Relative expression of Proglucagon mRNA (gray bar) and GLP-1 protein (black bar) in colonic mucosa of a random selection of control fed and FOS fed rats

mRNA and protein levels were normalized to Actin levels. Expression is shown as means ± SEM (n = 7). **p < 0.01, ***P < 0.001<p><b>Copyright information:</b></p><p>Taken from "Impaired barrier function by dietary fructo-oligosaccharides (FOS) in rats is accompanied by increased colonic mitochondrial gene expression"</p><p>http://www.biomedcentral.com/1471-2164/9/144</p><p>BMC Genomics 2008;9():144-144.</p><p>Published online 27 Mar 2008</p><p>PMCID:PMC2311291.</p><p></p

<i>In vitro</i> gastrointestinal digestion increases the translocation of polystyrene nanoparticles in an <i>in vitro</i> intestinal co-culture model

<div><p></p><p>The conditions of the gastrointestinal tract may change the physicochemical properties of nanoparticles (NPs) and therewith the bioavailability of orally taken NPs. Therefore, we assessed the impact of <i>in vitro</i> gastrointestinal digestion on the protein corona of polystyrene NPs (PS-NPs) and their subsequent translocation across an <i>in vitro</i> intestinal barrier. A co-culture of intestinal Caco-2 and HT29-MTX cells was exposed to 50 nm PS-NPs of different charges (positive and negative) in two forms: pristine and digested in an <i>in vitro</i> gastrointestinal digestion model. <i>In vitro</i> digestion significantly increased the translocation of all, except the “neutral”, PS-NPs. Upon <i>in vitro</i> digestion, translocation was 4-fold higher for positively charged NPs and 80- and 1.7-fold higher for two types of negatively charged NPs. Digestion significantly reduced the amount of protein in the corona of three out of four types of NPs. This reduction of proteins was 4.8-fold for “neutral”, 3.5-fold for positively charged and 1.8-fold for one type of negatively charged PS-NPs. <i>In vitro</i> digestion also affected the composition of the protein corona of PS-NPs by decreasing the presence of higher molecular weight proteins and shifting the protein content of the corona to low molecular weight proteins. These findings are the first to report that <i>in vitro</i> gastrointestinal digestion significantly affects the protein corona and significantly increases the <i>in vitro</i> translocation of differently charged PS-NPs. These findings stress the importance of including the <i>in vitro</i> digestion in future <i>in vitro</i> intestinal translocation screening studies for risk assessment of orally taken NPs.</p></div

Simulation of CFRP components subjected to dynamic crash loads

This paper deals with the investigation of a numerical simulation method to appropriately represent relevant failure mechanisms of carbon fiber reinforced plastic (CFRP) components subjected to dynamic crash loads. The presented work considers the stacked shell approach, using a stack of continuum shell elements and cohesive elements, and focuses on the calibration of simulation input parameters. Furthermore, modeling aspects are discussed to reduce mesh-dependencies for the simulation of progressive crushing. The validation of the numerical approach is performed on the basis of an extensive test program of CFRP crush absorbers on the structural level. The capability of current state-of-the-art technologies for the simulation of progressive crushing is identified. The simulations capture general failure effects and force-displacement characteristics for different designs and loading conditions. Drawbacks are identified in the definition of cohesive input parameters to obtain numerical stability for complex loading conditions. The numerical simulations were performed using the commercial finite element software Abaqus/Explicit