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51.
N. S. Melik-Nubarov I. D. Grozdova G. Yu. Lomakina M. V. Pokrovskaya V. S. Pokrovski S. S. Aleksandrova O. Yu. Abakumova O. V. Podobed D. V. Grishin N. N. Sokolov 《Applied Biochemistry and Microbiology》2017,53(2):165-172
N-hydroxysuccinimide ester of monomethoxy polyethylene glycol hemisuccinate was synthesized. It acylated amino groups in a molecule of recombinant L-asparaginase from Erwinia carotovora. A method of L-asparaginase modification by the obtained activated polyethylene glycol derivative was developed. The best results were produced by modification of the enzyme with a 25-fold excess of reagent relative to the enzyme tetramer. The modified L-asparaginase was isolated from the reaction mixture by gel filtration on Sepharose CL-6B. The purified bioconjugate did not contain PEG unbound to the protein, demonstrated high catalytic activity, and exhibited antiproliferative action on cell cultures. 相似文献
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HEYO VAN ITEN JULIANA DE MORAES LEME† SABRINA COELHO RODRIGUES† MARCELLO GUIMARÃES SIMÕES‡ 《Palaeontology》2005,48(3):619-622
Abstract: Vendoconularia triradiata Ivantsov and Fedonkin, recently described from Vendian (latest Proterozoic) strata of Russia, has been interpreted as a six-sided conulariid cnidarian. However, comparison of published illustrations of V . triradiata with Palaeozoic conulariids suggests that certain key features of the anatomy of V . triradiata should be reinterpreted. Specifically, features previously homologized with the corners of conulariid thecae may actually be homologous to the conulariid midlines. Under this new interpretation, the corners of the Vendoconularia theca were sulcate, and the midline of each face was non-sulcate and flanked by a pair of low internal carinae. This alternative set of hypotheses of homology makes the argument for a conulariid affinity for Vendoconularia stronger. 相似文献
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JULIANA DE MORAES LEME MARCELLO GUIMARÃES SIMÕES ANTONIO CARLOS MARQUES† HEYO VAN ITEN‡ 《Palaeontology》2008,51(3):649-662
Abstract: Results of a cladistic analysis of the suborder Conulariina Miller and Gurley, 1896, a major extinct (Vendian–Triassic) group of scyphozoan cnidarians, are presented. The analysis sought to test whether the three conulariid subfamilies (Conulariinae Walcott, 1886 , Paraconulariinae Sinclair, 1952 and Ctenoconulariinae Sinclair, 1952 ) recognized in the Treatise on Invertebrate Paleontology (TIP) are monophyletic. A total of 17 morphological characters were scored for 16 ingroup taxa, namely the genera Archaeoconularia, Baccaconularia, Climacoconus, Conularia, Conulariella, Conularina, Ctenoconularia, Eoconularia, Glyptoconularia, Metaconularia, Notoconularia, Paraconularia, Pseudoconularia, Reticulaconularia, Teresconularia and Vendoconularia. The extant medusozoan taxa Cubozoa, Stauromedusae, Coronatae and Semaeostomeae served as outgroups. Unweighted analysisof the data matrix yielded 1057 trees, and successive weighting analysis resulted in one of the 1057 original trees. The ingroup is monophyletic with two autapomorphies: (1) the quadrate geometry of the oral region; and (2) the presence of a mineralized (phosphatic) periderm. Within the ingroup, the clade (Vendoconularia, Teresconularia, Conularina, Eoconularia) is supported by the sinusoidal longitudinal geometry of the transverse ridges, and the much larger clade (Baccaconularia, Glyptoconularia, Metaconularia, Pseudoconularia, Conularia, Ctenoconularia, Archaeoconularia, Notoconularia, Climacoconus, Paraconularia, Reticulaconularia) is supported by the presence of external tubercles, which, however, were lost in the clade (Notoconularia, Climacoconus, Paraconularia, Reticulaconularia). As proposed by Van Iten et al. (2000) , the clade (Notoconularia, Climacoconus, Paraconularia, Reticulaconularia) is supported by the termination and alternation of the transverse ribs in the corner sulcus. The previously recognized subfamilies Conulariinae, Paraconulariinae and Ctenoconulariinae were not recovered from this analysis. The diagnostic features of Conulariinae (continuation of the transverse ornament across the corner sulcus and lack of carinae) and Ctenoconulariinae (presence of carinae) are symplesiomorphic or homoplastic, and Paraconulariinae is polyphyletic. The families Conulariellidae Kiderlen, 1937 and Conulariopsidae Sugiyama, 1942 , also recognized in the TIP, are monogeneric, and since they provide no additional phylogenetic information, should be abandoned. 相似文献
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Segizbaeva MO Pogodin MA Lavrova IN Balykin MV Aleksandrova NP 《Fiziologiia cheloveka》2011,37(2):52-59
The effect of head-down tilt on respiration and diaphragmal and parasternal muscles activity was investigated in 11 healthy subjects. The short-time (30 min) head-down tilt posture (-30 degrees relatively horizont) increased the inspiratory time (P < 0.05), decreased breathing frequency (P < 0.05), inspiratory and expiratory flow rate (P < 0.05) and increased the airway resistance (P < 0.05) compared with values in vertical posture. There were no significant changes in tidal volume and minute ventilation. Constant values of tidal volume and minute ventilation during head-down tilt were provided by increasing in EMG activity of parasternal muscles more then twice. It was established that the contribution of chest wall inspiratory muscles increased while the diaphragm's contribution decreased during head-down spontaneous breathing. Maximal inspiratory effort (Muller's maneuver) during head-down tilt evoked the opposite EMG-activity pattern: the contribution of inspiratory thoracic muscles was decreased and diaphragm's EMG-activity was increased compared with vertical posture. These results suggest that coordinate modulations in inspiratory muscles activity allows to preserve the functional possibility of human inspiratory muscles during short-time head-down tilt. 相似文献
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Aleksandrova LA 《Bioorganicheskaia khimiia》2011,37(6):723-744
The synthetic methods for 4'-C-modified nucleosides as well as structure activity relationship of obtained compounds towards hepatitis C virus are reviewed. 相似文献
58.
M. O. Segizbaeva M. A. Pogodin I. N. Lavrova M. V. Balykin N. P. Aleksandrova 《Human physiology》2011,37(2):171-177
The effect of a head-down tilt on the responses of the external respiration system and the functional capacity of the diaphragm
and parasternal muscles were investigated in 11 healthy subjects. A 30-min head-down tilt posture (−30° relative to the horizontal)
significantly increased the inspiratory time, decreased the respiration rate and the inspiratory and expiratory flow rates;
and increased the airway resistance compared to these values in the vertical posture. There were no significant changes in
tidal volume or minute ventilation. The electromyograms (EMGs) of the diaphragm and parasternal muscles showed that the constant
values of tidal volume and minute ventilation during head-down tilt could be provided by an increase in the electric activity
of the thoracic inspiratory muscles. It was established that the contribution of the thoracic inspiratory muscles increased,
while the diaphragms’ contribution decreased, during patient, spontaneous breathing. The maximal inspiratory effort (Muller’s
maneuver) during a head-down tilt evoked the opposite EMG-activity pattern: the contribution of inspiratory thoracic muscles
was decreased and the diaphragm EMG activity was increased compared to the vertical posture. These results suggest that coordinated
modulations in inspiratory muscle activity make it possible to preserve the functional reserve of human inspiratory muscles
during a short-term head-down tilt. 相似文献
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The Turtas Formation (the Upper Oligocene of Western Siberia), uncovered by the Zyryanka-1 Borehole, contain diverse assemblage of microfossils. The ecological composition (freshwater diatoms, spicules and gemmuloscleres of freshwater sponges, spores and pollen, as well as zygospores of Zygnematales algae) indicates the nonmarine nature of the Early Turtas Basin. In contrast to the assemblage of the Zhuravka horizon (southern regions of Western Siberia), the absence of Fagaceae and dinocysts of the genus Pseudokomewuia, as well as low numbers of Taxodiaceae–Cupressaceae and Betulaceae, are probably explained by local characteristics. 相似文献