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We studied the participation of JNK and p53 in the realization of the growth potential of different types of progenitors of the subventricular zone of mouse brain and secretion of neurotrophins by glial cells. The stimulating role of these signaling molecules in mitotic activity and specialization of multipotent neural stem cells was shown. It was found that JNK and p53 do not participate in the regulation of committed neuronal progenitor cells (clonogenic PSA-NCAM+ cells). A dependence of neurotrophic growth factors in individual populations of neuroglia on activity of these protein kinase and transcription factor was revealed. The role of JNK and p53 in astrocytes consists in stimulation of their secretion, and in microglial cells, on the contrary, in its inhibition. The secretory neurotrophic function of oligodendrogliocytes is not associated with JNK and p53 activity.

We studied the effect of an anthocyanin-containing complex from Sorbus aucuparia L. on the main indicators of erythropoiesis in the blood and bone marrow of mice against the background of doxorubicin treatment. It was shown that administration of an anthocyanincontaining complex from S. aucuparia L. prevented the development of anemic syndrome by stimulating regeneration of the erythroid lineage of hematopoiesis after its devastation by single administration of the cytostatic.

Purpose: High resolution investigation of spectral lines of space sources requires low intrinsic noise of the radio telescope receiving system. It is provided with both input cryogenic amplifiers and low phase noise of local oscillators. To make spectral studies, it is neces ary to be able to tune the frequencies of local oscillators with a small frequency step. The paper presents the results of developing the frequency synthesizers, which simultaneously provide both a very high frequency resolution and low level of phase noise. The results of measurements of natural noise of the RT-32 radio telescope radio receiving systems are given also. Design/methodology/approach: The RT-32 receiving systems are constructed as heterodyne receivers with two stages of frequency conversion. Tuning of receiving systems with a frequency step of 10 or 20 MHz is provided by local oscillators of the first frequency conversion stage, and precise tuning is provided due to the ultra-high resolution (0.0001 MHz) of DDS-based (direct digital synthesizer) local oscillators of the second frequency conversion stage. Findings: It is shown that the application of direct digital synthesizers is possible only with the low values of frequency multiplication factors, as well as under the conditions of careful filtering of all reference signals. The parameters of the local oscillators were measured with the N9951A spectrum analyzer (Keysight Technologies) with the high resolution and wide dynamic range. To measure the radio telescope receiving system noise characteristics, a special matched loads with the possibility of cooling down to the liquid nitrogen temperature were made. The noise temperature measurements were made in different cross sections of the RT-32 receiving system. Comparison of such measurements in different configurations makes it possible to provide a preliminary estimation of the RT-32 self noise in the C- and K-bands. Conclusions: The results of measurements of self noise of radio receiving systems and phase noise of local oscillators of the RT-32 radio telescope show that within the C-band the radio telescope is capable to perform high-sensitive studies in both a wide frequency band and a narrow frequency band with the high spectral resolution. Within the K-band, the natural noise is comparable (≈60÷80 K) with the external noise that also allows studying the radiation of maser radio sources. Key words: antenna, self noise, local oscillator, receiving system, radio telescope, RT-32, spectral lines Manuscript submitted 15.07.2020 Radio phys. radio astron. 2020, 25(3): 1 75-192 REFERENCES 1. ULYANOV, O. M., REZNICHENKO, O. M., ZAKHARENKO, V. V., ANTYUFEYEV, A. V., KOROLEV, A. M., PATOKA, O. M., PRISIAZHNII, V. I., POICHALO, A. V., VOITYUK, V. V., MAMAREV, V. N., OZHINSKII, V. V., VLASENKO, V. P., CHMIL, V. M., LEBED, V. I., PALAMAR, M. I., CHAIKOVSKII, A. V., PASTERNAK, YU. V., STREMBITSKII, M. A., NATAROV, M. P., STESHENKO, S. O., GLAMAZDYN, V. V., SHUBNY, A. S., KIRILENKO, A. A., KULIK, D. Y., KONOVALENKO, A. A., LYTVYNENKO, L. M. and YATSKIV, Y. S., 2019. Creating the RT-32 Radio Telescope on the Basic of MARK-4B Antenna System. 1. Modernization Project and First Results. Radio Phys. Radio Astron. vol. 24, no. 2, pp. 87–116. DOI: https://doi.org/10.15407/rpra24.02.087 2. ANTYUFEYEV, A. V., KOROLEV, A. M., PATOKA, O. M., SHULGA, V. M., ULYANOV, O. M., REZNICHENKO, O. M., ZAKHARENKO, V. V., PRISIAZHNII, V. I., POICHALO, A. V., VOITYUK ,V. V., MAMAREV, V. N., OZHINSKII, V. V., VLASENKO, V. P., CHMIL, V. M., LEBED, V. I., PALAMAR, M. I., CHAIKOVSKII, A. V., PASTERNAK, YU. V., STREMBITSKII, M. A., NATAROV, M. P., STESHENKO, S. O., GLAMAZDYN, V. V., SHUBNY, A. S., KIRILENKO, A. A., KULIK, D. Y. and PYLYPENKO, A. M., 2019. Creating the RT-32 Radio Telescope on the Basic of MARK-4B Antenna System. 1. Estimation of the Possibility for Making Spectral Observations of Radio Astronomical Objects. Radio Phys. Radio Astron . vol. 24, no. 3, pp. 163–183. DOI: https://doi.org/10.15407/rpra24.03.163 3. WOODBURN, L., NATUSCH, T., WESTON, S., THOMASSON, P., GODWIN, M., GRANET, C. and GULYAEV, S., 2015. Conversion of a New Zealand 30-metre telecommunications antenna into a radio telescope. Publ. Astron. Soc. Aust . vol. 32, id. e017. DOI: https://doi.org/10.1017/pasa.2015.13 4. YONEKURA, Y., SAITO, Y., SUGIYAMA, K., SOON, K. L., MOMOSE, M., YOKOSAWA, M., OGAWA, H., KIMURA, K., ABE, Y., NISHIMURA, A., HASEGAWA, Y., FUJISAWA, K., OHYAMA, T., KONO, Y., MIYAMOTO, Y., SAWADA-SATOH, S., KOBAYASHI, H., KAWAGUCHI, N., HONMA, M., SHIBATA, K. M., SATO, K., UENO, Y., JIKE, T., TAMURA, Y., HIROTA, T., MIYAZAKI, A., NIINUMA, K., SORAI, K., TAKABA, H., HACHISUKA, K., KONDO, T., SEKIDO, M., MURATA, Y., NAKAI, N. and OMODAKA, T., 2016. The Hitachi and Takahagi 32 m radio telescopes: Upgrade of the antennas from satellite communication to radio astronomy. Publ. Astron. Soc. Jpn . vol. 68, is. 5, id. 74. DOI: https://doi.org/10.1093/pasj/psw045 5. BELLOCHE, A., MESHCHERYAKOV, A. A., GARROD, R. T., ILYUSHIN, V. V., ALEKSEEV, E. A., MOTIYENKO, R. A., MARGULES, L., MULLER, H. S. P. and MENTEN, K. M., 2017. Rotational spectroscopy, tentative interstellar detection, and chemical modeling of N-methylformamid. Astron. Astrophys . vol. 601, id. A49. DOI: https://doi.org/10.1051/0004-6361/201629724 6. PENG, H., WU, Z., ZHANG, B., CHEN, Y., ZHENG, X., JIANG, D., SHEN, Z., CHEN, X. and SOTNIKOVA, YU. V., 2020. Radio properties of the OH megamaser galaxy IRAS 02524+2046. Astron. Astrophys .vol. 638, id. A78. DOI: https://doi.org/10.1051/0004-6361/202037559 7. GENTILE, K. and CUSHING, R. 1999. A Technical Tutorial on Digital Signal Synthesis, 1999 [online]. Analog Devices Inc. [viewed 25 July 2020]. Available from: https://www.analog.com/en/education/education-library/technical-tutorial-dds.html 8. ZAKHARENKO, V., KONOVALENKO, A., ZARKA, P., ULYANOV, O., SIDORCHUK, M., STEPKIN, S., KOLIADIN, V., KALINICHENKO, N., STANISLAVSKY, A., DOROVSKYY, V., SHEPELEV, V., BUBNOV, I., YERIN, S., MELNIK, V., KOVAL, A., SHEVCHUK, N., VASYLIEVA, I., MYLOSTNA, K., SHEVTSOVA, A., SKORYK, A., KRAVTSOV, I., VOLVACH, Y., PLAKHOV, M., VASILENKO, N., VASYLKIVSKYI, Y., VAVRIV, D., VINOGRADOV, V., KOZHIN, R., KRAVTSOV, A., BULAKH, E., KUZIN, A., VASILYEV, A., RYABOV, V., REZNICHENKO, A., BORTSOV, V., LISACHENKO, V., KVASOV, G., MUKHA, D., LITVINENKO, G., BRAZHENKO, A., VASHCHISHIN, R., PYLAEV, O., KOSHOVYY, V., LOZINSKY, A., IVANTYSHYN, O., RUCKER, H. O., PANCHENKO, M., FISCHER, G., LECACHEUX, A., DENIS, L., COFFRE, A. and GRIEs-MEIER, J.-M., 2016. Digital Receiversfor Low-Frequency Radio Telescopes UTR-2, URAN, GURT. J. Astron. Instrum. vol. 5, is. 4, id. 1641010. DOI: https://doi.org/10.1142/S2251171716410105 9. TEXAS INSTRUMENTS INC., 2019. LMX2595 20-GHz Wideband PLLATINUM™ RF Synthesizer With Phase Synchronization and JESD204B Support. Data Sheet [online]. [viewed 30 July 2020]. Available from: https://www.ti.com/lit/gpn/lmx2595 10. ANALOG DEVICES INC., 2020. HMC814LC3B, SMT GaAs MMIC x2 Active frequency multiplier, 13 - 24.6 GHz output. HMC814LC3B Data Sheet [online]. [viewed 30 July 2020]. Available from: https://www.analog.com/media/en/technical-documentation/data-sheets/hmc814.pdf 11. ANALOG DEVICES INC., 2019. Low Power 250 MSPS 10-Bit DAC 1.8 V CMOS Direct Digital Synthesizer. AD9913 Data Sheet [online]. [viewed 30 July 2020]. Available from: https://www.analog.com/media/en/technicaldocumentation/data-sheets/AD9913.pdf 12. ANALOG DEVICES INC., 2016. 3.5 GSPS Direct Digital Synthesizer with 12-Bit DAC. AD9914 Data Sheet [online]. [viewed 30 July 2020]. Available from: https://www.analog.com/media/en/technical-documentation/data-sheets/AD9914.pdf 13. CUSHING, R., 2000. Single-Sideband Upconversion of Quadrature DDS Signals to the 800-to-2500-MHz Band. Analog Dialogue [online]. vol. 34, no. 3 [viewed 25 July 2020]. Available from: URL: https://www.analog.com/media/en/analog-dialogue/volume-34/number-1/articles/single-sideband-upconversion-of-quadrature-dds-signals.pdf 14. ALEKSEEV, E. A. and ZAKHARENKO, V. V., 2007. Direct Digital Synthesizer at the Microwave Spectroscopy. Radio Phys. Radio Astron . vol. 12, no. 2, pp. 205–213. (in Russian). 15. ALEKSEEV, E. A., MOTIYENKO, R. A. and MARGULES, L., 2011. Millimeter- and Submillimeter-Wave Spectrometers on the Basis of Direct Digital Synthesizers. Radio Phys. Radio Astron . vol. 16, no. 3, pp. 313–327. (in Russian). DOI: https://doi.org/10.1615/RadioPhysicsRadioAstronomy.v3.i1.100 16. ALEKSEEV, E. A., ILYUSHIN, V. V. and MESCHERYAKOV, A. A., 2014. High-Precision Microwave Spectrometer with Sub-Doppler Spectral Resolution. Radio Phys. Radio Astron . vol. 19, no. 4, pp. 364–374. (in Russian). DOI: https://doi.org/10.15407/rpra19.04.364 17. ANALOG DEVICES INC., 2006. DC-to-2.5 GHz High IP3 Active Mixer. AD8343 Data Sheet [online]. [viewed 30 July 2020]. Available from: https://www.analog.com/media/en/technical-documentation/data-sheets/AD8343.pdf 18. ANALOG DEVICES INC., 2017. Wideband Synthesizer with Integrated VCO. ADF4351 Data Sheet [online]. [viewed 30 July 2020]. Available from: https://www.analog.com/media/en/technical-documentation/data-sheets/ADF4351.pdf 19. ANALOG DEVICES INC., 2016. MicroConverter® Multichannel 24-/16-Bit ADCs with Embedded 62 kB Flash and Single-Cycle MCU. ADuC845/ADuC847/ADuC848 Data Sheet [online]. [viewed 30 July 2020]. Available from: https://www.analog.com/media/en/technical-documentation/data-sheets/ADUC845_847_848.pdf 20. BLEIDERS, M., BEZRUKOVS, V. and ORBIDANS, A., 2017. Performance Evaluation of Irbene RT-16 Radio Telescope Receiving System. Latv. J. Phys. Tech. Sci. vol. 54, is. 6, pp. 42–53. DOI: https://doi.org/10.1515/lpts-2017-0040

We studied the peculiarities of the participation of ERK1/2 and р38 in regulation of various types of progenitor cells of the nervous tissue under conditions of ethanol-induced neurodegeneration modeled in vitro and in vivo. The stimulating role of these signaling molecules in the realization of the growth potential of intact multipotent neural stem cells and committed neuronal precursors (clonogenic PSA-NCAM+ cells) was demonstrated. In vitro exposure to neurotoxic doses of ethanol led to the loss of the specified role of ERK1/2 and p38 in the cell cycle regulation. Inversion of the role of both studied MAP-kinases in determining the proliferation status of neural stem cells after long-term administration of ethanol to experimental animals was revealed. In committed neuronal precursors, this inversion (inhibition of mitotic activity instead of activation) was revealed only for ERK1/2. In mice exposed to chronic alcoholization, ERK1/2 no longer participated in the process of specialization of both types of regeneration-competent cells of the nerve tissue. The revealed fundamental difference between the functions of ERK1/2 and p38 in the cell cycle regulation in neural stem cells and committed neuronal precursors under optimal conditions and during ethanol-induced neurodegeneration does not allow drawing definite conclusions about the prospect of using modifiers of their activity for the therapy for alcohol-related CNS pathologies.

Suppression of the production of granulocytic CSF under the effect of 5-fluorouracyl is related to disorders in the NF-κB-, cAMP-dependent signaling pathways and MAPK cascade. These secondary messengers are involved in the regulation of functional activity of nonadherent myelokaryocytes starting from day 10 of the experiment (initial period of the hemopoietic granulocytic stem regeneration after antimetabolite challenge). Granulocytic CSF does not play essential role in the formation of colony-stimulating activity of cells of the adherent and nonadherent fractions of the bone marrow. Only cAMP-dependent pathway is involved in the regulation of the realization of the granulocytic precursor growth potential in response to the challenge.

Purpose: Technical capabilities of the MARK-4B antenna system necessary for its further using as a 32-meter radiotelescope (RT-32) and making simultaneous spectral radioastronomical observations in the C and K frequency ranges, are investigated. Design/methodology/approach:The studies use the results of our own measurements made with the МАRK-4В antenna system, expert reviews, open information sources, technical documentation of the MARK-4B antenna system, radio astronomy and computer simulation methods and comparative analysis of this antenna main parameters with the corresponding parameters of the world’s best active radio telescopes. Combining different approaches allows us to determine the requirements for the receiving system, parameters of the spectrometer, calibration techniques and optimize the МАRK-4В antenna system modernization procedure. Findings: The radio telescope main parameters required for spectral observations in the C and K frequency ranges are determined. The antenna pointing system capabilities are specified. For the MARK-4B antenna system working frequency range, the main spectral lines of various molecules available for research have been considered. The transitions radiating the most intensive spectral lines are listed. The radio astronomical problems that can be solved using the MARK-4B in the mode of spectral observations are formulated. The required parameters of the spectrum analyzer and the receiver’s self-noise temperature are determined. Calibration techniques of the recorded signal are described, which are necessary for carrying out spectral observations. Conclusions: The here presented studies show that for making spectral observations based on the beam-waveguide MARK-4B antenna system, it is technically possible to create the RT-32 radio telescope with quality technical characteristics corresponding to the world-best analogs. Modernization of the beamwaveguide MARK-4B antenna system will allow at the first stage to create in Ukraine the dual-band radio-telescope permitting to make simultaneous spectral and/or continued observations in the C and K ranges. Henceforth, the amount of simultaneously working ranges can be increased.

We studied the participation of JNK and p53 in the realization of the growth potential of different types of progenitors of the subventricular zone of mouse brain and secretion of neurotrophins by glial cells. The stimulating role of these signaling molecules in mitotic activity and specialization of multipotent neural stem cells was shown. It was found that JNK and p53 do not participate in the regulation of committed neuronal progenitor cells (clonogenic PSA-NCAM

We studied the effect of an anthocyanin-containing complex from Sorbus aucuparia L. on the main indicators of erythropoiesis in the blood and bone marrow of mice against the background of doxorubicin treatment. It was shown that administration of an anthocyanincontaining complex from S. aucuparia L. prevented the development of anemic syndrome by stimulating regeneration of the erythroid lineage of hematopoiesis after its devastation by single administration of the cytostatic.

The in vitro and in vivo models of ethanol-induced neurodegeneration were used to evaluate the content and functional activity of various types of regeneration-competent cells in subventricular zone of the cerebral hemispheres in C57Bl/6JY mice. In nervous tissue culture, ethanol (65 mM) produced no effect on formation of neurospheres. When administered per os in a daily dose of 3 g/kg for 8 weeks, ethanol produced no effect on the number of neural CFU in situ. In both cases, ethanol reduced proliferative activity of neural CFU. Long-term administration of ethanol in vivo suppressed differentiation of neural stem cells and decreased the number of committed precursors (neural cluster-forming units) in the subventricular zone of cerebral hemispheres. In vitro application of ethanol stimulated secretion of humoral growth factors by the cluster-forming neural glial cells. In contrast, in vivo administration of ethanol suppressed this secretion.

The role of JAK/STAT3-mediated signaling pathway in the realization of the growth potential of mesenchymal precursor cells was examined in vitro. The stimulating role of JAKs and STAT3 towards proliferating activity of progenitor cells and their different role in the regulation of differentiation of the progenitor elements were demonstrated. Inhibitors of JAKs and STAT3 reduced the yield of fibroblast CFU and their mitotic activity. Blockade of JAKs accelerated and selective inactivation of STAT3 decelerated differentiation of progenitor cells.

We studied the role of some JAK in the effect of diterpene alkaloid songorine on realization of the growth potential of mesenchymal precursor cells. The participation of JAK1, JAK2, and JAK3 in stimulation of proliferation of the precursor cells was demonstrated. Specific inhibitors of these JAK reduced the yield of fibroblast CFU and the rate of their division. Inhibition of JAK2 against the background of songorine treatment increased the rate of precursor differentiation.

Psychopharmacological effects of JNK inhibitor were studied using a mouse model of posthypoxic encephalopathy. The preparation exhibited a pronounced cerebroprotective effect manifested in normalization of orientation and exploratory behavior and conditioned responses in posthypoxic mice. These effects were accompanied by marked elevation of neural stem cell content in the paraventricular region of the brain.

Mice with Lewis lung carcinoma were used to study the antitumor and antimetastatic effects of JAK3 inhibitor. The study revealed no effect of JAK3 inhibitor on the growth of primary tumor node, but found a pronounced inhibition of hematogenous spread of the pathologic process into the lungs. In vitro blockade of JAK3 in cultured Lewis lung carcinoma produced no effect on the count of the stem tumor cells and stimulated functions of committed elements. In addition, blockade of JAK3 significantly elevated maturation index of the tumor tissue.

Psychopharmacological effects of atisine-type diterpene alkaloid Z77 were studied under conditions of experimental posthypoxic encephalopathy. The preparation had a pronounced cerebroprotective effect consisting in normalization of orientation and exploratory behavior and conditioned activity in experimental animals. These changes were accompanied by significant increase in the number of neural stem cells in the paraventricular region of the brain and markedly enhanced production of neurotrophic growth factors by neural tissue microenvironment cells.

The role of NF-κB, cAMP/PKA, JAKs/STAT3, ERK1/2, p38, JNK, and p53 signaling pathways in the realization of growth potential of mesenchymal, neural, erythroid, and granulomonocytic progenitor cells were examined in vitro. Using selective blockers of signaling molecules, we revealed some principal distinctions of their involvement in determination of proliferation-differentiation status of the progenitor cells of different functional classes. The most salient peculiarities were observed in the roles of cAMP/PKA, JNK, and JAKs/STAT3 signaling pathways in the control of functions of various types of the regeneration-competent elements. The specific features of intracellular signaling revealed in histogenetically and functionally different progenitor cells attest to visibility of differentiated pharmacological stimulation of regeneration in individual tissues and prospectiveness in the development of targeted remedies for regenerative medicine based on modifiers of activity of the intracellular signaling molecules.

The role of JNK-mediated signal pathway and participation of p53 transcription factor in stimulation of realization of the growth potential of the mesenchymal precursor cells by alkaloid songorine were examined in vitro. Specific inhibitors of JNK and p53 enhanced stimulation of fibroblast colony/cluster formation and proliferative activity of mesenchymal precursor cells. Under these conditions, more pronounced effects were observed with early precursors of fibroblast CFU and in both cases were accompanied by a decrease in differentiation index of progenitor elements.

Protein kinase p38 was shown to contribute to the increase in production of granulocyte CSF by microenvironmental cells under conditions of restraint stress. Stimulation of colony-forming activity was not accompanied by the increase in maturation of clonogenic structures in the bone marrow granulocytic stem. This process was realized with the involvement of NF-κB-dependent signaling and p38 MAPK signaling pathway. Our study showed that the p38 MAPK signaling pathway plays an important role in the regulation of granulocytopoiesis, but not of erythropoiesis.

We studied the in vitro role of NF-κB-dependent signaling in the growth capacity of mesenchymal progenitor cells upon stimulation by basic fibroblast growth factor. Proliferative activity of progenitor cells was suppressed by specifi c inhibitors of this transcription factor (NF-κB), oridonin and aurothiomalate. These inhibitors had no effect on differentiation of fibroblast CFU.

We studied the role of cAMP- and IKK-2-dependent pathways under conditions of functional stimulation of mesenchymal progenitor cells by basic fibroblast growth factor. An adenylate cyclase inhibitor 2',5'-dideoxyadenosine had no effect on functional activity of early (primitive) mesenchymal precursors. This agent produced a stimulatory effect on proliferation of stromal precursor cells. Mitotic activity of mesenchymal progenitor cells was shown to decrease after treatment with a specific blocker of the IKK-2 kinase-inhibitor complex.

PI3- and MAP-kinase signaling pathways duplicate and interchange each other in production of agents that determine total erythropoietic activity under conditions of balanced erythropoiesis. The alternative p38-dependent MAP-kinase pathway is the major regulator of erythropoietic activity of adherent bone marrow cells. Blockade of PI3K and p38 signaling pathways stimulated production of erythropoietin by cells that do not produce it constitutively.

The role of JNK-mediated signal pathway and participation of p53 transcription factor in stimulation of mesenchymal precursor cell function by the fibroblast growth factor was studied. The levels of fibroblast colony- and cluster formation and proliferative activity of mesenchymal precursors increased in response to JNK and p53 specific inhibitors. JNK and p53 blockers did not change the rate of fibroblast growth factor-induced progenitor element differentiation.

We have demonstrated the possibility of stimulation of the function of various types of precursor cells with hyaluronidase modified with chondroitin sulfate. Parenteral administration of modified hyaluronidase increased the number of fibroblast, granulomonocyte, and erythroid CFU in the hemopoietic tissue. The changes in the pool of mesenchymal progenitor cells were more pronounced in comparison with those induced by native enzyme.

We studied the role of cAMP- and IKK-2-mediated pathways in the realization of growth potential of mesenchymal progenitor cells in vitro. It had been found that adenylate cyclase inhibitor 2',5'-dideoxyadenosine had no effect on the proliferation and differentiation of fibroblastic CFU. A decrease in differentiation rate of progenitor cells was observed after the treatment with specific IKK-2 blocker inhibitor-kinase complex.

The involvement of the studied signal cascades in the regulation of erythropoietin production by bone marrow nuclears under conditions of immobilization stress depends on the type of the hemopoiesis-inducing microenvironment cells and the period of blood system reaction to stress exposure. Secretory activity of monocytes is regulated mainly by PI3K improving cell resistance to disturbances. The functional role of signal cascades involved in the production of erythropoietin by T cells is determined by the stage of the common adaptation syndrome.

The leading role in the regulation of erythropoietic activity of adherent bone marrow cells under conditions of post-hemorrhagic anemia is played by classical MAP kinase pathway (ERK pathway). Erythropoietin is not the decisive factor in the formation of erythropoietic activity of adherent cells. PI3K, MAPK/ERK 1/2, and p38-signaling proteins are not the main regulators of local production of erythropoietin after 30% loss of circulating blood volume.

We consider the Cauchy problem for a first-order linear inhomogeneous differential equation for functions ranging in a Banach space in the case of a sectorial operator coefficient. We find conditions for the solvability of the Cauchy problem for the case in which the right-hand side is not necessarily a Holder function.

The effects of Fructus Sorbi aucupariae extract, originally saturated with anthocyans, on the development of Lewis lung carcinoma and B-16 melanoma in C57Bl/6 mice and the efficiency of cyclophosphamide treatment were studied. Antitumor activity of the extract and potentiation of the antimetastatic activity of the cytostatic were demonstrated. Studies on melanoma B-16 model revealed an increase in the counts of stromal progenitor cells in the tumor node and their accelerated maturation after treatment with the extract. No effects towards the tumor stem and committed cells were detected.

Involvement of individual JAK kinases in the realization of growth potential of mesenchymal progenitor cells was examined in vitro. Important role of JAK2 and JAK3 in determining the initial level of mitotic activity of progenitor cells was established. The yield of fibroblast CFUF was suppressed under the effect of specific inhibitors of JAK kinases. Blockade of JAK3 increased the rate of progenitor element differentiation. JAK1 had no effect on proliferation and differentiation status of progenitor cells.

We studied the dynamics of erythropoiesis in CBA mice during gestation against the background of treatment with iron-binding drug. The mechanisms of suppression of the bone marrow erythroid stem were evaluated. Administration of deferoxamine in a dose of 1 g/kg induced hypoplasia of the erythroid hemopoietic lineage. Suppression of bone marrow erythropoiesis manifested in a decrease of hemoglobin concentration and counts of reticulocytes, erythrocytes, and erythrokaryocytes. These changes were accompanied by a decrease in functional activity of erythropoietic precursors and secretion of erythropoietically active humoral factors by bone marrow myelokaryocytes. These data indicate that deferoxamine can be used for modeling of iron defi ciency anemia in pregnancy.

We studied the mechanisms of erythropoiesis stimulation and effectiveness of Poetam, a preparation containing release-active anti-erythropoietin antibodies as a supplement treatment for experimental iron deficiency anemia during gestation. The results confirmed potency of combined therapy to stimulate erythropoiesis, which was more efficacious in comparison with monotherapy as assessed by the count of erythrokaryocytes and erythroid progenitors in the hematopoietic tissue as well as by the content of erythrocytes and hemoglobin in the peripheral blood. Activation of erythropoiesis is related to the modulatory effect of Poetam on proliferative activity and differentiation of erythroid precursors, which in most aspects results from stimulatory action of Poetam on secretion of the hematopoietically active factors by adherent elements of the hematopoietic microenvironment.

Let be a Banach space and a non-increasing function such that as and is a Lipschitz function on .A linear operator is said to be -sectorial if there exist constants and such that the spectrum of lies in the set and there exists 0$ SRC=http://ej.iop.org/images/1064-5616/197/7/A02/tex_sm_3785_img13.gif/> such that for where is the resolvent of the operator .The properties of the operator exponential and fractional powers of a -sectorial operator are analysed alongside the question of the unique solubility of the Cauchy problem for the linear differential operator with -sectorial operator-valued coefficient.

The results of research aimed at the development of high-efficiency Ge/Si-based photodetectors for fiber-optic communication applications are reported. The photodetectors are designed as vertical p-i-n diodes on silicon-on-insulator substrates in combination with waveguide lateral geometry and contain Ge quantum-dot layers. The layer density of quantum dots is 1×1012 cm−2; the dot size in the plane of growth is ∼8 nm. Unprecedentedly high quantum efficiency suitable for the range of telecommunication wavelengths is attained; specifically, in the waveguides illuminated from the end side, the efficiency was as high as 21 and 16% at 1.3 and 1.55 µm, respectively.

A method has been devised for MBE fabrication of p-i-n photodiodes for the spectral range of 1.3–1.5 µm, based on multilayer Ge/Si heterostructures with Ge quantum dots (QDs) on a Si substrate. The sheet density of QDs is 1.2×1012 cm−2, and their lateral size is ∼8 nm. The lowest room-temperature dark current reported hitherto for Ge/Si photodetectors is achieved (2×10−5 A/cm2 at 1 V reverse bias). A quantum efficiency of 3% at 1.3 µm wavelength is obtained.

The role of cAMP- and IKK-2-dependent pathways in stimulation of the growth capacity of mesenchymal progenitor cells with alkaloid songorine was studied in vitro. Inhibitors of adenylate cyclase and IKK-2 were shown to abolish the increase in proliferative activity of progenitor cells. Moreover, blockade of the inhibitory kinase complex was accompanied by a decrease in the intensity of progenitor cell differentiation.

We studied the role of NF-κB/IKK-mediated signaling in the stimulation of growth potential of mesenchymal progenitor cells by alkaloid songorine in vitro. Specific NF-κB inhibitor oridonin abolished activation of proliferation and differentiation of progenitor cells. Aurothiomalate, a selective blocker of IKK-2, also suppressed mitotic activity of fibroblast precursors, but had no effect on the rate of the differentiation.

We studied the role of intracellular signaling molecules PI3K, МАРK ERK1/2, and р38 in stimulation of realization of the growth potential of mesenchymal progenitor cells by alkaloid songorine in vitro. Inhibitors of PI3K, ERK1/2 and р38 canceled the increase in proliferative activity of progenitor cells, the blockers of ERK1/2 and р38 reduced the intensity of progenitor cell differentiation.

Electrical characteristics of silicon Schottky diodes containing Ge quantum dot (QD) arrays are investigated. It has been found that the potential barrier height at the metal-semiconductor contact can be controlled by introducing dense QD layers, which is a consequence of the formation of a planar electrostatic potential of charged QDs. When the applied voltage is varied, the ideality factors of Schottky barriers exhibit oscillations due to the tunneling of holes through discrete levels in quantum dots.

Specifi c JNK and p53 inhibitors stimulated the formation of fi broblast colonies (CFU-F) and clusters (ClFU-F) and increased proliferative activity of mesenchymal progenitor cells. No effects of inhibitors of JNK and p53 on differentiation of progenitor elements were revealed.

A decrease in the total number of sperm cells and reduction of spermatogonium population were observed upon cytostatic damage of spermatogenous tissue caused by single paclitaxel administration. It was established that the paclitaxel-induced damage to the testicular tissue is underlain by reduction of its regenerative potential consisting in depletion of regional precursor pool. Changes in functional activity of progenitor cells were caused not only by direct action of paclitaxel, but also by suppression of the secretory function of the tissue microenvironment.

We studied the role of signaling pathways in the regulation of erythropoiesis against the background of myelosuppression caused by administration of 5-fluorouracil. The important role of cyclic AMP in the maturation of erythroid progenitors after cytostatic treatment was demonstrated. The secretory activity of myelokaryocytes during the period of erythroid hemopoiesis recovery is mainly regulated via the p38 MAPK signaling pathway; non-erythropoietin factors are involved in the formation of erythropoietic activity of adherent cells of the microenvironment.

The involvement of PI3K, ERK and p38-dependent signaling system in the regulation of functional activity of erythroid precursors after blood loss (30% of circulating volume) was studied. We demonstrated the important role of PI3K and p38 in the suppression of differentiation of erythroid precursors the contribution of p38 to stimulation of mitotic activity of erythroid CFU, which maintains the growth potential of the precursors at the optimal physiological level. The classical MAPK/ERK-kinase pathway does not determine the proliferative and differentiation status of erythroid CFU.

We studied the mechanisms of regenerative (wound healing) effects of songorine associated with functional activation of mesenchymal progenitor cells. The key role of FGF receptors on these progenitor cells in the stimulation of realization of their growth potential under the effect of the alkaloid was demonstrated. Under in vitro conditions, the antibodies to FGF receptor abolished the songorine-induced increase in the number of fibroblast colony-forming units in bone marrow cell culture. The intensity of differentiation of mesenchymal precursors remained unchanged.

We studied the effect of mobilization of bone marrow multipotent stem cells induced by intragastric administration of pegylated hyaluronate-endo-β-N-acetylhexosaminidase (Peg-HEAHA) on hemopoiesis under conditions of experimental chronic hepatitis. Peg-HEAHA increased the counts of hemopoietic precursors in the hemopoietic tissue against the background of their decelerated maturation. This was paralleled by a short-term decrease in the count of neutrophilic granulocyte in the bone marrow and a slight increase of neutrophil count in the peripheral blood.

The study examines the role of signal pathways in triggering the compensatory reactions in the blood system in response to the cytostatic administration. In vitro experiments elucidated the involvement of protein kinase p38 in the synthesis of granulocytic CSF by cells of hemopoietic microenvironment. The important role of the transcriptional factor NF-κB and protein kinase p38 in limitation of the processes of maturation of the hemopoietic precursors was demonstrated.