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In an attempt to prepare ultrastable aqueous foams composed entirely of food-grade ingredients, we describe the foamability and foam stability of aqueous phases containing either calcium carbonate particles (CaCO3), sodium stearoyl lactylate surfactant (SSL), or their mixtures. Techniques including zeta potential measurements, adsorption isotherm determination, contact angles and optical and cryo-scanning electron microscopy are used to probe the interaction between particles and surfactant molecules. Aqueous dispersions of inherently hydrophilic cationic CaCO3 nanoparticles do not foam to any great extent. By contrast, aqueous dispersions of anionic SSL, which forms a lamellar phase/vesicles, foam progressively on increasing the concentration. Despite their foamability being low compared to that of micelle-forming surfactant sodium dodecyl sulfate, they are much more stable to collapse with half-lives (of up to 40 days) of around 2 orders of magnitude higher above the respective aggregation concentrations. We believe that, in addition to surfactant lamellae around bubbles, the bilayers within vesicles contain surfactant chains in a solidlike state yielding indestructible aggregates that jam the aqueous films between bubbles, reducing the drainage rate and both bubble coalescence and gas-transfer between bubbles. In mixtures of particles and surfactant, the adsorption of SSL monomers occurs on particle surfaces, leading to an increase in their hydrophobicity, promoting particle adsorption to bubble surfaces. Ultrastable foams result with half-lives of around an order of magnitude higher again at low concentrations and foams which lose only around 30% of their volume within a year at high concentrations. In the latter case, we evidence a high surface density of discrete surfactant-coated particles at bubble surfaces, rendering them stable to coalescence and disproportionation.

Background: The 12-lead ECG is considered the gold standard to differentiate between selective (S), nonselective (NS) His bundle pacing (HBP), and right ventricular septal capture in routine clinical practice. We sought to assess the utility of device EGM recordings as a tool to identify the type of HBP morphology. Methods: One hundred forty-eight consecutive patients underwent HBP with a 3830 Select Secure lead (Medtronic, Inc) at 3 centers between October 2016 and October 2017. The near field V-EGM morphology (NF EGM), near field V-EGM time to peak (NF Time to peak ), and far-field EGM QRS duration (QRSd) were recorded while pacing the His lead with simultaneous 12-lead ECG rhythm strips. Results: Indications for HBP were sinus node dysfunction, atrioventricular conduction disease, and cardiac resynchronization therapy in 68 (46%), 56 (38%), and 24 (16%) patients, respectively. Baseline QRSd was 108±38 ms with QRSd >120 ms in 57 (39%) patients (27 right bundle branch block, 18 left bundle branch block, and 12 intraventricular conduction delay). S-HBP was noted in 54 (36%) patients. A positive NF EGM and NF Time to peak >40 ms were highly sensitive (94% and 93%, respectively) and specific (90% and 94%) for S-HBP irrespective of baseline QRSd. All 3 parameters (+NF EGM , NF Time to peak >40 ms, and far-field EGM QRSd <120 ms) had high negative predictive value (97%, 95%, and 92%). A novel device-based algorithm for S-HBP was proposed. EGM transitions correlated with ECG transitions during threshold testing and can help accurately differentiate between S-HBP, NS-HBP, and right ventricular septal pacing with a cumulative positive predictive value of 91% (positive predictive value =100% in patients with baseline QRSd <120 ms). Conclusions: We propose a novel and simple criteria for accurate differentiation between S-HBP, NS-HBP, and right ventricular septal capture morphologies by careful analysis of device EGMs alone. This study paves the way for future studies to assess autocapture algorithms for devices with HBP.

Using high-pressure homogenization to generate different droplet size distributions, the nucleation and crystallization of two fat systems [lard or a palm stearin/canola oil blend (PSCO)] were compared in bulk and emulsified form. Droplet size reduction decreased the final volume fraction of solid fat primarily in the lard system vs. the PSCO system, with a greater reduction in volume fraction using the homogenization regime that led to smaller droplets. Homogeneous and heterogeneous models showed that the nucleation rate generally decreased with a reduction in droplet size. However, the Gibbs surface energy (γ) was significantly underestimated using the homogeneous model, whereas the heterogeneous model fit the data adequately (P < 0.05). The temperature sensitivity of the calculated impurity concentration in all emulsified systems was droplet size dependent. The Avrami model showed the emulsified fats to have lower Avrami indices relative to the bulk fat as well as lower crystallization rate constants. Differences in the Avrami indices and the rate constants were more pronounced in the bulk and emulsified PSCO compared with lard.The triacylglycerols (TAG) contained in commercial foods are highly variable in composition, and hence in crystallization behavior. Control of the liquid-solid transition in such TAG is crucial for the proper development of microstructure in many foods, namely, those undergoing phase inversion, such as butter, ice cream, and spreads. The thermodynamic equilibrium of solid and liquid fat in a system does not necessarily reflect the pathway taken to achieve its degree of solidification. The crystallization kinetics of fats can be described by their nucleation rates, and these can be described by classical methods incorporating the thermodynamic driving force of the reaction with the frequency term of the reaction (1,2).However, classical crystallization theories that describe the behavior of bulk fats adequately are not necessarily applicable to dispersed systems, as the mechanism of nucleation can be either homogeneous or heterogeneous. Homogeneous nucleation occurs directly from the melt, in the absence of impurities. Conversely, heterogeneous nucleation occurs in the presence of impurities, viz., high-melting TAG, emulsifiers, dust, and so on (3,4). The prevailing mechanism depends on the degree of undercooling and/or the number of catalytic impurities present at the droplet surface or within its volume (5,6). Surface nucleation can be influenced by impurities, as investigated by Awad et al. (7), Kaneko et al. (8), and Hodate et al. (9), who found that nucleation rates were increased at the interface as a result of added hydrophobic impurities, yet crystal growth was retarded within droplets.Contrary to bulk systems, dispersed fats are far more likely to undergo homogeneous nucleation as potential impurities are compartmentalized, leading to independent nucleation and crystallization events. Thus, the impact of emulsification on the nucleation kinetics (homogeneous vs. heterogeneous) a...