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1.
Pectins are dietary fibers with different structural characteristics. Specific pectin structures can influence the gastrointestinal immune barrier by directly interacting with immune cells or by impacting the intestinal microbiota. The impact of pectin strongly depends on the specific structural characteristics of pectin; for example, the degree of methyl-esterification, acetylation and rhamnogalacturonan I or rhamnogalacturonan II neutral side chains. Here, we review the interactions of specific pectin structures with the gastrointestinal immune barrier. The effects of pectin include strengthening the mucus layer, enhancing epithelial integrity, and activating or inhibiting dendritic cell and macrophage responses. The direct interaction of pectins with the gastrointestinal immune barrier may be governed through pattern recognition receptors, such as Toll-like receptors 2 and 4 or Galectin-3. In addition, specific pectins can stimulate the diversity and abundance of beneficial microbial communities. Furthermore, the gastrointestinal immune barrier may be enhanced by short-chain fatty acids. Moreover, pectins can enhance the intestinal immune barrier by favoring the adhesion of commensal bacteria and inhibiting the adhesion of pathogens to epithelial cells. Current data illustrate that pectin may be a powerful dietary fiber to manage and prevent several inflammatory conditions, but additional human studies with pectin molecules with well-defined structures are urgently needed.Subject terms: Mucosal immunology, Translational immunology 相似文献
2.
Groothaert MH Smeets PJ Sels BF Jacobs PA Schoonheydt RA 《Journal of the American Chemical Society》2005,127(5):1394-1395
This work reports on the capability of the O2-activated Cu-ZSM-5 and Cu-MOR zeolites to selectively convert methane into methanol at a temperature of 398 K. A strong correlation between (i) the activity and (ii) the intensity of the 22 700 cm-1 UV-vis band, assigned to the bis(mu-oxo)dicopper core, is found (i) as a function of the reaction temperature, (ii) as a function of the Cu loading of the zeolite, and (iii) in comparison to other Cu materials. These three lines of evidence firmly support the key role of the bis(mu-oxo)dicopper core in this selective, low-temperature hydroxylation of methane. 相似文献
3.
Fred van de Velde Fanny Weinbreck Marijke W. Edelman Erik van der Linden R. Hans Tromp 《Colloids and surfaces. B, Biointerfaces》2003,31(1-4):159-168
Confocal scanning laser microscopy (CSLM) has been used to study the behaviour of mixtures of proteins, gelatine, whey proteins and β-lactoglobulin, and polysaccharides, dextran, gellan gum, carrageenan, gum Arabic, and starch. CSLM proved to be a suitable technique to visualise the microstructure of these (phase separated) mixtures in two and three-dimensional images. Contrast through fluorescence is obtained either by covalent labelling (polysaccharides and proteins) or non-covalent labelling (proteins and starch). Double and triple labelling allows the visualisation of individual components in a complex mixture of biopolymers. 相似文献
4.
Muylaert I Borgers M Bruneel E Schaubroeck J Verpoort F Van Der Voort P 《Chemical communications (Cambridge, England)》2008,(37):4475-4477
Ordered mesoporous phenol/formaldehyde polymers are presented as an ultra stable heterogeneous support for vanadium oxide. 相似文献
5.
Residual Monomer Reduction in Polymer Latex Products by Extraction with Supercritical Carbon Dioxide
Marijke Aerts Jan Meuldijk Maartje Kemmere Jos Keurentjes 《Macromolecular Symposia》2011,302(1):297-304
Summary: Extraction of residual monomer from a latex product with supercritical carbon dioxide ((sc)CO2) in a column was studied. Operating conditions were chosen at 35 °C and 100 bar. For reducing the residual styrene level in a polystyrene latex from 104 ppm to 100 ppm and from 104 ppm to 10 ppm, a countercurrent bubble column with latex as continuous and (sc)CO2 as dispersed phase is suggested. Monomer partitioning was demonstrated to be a key parameter in the equipment design. Monomer transport was found to be governed by the shuttle effect, caused by Brownian motion of the latex to and from the H2O/CO2 interface. The drift-flux approach was followed to determine the column flooding conditions. Small column volumes are obtained. (sc)CO2 is a promising extraction medium for residual monomer reduction in latex products. Performance towards steam stripping is better as the final residual monomer level becomes lower. 相似文献
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7.
Equivalent diffusion coefficient and equivalent diffusion accessible porosity of a stratified porous medium 总被引:2,自引:0,他引:2
Diffusion is an important transport process in low permeability media, which play an important role in contamination and remediation
of natural environments. The calculation of equivalent diffusion parameters has however not been extensively explored. In
this paper, expressions of the equivalent diffusion coefficient and the equivalent diffusion accessible porosity normal to
the layering in a layered porous medium are derived based on analytical solutions of the diffusion equation. The expressions
show that the equivalent diffusion coefficient changes with time. It is equal to the power average with p = −0.5 for small times and converges to the harmonic average for large times. The equivalent diffusion accessible porosity
is the harmonic average of the porosities of the individual layers for all times. The expressions are verified numerically
for several test cases. 相似文献
8.
Lenneke WA van Hooijdonk Muhammad Ichwan Thomas F Dijkmans Theo G Schouten Marijke WA de Backer Roger AH Adan Fons J Verbeek Erno Vreugdenhil Carlos P Fitzsimons 《BMC neuroscience》2009,10(1):2-19
Background
In the adult hippocampus, the granule cell layer of the dentate gyrus is a heterogeneous structure formed by neurons of different ages, morphologies and electrophysiological properties. Retroviral vectors have been extensively used to transduce cells of the granule cell layer and study their inherent properties in an intact brain environment. In addition, lentivirus-based vectors have been used to deliver transgenes to replicative and non-replicative cells as well, such as post mitotic neurons of the CNS. However, only few studies have been dedicated to address the applicability of these widespread used vectors to hippocampal cells in vivo. Therefore, the aim of this study was to extensively characterize the cell types that are effectively transduced in vivo by VSVg-pseudotyped lentivirus-based vectors in the hippocampus dentate gyrus. 相似文献9.
Larring Yngve Pishahang Mehdi Tolchard Julian Lind Anna M. Sunding Martin F. Stensrød Ruth E. Jacobs Marijke Snijkers Frans van der Kolk Tjalling Albertsen Knuth 《Journal of Thermal Analysis and Calorimetry》2020,140(2):577-589
Journal of Thermal Analysis and Calorimetry - The CLOU performance of the CaTixMn0.9?xMg0.1O3 (CMTM) perovskite-type system was investigated, comparing materials produced at laboratory scale... 相似文献
10.
Marijke De Soete 《Journal of Geometry》1987,29(1):50-60
In [2] we dealt with a characterization of the generalized quadrangle Q(4,q), q odd, by introducing the concept of (0,2)-set. The aim of this paper is to give a characterization of P(Q(4,q),L), q odd and L an arbitrary regular line of Q(4,q), by constructing these (0,2)-sets and using the result of [2]. 相似文献