Drying-mediated patterns in colloid-polymer suspensions

Drying-mediated patterning of colloidal particles is a physical phenomenon that must be understood in inkjet printing technology to obtain crack-free uniform colloidal films. Here we experimentally study the drying-mediated patterns of a model colloid-polymer suspension and specifically observe how the deposit pattern appears after droplet evaporation by varying particle size and polymer concentration. We find that at a high polymer concentration, the ring-like pattern appears in suspensions with large colloids, contrary to suppression of ring formation in suspensions with small colloids thanks to colloidpolymer interactions. We attribute this unexpected reversal behavior to hydrodynamics and size dependence of colloid-polymer interactions. This finding would be very useful in developing control of drying-mediated self-assembly to produce crack-free uniform patterns from colloidal fluids.ope

Plasticity and rectangularity in survival curves

Living systems inevitably undergo a progressive deterioration of physiological function with age and an increase of vulnerability to disease and death. To maintain health and survival, living systems should optimize survival strategies with adaptive interactions among molecules, cells, organs, individuals, and environments, which arises plasticity in survival curves of living systems. In general, survival dynamics in a population is mathematically depicted by a survival rate, which monotonically changes from 1 to 0 with age. It would be then useful to find an adequate function to describe complicated survival dynamics. Here we describe a flexible survival function, derived from the stretched exponential function by adopting an age-dependent shaping exponent. We note that the exponent is associated with the fractal-like scaling in cumulative mortality rate. The survival function well depicts general features in survival curves; healthy populations exhibit plasticity and evolve towards rectangular-like survival curves, as examples in humans or laboratory animals

Fermentation by Lactobacillus enhances anti-inflammatory effect of Oyaksungisan on LPS-stimulated RAW 264.7 mouse macrophage cells

<p>Abstract</p> <p>Background</p> <p>Oyaksungisan (OY) has been used as a traditional drug in east-Asian countries. However, its effect on inflammation still remains unknown. In this study, to provide insight into the biological effects of OY and OY fermented by <it>Lactobacillus</it>, we investigated their effects on lipopolysaccharide (LPS)-mediated inflammation in the RAW 264.7 murine macrophage cells.</p> <p>Methods</p> <p>The investigation was focused on whether OY and fermented OYs could inhibit the production of pro-inflammatory mediators such as nitric oxide (NO) and prostaglandin (PG) E₂as well as the expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-α, interleukin (IL)-6, nuclear factor (NF)-κB and mitogen-activated protein kinases (MAPKs) in LPS-stimulated RAW 264.7 cells.</p> <p>Results</p> <p>We found that OY inhibits a little LPS-induced NO, PGE₂, TNF-α and IL-6 productions as well as the expressions of iNOS and COX-2. Interestingly, the fermentation significantly increased its inhibitory effect on the expression of all pro-inflammatory mediators. Furthermore, the fermented OYs exhibited elevated inhibition on the translocation of NF-κB p65 through reduced IκBα degradation as well as the phosphorylations of extracellular signal-regulated kinase (ERK), p38 and c-Jun NH₂-terminal kinase (JNK) MAPKs than untreated control or original OY.</p> <p>Conclusions</p> <p>Finally, the fermentation by <it>Lactobacillus </it>potentiates the anti-inflammatory effect of OY by inhibiting NF-κB and MAPK activity in the macrophage cells.</p