1,896 research outputs found
Protein-based materials, toward a new level of structural control
Through billions of years of evolution nature has created and refined structural proteins for a wide variety of specific purposes. Amino acid sequences and their associated folding patterns combine to create elastic, rigid or tough materials. In many respects, nature’s intricately designed products provide challenging examples for materials scientists, but translation of natural structural concepts into bio-inspired materials requires a level of control of macromolecular architecture far higher than that afforded by conventional polymerization processes. An increasingly important approach to this problem has been to use biological systems for production of materials. Through protein engineering, artificial genes can be developed that encode protein-based materials with desired features. Structural elements found in nature, such as β-sheets and α-helices, can be combined with great flexibility, and can be outfitted with functional elements such as cell binding sites or enzymatic domains. The possibility of incorporating non-natural amino acids increases the versatility of protein engineering still further. It is expected that such methods will have large impact in the field of materials science, and especially in biomedical materials science, in the future
Individualisation of Mycophenolate Mofetil Therapy: Explaining variability in mycophenolic acid pharmacokinetics and introducing therapeutic
The prodrug mycophenolate mofetil contains the active compound mycophenolic acid (MPA), which has
immunosuppressive properties. It is used to prevent acute rejection after solid organ transplantation.
In renal transplantation, the dose recommendation for mycophenolate mofetil is 1000 mg twice daily
for adult patients. This fixed dose strategy for mycophenolate mofetil is remarkable in the field of
transplantation as most other immunosuppressive drugs are used in an individualised dose, often
based on drug concentration measurements. During the use of mycophenolate mofetil in the past ten
years, data have become available which provide four reasons to question the justification of a fixed
mycophenolate mofetil dose. The first reason is the existence of a concentration-effect relationship: the
risk for acute rejection is lower when exposure to MPA is higher. This has led to the adoption of a target
exposure range for MPA area-under-the-curve (AUC0-12) values of 30 to 60 mg*h/L. The second reason
is the large between-patient variability in MPA pharmacokinetics, reported to be more than 10-fold for
MPA AUC0-12. The third reason is that MPA exposure increases over time after transplantation despite
a fixed dose. Finally, exposure to MPA is significantly influenced by the use of several other drugs.
The result of these four factors is that with the use of a standard dose of mycophenolate mofetil, an
important subset of renal transplant recipients will have MPA exposure outside the target range, and
may therefore be at risk for acute rejection or toxicity. Individualisation of the mycophenolate mofetil
dose is likely to improve exposure to MPA and may optimise clinical outcome.
The aim of this thesis was to develop recommendations about when and how to individualise
the mycophenolate mofetil dose. Two hypotheses in this regard were addressed, formulated in
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Territorial Factors in a Globalised Art World?
In comparison to other disciplines of high culture, the visual arts seem to be the most suitable to internationalise (cf. Crane, 1992; Janssen, Kuipers & Verboord, 2008). The global diffusion of visual art works, for example, is far less complex than that of the performing arts, which entails an impressive transportation operation of both goods – instruments, sets, costumes – and the actors involved, such as orchestra musicians, theatre company actors or dancers. The global distribution of literature, meanwhile, is easier to achieve than is the case for the visual arts, yet language obstacles manifestly hinder its internationalisation (Heilbron, 1999; Janssen, 2009; Sapiro, 2010). Indeed, the only way to overcome such hurdles is when the author provides a translation of the work, or when the reader learns the foreign language in which it is written (De Swaan, 2001). This is similar in the case of theatre plays or the cinema (Hofstede, 2000). On the other hand, the visual language is deemed to be universal and is unhindered by these issues. In short, while the internationalisation of other domains demands different kinds of investment, the visual arts seem to have the best conditions for artists to conquer the world
Standaardnederlands, de sleutel tot integratie in Vlaanderen? Over de uitdagingen van niet-standaardtaal voor NT2-leerders in Vlaanderen
Flanders strongly encourages newcomers to take language courses to learn the official language, on the assumption that certified competence in Dutch will enhance integration. However, in Dutch L2-education the focus lies on Standard Dutch, and this contrasts to everyday spoken encounters in Flanders, where Standard Dutch is rarely used. Despite the perceived importance of learning the official language of the host society, the attested contrast between policy and language reality has up to now not been given much attention. In this publication we go into the results of a linguistic-ethnographic study conducted with language learners living in East-Flanders. We show that non-standard Dutch used by L1-speakers of Dutch sometimes causes comprehension difficulties in their interactions with the language learners. Based on interactional and interview data, we reflect on the question if L2-education should pay more attention to non-standard Dutch in class
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