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91.
G. S. Volkov V. I. Zaitsev E. V. Grabovski M. V. Fedulov V. V. Aleksandrov N. I. Lakhtyushko 《Plasma Physics Reports》2010,36(3):191-199
Results are presented from experimental studies of Z-pinches produced by implosion of aluminum and tungsten cylindrical wire
arrays in the Angara-5-1 facility. The electron temperature T
e
and density n
e
of the high-temperature pinch plasma have been determined by analyzing line emission from multicharged ions. For the same
mass and radius of the array and the same number of wires in it, the intensity of line emission of H- and He-like Al ions
from an imploded Al + W wire array containing even a small amount of tungsten (7 wt %) is one order of magnitude lower than
that from an Al array. As the W content increases, the total soft X-ray (SXR) yield increases, while the duration of the SXR
pulse decreases. For the 30% W content in the array, the power and duration of the SXR pulse are nearly the same as those
recorded during the implosion of a W array with the same linear mass and radius and the same number of wires. Results are
also presented from experiments with nested wire arrays in which the outer and inner shells were made of Al and W wires, respectively.
It is found that, in this case, the effect of tungsten on the line emission of aluminum is much weaker than that in experiments
with arrays in which tungsten and aluminum wires were placed in the same shell, even if the mass of the inner (tungsten) shell
was larger than that of the outer (aluminum) one. At the same time, the inner W shell plays a significant role in the implosion
dynamics of a nested wire array, reducing the duration of the SXR pulse and increasing the SXR power. 相似文献
92.
Tupitsyn NN Yaryghin VN Bryukhovetskiy AS Grivtsova LY Mentkevich GL Dolgopolov IS Zaitsev AY Davydov MI 《Journal of biological regulators and homeostatic agents》2006,20(1-2):36-40
Immunophenotype of mobilized stem blood cells (CD34+) was studied in 29 patients with late post-traumatic spinal lesions. The CD34+ cells demonstrated different levels of expression of CD45, CD38, monomorphic determinants HLA-DR and gp130 epitopes. Most patients presented with a CD34+ cell fraction with no or low expression of common leukocytic antigen CD45. Only 2 patients had greater than 15 percent of HLA-DR-CD38- cells in the CD34+ fraction. A common transducer molecule of interleukin-6 family cytokines gp130 was expressed on stem (CD34+) cells in all the cases, 26 percent of the patients had an activated gp130 phenotype, i.e. a combination of C7+ and A1- epitopes. 相似文献
93.
Andrey V. Lyashenko Isabel Bento Viatcheslav N. Zaitsev Nadezhda E. Zhukhlistova Yuliya N. Zhukova Azat G. Gabdoulkhakov Ekaterina Y. Morgunova Wolfgang Voelter Galina S. Kachalova Elena V. Stepanova Ol`ga V. Koroleva Victor S. Lamzin Vladimir I. Tishkov Christian Betzel Peter F. Lindley Al`bert M. Mikhailov 《Journal of biological inorganic chemistry》2006,11(8):963-973
Laccases are members of the blue multi-copper oxidase family. These enzymes oxidize substrate molecules by accepting electrons at a mononuclear copper centre and transferring them to a trinuclear centre. Dioxygen binds to the trinuclear centre and following the transfer of four electrons is reduced to two molecules of water. The X-ray structure of a laccase from Cerrena maxima has been elucidated at 1.9 A resolution using synchrotron data and the molecular replacement technique. The final refinement coefficients are Rcryst = 16.8% and Rfree = 23.0%, with root mean square deviations on bond lengths and bond angles of 0.015 A and 1.51 degrees , respectively. The type 1 copper centre has an isoleucine residue at the axial position and the "resting" state of the trinuclear centre comprises a single oxygen (OH) moiety asymmetrically disposed between the two type 3 copper ions and a water molecule attached to the type 2 ion. Several carbohydrate binding sites have been identified and the glycan chains appear to promote the formation of well-ordered crystals. Two tyrosine residues near the protein surface have been found in a nitrated state. 相似文献
94.
Oknina LB Sharova EV Georgievskaia NA Kulikov MA Zaitsev OS Boldyreva GN Masherov EL 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》2006,56(6):757-766
In order to reveal features of the brain reactions to external stimuli in the course of consciousness recovery after a severe craniocerebral injury, component P300 of acoustic evoked potential was analyzed in 9 patients with chronic and 32 patients with reversible unconsciousness. In patients with chronic unconsciousness, P300 parameters displayed a linear correlation with the current functional state. However, this component remained significantly different from its normal shape and varied only in a narrow range. In patients with reversible unconsciousness, time course of changes in amplitude and latency between recovery stages was of linear character with a tendency to normalization. The findings suggest that, in reversible unconsciousness states, processing of sensory information at different recovery stages may be performed with various functional systems that determine varying quality of processing, whereas changes in chronic unconsciousness are caused by a decrease in the number of active elements within the same functional system. 相似文献
95.
96.
P. V. Mokrushnikov L. E. Panin B. N. Zaitsev N. S. Doronin A. I. Kozelskaya A. V. Panin 《Biophysics》2011,56(6):1074-1077
Mechanisms of interaction of quartz and corundum nanocrystals with erythrocyte membranes were studied by means of atomic force
microscopy and fluorescence analysis. Hydrophobic, chemically inert nanocrystals larger than a critical size (20–25 nm) can
bind to erythrocyte membranes without damaging them. If the size of the nanocrystals is less than 15 nm, they can penetrate
into the lipid bilayer membranes. This decreases the membrane microviscosity, and pores appear, which leads to cell lysis.
A thermodynamic explication of the critical size of the nanocrystals is given. 相似文献
97.
Slava RomMarco Pacifici Giovanni PassiatoreSusanna Aprea Agnieszka WaligorskaLuis Del Valle Francesca Peruzzi 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》2011,1813(10):1836-1844
The Src-homology 3 (SH3) domain is one of the most frequent protein recognition modules (PRMs), being represented in signal transduction pathways and in several pathologies such as cancer and AIDS. Grb2 (growth factor receptor-bound protein 2) is an adaptor protein that contains two SH3 domains and is involved in receptor tyrosine kinase (RTK) signal transduction pathways. The HIV-1 transactivator factor Tat is required for viral replication and it has been shown to bind directly or indirectly to several host proteins, deregulating their functions. In this study, we show interaction between the cellular factor Grb2 and the HIV-1 trans-activating protein Tat. The binding is mediated by the proline-rich sequence of Tat and the SH3 domain of Grb2. As the adaptor protein Grb2 participates in a wide variety of signaling pathways, we characterized at least one of the possible downstream effects of the Tat/Grb2 interaction on the well-known IGF-1R/Raf/MAPK cascade. We show that the binding of Tat to Grb2 impairs activation of the Raf/MAPK pathway, while potentiating the PKA/Raf inhibitory pathway. The Tat/Grb2 interaction affects also viral function by inhibiting the Tat-mediated transactivation of HIV-1 LTR and viral replication in infected primary microglia. 相似文献
98.
Chervyakova OV Strochkov VM Sultankulova KT Sandybayev NT Zaitsev VL Mamadaliyev SM 《Gene》2011,476(1-2):15-19
The high pathogenic strains of the avian influenza H5N1 virus isolated in Kazakhstan have NS of different genotypes. The influenza virus strains isolated in 2005 is of NS1E Qinghai genotype. A/swan/Mangystau/3/2006 strain is of NS2A genotype that is typical for Gs/Gd-like strains. The results of the analysis allow assuming that A/swan/Mangystau/3/2006 strain has been brought onto the territory of Kazakhstan from the European part of the continent along the Black Sea-Mediterranean flyway. 相似文献
99.
Measurement and Correction of Microscopic Head Motion during Magnetic Resonance Imaging of the Brain
Julian Maclaren Brian S. R. Armstrong Robert T. Barrows K. A. Danishad Thomas Ernst Colin L. Foster Kazim Gumus Michael Herbst Ilja Y. Kadashevich Todd P. Kusik Qiaotian Li Cris Lovell-Smith Thomas Prieto Peter Schulze Oliver Speck Daniel Stucht Maxim Zaitsev 《PloS one》2012,7(11)
Magnetic resonance imaging (MRI) is a widely used method for non-invasive study of the structure and function of the human brain. Increasing magnetic field strengths enable higher resolution imaging; however, long scan times and high motion sensitivity mean that image quality is often limited by the involuntary motion of the subject. Prospective motion correction is a technique that addresses this problem by tracking head motion and continuously updating the imaging pulse sequence, locking the imaging volume position and orientation relative to the moving brain. The accuracy and precision of current MR-compatible tracking systems and navigator methods allows the quantification and correction of large-scale motion, but not the correction of very small involuntary movements in six degrees of freedom. In this work, we present an MR-compatible tracking system comprising a single camera and a single 15 mm marker that provides tracking precision in the order of 10 m and 0.01 degrees. We show preliminary results, which indicate that when used for prospective motion correction, the system enables improvement in image quality at both 3 T and 7 T, even in experienced and cooperative subjects trained to remain motionless during imaging. We also report direct observation and quantification of the mechanical ballistocardiogram (BCG) during simultaneous MR imaging. This is particularly apparent in the head-feet direction, with a peak-to-peak displacement of 140 m. 相似文献
100.
Ferroptosis: an iron-dependent form of nonapoptotic cell death 总被引:3,自引:0,他引:3
Dixon SJ Lemberg KM Lamprecht MR Skouta R Zaitsev EM Gleason CE Patel DN Bauer AJ Cantley AM Yang WS Morrison B Stockwell BR 《Cell》2012,149(5):1060-1072
Nonapoptotic forms of cell death may facilitate the selective elimination of some tumor cells or be activated in specific pathological states. The oncogenic RAS-selective lethal small molecule erastin triggers a unique iron-dependent form of nonapoptotic cell death that we term ferroptosis. Ferroptosis is dependent upon intracellular iron, but not other metals, and is morphologically, biochemically, and genetically distinct from apoptosis, necrosis, and autophagy. We identify the small molecule ferrostatin-1 as a potent inhibitor of ferroptosis in cancer cells and glutamate-induced cell death in organotypic rat brain slices, suggesting similarities between these two processes. Indeed, erastin, like glutamate, inhibits cystine uptake by the cystine/glutamate antiporter (system x(c)(-)), creating a void in the antioxidant defenses of the cell and ultimately leading to iron-dependent, oxidative death. Thus, activation of ferroptosis results in the nonapoptotic destruction of certain cancer cells, whereas inhibition of this process may protect organisms from neurodegeneration. 相似文献