Search results for "Permeability"

Endotoxaemia resulting from decreased serotonin tranporter (5-HTT) function: A reciprocal risk factor for depression and insulin resistance?

2015

International audience; Depression and diabetes are serious diseases with an increasing global prevalence. Intriguingly, recent meta-analyses have highlighted an asymmetrical relationship between the two conditions as depressed patients were found to display a higher risk of developing type 2 diabetes than those individuals suffering from diabetes are to become depressed. Based on recent findings, we favor a hypothesis where by decreased peripheral serotonin (5-HT) transporter (5-HTT) function is a reciprocal risk factor for the comorbidity of depression and diabetes, as it can trigger inflammatory pathogenetic mechanisms of both conditions. Higher intestinal levels of 5-HT and 5-HT3 recept…

Cellulose Nanocrystals from Lignocellulosic Raw Materials

2017

Cellulose nanocrystals (CNCs) are unique, renewable top-down nano particles from which coatings with improved gas barrier properties and new functionalities can be prepared. In this paper, the potential for obtaining such high performing nanocrystals from low-cost lignocellulosic by-products or raw materials is proved by a comparison study on CNCs obtained both from cotton linters and kraft pulp, by means of the ammonium persulfate (APS) process. Morphological and chemical characterization of the nanocrystals obtained, as well as the main functional properties of the poly(ethylene terephthalate) coated films, showed quite similar characteristics and performances of CNCs obtained from pure c…

Deformation mechanism and hydraulic properties of normal and strike-slip fault zones in porous carbonates outcropping in central and southern Italy.

2013

Deformation of porous carbonate grainstones takes generally place by compactive shear banding, which initially produce single bands that may evolve during incremental strain into zones of multiple bands and, eventually, fault zones with discrete slip surfaces. The several processes associated to increased deformation are recorded in the aforementioned structural elements. In fact, they are characterized by a different texture, porosity, dimensional attributes (length, thickness, displacement). Fault zones are characterized by inner fault cores made of cataclastic material surrounded by thicker damage zones including single bands and zones of bands. In this work, we present the results of in…

1D Compression Behaviour of Opalinus Clay

2017

One of the main concerns related to tunnel excavations, drilling operations and wellbore stability in shales is the generation of excess pore water pressure due to changes in mechanical stress; therefore the consolidation of shales is a fundamental process that must be considered. This paper presents a compre- hensive methodology for analysing the compression and consolidation behaviour of shales. An apparatus to perform high-pressure oedometric tests is presented and an analytical method is introduced to analyse the shale consolidation behaviour, which allows information to be gathered on the coeffi cient of consolidation, stiffness, poroelastic properties, and permeability of the tested m…

2+2=7. If the project improves its parts

2016

The International Open City Summer School of Piacenza 2015 involved the participants in the design of a spread museum of the agriculture between rural and urban areas, crossing the old town of Piacenza. The submitted project, processed in that workshop, is an occasion to call in question the different scales of the design and some linked themes like the measure, the porosity and the permeability of the architecture and the town. Within the design of the museum, the experimentation of an “intermediate scale” reached us to the need of the architecture as connection of various parts, thus to the difference between mending and making something new. At the end, the challenge is that the sum of t…

Fluid-structure interaction and flow redistribution in membrane-bounded channels

2019

The hydrodynamics of electrodialysis and reverse electrodialysis is commonly studied by neglecting membrane deformation caused by transmembrane pressure (TMP). However, large frictional pressure drops and differences in fluid velocity or physical properties in adjacent channels may lead to significant TMP values. In previous works, we conducted one-way coupled structural-CFD simulations at the scale of one periodic unit of a profiled membrane/channel assembly and computed its deformation and frictional characteristics as functions of TMP. In this work, a novel fluid&ndash

Performance Comparison of Alternative Hollow-Fiber Modules for Hemodialysis by Means of a CFD-Based Model

2022

Commercial hemodialyzers are hollow-fiber cylindrical modules with dimensions and inlet–outlet configurations dictated mostly by practice. However, alternative configurations are possible, and one may ask how they would behave in terms of performance. In principle, it would be possible to depart from the standard counter-flow design, while still keeping high clearance values, thanks to the increase in the shell-side Sherwood number (Sh) due to the cross-flow. To elucidate these aspects, a previously developed computational model was used in which blood and dialysate are treated as flowing through two interpenetrating porous media. Measured Darcy permeabilities and mass transfer coefficients…

Gliadin, zonulin and gut permeability: effects on celiac and non-celiac intestinal mucosa and intestinal cell lines.

2006

On the hydro-mechanical behaviour of remoulded and natural Opalinus Clay shale

2016

The geo-energy sector makes use of advanced technologies such as shale gas extraction, CO2 sequestration and nuclear waste geological disposal that rely on the exploitation of shale formations. Due to the great depths involved in these applications and the difficulties in retrieving intact samples, remoulded shale specimens are often adopted for hydro-mechanical testing. Remoulded and intact shales may substantially differ in their hydro-mechanical behaviour due to the particular structure of the natural material, which is the result of diagenesis and burial history. This paper presents an experimental campaign aimed at (i) characterizing the role of diagenesis and depth for Opalinus Clay s…

Bioadhesive monolayer film for the in vitro transdermal delivery of sumatriptan

2006

The work presented here aims to develop a bioadhesive monolayer film containing sumatriptan as adjuvant for the treatment of headache pain in a severe migraine attack. Permeation experiments were performed from the films prepared and from the respective solution, to evaluate the relevant permeation parameters. The effect of the penetration enhancers Transcutol, 2-pyrrolidone, and polyethylene glycol 600 was evaluated. The results obtained show that Transcutol and 2-pyrrolidone decreased sumatriptan permeation from solution, whereas a modest increase was produced by polyethylene glycol 600. The enhancers produced the same effects when they were included in the film. Compared to solution, the…