip strength, but faster gait speed while being more dependent on assistance to perform daily activities (all p < 0.05). Cognitive function was more strongly associated than nutritional status with physical function. Rural older Indonesians living in Yogyakarta were more likely than urban older people to be malnourished and cognitively impaired, and to have associated reductions in functional capacity and independence. Strategies to improve cognitive function and nutritional status are therefore important for the wellbeing of Indonesian citizens.Tony Arjuna, Stijn Soenen, Rasita Amelia Hasnawati, Kylie Lange, Ian Chapman and Natalie D. Luscombe-Mars

    Mapping children's presence in the neighbourhood

    Get PDF
    Within the work of Gert Biesta, public spaces are considered as the main fields where processes of civic learning can take place. Learning is always “in place and time”. Place matters, not only as a spatial background or set of conditions , but as a pedagogical process in itself. So in order to facilitate processes of civic learning we need to understand how spaces function as a co-educator in its own right.. In my PhD I studied how the neighbourhood can be understood as a co-educator. The processes through which children are socialised into a given order are not universal, nor neutral. One might state that children grow up into very different orders. The neighbourhood is an important factor into these diversified socialisation processes, but the neighbourhood is also made by its residents and users themselves, including children. This emphasises that socialisation is a relational process and not a functional oneway introduction of children into a prescribed social ordeIn this contribution, a methodological framework will be developed for understanding and studying the neighbourhood of children as a co-educator. The basis of this framework is formed by the synergy between spatial, social and personal dimensions of the neighbourhood

    Food services using energy- and protein-fortified meals to assist vulnerable community-residing older adults meet their dietary requirements and maintain good health and quality of life: findings from a pilot study

    Get PDF
    The effects of "standard (STD)" vs. "protein- and energy-enriched (HEHP)" food-service meals on the nutrient intake, nutritional status, functional capacity, and wellbeing of older adults was investigated using a 12 week, double-blinded, parallel group design. All participants received dietetics counseling and either an STD (2.3 MJ and 30 g protein per meal) or a HEHP (4.6 MJ and 60 g protein) hot lunchtime meal for at least 3 days/week; those who did not want food-service meals were included in the control group (CON). Twenty-nine participants completed the study (STD = 7; HEHP = 12; CON = 10). From baseline to week 12, the HEHP subjects increased their mean daily energy intake from 6151 ± 376 kJ to 8228 ± 642 kJ (p = 0.002 for effect of time) and protein intake from 67 ± 4 g to 86 ± 8 g (p = 0.014 for effect of time). The MNA (Mini Nutritional Assessment) score was increased significantly in HEHP by 4.0 ± 1.1 points (p = 0.001), but not in the STD and CON groups (2.8 ± 2.1 points and 1.8 ± 1.1 points, p > 0.05). No difference was found for other clinical outcomes between the groups. The findings indicate that provision of HEHP-fortified food-service meals can increase energy and protein intake and improve the nutritional status of nutritionally at-risk older people.Tony Arjuna, Michelle Miller, Tomoko Ueno, Renuka Visvanathan, Kylie Lange, Stijn Soenen, Ian Chapman and Natalie Luscombe-Mars

    IPC2008-64295 RECENT DEVELOPMENTS OF HIGH STRENGTH LINEPIPE STEELS ON COIL

    Get PDF
    ABSTRACT The present paper deals with the recent steel development for linepipe applications at ArcelorMittal. With the recent upgrade of the downcoiler capabilities in three European steel plants it is now possible to supply hot rolled coils in width up to 2150mm for the economical production of X70 large diameter, spiral welded transmission trunk lines with 25.4mm wall thickness. In view of the increased dimensional feasibility range a couple of new product development projects had been launched. Two of these products with very demanding application properties are already being industrialized. It concerns respectively X70 in 22mm thickness with improved low temperature BDWTT properties (85% shear area at -10°C) and X80 in 16mm, likewise with low temperature BDWTT properties and, additionally, with low Y/T ratio. The first preseries deliveries have been successfully transformed to pipes in one of our client&apos;s spiral welded pipe mill. Another product development project which is still in the conception phase concerns the development of X100 in thickness up to 12.7mm. The actual progress of the mentioned projects will be documented here. Key for the realization of such demanding products is a precise control of the final microstructure. This is in particular true for high strength steels with improved toughness. Therefore, a lot of research efforts were spent in order to understand the link between microstructures and properties. Our current understanding will be detailed in this paper
    • 

    corecore