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Krasavin M.,Yaroslavl State Pedagogical University | Parchinsky V.,Chemical Diversity Research Institute
Tetrahedron Letters | Year: 2010

A novel approach to skeletally diverse 3-oxoisoindolines has been developed which includes preparation of Ugi adducts containing thiophene and fumaric acid residues. When treated with excess m-CPBA at room temperature, these precursors undergo a simple oxidative cycloaddition/aromatization transformation and the corresponding 3-oxoisoindoline products are isolated in fair chemical yield over two steps. The second step is thought to include S-oxidation/IMDA/S-oxidation/ SO2 extrusion/aromatization events. © 2010 Elsevier Ltd. All rights reserved.


Tikhomirova I.A.,Yaroslavl State Pedagogical University | Oslyakova A.O.,Yaroslavl State Pedagogical University | Mikhailova S.G.,Yaroslavl State Pedagogical University
Clinical Hemorheology and Microcirculation | Year: 2011

We estimated hemorheological parameters of vein blood samples and cutaneous microvascular blood flow in patients with acute ischemic stroke and in controls. The worsened blood rheological properties were registered in patients with stroke: the enhanced whole blood viscosity was due to the substantial increase of plasma viscosity and the impairment of microrheological blood properties: elevated erythrocyte aggregability and decreased deformability compared to the healthy group. The decrease of oxygen consumption fixed by rheological methods and by laser Doppler flowmetry led us to conclude that the tissue hypoxia took place in patients with stroke. The regulatory mechanisms aimed to maintain blood supply to tissue were activated under cerebral infarction and the impact of unfavorably changed rheological blood properties was markedly enhanced. Revealed close interrelations between rheological and microcirculation parameters testified the important role of hemorheological factors in maintenance of microvascular blood flow and oxygen delivery to tissue. © 2011 IOS Press and the authors. All rights reserved.


Sapegin A.V.,Yaroslavl State Pedagogical University | Kalinin S.A.,Yaroslavl State Pedagogical University | Smirnov A.V.,Yaroslavl State Pedagogical University | Dorogov M.V.,Yaroslavl State Pedagogical University | Krasavin M.,Griffith University
Tetrahedron | Year: 2014

A streamlined synthetic methodology towards novel tetracyclic 1,4-oxazepines from readily available precursors is described. The compounds, designed as more soluble version of the earlier described, poorly soluble dibenzo[b,f][1,4]oxazepines, were obtained in high yields and as a single regioisomer as a result of three tandem chemical events - nucleophilic aromatic substitution, Smiles rearrangement and denitrocyclization. © 2014 Elsevier Ltd. All rights reserved.


Muravyov A.V.,Yaroslavl State Pedagogical University | Tikhomirova I.A.,Yaroslavl State Pedagogical University
Clinical Hemorheology and Microcirculation | Year: 2013

This study was designed to investigate the dependency of the red blood cell deformability upon activation of extra- and intracellular signaling pathways. Exposures of red blood cells (RBCs) to catecholamines and to insulin led to positive change in the RBC deformability. When forskolin, a stimulator of adenylyl cyclase (AC), was added to RBC suspension, the RBC deformability was increased. Somewhat more significant deformability rise appeared after RBC incubation with dB-AMP. The inhibitors of phosphodiesterase (PDE) activity increased red cell deformability. These results revealed a considerable role of the AC-cAMP signaling system in the regulation of red blood cell deformability. The rise of the red blood cell Ca2+ influx, stimulated by mechanical loading or A23187 was accompanied by a marked lowering of RBC deformability. At the same time blocking of Ca2+ entry into RBC by verapamil or Ca 2+ chelating by EGTA led to significant deformability rise. The comparison of the effect of the different protein kinases on the red blood cell deformability showed that it was altered more considerable under PKA activation by forskolin or dB-cAMP than by other protein kinases. There was a lesser but quite statistically significant effect of tyrosine protein kinase (TPK) on RBC microrheology. Whereas the microrheological effect of PKC was not so considerable. The problem of the short-term regulation of red blood cell microrheology is examined. The latter includes: the modes of activation of extra- and intracellular molecular signaling pathways, ligand - receptor interaction, second messengers, membrane protein phosphorylation. On the whole the total data clearly show that the red cell deformability changes are connected with activation of different extra - and intracellular signaling pathways. It seems reasonable to suppose that red blood cell deformability changes were mainly associated with activation of the AC-cAMP-PKA pathway, and with decrease of Ca2+ entry into cells. © 2013 - IOS Press and the authors. All rights reserved.


Voronin L.V.,Yaroslavl State Pedagogical University
Inland Water Biology | Year: 2010

Data on the occurrence, abundance, and species composition of fungi in the ecotopes of small acid lakes are presented. The role of fungi in acid-lake ecosystems is discussed. © 2010 Pleiades Publishing, Ltd.


Sarnpitak P.,Griffith University | Tsirulnikov S.,Yaroslavl State Pedagogical University | Krasavin M.,Griffith University
Tetrahedron Letters | Year: 2012

A hitherto undescribed TMSCl-promoted reaction of thiosemicarbazones was found to give rare N 1,N 3-disubstituted formamidrazones in fair to excellent yields. The scope of this new reaction was investigated and a plausible mechanism proposed. © 2012 Elsevier Ltd. All rights reserved.


Muravyov A.,Yaroslavl State Pedagogical University | Tikhomirova I.,Yaroslavl State Pedagogical University
Advances in Experimental Medicine and Biology | Year: 2012

To assess the physiological role of intracellular Ca 2+ in the changes of microrheological red blood cell (RBC) properties (RBC deformability and aggregation), we employed several types of chemicals that can increase and decrease of the intracellular Ca 2+ concentration. The rise of Ca 2+ influx, stimulated by mechanical loading, A23187, thrombin, prostaglandin F 2α was accompanied by a moderate red cell deformability lowering and an increase of their aggregation. In contrast, Ca 2+ entry blocking into the red cells by verapamil led to a significant RBC aggregation decrease and deformability rise. Similar microrheological changes were observed in the red blood cells treated with phosphodiesterase inhibitors IBMX, vinpocetine, rolipram, pentoxifylline. When forskolin (10 μM), an AC stimulator was added to RBC suspension, the RBC deformability was increased (p <0.05). Somewhat more significant deformability rise appeared after RBC incubation with dB-AMP. Red cell aggregation was significantly decreased under these conditions (p<0.01). On the whole the total data clearly show that the red cell aggregation and deformation changes were connected with an activation of both intracellular signaling pathways: Ca 2+ regulatory mechanism and Gs-protein/adenylyl-cyclase-cAMP system. And the final red cell microrheological regulatory effect is connected with the crosstalk between these systems. © 2012 Springer Science+Business Media B.V.


Voronin L.V.,Yaroslavl State Pedagogical University
Inland Water Biology | Year: 2014

The occurrence, abundance, and taxonomical composition of fungi have been analyzed for different compounds of the freshwater ecosystems of various natural zones (from tundra to desert), particularly, for plankton, benthos, on living and dead plant substrates, and on some fish species. The role of terrigenous fungi in the freshwater ecosystems is discussed. © 2014, Pleiades Publishing, Ltd.


Lakontseva E.,Yaroslavl State Pedagogical University | Krasavin M.,Yaroslavl State Pedagogical University
Tetrahedron Letters | Year: 2010

N-Cyanoacetyl-N′-trifluoroacetyl-N′-alkylhydrazines, prepared via hydrazino-Ugi reaction, provided different pyrazol-3-ones when exposed to mildly acidic and mildly basic conditions at 60 °C. These approaches offer a facile access to two different pyrazol-3-one-containing chemotypes in a diversity-oriented fashion, in only two chemical operations from simple precursors. © 2010 Elsevier Ltd. All rights reserved.


Wierzbowski H.,Polish Academy of Sciences | Rogov M.A.,Russian Academy of Sciences | Matyja B.A.,University of Warsaw | Kiselev D.,Yaroslavl State Pedagogical University | Ippolitov A.,Russian Academy of Sciences
Global and Planetary Change | Year: 2013

New isotope (δ18O, δ13C) and elemental (Mg/Ca, Sr/Ca) data of well-preserved belemnite rostra, ammonite and gastropod shells from the Middle Oxfordian-Lower Kimmerdgian (Densiplicatum-Kitchini zones) of the Russian Platform are presented. This record is supplemented with published data from the Upper Callovian-Lower Kimmeridgian interval (Athleta-Kitchini zones). Significant differences in average temperatures calculated from δ18O values of particular fossil groups (5-15°C) show the thermal gradient and the presence of cold bottom waters in the Middle Russian Sea during the Late Callovian-Middle Oxfordian. An Upper Oxfordian-lowermost Kimmeridgian decrease in δ18O values and an increase in Sr/Ca ratios of cylindroteuthid belemnite rostra likely reflect a warming of the bottom waters of ca. 3.5°C. The gradual Late Oxfordian-earliest Kimmeridgian warming is followed by an abrupt temperature rise of 3-6°C that occurred at the transition of the Early Kimmeridgian Bauhini and Kitchini chrons.The occurrences of cold bottom waters and of (Sub)Mediterranean ammonites and belemnites in the Middle Russian Sea at the Middle-Late Jurassic transition are regarded as a result of the opening of seaways during a sea level highstand. The bottom waters are considered to have been formed in the cool Boreal Sea. The subsequent retreats of the cold bottom waters and of the (Sub)Mediterranean cephalopods from the Middle Russian Sea in the Late Oxfordian are explained by the restriction of water circulation during a sea-level fall. The Early Kimmeridgian rise of bottom temperatures of the sea is linked to a global climate warming. The data presented do not support a major cooling of the Arctic and a consequent glaciation in this region at the Middle-Late Jurassic transition. Since occurrences of cold water masses are diachronous in different European basins, the observed variations in sea water temperatures are interpreted as a result of changes in marine currents and water circulation.δ13C values of belemnite rostra from the Russian Platform are scattered but show the long-term Upper Callovian-Middle Oxfordian positive excursion consistent with the previously published isotope records of the Boreal Realm and terrestrial organic matter. © 2013 Elsevier B.V.

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