1,721,188 research outputs found
Op weg naar een toxicologisch relevante definitie van nanomaterialen
No full textIntroduction and Background:
Nanotechnology is one of the fastest growing technologies in the current century and is applied in many aspects of our daily life as Manufactured Nanoparticles (MNPs) or as Manufactured Nanomaterials (MNMs), e.g. in cosmetics and skin care products, clothing, food additives, waste water treatment, specific drug delivery in the body etc. Growing production and use of Manufactured nanomaterials (MNMs) increased the risk of human exposures and raised the global concern over the potential adverse effects of MNMs. In real world applications and in exposure scenarios, MNMs also exist as aggregates and/or agglomerates (AA) of primary particles with one or more external dimensions in the size range of 1 to 100 nm. However, the biological behaviour/toxicity of the AA is not explored in detail. In addition, the current EU definition for the MNM also comprised of AA, but its toxicological relevance is not verified. Such a discrepancy, not only affecting the risk assessment of MNMs but also hamper the application of regulations and the development of guidelines to monitor SNPs in products and goods.
Methods:
The nano-silica (nSiO2) will be used as a model to evaluate the influence of AA on toxicity and for size distribution, nano-titanium dioxide (nTiO2) will be used. In in vitro studies, MNMs will be exposed to human cell lines such as pulmonary human cell lines (e.g.16 HBE), intestinal cell lines (e.g. Caco2 cells) and macrophages (derived from monocytes THP-1). At the end of exposure, end points such as markers of inflammation (ELISA), oxidative stress (glutathione content) and genotoxicity (comet assay) will be assessed. For in-vivo studies, Swiss albino male mice will be exposed to MNM at different doses and sacrificed at different time points. At the end of exposure, the cells (lung, BAL, blood) will be routinely processed for comet assay to determine the genotoxic potential and, to investigate the other biological end points such as tissue damage, translocation of nanomaterial, markers of inflammation and oxidative stress.
Expected outcomes:
From the results of in vitro and in vivo studies, the influence of MNM AA and size distribution on toxicity will be compared and analysed. The biological responses due to chronic MNM exposure will also be evaluated. Furthermore, a better understanding of MNM interference at the biological barriers and potential to translocate across these barriers will be established. Subsequently, this project will contribute to build knowledge on the potential risk of MNM for the environment and for human beings, such that a safer use of these materials can be implemented. Building knowledge in this area is one of the prerequisite to safer design and further improvement of the nanotechnologies.status: Published onlin
Impact of lung surfactant on wettability and cytotoxicity of nanoparticles
No full textThe importance of nanoparticle characterization for nanotoxicology has been extensively emphasized and it has been universally agreed that the most important parameters for characterizing nanomaterials are specific surface area and surface properties (chemistry, hydro-philicity/phobicity, charge etc.). This study is proposing the use of enthalpy of wetting which depends on both specific surface area and surface properties, is easily measurable and proves to be highly relevant for predicting nanoparticles' dispersion state and their interaction with the lungs. It also shows the conditioning effect of the lung surfactant main component, DPPC on the surface of particles when used in concentrations which mimic pulmonary exposure more closely
EXIMIOUS SOP for collection, storage and shipment of biological samples (updated version 3)
No full textThis deliverable presents the standard operating procedures (SOP) for the collection, processing and shipment of biological samples in the EXIMIOUS human cohort studies.
It is first described how the sampling relates to the project’s objectives and work plan. Biological samples are collected and processed in relation to WP3, WP4 and WP5. Thereafter, the process of collection, processing and shipment is described in detail with step-by-step instructions. Partners handling the biological samples will follow the instructions presented in this deliverable
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
EXIMIOUS questionnaire for participants
No full textThis research data entails a questionnaire for the collection of exposome information in the different EXIMIOUS cohorts. It interrogates basic demographic and anthropometric information, education, habits regarding smoking, diet, alcohol, and exercise, hobbies and activities, household product use, pets, metal implants, tattoos, sleeping difficulties, and post-COVID hygiene. The questionnaire is in English but is also available in other languages (Dutch, Danish, Spanish, and Romanian) upon request
- …
