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Search Results: 1 - 10 of 13721 matches for " Arutyunyan Anna "
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The Fatigue Fracture Criterion Based on the Latent Energy Approach  [PDF]
Alexander R. Arutyunyan, Robert A. Arutyunyan
Engineering (ENG) , 2010, DOI: 10.4236/eng.2010.25041
Abstract: The extensive literature on the fatigue problem, published for more than one hundred years, is reviewed by the known scientists [1,2]. As it follows from these investigations, the fundamental amount of failures in engineering practice connected with the fatigue fractures of materials and structure elements. The fatigue problem is complicated one and it is not solved yet. So the theoretical and experimental investigations of this problem will be continued. In our paper the energy approach to formulate the fatigue strength criterion is proposed. The criterion is based on the conception of the latent energy [3-7]. This conception was not applied previously to the fatigue problem. The latent energy is consumed to generate the irreversible deformation and to damage and fracture of metallic materials. So the fatigue fracture criterion can be formulated using the results of latent energy measurements in the macro experiments. This is most impotent advantage of the proposed approach. The logistic function is used to describe the dependence of latent energy from the value of irreversible deformation. It is assumed that the cyclic strength of metals is defined by the latent energy, stored in specimen, when it is reached the critical value in accordance with the logistic curve in a saturation zone. This proposal is used to formulate the fatigue strength criterion. The functions and parameters of received criterion are concretized and comparisons with experimental results for axial cyclic tension for sheet aluminum alloy specimens are given.
Expression of cassini, a murine gamma-satellite sequence conserved in evolution, is regulated in normal and malignant hematopoietic cells
Arutyunyan Anna,Stoddart Sonia,Yi Sun-ju,Fei Fei
BMC Genomics , 2012, DOI: 10.1186/1471-2164-13-418
Abstract: Background Acute lymphoblastic leukemia (ALL) cells treated with drugs can become drug-tolerant if co-cultured with protective stromal mouse embryonic fibroblasts (MEFs). Results We performed transcriptional profiling on these stromal fibroblasts to investigate if they were affected by the presence of drug-treated ALL cells. These mitotically inactivated MEFs showed few changes in gene expression, but a family of sequences of which transcription is significantly increased was identified. A sequence related to this family, which we named cassini, was selected for further characterization. We found that cassini was highly upregulated in drug-treated ALL cells. Analysis of RNAs from different normal mouse tissues showed that cassini expression is highest in spleen and thymus, and can be further enhanced in these organs by exposure of mice to bacterial endotoxin. Heat shock, but not other types of stress, significantly induced the transcription of this locus in ALL cells. Transient overexpression of cassini in human 293 embryonic kidney cells did not increase the cytotoxic or cytostatic effects of chemotherapeutic drugs but provided some protection. Database searches revealed that sequences highly homologous to cassini are present in rodents, apicomplexans, flatworms and primates, indicating that they are conserved in evolution. Moreover, CASSINI RNA was induced in human ALL cells treated with vincristine. Surprisingly, cassini belongs to the previously reported murine family of γ-satellite/major satellite DNA sequences, which were not known to be present in other species. Conclusions Our results show that the transcription of at least one member of these sequences is regulated, suggesting that this has a function in normal and transformed immune cells. Expression of these sequences may protect cells when they are exposed to specific stress stimuli.
Lack of Bcr and Abr Promotes Hypoxia-Induced Pulmonary Hypertension in Mice
Min Yu, Dapeng Gong, Min Lim, Anna Arutyunyan, John Groffen, Nora Heisterkamp
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0049756
Abstract: Background Bcr and Abr are GTPase activating proteins that specifically downregulate activity of the small GTPase Rac in restricted cell types in vivo. Rac1 is expressed in smooth muscle cells, a critical cell type involved in the pathogenesis of pulmonary hypertension. The molecular mechanisms that underlie hypoxia-associated pulmonary hypertension are not well-defined. Methodology/Principal Findings Bcr and abr null mutant mice were compared to wild type controls for the development of pulmonary hypertension after exposure to hypoxia. Also, pulmonary arterial smooth muscle cells from those mice were cultured in hypoxia and examined for proliferation, p38 activation and IL-6 production. Mice lacking Bcr or Abr exposed to hypoxia developed increased right ventricular pressure, hypertrophy and pulmonary vascular remodeling. Perivascular leukocyte infiltration in the lungs was increased, and under hypoxia bcr?/? and abr?/? macrophages generated more reactive oxygen species. Consistent with a contribution of inflammation and oxidative stress in pulmonary hypertension-associated vascular damage, Bcr and Abr-deficient animals showed elevated endothelial leakage after hypoxia exposure. Hypoxia-treated pulmonary arterial smooth muscle cells from Bcr- or Abr-deficient mice also proliferated faster than those of wild type mice. Moreover, activated Rac1, phosphorylated p38 and interleukin 6 were increased in these cells in the absence of Bcr or Abr. Inhibition of Rac1 activation with Z62954982, a novel Rac inhibitor, decreased proliferation, p38 phosphorylation and IL-6 levels in pulmonary arterial smooth muscle cells exposed to hypoxia. Conclusions Bcr and Abr play a critical role in down-regulating hypoxia-induced pulmonary hypertension by deactivating Rac1 and, through this, reducing both oxidative stress generated by leukocytes as well as p38 phosphorylation, IL-6 production and proliferation of pulmonary arterial smooth muscle cells.
THE CONDITIONS OF PREDICTION OF THE PARAMETRIC COMPONENTS OF THE TERMINATION CONTROL SYSTEM OF THE UNMANNED AERIAL VEHICLE FLIGHT PATH
Yaroslav Kondrashov,Artashes Arutyunyan,Igor Kravchyshyn
Proceedings of National Aviation University , 2011,
Abstract: . According to the results of measurements on board of Unmanned Aerial Vehicle the distancevector D is formed in the inertial coordinate system, and in mathematical modeling - in the Greenwichsystem of coordinates. The velocity vector k V is formed by the navigation system in the trajectory coordinatesystem. Defined by this way the initial conditions gives the possibility to predict the terminal parameters offlight (descent) of Unmanned Aerial Vehicle.Keywords: control system of the unmanned aerial vehicle flight path and landing, motion parameters,termination control.
Hybrid procedures in treatment of multilevel lesions of the brachiocephalic arteries
Arutyunyan Goar,Annenkova Elena,Sinyavin GV
BMC Proceedings , 2013, DOI: 10.1186/1753-6561-7-s1-p5
Abstract:
ANALYSIS OF THE POSSIBILITIES OF THE IMPROVEMENT OF THE BORE TECHNOLOGY AND CONDITIONS TO ITS EX-PLOITATION AT DECISION OF THE PROBLEMS OF INCREASING TO EFFICIENCY OF OIL PRODUCTION WITH COMPLICATED CONDITION Анализ возможностей совершенствования буровой техники и условий её эксплуатации при решении задач повышения эффективности нефтедобычи с осложнёнными условиями
Antoniadi D. G.,Savenok O. V.,Arutyunyan A. S.
Polythematic Online Scientific Journal of Kuban State Agrarian University , 2013,
Abstract: In the article, we have motivated the definition of the problem of increasing of efficiency of oil production with complicated conditions. We have also considered general system problems of increasing of the efficiency of oil production with the methods of the improvement and renovations of the equipment: the equipment for optimization of the factor of the extraction of oil; oil well rod pumping units and principles of energy saving on the late stage of the production of the bore holes with complicated condition of exploitation. It is shown, that the equipment allows optimizing the factor of the extraction of oil when developing hard extraction oil stocks, combined with modern technology and methods
MODELING OF CULTIVATION ON PRODUCTIVITY LACTIC ACID PRODUCER LACTOCOCCUS LACTIS CH5 Моделирование процесса культивирования процесса биосинтеза-молочной кислоты Lactococcus Lactis СН5
Ilushka I. V.,Dotsenko S. P.,Borovskiy A. B.,Arutyunyan M. M.
Polythematic Online Scientific Journal of Kuban State Agrarian University , 2012,
Abstract: The equations for evaluation of the stationary state of lactic acid microbiological synthesis have been received. The kinetic dependencies for specific biomass growth rate, consumption of the substrate are given. The particular qualities of growth of homofermentative lactic acid producer Lactococcus lactis CH5 depending on the composition nutrient medium: glucose and yeast autolysate concentration are examined. The influence of the method of cultivation on the productivity and the speed of the lactis acid synthesis are analyzed
RESEARCH OF PHASE BALANCES OF LIQUID-SOLID PENTONARY ALLOY MATERIALS OF LOW-MELT METALS WITH CALCULATING METHOD Исследование фазовых равновесий жидкость – твердое пятикомпонентных сплавов легкоплавких металлов расчетным методом
Dotsenko S. P.,Arutyunyan M. M.,Fursina A. B.,Arustamova I. S.
Polythematic Online Scientific Journal of Kuban State Agrarian University , 2012,
Abstract: The article is devoted to the research and working out of calculation method of thermodynamic data and phase diagrams of pentonary alloy materials of low-melt
The incidence of childhood leukemia in Armenia, 1991-2002
Nersesyan Armen K.,Daghbashyan Smbat S.,Danielyan Samvel H.,Arutyunyan Rouben M.
Archive of Oncology , 2003, DOI: 10.2298/aoo0304277n
Abstract: The incidence of leukemia in children aged from 0 to 14 years in Armenia was analyzed for the period from 1991 to 2002. During 12 years the incidence of leukemia was not changed substantially. The crude rate of the incidence of leukemia was comparable with data of many countries. But at the same time a comparatively high male/female incidence ratio was registered, which was also comparable with incidence ratio in some of both developed and developing countries. It may be supposed that the incidence of leukemia in children in Armenia is not connected with parental exposure to chemicals.
Micronucleus level in exfoliated buccal mucosa cells of cancer patients
Nersesyan Armen K.,Vardazaryan Nina S.,Gevorgyan Ani L.,Arutyunyan Rouben M.
Archive of Oncology , 2002, DOI: 10.2298/aoo0201035n
Abstract: Micronucleus levels in exfoliated buccal mucosa cells of patients with primary breast, lung, cervix uteri cancer, and patients with Hodgkin's disease were studied (n=59). Significantly increased number of micronuclei in cells of cancer patients was observed compared with healthy persons (n=45). The evaluation of micronuclei number in buccal mucosa cells shows genomic instability in somatic cells of humans.
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