4,028 research outputs found
The therapeutic management of gut barrier leaking: the emerging role for mucosal barrier protectors
OBJECTIVE:
Gut barrier is a functional unit organized as a multi-layer system and its multiple functions are crucial for maintaining gut homeostasis. Numerous scientific evidences showed a significant association between gut barrier leaking and gastro-intestinal/extra-intestinal diseases.
MATERIALS AND METHODS:
In this review we focus on the relationship between gut barrier leaking and human health. At the same time we speculate on the possible new role of gut barrier protectors in enhancing and restoring gut barrier physiology with the final goal of promoting gut health.
RESULTS:
The alteration of the equilibrium in gut barrier leads to the passage of the luminal contents to the underlying tissues and thus into the bloodstream, resulting in the activation of the immune response and in the induction of gut inflammation. This permeability alteration is the basis for the pathogenesis of many diseases, including infectious enterocolitis, inflammatory bowel diseases, irritable bowel syndrome, small intestinal bacterial overgrowth, celiac disease, hepatic fibrosis, food intolerances and also atopic manifestations. Many drugs or compounds used in the treatment of gastrointestinal disease are able to alter the permeability of the intestinal barrier. Recent data highlighted and introduced the possibility of using gelatin tannate, a mucosal barrier protector, for an innovative approach in the management of intestinal diseases, allowing an original therapeutic orientation with the aim of enhancing mucus barrier activity and restoring gut barrier.
CONCLUSIONS:
These results suggest how the mucus layer recovering, beside the gut microbiota modulation, exerted by gut barrier protectors could be a useful weapon to re-establish the physiological intestinal homeostasis after an acute and chronic injury
CMC Spheres in the Heisenberg Group
We study a family of spheres with constant mean curvature (CMC) in the Riemannian Heisenberg group H1. These spheres are conjectured to be the isoperimetric sets of H1. We prove several results supporting this conjecture. We also focus our attention on the sub-Riemannian limit
A Non-equilibrium STM model for Kondo Resonance on surface
Based on a no-equilibrium STM model, we study Kondo resonance on a surface by
self-consistent calculations. The shapes of tunneling spectra are dependent on
the energy range of tunneling electrons. Our results show that both
energy-cutoff and energy-window of tunneling electrons have significant
influence on the shapes of tunneling spectra. If no energy-cutoff is used, the
Kondo resonances in tunneling spectrum are peaks with the same shapes in the
density of state of absorbed magnetic atoms. This is just the prediction of
Tersoff theory. If we use an energy cutoff to remove high-energy lectrons, a
dip structure will modulate the Kondo resonance peak in the tunneling spectrum.
The real shape of Kondo peak is the mixing of the peak and dip, the so-called
Fano line shape. The method of self-consistent non-equilibrium matrix Green
function is discussed in details.Comment: 11 pages and 8 eps figur
The Cheeger problem in abstract measure spaces
We consider nonnegative (Formula presented.) -finite measure spaces coupled with a proper functional (Formula presented.) that plays the role of a perimeter. We introduce the Cheeger problem in this framework and extend many classical results on the Cheeger constant and on Cheeger sets to this setting, requiring minimal assumptions on the pair measure space perimeter. Throughout the paper, the measure space will never be asked to be metric, at most topological, and this requires the introduction of a suitable notion of Sobolev spaces, induced by the coarea formula with the given perimeter
Efficient chemo-enzymatic transformation of animal biomass waste for eco-friendly leather production
Enzymatically processed animal biomass derived from treated bovine hides (wet blue scraps) is herein used as building block for the synthesis of a novel biopolymer. An enzymatic hydrolysis process allows to produce water-soluble lower molecular weight proteins (Bio-A), which are then reacted with glycerol and maleic anhydride (MA) in order to obtain a new intermediate (Bio-IA). With Bio-IA in hand, co-polymerization in the presence of acrylic acid is then carried out. Hydrolysed biomass, intermediates and the final biopolymer (Bio-Ac) have been characterized by means of NMR, FTIR and GPC analysis. Bio-Ac shows good performance when used as retanning agent to produce leather. Physical and mechanical properties of the leather treated with Bio-Ac have been compared with acrylic resin retanned leather, showing similar performance. The reported protocol represents an environmental-friendly interesting alternative to traditional petrochemical based retanning agents, commonly used by the leather industry
Polar cap absorption events of November 2001 at Terra Nova Bay, Antarctica
Polar cap absorption (PCA) events recorded during November 2001 are investigated by observations of ionospheric absorption of a 30MHz riometer installed at Terra Nova Bay (Antarctica), and of solar proton flux, monitored by the NOAA-GOES8 satellite in geo-synchronous orbit. During this period three solar proton events (SPE) on 4, 19 and 23 November occurred. Two of these are among the dozen most intense events since 1954 and during the current solar cycle (23rd), the event of 4 November shows the greatest proton flux at energies &gt;10MeV. Many factors contribute to the peak intensity of the two SPE biggest events, one is the Coronal Mass Ejection (CME) speed, other factors are the ambient population of SPE and the shock front due to the CME. During these events absorption peaks of several dB (~20dB) are observed at Terra Nova Bay, tens of minutes after the impact of fast halo CMEs on the geomagnetic field. </p><p style="line-height: 20px;"> Results of a cross-correlation analysis show that the first hour of absorption is mainly produced by 84–500MeV protons in the case of the 4 November event and by 15–44MeV protons for the event of 23 November, whereas in the entire event the contribution to the absorption is due chiefly to 4.2–82MeV (4 November) and by 4.2–14.5MeV (23 November). Good agreement is generally obtained between observed and calculated absorption by the empirical flux-absorption relationship for threshold energy <i>E<sub>0</sub></i>=10MeV. From the residuals one can argue that other factors (e.g. X-ray increases and geomagnetic disturbances) can contribute to the ionospheric absorption.<br><br><b>Key words.</b> Ionosphere (Polar Ionosphere, Particle precipitation) – Solar physics (Flares and mass ejections
SiGe quantum dots for fast hole spin Rabi oscillations
We report on hole g-factor measurements in three terminal SiGe self-assembled
quantum dot devices with a top gate electrode positioned very close to the
nanostructure. Measurements of both the perpendicular as well as the parallel
g-factor reveal significant changes for a small modulation of the top gate
voltage. From the observed modulations we estimate that, for realistic
experimental conditions, hole spins can be electrically manipulated with Rabi
frequencies in the order of 100MHz. This work emphasises the potential of
hole-based nano-devices for efficient spin manipulation by means of the
g-tensor modulation technique
Development and validation of a new standard area diagram set to estimate severity of soybean rust.
TÃtulo em português: Desenvolvimento e validação de uma nova escala diagramática para estimar severidade de ferrugem asiática da soja
1H NMR profiling and chemometric analysis for ripening and production characterization of Grana Padano cheese
Grana Padano (GP) cheese is a renowned PDO Italian cheese whose nutritional characteristics and market price are influenced by the ripening stage. In this work, it was demonstrated that the combined use of untargeted 1H NMR profiling and chemometric analysis can be used as a powerful tool to quantitatively characterize GP ripening and production, focusing on both aqueous and lipid fractions. An initial exploratory analysis revealed substantial variations in the aqueous fraction attributable to aging time, year and season of production. Multivariate analysis was adopted to show these differences, mainly attributable to amino acids. In contrast, the lipid fraction analysis highlighted the impact of production season on fatty acid unsaturation, influenced by feed variations. As regards the production process, this study focuses on the variations induced by bactofugation. In this respect, the aqueous fraction was found to be extensively influenced by this centrifugation step, affecting compounds crucial to organoleptic characteristic
Cortical-Inspired Wilson–Cowan-Type Equations for Orientation-Dependent Contrast Perception Modelling
We consider the evolution model proposed in BertalmÃo (Front Comput Neurosci 8:71, 2014), BertalmÃo et al. (IEEE Trans Image Process 16(4):1058–1072, 2007) to describe illusory contrast perception phenomena induced by surrounding orientations. Firstly, we highlight its analogies and differences with the widely used Wilson–Cowan equations (Wilson and Cowan in BioPhys J 12(1):1–24, 1972), mainly in terms of efficient representation properties. Then, in order to explicitly encode local directional information, we exploit the model of the primary visual cortex (V1) proposed in Citti and Sarti (J Math Imaging Vis 24(3):307–326, 2006) and largely used over the last years for several image processing problems (Duits and Franken in Q Appl Math 68(2):255–292, 2010; Prandi and Gauthier in A semidiscrete version of the Petitot model as a plausible model for anthropomorphic image reconstruction and pattern recognition. SpringerBriefs in Mathematics, Springer, Cham, 2017; Franceschiello et al. in J Math Imaging Vis 60(1):94–108, 2018). The resulting model is thus defined in the space of positions and orientation, and it is capable of describing assimilation and contrast visual bias at the same time. We report several numerical tests showing the ability of the model to reproduce, in particular, orientation-dependent phenomena such as grating induction and a modified version of the Poggendorff illusion. For this latter example, we empirically show the existence of a set of threshold parameters differentiating from inpainting to perception-type reconstructions and describing long-range connectivity between different hypercolumns in V1
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