Electrically tunable liquid crystal lens with 30 mm diameter is presented based on the refractive Fresnel concept. Relatively large optical power variation range (from - 0.74 to +0.
View Article and Find Full Text PDFWe describe an electrically tunable liquid crystal microlens array with a 65 mm clear aperture that allows the dynamic symmetric broadening of white light without mechanical movements. The fundamental mechanism of broadening is demonstrated to involve a spatial twist of molecular orientation. Continuous variations of the light divergence angle are obtained in a very large dynamic range (from 8° to 50°).
View Article and Find Full Text PDFIn this contribution we present graph theoretical approach to image processing focus on biological data. We use the graph cut algorithms and extend them for obtaining segmentation of biological data. We deal with tumor brain cells and rats brain to show the existence and presence of inflammatory molecules.
View Article and Find Full Text PDFRadiobiological investigations of natural populations of Myodes glareolus (bank vole) from the Chornobyl Exclusion Zone, namely within a highly radioactive site of the Red Forest were carried out. The complex of hematological and cytogenetic parameters of the bank voles inhabiting the contaminated site was studied before the site was flooded, in 2012, and after it drained, in 2015. A significant increase in micronucleated polychromatic erythrocytes, alterations in bone marrow and peripheral blood cell counts were observed in the population of 2015 in comparison with the group of 2012 and animals from the reference site.
View Article and Find Full Text PDFWe investigate electrically tunable liquid crystal (LC) microlenses and microprisms based on double dielectric optically hidden (DDOH) layers. Comparative theoretical study of the spatial resolution limits in the creation of a spatially modulated electric field by the DDOH layer is conducted. Both the depth of the resulting optical phase modulation and its deviation from the desired wavefront are obtained for sine and sawtooth geometries of the DDOH layer's structure.
View Article and Find Full Text PDFA mobile phone camera with an innovative electrically tunable liquid crystal lens (TLCL) concept is demonstrated. We first report the comparative theoretical and experimental analyses of the performance of a traditional "modal control" TLCL versus a TLCL using a floating (unpowered) transparent electrode (FTE). It is shown that the appropriate choice of voltage and frequency values of the driving electric signal may improve significantly (almost twice) the optical quality of the lens using the FTE.
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
March 2017
In this work we theoretically analyze the performance trends of a liquid crystal lens based on the optically hidden dielectric double layer principle. We demonstrate possible ways to optimize the lens as a function of the material and geometric parameters used. The impact of relative dielectric constants, conductivities, and dimensions of the components of the hidden dielectric layer, as well as the thickness and the temperature of the liquid crystal material, are demonstrated.
View Article and Find Full Text PDFObjective: to evaluate the state of to assess the state of hematopoietic system of experimental rats according to the geno and cytotoxic effects in bone marrow and changes in morphology composition of peripheral blood caused by prolonged 131I intake.
Materials And Methods: Within 15 days sodium iodide with activity of 29,3 kBq/animal was daily orally administered to Wistar rats. At 1, 2, 3, 7 and 15 days specific radioisotope activity, level of micronuclei in bone marrow cells, cyto toxicity index, number of erythrocytes and leucocytes in peripheral blood were determined.
J Opt Soc Am A Opt Image Sci Vis
May 2015
Theoretical modeling is performed for a liquid crystal (LC) lens that uses a combination of two dielectric lenses and voltage dividing principle to shape the electric field in space. Electric field, LC reorientation, and optical phase retardation profiles are obtained by numerical simulations. The obtained results are compared with experimental ones, and good agreement is obtained validating the proposed two-dimensional model that uses a limited number of dielectric and geometrical control parameters for this type of lens.
View Article and Find Full Text PDFThe autofocusing separation of nine antibiotics was investigated: tetracycline and chloramphenicol in large-scale batches, and seven others in gram preparation amounts. All except one were found to be heterogeneous in autofocusing, and 2-4 well-characterized fractions emerged. These heterogeneities are described and the industrial utilization of the procedure is suggested.
View Article and Find Full Text PDFCesk Epidemiol Mikrobiol Imunol
September 1983
Physiol Bohemoslov
June 1978
The authors studied the effect of a protein-free diet on 14C-thymidine incorporation into rat liver DNA in vivo and found, after 2-3 weeks, a marked decrease in uptake of the radioactive base into the liver DNA, followed by a decrease in the proportion of DNA in liver cell homogenates. The total nuclear count/mg liver tissue displayed an increase during protein depletion, except for the 5th week, when a decrease was recorded. The incorporation of 14C thymidine into the brain DNA likewise displayed no great differences, although a significant drop was observed during the 2nd to 4th week of depletion.
View Article and Find Full Text PDFThe authors studied the response of the regulation of proteosynthesis in the rat organism at the level of a model protein--haemoglobin--during developing protein depletion, comparing the response of rats encountering this situation for the first time with the response of animals specially prepared for it by a multiple depletion-repletion cycle. The changes in the response of both groups of animals to the same stimulus indicate that the data acquired in experience of these states are stored in the organism and form the basis of its changed response to a fresh load. The authors did not study the mechanism and site of storage of the information in question, or the mechanism of coordinated regulation, but they expressed the hypothesis that central regulation of protein biosynthesis could be involved.
View Article and Find Full Text PDFPhysiol Bohemoslov
June 1977
The authors attempted to determine whether repeated protein depletion would produce changes in the organism's response to this unfavourable situation indicative of the preservation of information on past depletion and of its inclusion in the formation of the organism's defences against repetition of this unphysiological state. It can be concluded from the results that the anticipated trend was demonstrated. The question of the site of origin, storage and action of this information was not resolved.
View Article and Find Full Text PDFComparison of the dynamics of changes in the proportion of the serum protein during progressive protein depletion in rats specially adapted to this situation and animals exposed to it for the first time, led the authors to conclude that the regulation of proteosynthesis is largely adaptable, that it can be influenced by nutritional leads and that the organism probably stores information on past nutritional loads and makes use of it to help to overcome fresh insults.
View Article and Find Full Text PDFThe authors submit the results of a study of the effect of rhytmic alternation of protein depletion and repletion on the quantitative and qualitative proportion of haemoglobin in the rat. The results show that four weeks' depletion caused significant changes in the studied parameters, but that two weeks' repletion restored them to normal. The organism's responses to repeated depletion-repletion states were heterogeneous as regards the size, quality and trend of the changes, indicating that the organism's defences against depletion can be influenced by repeated administration in the form of a kind of "training".
View Article and Find Full Text PDFPhysiol Bohemoslov
July 1976
Study of the quantitative distribution of cystinaminopeptidase activity in the serum of pregnant and control animals (cow, sheep and rat) by the isoelectric focusing method showed heterogeneity of the cystinaminopeptidase activity of the animals' serum enzymatic system, which was well pronounced in the cow and rat and less pronounced in the sheep. The authors assume from their results that the principal difference between the pregnant and control animals is not the total increase in the level of activity of the enzyme in question, but the shift in its incidence, or the increase in activity at a given pH. It is possible that pregnancy, in man and animals, produces in the serum cystinaminopeptidase system (which is evidently heterogeneous even under normal, physiological conditions) given changes, i.
View Article and Find Full Text PDFThe authors studied the splitting dynamics of the synthetic chromogenic substrate (S-benzyl-L-cysteine-p-nitroanilide) specific of serum cystine aminopeptidase, depending on a wide range of pH (from 2.5 to 8.0) by means of an enzymatic serum system of pregnant women and selected animals (sheep, cows, sewer-rats), compared with non-pregnant controls.
View Article and Find Full Text PDFPhysiol Bohemoslov
October 1975
The authors studied the dynamics of natural substrates of neurohumoral origin (oxytocin and lysine-vasopressin) by the serum of pregnant and nonpregnant women in relation to the pH in the medium, within pH limits of 2.5 to 8. The values obtained in a polarographic study of depression of the complex oxytocin and lysine-vasopressin polarographic wave by pregnancy and non-pregnancy sera and the results of a parallel analysis of free amino acids of the inactivated substrates under the same conditions showed that, apart from deep degradation of the studied substrates at the optimum pH (5.
View Article and Find Full Text PDFPhysiol Bohemoslov
December 1975
The authors studied the effect of protein depletion on the RNA content of rat liver and brain and on the incorporation of 14C-leucine into the microsomal and soluble liver and brain fractions. They failed to find a direct relationship between the amount of RNA and the rate of proteosynthesis in the organs in question. The changes found in 14-C-leucine incorporation are discussed in relation to previous studies.
View Article and Find Full Text PDFThe functional state of the rat liver, brain and muscle proteosynthetic apparatus during developing protein depletion was studied, with special reference to the effect of brain cytosols on the synthetic capacity of liver and muscle ribosomes. The results indicate that both stimulant and inhibitory agents (so far unidentified) may be present in brain cytosols during protein depletion.
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