hTERT-Driven Immortalization of RDEB Fibroblast and Keratinocyte Cell Lines Followed by Cre-Mediated Transgene Elimination

The recessive form of dystrophic epidermolysis bullosa (RDEB) is a crippling disease caused by impairments in the junctions of the dermis and the basement membrane of the epidermis. Using ectopic expression of hTERT/hTERT + BMI-1 in primary cells, we developed expansible cultures of RDEB fibroblasts and keratinocytes. We showed that they display the properties of their founders, including morphology, contraction ability and expression of the respective specific markers including reduced secretion of type VII collagen (C7). The immortalized keratinocytes retained normal stratification in 3D skin equivalents. The comparison of secreted protein patterns from immortalized RDEB and healthy keratinocytes revealed the differences in the contents of the extracellular matrix that were earlier observed specifically for RDEB. We demonstrated the possibility to reverse the genotype of immortalized cells to the state closer to the progenitors by the Cre-dependent hTERT switch off. Increased β-galactosidase activity and reduced proliferation of fibroblasts were shown after splitting out of transgenes. We anticipate our cell lines to be tractable models for studying RDEB from the level of single-cell changes to the evaluation of 3D skin equivalents. Our approach permits the creation of standardized and expandable models of RDEB that can be compared with the models based on primary cell cultures.     

Estimation of the Alignment Parameters of a Scanning Device with a Multirow Focal Plane Array

Scanning devices based on multirow focal plane arrays providing increased resolution impose much more stringent requirements on alignment than single-row arrays. This paper presents a new method for measuring and estimating the scanning speed and the angle of orientation of a multirow focal plane array relative to the scanning direction — the parameters that determine the quality of the discrete image formed. The method is based on an analysis of the image of a simple test object — an optical slit. An algorithm for estimating these parameters is proposed which provides high-accuracy estimates under fairly weak requirements for the image quality of the test object. The estimation accuracy was calculated analytically and confirmed by simulation modeling.     

On a peculiar feature of longitudinal differential protection of generators reacting to vector values of currents

The possibility of activation delay of longitudinal differential protection of generators reacting to vector values is considered. This work presents calculated data for currents of three-phase short circuits for a turbogenerator operating in combination with a transformer as a function of number of short circuited turns in generator winding.     

Specific features of detecting point objects in images formed by a detector array

The efficiency of detecting point objects in images obtained by a photodetector array is analyzed. It is shown that the detection efficiency depends both on the image processing method and on the relationship between the sizes of the array elements, the gaps between these elements, and the point spread function of the optical system forming the image. Results of a computational experiment are given, which confirm the existence of an optimal relationship between these parameters.     

EPR spectra and relaxation times of natural π-conjugated polymers doped with iodine

The magnetic properties of natural π-conjugated polymers doped with iodine have been studied by EPR spectroscopy. It is established that an increase in the spin susceptibility upon doping is caused by the formation of π-electron radicals localized at the aromatic fragments of the polymer. Dependences of the spin-spin and spin-lattice relaxation times of these radicals on the doping level have been experimentally determined.     

Self-Ignition of Fuel Consisting of Hydrogen Peroxide,Kerosene, and Pyrophoric Additives

Abstract—The possibility of creating an environmentally safe self-igniting fuel mixture for liquid-propellant rocket engines is investigated. The mixture is based on kerosene with pyrophoric additives and an oxidant: highly concentrated hydrogen-peroxide solution. The self-ignition of the components is studied experimentally. Tests are also conducted in the combustion chamber of a low-thrust liquid-propellant rocket engine.     

Savart — Masson effect in granular media

The paper describes experimental results for the Savart — Masson effect in a perfect granular medium under shearing. The relationships between displacement jumps, forces, gravitation load and the medium state are determined, and the dynamics of individual jumps is analyzed. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 13–18, November–December, 2008.