Catastrophic thermal destabilization of two-dimensional close-packed emulsions due to synchronous coalescence initiation.

The mechanisms for phase separation in highly concentrated emulsions when subjected to a thermal phase transition remain to be elucidated. Here, we create a hexagonally close-packed monodisperse emulsion in 2D and show that during a cool-heat cycle, the emulsion fully destabilizes akin to phase separation. The mechanism for this catastrophic destabilization is found to be spontaneous coalescence initiation that synchronously occurs between every solidified droplet and its neighbors. This synchronous coalescence initiation establishes system-wide network connectivity in the emulsion causing large-scale destabilization. This system-wide coalescence initiation is found to be insensitive to droplet size and tested surfactants, but dependent on network connectivity and crystal content of individual droplets.

Collective nucleation dynamics in two-dimensional emulsions with hexagonal packing.

We report a mechanism for nucleation in a monolayer of hexagonally packed monodisperse droplet arrays. Upon cooling, we observe solidified droplets to nucleate their supercooled neighbors giving rise to an autocatalyticlike mechanism for accelerated crystallization. This collective mode of nucleation depends on the strength and nature of droplet contacts. Intriguingly, the statistical distribution of the solidified droplet clusters is found to be independent of emulsion characteristics except surfactant. In contrast to classical nucleation theory, our work highlights the need to consider collective effects of nucleation in supercooled concentrated emulsions where droplet crowding is inevitable.

Levels of Blood Biomarkers among Patients with Myocardial Infarction in Comparison to Control Group.

BACKGROUND: Myocardial infarction (MI) as a term for a heart attack happens due to reduced blood flow to heart myocardium and lack of oxygen supply caused by plaques in the interior walls of coronary arteries. With respect to the importance of MI etiology, we aimed to study the relationship of MI and blood examination variables. METHODS: This study was conducted in Mazandaran Heart Center as a hospital-based case-control Comprising 894 participants including 465 cases and 429 controls, individually matched by sex and age. Considered blood markers were analyzed using routine laboratory methods and equipment. RESULTS: Of all participants, 64.3% of the cases and 51.0% of the controls were males with a mean age of 61.2 (±13.8) in cases and 62.4 (±14.) in controls. We could not find any differences between cases and controls for total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and alkaline-phosphatase (ALP) (P>0.05). However, levels of creatine-kinase-muscle/brain (CK-MB) (P<0.0001), fasting-blood-sugar (FBS) (P<0.0001), aspartate-aminotransferase (AST) (P<0.0001), alanine-transferase (ALT) (P<0.0001) and erythrocyte sedimentation rate (ESR) (P=0.001) were significantly higher in cases compared to the controls (P<0.05). Multivariable analyses revealed that the risk of MI was associated with high levels of AST (adjusted OR=24.3, 95%CI=3.5±165.6, P=0.001) and LDL (adjusted OR=7.4, 95%CI=1.0±51.8, P=0.001). CONCLUSION: Our investigation indicated that the levels of CK-MB, FBS, AST, ALT and ESR were significantly higher in patients with MI. Besides, our findings showed that the risk of MI in cases with high levels of AST and LDL was about 24 and 7 times more than the control group respectively.

Microfluidic production of size-tunable hexadecane-in-water emulsions: Effect of droplet size on destabilization of two-dimensional emulsions due to partial coalescence.

HYPOTHESIS: Despite numerous studies, the mechanism of destabilization of oil-in-water emulsions during cooling-heating cycles is unclear due to indirect measurements and lack of direct control over the droplet size. It is hypothesized that emulsions with a smaller droplet size are more resistant to destabilization than emulsions containing larger droplets since the probability of initiating partial coalescence and forming large-scale aggregates is lower for small droplets. EXPERIMENTS: Monodisperse hexadecane-in-water emulsions with controlled droplet sizes were produced using a microfluidic valve-based flow-focusing device and varying the system parameters. A unique approach was developed to create a two-dimensional (2D) array of droplets enabling visualization of the destabilization process due to temperature cycling. The influence of droplet size on partial coalescence and destabilization was investigated. FINDINGS: In the 2D emulsion, destabilization proceeds through a combination of spontaneous coalescence events that yield small-scale structures followed by formation of large-scale structures by coalescence propagation. We find that emulsion destabilization increases with droplet size. Quantifying the frequency of n-body coalescence events reveals that in emulsions with small droplets coalescence propagation is hindered. Phenomena involving restructuring, growth and cross-linking of droplet aggregates are identified as the key features of the emulsion destabilization mechanism.