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Search Results: 1 - 10 of 461757 matches for " Ermakov A.A. "
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THE MODEL FOR AUXIN REGULATED AtPIN1 EXPRESSION IN THE ROOT APICAL MERISTEM
Ermakov A.A.,V.V. Chernova,A.V. Doroshkov,S.S. Sangaev
Journal of Stress Physiology & Biochemistry , 2012,
Abstract: Plant hormone auxin regulates many aspects of plant growth and development. PIN-FORMED (PIN) gene family encodes transmembrane proteins, which mediate auxin efflux. PIN proteins are asymmetrically localized within cells, thereby forming in tissue auxin concentration gradients and maxima. Auxin has various effects on PIN1 expression in a cell providing for both positive and negative feedbacks on its own transport [1]. Earlier we proposed that this dual regulation determines stem cell niche maintenance in root apical meristem [2].Using two reporter lines of Arabidopsis thaliana we investigated dose-response auxin regulation of PIN1 expression at the levels of RNA and protein. PIN1::PIN1-GFP containing part of PIN1 coding region reveals both transcriptional and posttranscriptional regulation, whereas pPIN1::GUS displays only transcriptional regulation. The reporter line pPIN1::GUS[-1388;+82] was created by authors; PIN1::PIN1-GFP was provided by Alexis Peaucelle (INRA, France). PIN1::PIN1-GFP and pPIN1::GUS seedlings were grown in a 16 hours light/8 hours dark cycle at 25/22°C on 1/2MS with sucrose. Before microscopic analysis 3 dag seedlings were incubated for 24 h in liquid 1/2MS supplemented with different IAA concentrations. The experimental images were analyzed using ImageJ program.We found the following changes in PIN1 expression pattern in the root for both lines under low and moderate auxin treatments: (1) increased domain of PIN1 expression in the root meristem; (2) ectopic expression in epidermis and cortex, (3) increased level of PIN1 expression in provascular cells. However, we observed differences in PIN1 expression between the lines: in columella and under high auxin concentrations. The experimental data suggests posttranslational PIN1 regulation by high auxin concentrations. A mathematical model [2] was extended to describe the observed phenomena. The model simulation well agrees with the experimental data and predicts new aspects on the mechanisms of auxin transport in the root meristem.
Effects of Steel Fibers and Iron Filings on Thermal and Mechanical Properties of Concrete for Energy Storage Application  [PDF]
A.A. Adeyanju, K. Manohar
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2011, DOI: 10.4236/jmmce.2011.1015111
Abstract: An experimental study on the thermal properties of iron filings and steel-fiber-reinforced concrete for solar/thermal energy storage application is presented in this report. It takes into account the results of measurements of thermal conductivity, thermal resistivity, thermal diffusivity and the results of compressive strength, density as well as energy storage capacity calculated from the knowledge of the above measured parameters. The experimental testing method is described as well: based upon the linear heat source theory, it requires the use of a special probe to be inserted into the sample. The experimentation was forwarded to test concrete aggregate mixtures with three different sizes and same quantity of steel fibers; two different quantities of iron filings and one plain concrete. The measurements were carried out from the pouring time of cubic samples and were ended up when hardened conditions were achieved. The results indicate that the steel fibers and iron filings have influence on the thermal and mechanical properties of the concretes tested, thus the iron filings and steel fibers reinforced concrete is suitable for better solar/thermal energy storage due to an increase in storage capacity over plain concrete.
Utiliza??o prática da análise de crescimento vegetal
Lucchesi, A.A.;
Anais da Escola Superior de Agricultura Luiz de Queiroz , 1984, DOI: 10.1590/S0071-12761984000100011
Abstract: the objective of this work is to determlne elements for utilization of quantitative analysis on plant growth, which is a valuable complement of experimental analysis in crop science, mainly plant productivity research.
Around voltammetry: from colouring matters to beer
Barros,A.A.;
Portugaliae Electrochimica Acta , 2006,
Abstract: this paper is based on the plenary lecture that i was invited to present in the viii encontro ibérico de electroquímica and xiii encontro da sociedade portuguesa de electroquímica, a meeting which was "a tribute to the late prof. jo?o cabral".the best way i found to honour his memory was to present the highlights of an investigation of 25 years in voltammetry, which would never happen without the enthusiasm and the guidance of prof. jo?o cabral. after a first publication, in 1986, on the adsorptive stripping voltammetry of synthetic colouring matters, our investigation was soon directed towards the new analytical possibilities opened by the appearance of new voltammetric instrumentation capable of very fast potential scans. the instrumental elimination of oxygen interference obtained in the fast adsorptive stripping of some species reversibly reducible on the hanging mercury drop electrode (hmde) was a first achievement, immediately followed by the development of a hmde flow detector for the determination of those species. this detector is being applied in the flow determination of several compounds, with the determination of diacetyl deserving a special reference. in fact the determination of this compound it is very important for the brewing industry and it was possible to develop an equipment capable of its determination in flow: diacetyl is extracted from beer by pervaporation, then derivatized with orto-phenytlenediamine and finally determined by hmde adsorptive stripping voltammetry.
Effect of Non-aqueous Solvents on the Rate of Production of Copper Powder from Copper Sulphate Solution by Cementation on Stationary Zinc Sheet and Rotating Zinc Cylinder
Taha,A.A.;
Portugaliae Electrochimica Acta , 2004,
Abstract: the rate of copper ii/zinc cementation from copper sulphate solutions in the absence and in the presence of methanol (ch3oh) and dimethyl sulphoxide (dmso) has been studied and the reaction was found to follow first-order kinetics. the influence of several parameters on the course of the reaction, such as cylinder rotation speed, initial concentration of cu2+ ions, temperature and concentration of organic solvent, was investigated. in the case of ch3oh, rotating zinc cylinder was used, while in the presence of dmso stationary zinc sheet and rotating zinc cylinder were used. it was found that (1) the percentage inhibition caused by methanol ranged from 10.70 to 58.38 depending on the concentration of the alcohol used; (2) the rate of cementation in the presence of dmso using rotating zinc cylinder > the rate of cementation in the presence of dmso using stationary zinc sheet; (3) the rate of cementation on zinc cylinder in the presence of dmso < the rate of cementation in the presence of ch3oh. different reaction conditions, and the physical properties of solutions are studied to obtain dimensionless correlation among all these parameters. thermodynamic parameters δs*, δh* and δg* were studied.
Medicina Baseada em Evidências: a arte de aplicar o conhecimento científico na prática clínica
Lopes, A.A.;
Revista da Associa??o Médica Brasileira , 2000, DOI: 10.1590/S0104-42302000000300015
Abstract: this article was written with the objective of describing the concept of evidence based medicine (ebm) and the competences required for its practice. ebm should be viewed as an integration of clinical experience with the ability to analyze and rationally apply the scientific information while taking care of patients. the application of methods and strategies to enhance the scientific background of the physician while taking into account the humanitarian values of the medical profession should contribute to improve the quality of the medical care that is offered in brazil. the medical schools and associations may play important roles in the promotion of ebm.
Seed improvement by selection and invigoration
Powell, A.A.;
Scientia Agricola , 1998, DOI: 10.1590/S0103-90161998000500023
Abstract: the basis of differences in seed quality are described for two groups of crops, grain legumes and vegetables and approaches to the improvement of quality are proposed. in grain legumes the major factors affecting seed quality are imbibition damage, seed ageing and their interaction. it is proposed that use of seed vigour tests, specifically the electrical conductivity test, to identify the incidence of imbibition damage and ageing allows the selection of seed lots for sale and for use under different field conditions. alternatively in grain legume species in which there is a genotypic influence on predisposition to imbibition damage the approach to seed improvement may lie through selection in breeding programmes. thus identification of testa characteristics that favour slow imbibition would enable selection for these characteristics. seed ageing is also the major cause of reduced seed quality in vegetable species, leading to slow and asynchronous germination. an approach to their seed improvement has been the development of seed invigoration treatments based on seed hydration. the principle of these treatments is described and several treatments outlined, with emphasis being given to aerated hydration, a treatment completed within 36h. the physiological basis of improvement by invigoration is discussed.
TRANSRECTAL ULTRASOUND-GUIDED BIOPSY A PROSPECTIVE STUDY OF PATIENTS TOLERANCE AND COMPLICATIONS
A.A. ELABBADY
African Journal of Urology , 2001,
Abstract: Objectives To determine the morbidity and patient tolerance of TRUS-guided biopsy from suspected malignant prostate or pelvic recurrence after radical cystectomy. Patients and Methods This prospective study comprised 113 patients who underwent TRUS-guided biopsy from the prostate or from pelvic recurrence following radical cystectomy. The patients' tolerance was assessed by scoring the severity of discomfort during the procedure and their acceptance was estimated by questionnaires following it. Results Most patients (56.6%) experienced either no discomfort at all or only mild pain during the procedure. Intravenous sedation was needed in 31% of the patients and general anaesthesia was necessary in two patients. Haematuria was the commonest complication (59.6%) followed by rectal bleeding and haemospermia, which occurred in 36.7% and 17.4% of the patients, respectively. A vasovagal attack occurred in one patient. There was one major complication, a prostatic abscess which resulted in a temporary urethro-rectal fistula. Conclusion TRUS-guided core biopsy is safe with frequent minor but` very rare major complications. The majority of the patients tolerate the procedure with accepted discomfort but a considerable number of patients need sedation to complete the procedure effectively. African Journal of Urology Vol. 7 No. 2 (May 2001): pp 57-61 Biopsie Transrectale Echoguidée: Etude Prospective de la Tolérance des Patients et des Complications Objectif Evaluer la tolérance et l'acceptance des patients de la biopsie transrectale échoguidée. Patients et Méthodes Cette étude prospective comprenait 113 patients qui ont bénéficié d'une biopsie transrectale échoguidée de la prostate ou d'une récurrence pelvienne après cystectomie radicale. La tolérance des patients était évaluée en cotant la sévérité du disconfort pendant la procé-dure et leur acceptance était estimée par des questionnaires ensuite. Résultats La plupart des patients (56,6%) ne ressentaient pas du tout de disconfort ou ressentaient seulement une douleur mineure pendant la procédure. Une sédation intraveineuse a été nécessaire chez 31% des patients et une anesthésie générale a été nécessaire dans 2 cas. L'hématurie était la complication la plus fré-quente, suivie de rectorragies et d'hématospermie survenues chez 36,7% et 17,4% des patients, respectivement. Une attaque vaso-vagale est survenue chez un patient. Il y avait une complication majeure: un abcès prostatique ayant évolué à une fistule uréthro-rectale temporaire. Conclusion La biopsie transrectale échoguidée est anodine, ses complications mineures sont fréquentes mais les complications majeures sont très rares. La majorité des patients tolèrent la procédure avec disconfort accepté mais un nombre considérable de patients nécessitent une sédation pour compléter efficace-ment la procédure. African Journal of Urology Vol. 7 No. 2 (May 2001): pp 57-61
MOLECULAR STUDY OF NUCLEPROTEIN GENE OF RABIES VIRUS ISOLATES FROM DOG BRAINS
A.A. Adeiga
African Journal of Clinical and Experimental Microbiology , 2002,
Abstract: Rabies is an endemic disease in Nigeria and it produces disease in warm-blooded animal species. In this report, molecular techniques have been used to study seven rabies isolates from the brain of Dogs in Lagos. Analysis of the 1400-b.p RT-PCR products of the N gene and the views by sequencing and restriction endonuclease analysis enabled division of isolates into 3 types. The conclusion from the study is that RT-PCR and restriction endonuclease analysis of the amplified products of the N gene would allow identification and differentiation of rabies virus strains in a location and in different parts of Nigeria. (Af. J. of Clinical and Experimental Microbiology: 2002 3(2): 48-54)
Electrochemical Behavior of Vanadium in Azide Electrolyte in Comparison with the Behavior in Halogen Ions-Containing Electrolytes
A.A. Ghoneim
The Open Electrochemistry Journal , 2009, DOI: 10.2174/1876505X00901010042]
Abstract: The influence of azide ion concentration and temperature on the electrochemical behavior of vanadium was studied using open-circuit potential (OCP), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The steady state potential (Ess) is a linear function of azide ion concentration. Polarization measurements have shown that the rate of corrosion icorr increases with increasing the azide ion concentration as well as increasing solution temperature. EIS investigations under open-circuit conditions confirm these results as can be identified by the decrease of the polarization resistance (Rox) and oxide thickness (1/Cox) with increasing the azide ion concentration. The measured impedance responses were analyzed using a constant phase element (CPE) model with its complex transfer function. The behavior of vanadium in the azide medium is also compared to that in other halide salt solutions, it was found that the tendency for spontaneously grown thicker oxide film increases in the order: Br ̄ > Cl ̄ > I ̄ > N 3  ̄ > F ̄.
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