Structural organization and morphometric parameters in system of excretory ducts of human labial glands

With the aim of conformity and structural features revealing and space organization of excretory ducts of small salivary glands system of human being, the histology of wall of labial excretory ducts is studied, morphometry of their major size is carried out (external diameter, space, width of wall). In the system of excretory ducts of labial gland of human being, the change of size of their external and internal diameter is revealed, which is seen on the cutting and 3-D models such local sharp narrowing and ampula-shaped widening of ducts. The phenomenon of some excretory ducts spiralization together with their siphon structure has been noted. The general tendency is preserved; it is marked by the existence of the greatest pass ability for secretion within interlobular and common excretory ducts and retention areas in the places of their narrowing. Certain regularity of mutual location of ducts and some chains of hemomicrocirculatory flow. Collector venules are located in place formation agreeably innerlobules, lobules, interlobules. Received morphological results will serve to explaining of the mechanism of the movement of secrete through complect – branching system excretory ducts of the smaller salivary glands of the human organism

Proton transport in water and DNA components: A Geant4 Monte Carlo simulation

Accurate modeling of DNA damages resulting from ionizing radiation remains a challenge of today's radiobiology research. An original set of physics processes has been recently developed for modeling the detailed transport of protons and neutral hydrogen atoms in liquid water and in DNA nucleobases using the Geant4-DNA extension of the open source Geant4 Monte Carlo simulation toolkit. The theoretical cross sections as well as the mean energy transfers during the different ionizing processes were taken from recent works based on classical as well as quantum mechanical predictions. Furthermore, in order to compare energy deposition patterns in liquid water and DNA material, we here propose a simplified cellular nucleus model made of spherical voxels, each containing randomly oriented nanometer-size cylindrical targets filled with either liquid water or DNA material (DNA nucleobases) both with a density of 1 g/cm3. These cylindrical volumes have dimensions comparable to genetic material units of mammalian cells, namely, 25 nm (diameter) 25 nm (height) for chromatin fiber segments, 10 nm (d) 5 nm (h) for nucleosomes and 2 nm (d) 2 nm (h) for DNA segments. Frequencies of energy deposition in the cylindrical targets are presented and discusse