Role of radicals in UV-initiated postplasma grafting of poly-ε-caprolactone: an electron paramagnetic resonance study

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Working Paper 10-08 - The PLANET Model: Methodological Report

Freight and passenger transport model, Transport externalities

Nonthermal Plasma Technology as a Versatile Strategy for Polymeric Biomaterials Surface Modification: A Review

In modern technology, there is a constant need to solve very complex problems and to fine-tune existing solutions. This is definitely the case in modern medicine with emerging fields such as regenerative medicine and tissue engineering. The problems, which are studied in these fields, set very high demands on the applied materials. In most cases, it is impossible to find a single material that meets all demands such as biocompatibility, mechanical strength, biodegradability (if required), and promotion of cell-adhesion, proliferation, and differentiation. A common strategy to circumvent this problem is the application of composite materials, which combine the properties of the different constituents. Another possible strategy is to selectively modify the surface of a material using different modification techniques. In the past decade, the use of nonthermal plasmas for selective surface modification has been a rapidly growing research field. This will be the highlight of this review. In a first part of this paper, a general introduction in the field of surface engineering will be given. Thereafter, we will focus on plasma-based strategies for surface modification. The purpose of the present review is twofold. First, we wish to provide a tutorial-type review that allows a fast introduction for researchers into the field. Second, we aim to give a comprehensive overview of recent work on surface modification of polymeric biomaterials, with a focus on plasma-based strategies. Some recent trends will be exemplified. On the basis of this literature study, we will conclude with some future trends for research

Improving liquid chromatography efficiency: channels structured with micro-pillars

Band dispersion has been measured in micromachined separation channels structured with orderly disposed cylindrical micropillars. It was found that with an optimal channel design the band broadening could be lower by a factor of 3 than in packed columns with a comparable particle size. The positioning of the row of pillars closest to the side wall was a decisive factor in influencing band broadening

Occurrence cubes : a new paradigm for aggregating species occurrence data

In this paper we describe a method of aggregating species occurrence data into what we coined “occurrence cubes”. The aggregated data can be perceived as a cube with three dimensions - taxonomic, temporal and geographic - and takes into account the spatial uncertainty of each occurrence. The aggregation level of each of the three dimensions can be adapted to the scope. Built on Open Science principles, the method is easily automated and reproducible, and can be used for species trend indicators, maps and distribution models. We are using the method to aggregate species occurrence data for Europe per taxon, year and 1km2 European reference grid, to feed indicators and risk mapping/modelling for the Tracking Invasive Alien Species (TrIAS) project

The role of scaffold architecture and composition on the bone formation by adipose-derived stem cells

Scaffold architecture and composition are crucial parameters determining the initial cell spatial distribution and consequently bone tissue formation. Three-dimensional poly-ε-caprolactone (PCL) scaffolds with a 0/90° lay-down pattern were plotted and subjected to 1) an oxygen plasma (PCL O) or 2) a post-argon plasma modification with gelatine and fibronectin (PCL Fn). These scaffolds with an open pore structure were compared with more compact scaffolds fabricated by conventional processing techniques: oxidized polylactic acid (LA O) and collagen (COL) scaffolds. Human adipose tissue derived stem cell/scaffold interaction was studied. The study revealed that the biomimetic surface modification of plotted scaffolds did not increase the seeding efficiency. The proliferation and colonization was superior for PCL Fn in comparison with PCL O. The plotted PCL Fn was completely colonized throughout the scaffold whereas conventional scaffolds only at the edge. Protein-based scaffolds (PCL Fn and COL) enhanced the differentiation, although plotted scaffolds showed a delay in their differentiation compared with compact scaffolds. In conclusion, protein modification of plotted PCL scaffolds enhances uniform tissue formation but shows a delayed differentiation in comparison with compact scaffolds. The present study demonstrates that biomimetic PCL scaffolds could serve as a guiding template to obtain a uniform bone tissue formation in vivo

The effects of hypo- and hyperglycemia during lipolysis-like conditions on bovine oocyte maturation, subsequent embryo developmental and glucose metabolism

Abstract of a conference paper presented at the 31st meeting of the European Embryo Transfer Associaton, 11-12 September 2015, Ghent, Belgium

Whip: Human and machine-readable specifications for data

Different tools and technologies are available to clean and harmonize data. Independent of the tool used, the ability to assess the quality of a data set and identify potential errors is crucial for harmonization efforts. The necessity becomes even more apparent in the context of data publication, (re)use and aggregation. Documentation and guidelines about the data requirements provide guidance in this process and enable to communicate what to expect from the data, but are mostly intended for humans only. To facilitate the harmonization process, we propose the usage of a specification file, describing the constraints to which the data should comply. Its syntax is human- and machine-readable, so it can be used to communicate expected data quality/conformity and to validate data automatically. The scope of the set of specifications can be specific to a dataset, researcher or research community, which allows bottom-up and top-down adoption. As an example, we apply the specifications to verify data mapped to the biodiversity information standard Darwin Core. In this talk, we will present "whip", a proposed syntax and format to express data specifications. Whip allows to define column-based constraints for tabular (tidy) data with a number of rules. We will also demonstrate a software application (called "pywhip") to validate data sets using these specifications. We hope it will trigger a discussion on how to express data specifications and communicate data quality expectations