Search results for " permeability"

Anti-inflammatory glycoterpenoids from Scrophularia auriculata.

2000

The activity of the four glycoterpenoids: two saponins, verbascosaponin A and verbascosaponin, and two iridoids, scropolioside A and scrovalentinoside, isolated from Scrophularia auriculata ssp. pseudoauriculata, were studied in different models of acute and chronic inflammation. Both saponins significantly inhibited the mouse paw edema induced by carrageenan and ear edema induced by single and multiple doses of 12-O-tetradecanoylphorbol 13-acetate (TPA). Verbascosaponin A showed a potency twice as high as that of indomethacin in the acute TPA model. Verbascosaponin A and scropolioside A were active after a long latency period against ethyl phenylpropiolate edema, as are glucocorticoids. Wh…

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…

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

Alpha-toxin of Staphylococcus aureus

1991

Alpha-toxin, the major cytotoxic agent elaborated by Staphylococcus aureus, was the first bacterial exotoxin to be identified as a pore former. The protein is secreted as a single-chain, water-soluble molecule of Mr 33,000. At low concentrations (less than 100 nM), the toxin binds to as yet unidentified, high-affinity acceptor sites that have been detected on a variety of cells including rabbit erythrocytes, human platelets, monocytes and endothelial cells. At high concentrations, the toxin additionally binds via nonspecific absorption to lipid bilayers; it can thus damage both cells lacking significant numbers of the acceptor and protein-free artificial lipid bilayers. Membrane damage occu…

Ni2+ toxicity in rice: effect on membrane functionality and plant water content.

2007

The heavy metal nickel is an essential mineral trace nutrient found at low concentrations in most natural soils. However, it may reach toxic levels in certain areas and affect a number of biochemical and physiological processes in plants. Wilting and leaf necrosis have been described as typical visible symptoms of Ni(2+) toxicity. The plasma membrane (PM) of root cells constitutes the first barrier for the entry of heavy metals but also a target of their toxic action. This work studies the relationship between disturbances of membrane functionality and the development of the typical symptoms of Ni(2+) toxicity. Rice plants (Oryza sativa L. cv. Bahia) grown in nutrient medium containing 0.5m…