Search results for "Digest"

Absorption and intestinal catabolism of fatty acids in the rat: effect of chain length and unsaturation

1991

Simultaneous portal blood absorption and intestinal mucosal catabolism of labelled fatty acids were investigated. Anaesthetized adult Wistar rats were infused intraduodenally either with 90 mumol of capric (C10:0), oleic (C18:1), linoleic (C18:2) or arachidonic (C20:4) 1-14C acids or with 30 mumol of each labelled fatty acid in addition to 30 mumol of oleic acid and 30 mumol of monopalmitin. For mixed infusates, experiments were carried out with two additional long-chain fatty acids: palmitic (C16:0) and erucic (C22:1) 1-14C acids. Radioactivity was quantified in the lipids and in the catabolic products in portal blood recovered at 5 min intervals for 1 h after infusion. At the end of the e…

Exploring the limits of anaerobic biodegradability of urban wastewater by AnMBR technology

2018

[EN] Anaerobic membrane bioreactors (AnMBRs) can achieve maximum energy recovery from urban wastewater (UWW) by converting influent COD into methane. The aim of this study was to assess the anaerobic biodegradability limits of urban wastewater with AnMBR technology by studying the possible degradation of the organic matter considered as non-biodegradable as observed in aerobic membrane bioreactors operated at very high sludge retention times. For this, the results obtained in an AnMBR pilot plant operated at very high SRT (140 days) treating sulfate-rich urban wastewater were compared with those previously obtained with the system operating at lower SRT (29 to 70 days). At 140 days SRT the …

Fisiología de la secreción pancreática

2005

Controllable membrane remodeling by a modified fragment of the apoptotic protein Bax.

2021

Intrinsic apoptosis is orchestrated by a group of proteins that mediate the coordinated disruption of mitochondrial membranes. Bax is a multi-domain protein that, upon activation, disrupts the integrity of the mitochondrial outer membrane by forming pores. We strategically introduced glutamic acids into a short sequence of the Bax protein that constitutively creates membrane pores. The resulting BaxE5 peptide efficiently permeabilizes membranes at acidic pH, showing low permeabilization at neutral pH. Atomic force microscopy (AFM) imaging showed that at acidic pH BaxE5 established several membrane remodeling modalities that progressively disturbed the integrity of the lipid bilayer. The AFM…

Ischemia and post-ischemic regeneration of the small intestinal mucosa

1978

After ligation of the vascular arcades of the upper jejunum in rats, the ischemic damage to the intestinal mucosa and its regenerative behavior after ischemia lasting 120 minutes were investigated with histological and enzyme-histochemical methods. During the ischemic injury of the jejunal mucosa, there is rejection of hydropically swollen epithelial cells into the intestinal lumen advancing from the tip to the base of the villi without a previously detectable loss of activity of the enzymes investigated. At the end of ischemia lasting 120 minutes, there is complete destruction of the villi as well as the upper portions of the crypts. After rapid re-epithelialization of the mucosal surface …

Functional Polymer-Opals from Core-Shell Colloids

2007

Colloidal photonic crystals were prepared from monodisperse core-shell particles. The shell is hereby formed from a functional monomer, such as glycidylmethacrylate or different reactive ester monomers, which can perform chemical reactions and the core from a standard monomer, which yields highly monodisperse colloids. It was possible to crystallize the core-shell particles into artificial opals with excellent optical properties. Reactions on the functional surface of the colloids were carried out, which lead to a dramatic rise in the mechanical stability or to a functionalization of His-tagged silicatein, which acts as nanoreactor to synthesize and immobilize gold nanoparticles from auric …

Re-entrant glass transition in a colloid-polymer mixture with depletion attractions.

2002

Performing light scattering experiments we show that introducing short-ranged attraction to a colloidal suspension of nearly hard spheres by addition of free polymer produces new glass transition phenomena. We observe a dramatic acceleration of the density fluctuations amounting to the melting of a colloidal glass. Increasing the strength of the attractions the system freezes into another nonergodic state sharing some qualitative features with gel states occurring at lower colloid packing fractions. This reentrant glass transition is in qualitative agreement with recent theoretical predictions.

Controlling the wetting properties of the Asakura-Oosawa model and applications to spherical confinement.

2012

We demonstrate for the Asakura-Oosawa model and an extension of this model that uses continuous rather than hard potentials, how wetting properties at walls can be easily controlled. By increasing the interaction range of the repulsive wall potential acting on the colloids (while keeping the polymer-wall interactions constant) polymers begin to substitute colloids at walls and the system can be driven from complete wetting of colloids via partial wetting to complete wetting of polymers. As an application, we discuss the morphology and wetting behavior of colloid-polymer mixtures in spherical confinement. We apply the recently developed 'ensemble switch method' where the Hamiltonian is exten…

Salt and fat contents influence the microstructure of model cheeses, chewing/swallowing andin vivoaroma release

2013

The effects of the lipid/protein ratio (20/28, 24/24, 28/20) and salt content of model cheeses were investigated simultaneously with respect to chewing behaviour, swallowing events and in vivo aroma release. Chewing parameters were measured by electromyography. Swallowing events were recorded manually. In vivo aroma release was investigated using nose-space on-line atmospheric pressure chemical ionisation-mass spectrometry. The values for chewing activity and time before swallowing were higher with lower lipid/protein ratios and lower salt contents, due to the greater mechanical resistance of the model cheeses. The corresponding microstructure was made up of smaller and more circular fat dr…

Static Digestion Models: General Introduction

2015

Several in vitro methods have been developed to simulate the physiological conditions of the human gastrointestinal digestion, the simplest being the static methods. The following chapter clarifies the concepts of bioaccessibility and dialyzability, and describes the conditions (pH, enzymes, agitation, etc.) to be applied in oral, gastric and intestinal phases when assessing a food component (nutrient, bioactive or toxin) or a food product, in a single or multi-phase model. The advantages and disadvantages of the static models vs. dynamic and in vivo models are discussed, and a review of specific conditions applied on nutrients (minerals, vitamins, proteins, fatty acids, etc.) and bioactive…