Morphofunctional Changes in Oral Mucosa Vessels when Healing a Wound Defect Using a Polymer Membrane

This works aims to study morphofunctional changes in the vessels of the oral mucosa during regeneration of a wound defect with and without a polymer membrane.An experiment was carried out on 35 white Wistar rats divided into three groups: control, experimental 1 and experimental 2. To form a wound defect, a flap of the oral mucosa was excised, which was covered by a polymeric piezoelectric membrane in the rats of group 2. Histological examination was carried out on the 3rd, 7th and 12th days: the control material was taken, histological preparations were made according to the standard method. In the lesion focus and surrounding tissues, specific areas and numerical densities of arterioles, venules and capillaries were determined; the pericapillary diffusion index, Kernogan index and arterio-venular ratio were calculated.On the 3rd day, all indicators in all experimental groups did not significantly differ from each other, but had significant differences from the control group. On the 7th day of the study, in the 1st group, the numerical density of open arterioles and venules corresponded to the control group. In group 2, the numerical density of capillaries and altered venules, as well as the index of pericapillary diffusion, significantly differed from the control. On the 12th day of the study, the numerical density of open venules reached control values in the uncoated group. In the 2nd group, all indicators corresponded to the control values.Protection of the wound defect from microbial contamination and re-traumatization, the presence of piezoelectric properties of the membrane under study contributed to a more effective restoration of vessels. This confirms the efficacy of the membrane under study when used as a wound covering.

Silicon nanowire/polymer membrane for infrared visualization via third-harmonic generation

Nonlinear harmonic generation in nanostructures is one of the key topics in nanophotonics, as it allows infrared-to-visible light conversion at the nanoscale.his work reports on the efficient third-harmonic generation in a free-standing Si nanowire array encapsulated into a polymer membrane. High nonlinearity of Si material X 31112.45 ≈ 10 –19m2 /V 2 and light coupling with optical resonances in the nanowires yield a strong third-harmonic signal and efficient infrared (1200 — 2000nm) to visible (400 — 666nm) upconversion. The fabricated membranes demonstrate high flexibility and semitransparency, which makes them convenient to use as visualizers.