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111.
Khennaoui Amina Aicha Ouannas Adel Boulaaras Salah Pham Viet-Thanh Taher Azar Ahmad 《The European physical journal. Special topics》2020,229(6-7):1083-1093
The European Physical Journal Special Topics - This paper studies the dynamics of a new fractional-order map with no fixed points. Through phase plots, bifurcation diagrams, largest Lyapunov... 相似文献
112.
Journal of Applied Spectroscopy - Simple, rapid, and sensitive spectroscopic methods have been proposed to determine the antifungal drug mebendazole. These methods adapted the reduction of ferric... 相似文献
113.
This paper presents a metaheuristic solution approach based on Tabu search for the open-pit mine production scheduling problem with metal uncertainty. To search the feasible domain more extensively, two different diversification strategies are used to generate several initial solutions to be optimized by the Tabu search procedure. The first diversification strategy exploits a long-term memory of the search history. The second one relies on the variable neighborhood search method. Numerical results on realistic large-scale instances are provided to indicate the efficiency of the solution approach to produce very good solutions in relatively short computational times. 相似文献
114.
Roberto Flammini Frédéric Wiame Rachid Belkhou Amina Taleb-Ibrahimi Paolo Moras 《Surface science》2012,606(15-16):1215-1220
The thermal stability of the Co/β-Si3N4/Si(111) interface has been studied by high-resolution photoemission spectroscopy in a temperature range extending from room temperature to 650 °C. It is demonstrated the ability of a very thin crystalline buffer layer of silicon nitride to prevent the interfacial reaction between cobalt and silicon at room temperature. The behaviour of the interface at higher temperature shows the formation of cobalt silicides already at 300 °C. Moreover, the presence of new components in the decomposition of the photoemission spectra is discussed in the light of the existing literature. 相似文献
115.
RM Schweller J Zimak DY Duose AA Qutub WN Hittelman MR Diehl 《Angewandte Chemie (International ed. in English)》2012,51(37):9292-9296
DNA-based erasers: The designed strand-displacement reactions between dynamic DNA probes (carrying fluorescent dyes () and quencher domains (?)) and DNA-antibody conjugates generate detachable immunofluoresence-reporting complexes that can be assembled (first image) and disassembled (second image) reversibly within fixed cells. With this system, different protein targets can be imaged sequentially within the same cells (third image). 相似文献
116.
Interactions between quaternary amino or guanidino groups with anions are ubiquitous in nature and have been extensively studied phenomenologically. However, little is known about the binding energies in non-covalent complexes containing these functional groups. Here, we present a first study focused on quantifying such interactions using complexes of phosphorylated A(3)pXA(3)-NH(2) (X = S, T, Y) peptides with decamethonium (DCM) or diaguanidinodecane (DGD) ligands as model systems. Time- and collision energy-resolved surface-induced dissociation (SID) of the singly charged complexes was examined using a specially configured Fourier transform ion cyclotron resonance mass spectrometer (FTICR-MS). Dissociation thresholds and activation energies were obtained from RRKM modeling of the experimental data that has been described and carefully characterized in our previous studies. For systems examined in this study, covalent bond cleavages resulting in phosphate abstraction by the cationic ligand are characterized by low dissociation thresholds and relatively tight transition states. In contrast, high dissociation barriers and large positive activation entropies were obtained for cleavages of non-covalent bonds. Dissociation parameters obtained from the modeling of the experimental data are in excellent agreement with the results of density functional theory (DFT) calculations. Comparison between the experimental data and theoretical calculations indicate that phosphate abstraction by the ligand is rather localized and mainly affected by the identity of the phosphorylated side chain. The hydrogen bonding in the peptide and ligand properties play a minor role in determining the energetics and dynamics of the phosphate abstraction channel. 相似文献
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119.
Hadj-Taieb N Tounsi H Chabchoub A Abid N Gargouri A 《Applied biochemistry and biotechnology》2011,165(7-8):1652-1660
Zymogram analysis is a useful tool for the identification of several enzymes. The present study was undertaken to investigate the efficiency gains from the characterization of pectic enzymes on zymograms by staining of pectin-agarose overlays using cetyl trimethyl ammonium bromide also known as cetrimide or CTAB. The method is based on the fact that the enzymatic hydrolysis of the pectic substrates included in the agarose matrix gel inhibited their precipitation by CTAB, leading to the appearance of cleared zones in front of the pectin hydrolases and lyases. Conversely, esterases led to the increase of pectin precipitation. Fungal pectinolytic enzymes were separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and subjected to the zymogram detection technique, using two pectin substances, namely citrus pectin and polygalacturonic acid. Overall, the findings presented in the current study indicate that several elements (ions, salts, pH, temperature, chelators, and reducing agents) may significantly affect the results of zymogram analysis and can, therefore, be employed to enhance the discriminatory and operational potential of the analysis in terms of accurate discrimination between several pectinolytic activities involved and effective implementation of the purification procedures required in the process. 相似文献
120.
Moyer SC Cotter RJ Woods AS 《Journal of the American Society for Mass Spectrometry》2002,13(3):274-283
An investigation of phosphate loss from phosphopeptide ions was conducted, using both atmospheric pressure matrix-assisted laser desorption/ionization (AP MALDI) and electrospray ionization (ESI) coupled to an ion trap mass spectrometer (ITMS). These experiments were carried out on a number of phosphorylated peptides in order to investigate gas phase dephosphorylation patterns associated with phosphoserine, phosphothreonine, and phosphotyrosine residues. In particular, we explored the fragmentation patterns of phosphotyrosine containing peptides, which experience a loss of 98 Da under collision induced dissociation (CID) conditions in the ITMS. The loss of 98 Da is unexpected for phosphotyrosine, given the structure of its side chain. The fragmentation of phosphoserine and phosphothreonine containing peptides was also investigated. While phosphoserine and phosphothreonine residues undergo a loss of 98 Da under CID conditions regardless of peptide amino acid composition, phosphate loss from phosphotyrosine residues seems to be dependent on the presence of arginine or lysine residues in the peptide sequence. 相似文献