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81.
Tobias Baumann Matthias Hauf Fabian Schildhauer Katharina B. Eberl Patrick M. Durkin Erhan Deniz Jan G. Lffler Carlos G. Acevedo‐Rocha Jelena Jaric Berta M. Martins Holger Dobbek Jens Bredenbeck Nediljko Budisa 《Angewandte Chemie (International ed. in English)》2019,58(9):2899-2903
Allosteric information transfer in proteins has been linked to distinct vibrational energy transfer (VET) pathways in a number of theoretical studies. Experimental evidence for such pathways, however, is sparse because site‐selective injection of vibrational energy into a protein, that is, localized heating, is required for their investigation. Here, we solved this problem by the site‐specific incorporation of the non‐canonical amino acid β‐(1‐azulenyl)‐l ‐alanine (AzAla) through genetic code expansion. As an exception to Kasha's rule, AzAla undergoes ultrafast internal conversion and heating after S1 excitation while upon S2 excitation, it serves as a fluorescent label. We equipped PDZ3, a protein interaction domain of postsynaptic density protein 95, with this ultrafast heater at two distinct positions. We indeed observed VET from the incorporation sites in the protein to a bound peptide ligand on the picosecond timescale by ultrafast IR spectroscopy. This approach based on genetically encoded AzAla paves the way for detailed studies of VET and its role in a wide range of proteins. 相似文献
82.
Serkan Dag E. Erhan Arman Bora Yildirim 《International Journal of Solids and Structures》2010,47(25-26):3480-3488
This article introduces a computational method based on the Jk-integral for mixed-mode fracture analysis of orthotropic functionally graded materials (FGMs) that are subjected to thermal stresses. The generalized definition of the Jk-integral is recast into a domain independent form composed of line and area integrals by utilizing the constitutive relations of plane orthotropic thermoelasticity. Implementation of the domain independent Jk-integral is realized through a numerical procedure developed by means of the finite element method. The outlined computational approach enables the evaluation of the modes I and II stress intensity factors, the energy release rate, and the T-stress. The developed technique is validated numerically by considering two different problems, the first of which is the problem of an embedded crack in an orthotropic FGM layer subjected to steady-state thermal stresses; and the second one is that of periodic cracks under transient thermal loading. Comparisons of the mixed-mode stress intensity factors evaluated by the Jk-integral based method to those calculated through the displacement correlation technique (DCT) and to those available in the literature point out that, the proposed form of the Jk-integral possesses the required domain independence and leads to numerical results of high accuracy. Further results are presented to illustrate the influences of the geometric and material constants on the thermal fracture parameters. 相似文献
83.
Erhan Demirel Hakan Durmaz Gurkan Hizal Umit Tunca 《Journal of polymer science. Part A, Polymer chemistry》2016,54(4):480-486
The aliphatic polyurethane with pendant alkyne, perfluorophenyl, and anthracene moieties (PU‐anthracene) was prepared from polycondensation of anthracene, alkyne, and perfluorophenyl functional‐diols with hexamethylenediisocyanate in the presence of dibutyltindilaurate (DBTL) in CH2Cl2 at room temperature for 10 days. Thereafter, the PU‐(anthracene‐co‐alkyne‐co‐perfluorophenyl) (Mn,GPC = 15,400 g/mol, Mw/Mn= 1.37, relative to PS standards) was sequentially clicked with benzyl azide, octylamine, and 4‐(2‐hydroxyethyl)?10‐oxa‐4‐azatricyclo[5.2.1.02,6]dec‐8‐ene‐3,5‐dione (adduct alcohol) via copper‐catalyzed azide‐alkyne cycloaddition, active ester substitution and Diels–Alder reactions, respectively, to finally yield PU‐(hydroxyl‐co‐benzyltriazole‐co‐octylamine). The PUs were characterized using 1H NMR, GPC, and DSC. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 480–486 相似文献
84.
85.
Gültekin Çelik Erhan Akin Hamdi Şükür Kiliç 《International journal of quantum chemistry》2007,107(2):495-500
The transition probabilities between individual and multiplet lines for some quartet terms of excited p‐d and d‐p transition arrays of nitrogen atom have been calculated using the weakest bound electron potential model (WBEPM) theory. For determination relevant parameters, we employed both numerical Coulomb approximation (NCA) method and numerical nonrelativistic Hartree–Fock (NRHF) wave functions for expectation values of radii. The necessary energy values have been taken from experimental energy data in the literature. The expectation values of radii obtained using the two different methods have been employed in the calculation of transition probabilities of all transition arrays. The results obtained have been compared with either each other or NIST data. Good agreement with accepted values taken from NIST has been observed for related excited transitions. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 相似文献
86.
Summary Reactions of Group VIII metal halides [CoCl2, NiCl2, K2PdCl4, PdCl2(PhCN)2 and PtCl2] with tetrasulphurtetranitrogendioxide, S4N4O2, have been investigated. The cobalt reaction yields Co(S2N2H)2, Co(S2N2H)(S3N) and Co(S3N)2. The usefulness of metal centres for trapping reactive sulphur-nitrogen centres is discussed. 相似文献
87.
In this paper necessary and sufficient conditions are deduced for the close‐to‐convexity of some special combinations of Bessel functions of the first kind and their derivatives by using a result of Shah and Trimble about transcendental entire functions with univalent derivatives and some newly discovered Mittag–Leffler expansions for Bessel functions of the first kind. 相似文献
88.
This paper presents the application of simulated annealing (SA), Tabu search (TS) and hybrid TS–SA to solve a real-world mining optimisation problem called open pit block sequencing (OPBS). The OPBS seeks the optimum extraction sequences under a variety of geological and technical constraints over short-term horizons. As industry-scale OPBS instances are intractable for standard mixed integer programming (MIP) solvers, SA, TS and hybrid TS–SA are developed to solve the OPBS problem. MIP exact solution is also combined with the proposed metaheuristics to polish solutions in feasible neighbourhood moves. Extensive sensitivity analysis is conducted to analyse the characteristics and determine the optimum sets of values of the proposed metaheuristics algorithms’ parameters. Computational experiments show that the proposed algorithms are satisfactory for solving the OPBS problem. Additionally, this comparative study shows that the hybrid TS–SA is superior to SA or TS in solving the OPBS problem in several aspects. 相似文献
89.
90.
Erhan Zor Yasemin Oztekin Lina Mikoliunaite Jaroslav Voronovic Almira Ramanaviciene Zilvinas Anusevicius Haluk Bingol Arunas Ramanavicius 《Journal of Solid State Electrochemistry》2014,18(6):1529-1536
In this study, two ortho-quinoidal compounds, 1,10-phenanthroline-5,6-dione (PD) and 9,10-phenanthrenequinone (PQ), were examined as electron transfer mediators suitable for amperometric glucose biosensors. The dependences of the electrochemical responses of PD- and PQ-based amperometric glucose biosensors on varied concentrations of glucose were investigated under aerobic and anaerobic conditions. The PD-modified graphite rod (GR) electrode revealed a current response seven times higher than that of the PQ-modified GR electrode. The reactivity indices of ortho-quinoidals assessed by means of B3LYP functional method applying 6-311G(D) basis set showed that the electron-accepting potency for PD was markedly higher as compared with that of PQ. Compared to PQ, considerably higher reactivity of PD has been defined in the reactions with NADP+-ferredoxin reductase (FNR, EC 1.18.1.2) as a model single-electron transfer FAD-dependent enzyme, which provided an additional evidence for PD as a more efficient mediator compared to PQ. This study illustrates that PD can be applied as a redox mediator for glucose oxidase and it could be more suitable for a reagent-less biosensor design than PQ. 相似文献