Prognostic Analysis of Human Pluripotent Stem Cells Based on Their Morphological Portrait and Expression of Pluripotent Markers

The ability of human pluripotent stem cells for unlimited proliferation and self-renewal promotes their application in the fields of regenerative medicine. The morphological assessment of growing colonies and cells, as a non-invasive method, allows the best clones for further clinical applications to be safely selected. For this purpose, we analyzed seven morphological parameters of both colonies and cells extracted from the phase-contrast images of human embryonic stem cell line H9, control human induced pluripotent stem cell (hiPSC) line AD3, and hiPSC line HPCASRi002-A (CaSR) in various passages during their growth for 120 h. The morphological phenotype of each colony was classified using a visual analysis and associated with its potential for pluripotency and clonality maintenance, thus defining the colony phenotype as the control parameter. Using the analysis of variance for the morphological parameters of each line, we showed that selected parameters carried information about different cell lines and different phenotypes within each line. We demonstrated that a model of classification of colonies and cells by phenotype, built on the selected parameters as predictors, recognized the phenotype with an accuracy of 70–75%. In addition, we performed a qRT-PCR analysis of eleven pluripotency markers genes. By analyzing the variance of their expression in samples from different lines and with different phenotypes, we identified group-specific sets of genes that could be used as the most informative ones for the separation of the best clones. Our results indicated the fundamental possibility of constructing a morphological portrait of a colony informative for the automatic identification of the phenotype and for linking this portrait to the expression of pluripotency markers.     

Subcritical state diagnosis for nuclear power plant containing RBMK-1000

Leningrad Reactor Research Institute. Translated from Atomnaya Énergiya, Vol. 70, No. 3, pp. 180–182, March, 1991.     

Nanodimensional changes in the structure of ion-irradiated silicon crystals at a depth exceeding the ion range

Atomic force microscopy reveals changes in the surface micromorphology of ion-irradiated silicon crystals in the course of dynamic chemical polishing and selective etching to a depth significantly exceeding the range of 40-keV Ar⁺ ions.     

Special Features of the Calculation of the Stress–Strain State of VVÉR Second-Loop Pipelines with Erosion–Corrosion Thinning

Some details of an algorithm and computational results are presented for VVÉR second-loop pipelines exhibiting erosion–corrosion wear. The program makes it possible to perform calculations of thinnings for a complicated shape which gradually vary in two mutually perpendicular directions. The calculations were performed for rectilinear sections of a pipe and a zone near a bend. The computational results can be displayed in graphical form in color and in a black-and-white.