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排序方式: 共有346条查询结果,搜索用时 11 毫秒
1.
Markos A. Katsoulakis Panagiotis E. Souganidis 《Communications in Mathematical Physics》1995,169(1):61-97
We study themacroscopic limit of an appropriately rescaledstochastic Ising model withlong range interactions evolving withGlauber dynamics as well as the correspondingmean field equation, which is nonlinear and nonlocal. In the limit we obtain an interface evolving with normal velocity k, wherek isthe mean curvature and thetransport coefficient is identified by aneffective Green-Kubo type formula. The above assertions are valid for all positive times, the motion of the interface being interpreted in theviscosity sense after the onset of the geometric singularities.Supported by ONRPartially supported by NSF, ARO, ONR and the Alfred P. Sloan Foundation 相似文献
2.
Panagiotis Soules 《Archiv der Mathematik》2003,80(5):449-457
For soluble groups, the Fitting length is bounded by a function of the maximum order
of the Fitting subgroups of 2-generator subgroups. 相似文献
3.
Lianos P 《Journal of fluorescence》2004,14(1):11-15
This work is a short review of studies on nanocomposite organic-inorganic gels by stretched-exponential analysis of fluorescence decay profiles. Emphasis is given to the conditions which allow maximum probe mobility and minimum confinement conditions with the aim to assess ionic conductivity in these materials and with the purpose to employ them with dye-sensitized photoelectrochemical solar cells and other analogous systems. 相似文献
4.
Evangelia Chronopoulou Panagiotis Madesis Athanasios Tsaftaris Nikolaos E. Labrou 《Applied biochemistry and biotechnology》2014,172(2):595-609
Glutathione transferases (GSTs, EC 2.5.1.18) are ubiquitous proteins in plants that play important roles in stress tolerance and in the detoxification of toxic chemicals and metabolites. In this study, we systematically examined the catalytic diversification of a GST isoenzyme from Phaseolus vulgaris (PvGST) which is induced under biotic stress treatment (Uromyces appendiculatus infection). The full-length cDNA of this GST isoenzyme (termed PvGSTU3-3) with complete open reading frame, was isolated using RACE-RT and showed that the deduced amino acid sequence shares high homology with the tau class plant GSTs. PvGSTU3-3 catalyzes several different reactions and exhibits wide substrate specificity. Of particular importance is the finding that the enzyme shows high antioxidant catalytic function and acts as hydroperoxidase, thioltransferase, and dehydroascorbate reductase. In addition, its K m for GSH is about five to ten times lower compared to other plant GSTs, suggesting that PvGSTU3-3 is able to perform efficient catalysis under conditions where the concentration of reduced glutathione is low (e.g., oxidative stress). Its ability to conjugate GSH with isothiocyanates may provide an additional role for this enzyme to act as a regulator of the released isothiocyanates from glucosinolates as a response of biotic stress. Molecular modeling showed that PvGSTU3-3 shares the same overall fold and structural organization with other plant cytosolic GSTs, with major differences at their hydrophobic binding sites (H-sites) and some differences at the level of C-terminal domain and the linker between the C- and N-terminal domains. PvGSTU3-3, in general, exhibits restricted ability to bind xenobiotics in a nonsubstrate manner, suggesting that the biological role of PvGSTU3-3, is restricted mainly to the catalytic function. Our findings highlight the functional and catalytic diversity of plant GSTs and demonstrate their pivotal role for addressing biotic stresses in Phaseolus vulgaris. 相似文献
5.
Paraskevi Tziona Panagiotis Theodosis-Nobelos Georgios Papagiouvannis Anthi Petrou Chryssoula Drouza Eleni A. Rekka 《Molecules (Basel, Switzerland)》2022,27(7)
The synthesis of derivatives of three nonspecific COX-1 and COX-2 inhibitors, ibuprofen, ketoprofen, naproxen is presented. These acids were connected via an amide bond with an amino acid (L-proline, L-tyrosine, and beta-alanine) used as a linker. The amino acid carboxylic group was esterified with 3,4,5 trimethoxybenzyl alcohol. The activity of the novel derivatives was examined in vivo on carrageenan-induced inflammation, and in vitro, as cyclooxygenase and lipoxygenase inhibitors. It was found that the new compounds were more potent anti-inflammatory agents than the parent drugs. Thus, the ibuprofen (21) and ketoprofen (16) derivatives reduced rat paw edema by 67 and 91% (the reduction by the relevant NSAIDs was 36 and 47%, respectively). They inhibited COX-2 more than the starting drugs (21 by 67%, ibuprofen 46%, 19 by 94%, ketoprofen 49%). Docking of compounds on the active sites of COX-1 and COX-2 reflects their in vitro activity. Thus, 19 adopts an unfavorable orientation for COX-1 inhibition, but it binds effectively in the binding pocket of COX-2, in agreement with the absence of activity for COX-1 and the high inhibition of COX-2. In conclusion, the performed structural modifications result in the enhancement of the anti-inflammatory activity, compared with the parent NSAIDs. 相似文献
6.
A multi-objective mixed integer programming model for equity portfolio construction and selection is developed in this study,
in order to generate the Pareto optimal portfolios, using a novel version of the well known ε-constraint method. Subsequently, an interactive filtering process is also proposed to assist the decision maker in making
his/her final choice among the Pareto solutions. The proposed methodology is tested through an application in the Athens Stock
Exchange. 相似文献
7.
Yannis Kallinderis Eleni M. Lymperopoulou Georgios Spyridonos Panagiotis Antonellis 《国际流体数值方法杂志》2019,91(2):63-96
Curved geometries and the corresponding near-surface fields typically require a large number of linear computational elements. High-order numerical solvers have been primarily used with low-order meshes. There is a need for curved, high-order computational elements. Typical near-surface meshes consist of hexahedral and/or prismatic elements. The present work studies the employment of quadratic meshes that are relatively coarse for field simulations. Directionally quadratic high-order elements are proposed for the near-surface field regions. The quadratic meshes are compared with the conventional low-order ones in terms of accuracy and efficiency. The cases considered include closed surface volume calculations, as well as computation of gradients of several analytic fields. A special method of adaptive local quadratic meshes is proposed and evaluated. Truncation error analysis for quadratic grids yields comparison with the conventional linear hexahedral/prismatic meshes, which are subject to typical distortions such as stretching, skewness, and torsion. 相似文献
8.
In this paper, we address the flowpath design issue of Automated Guided Vehicle Systems (AGVSs). In particular, we concentrate on the design of unidirectional flowpaths (i.e. vehicles are restricted to travel only in one direction along a given segment of the flowpath). We have developed intelligent heuristics — simulated annealing and tabu search algorithms for the design of unidirectional AGVSs. Different versions of simulated annealing and tabu search algorithms are implemented. Our extensive computational results indicate that both simulated annealing and tabu search yield solutions of adequate quality for all practical purposes. A tabu search implementation with the use of a frequency-based memory structure dominates all tested heuristics in terms of solution quality (i.e. percent deviation from optimality), with an impressive average performance over 45 test problems of less than 0.85% deviation from optimality. 相似文献
9.
Olga Serifi Fotios Tsopelas Anna‐Maria Kypreou Maria Ochsenkühn‐Petropoulou Panagiotis Kefalas Anastasia Detsi 《Journal of Physical Organic Chemistry》2013,26(3):226-231
The electrochemical behaviour of 13 chalcone analogues was systematically studied by means of cyclic voltammetry and chronoamperometry at a glassy carbon (GC), gold and platinum working electrodes using two different supporting electrolyte/solvent combinations. It was found that chalcone analogues can be easily oxidized at both GC and gold working electrodes, but not at a platinum electrode. Principal component analysis was further employed to reveal similarities/dissimilarities between oxidation potentials, chronoamperometric signals and ability of the compounds to scavenge the reactive oxygen species H2O2. The study reveals the inverse proportional relationship between the scavenging ability of H2O2, expressed as IC50, and chronoamperometric signal at 800 mV using gold as working electrode. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
10.