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Variability within certifying of ductal carcinoma inside situ amid a major international band of pathologists.
We present a theoretical explanation for this disparity and predict the values of the contact angles using prevalent thermodynamic models of wetting and contact-angle hysteresis on rough substrates. The theoretical prediction is in good agreement with the experimental observations.
The dynamic contact angles measured by the sessile-droplet and captive-bubble methods deviate from the supplementary principle as the surface roughness is increased. We present a theoretical explanation for this disparity and predict the values of the contact angles using prevalent thermodynamic models of wetting and contact-angle hysteresis on rough substrates. The theoretical prediction is in good agreement with the experimental observations.Bacterial anchoring to limestone rocks is thought to occur by selective adsorption of biomolecules found in the extracellular matrix, such as polysaccharides. click here Here we study the adsorbed structure of a model matrix polysaccharide, sodium alginate, at the calcite/water interface using neutron reflection (NR). Sodium alginate was found to form highly hydrated layers extending up to 350 Å into solution at concentrations up to 2.5 ppm (the inflection point of the adsorption isotherm). The adsorption of alginate was driven by dissolution of the calcite surface through complexation of free calcium ions. This was shown using two alginates with differing ratios of sugar residues. Alginates with a higher proportion of guluronic acid (G) have a higher affinity for calcium ions and were found to cause the surface to dissolve to a greater extent and to adsorb more at the surface when compared to alginates with a higher proportion of mannuronic acid (M). Adding magnesium to the high G alginate solution reduced dissolution of the surface and the adsorbed amount. In this work, we have shown that polysaccharide adsorption to sparingly soluble calcite interfaces is closely related to polymer conformation and affinity for free calcium ions in solution.
Colloidal particles that interact via a long-ranged repulsive barrier in combination with a very short-ranged attractive minimum can "polymerize" to form highly anisotropic structures. Motivated by previous experimental achievements in non-aqueous solvents, and recent theoretical predictions, we hypothesize that it is possible to construct clusters that resemble linear or branched polymers, in aqueous solution. If these clusters are not too large, they may even remain dispersed, but even if they grow large enough to sediment, they may be collected and used in future applications.

In this work, we specifically synthesize poly (ethylene glycol) (PEG) chains, grafted onto poly (styrene) (PS) particles in aqueous solution, and adjust the conditions so that strongly anisotropic and isolated polymer-like clusters are formed. These conditions include a very low ionic strength (the particles are weakly charged), a relatively high temperature, and a low particle concentration. An important criterion is that the pahe short-ranged attraction. We were indeed able to establish highly anisotropic structures, that resemble linear or branched polymers, which we could image by CLSM. The average degree of polymerization could be adjusted by a variation of the particle concentration.
According to our Zeta potential measurements, the particles indeed carry a weak negative charge, presumably due to ion specific adsorption. Furthermore, by ensuring that the ionic strength is very low, with a Debye length similar to the particle size, we could use temperature to control the hydrophobicity of the grafted PEG layer, and thus the strength of the short-ranged attraction. We were indeed able to establish highly anisotropic structures, that resemble linear or branched polymers, which we could image by CLSM. The average degree of polymerization could be adjusted by a variation of the particle concentration.
For an oil droplet on calcite with an intervening brine film, the water contact angle θ
may be reduced markedly (greater water wetness) with surface modified silica nanoparticles (NP). Modification with cationic, anionic, and nonionic ligands may be used to control the nanoparticle adsorption and interactions at the oil-brine and brine-calcite interfaces to influence the rate and degree of reduction in θ
.

The colloidal stability at 25°C was determined in concentrated divalent brine (8wt% NaCl and 2wt% CaCl
) with dynamic light scattering, and the NP adsorption was determined on calcite. The NP adsorption at the oil-brine interface was characterized with the elastic dilational modulus. θ
was measured for model decane-stearic acid droplets and crude oil droplets on calcite from 25 to 80°C.

The fastest rate and greatest extent of reduction in θ
for grafted ligands followed the order cationic quaternary trimethylamine>sulfonate>methyl phosphonate>gluconamide. New mechanisms for reduction in θ
were demonstrated on the basis of changes in interactions from NP adsorption at each interface. The greatest efficacy for the cationic NPs results from the weakest adsorption on calcite, steric repulsion at the three-phase contact line and the greatest desorption of carboxylate surfactants from the calcite.
gluconamide. New mechanisms for reduction in θw were demonstrated on the basis of changes in interactions from NP adsorption at each interface. The greatest efficacy for the cationic NPs results from the weakest adsorption on calcite, steric repulsion at the three-phase contact line and the greatest desorption of carboxylate surfactants from the calcite.
The objective is to elucidate the multiscale dynamics of water within natural mixtures of minerals, green earth pigments that are mainly composed of phyllosilicates containing large amount of iron. In particular, the interaction of water with the different kinds of surfaces has to be probed. One issue is to examine the influence of surface type, basal or edge, on the dispersion quality.

The study was carried out using
H variable field NMR relaxometry on various green earth pigment dispersions and concentrations. To analyse the data, a new analytical model was developed for natural phyllosilicates containing large amount of paramagnetic centres.

The proposed theoretical framework is able to fit the experimental data for various samples using few parameters. It allows to determining water diffusion and residence times in complex phyllosilicate dispersions. Furthermore, it makes it possible to differentiate the contribution of the basal and edge surfaces and their respective surface area in interaction with water.
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