Reconstruction of proliferative activity of hair follicle cells based on the geometric parameters of the hair shaft
Proliferative activity and differentiation rate of hair follicle cells determine the shape of the hair and parameters of hair growth. The hair growth rate and changes of geometric parameters of the hair shaft during its elongation (in time) are analyzed to reconstruct the proliferation dynamics of follicle matrix cells. The reconstruction demonstrated that the number of cells of hair follicle matrix increases in a typical manner, including the phase of exponential growth and the stationary phase.
Understanding hair follicle cycling: a systems approach.
Continuous stem cell regeneration is essential for the repair and maintenance of many organs, rendering an understanding of the mechanisms underlying this phenomenon of prime importance. In this respect the hair follicle system provides an excellent test bed: mammalian skin contains thousands of hair follicles, each of which undergoes continuous regenerative cycling events that can be visualized via changing pigmentation patterns. Moreover, the system is inherently two-dimensional and reasonably easy to manipulate experimentally. Combined, the hair follicle system is an ideal candidate for an integrated theoretical and experimental approach that characterizes events occurring over multiple spatial and temporal scales. In this work we summarise recent developments in the field, and outline our hopes for future iterations of modelling and experiment.
Study on Electrical Explosion Mechanism and Ignition Characteristics of Copper and Aluminum Powder Under Ignition Solid Propellant
In order to study the characteristic of the electrical explosion of copper and aluminum powders, a multilayer generator was designed, an experimental system was set up, and the parameters of metal powder electrical explosion were measured and analyzed. The results show that the duration of the electrical explosion process increases significantly due to the addition of metal powder. The duration of aluminum powder electrical explosion jet flow is ~86.36 ms due to its self-sustained combustion, which releases a large amount of energy, and a small fraction of aluminum powder particles is not burned. The duration of copper powder electrical explosion jet flow is ~15.84 ms, and most of the copper powder particles are in the solid state. The current pause process is absent; instead, the first discharge process is connected to the second discharge process. The effect of copper powder on the first discharge process is greater than that of aluminum powder. Furthermore, the ignition ability of copper powder electrical explosion to solid propellant is stronger than that of aluminum powder in a closed bomb experiment. These results are indubitably meaningful for the application of metal powder electrical explosion and ignition of solid propellant in an electrothermal chemical gun.