Electrooxidative behavior and determination of trifluoperazine at multiwalled carbon nanotube-modified glassy carbon electrode

The mechanism of electrochemical oxidation of trifluoperazine has been proposed on the basis of cyclic and differential pulse voltammetry at a multiwalled carbon nanotube-modified glassy carbon electrode. The modified electrode exhibits catalytic activity, high sensitivity, and stability. The oxidation process exhibited an adsorption-controlled behavior. Also, depending on this adsorption control, a sensitive electroanalytical method for the determination of trifluoperazine has been investigated by adsorptive stripping differential pulse voltammetry. Under the optional conditions, the anodic peak current was linear to the trifluoperazine concentration over the range of 2.08 10^?8?M to 1.67 10^?6?M, and the limit of detection was 7.49 10^?10?M. The modified electrode had good stability and repeatability, and it was successfully applied to the determination of trifluoperazine in pharmaceuticals.     

International disaster relief planning with fuzzy credibility

As a consequence of more extensive collaboration between countries, the need for better humanitarian relief assistance has become a significant challenge to the international community. In case of a disaster exceeding the national response capacity of the affected country, donor countries provide the relief items, which are then consolidated at collection points to be shipped to points of delivery in the stricken country. After the items are transported to the point of delivery, the responsible authority in distributing aids to vulnerable populations then becomes the national relief agencies. In this context, we propose an international relief planning model that can handle the uncertain information while maximizing the credibility of the international agencies in the most cost efficient way.     

One‐pot preparation of 3‐miktoarm star terpolymers via click [3 + 2] reaction

The preparation of 3‐miktoarm star terpolymers using nitroxide mediated radical polymerization (NMP), ring opening polymerization (ROP), and click reaction [3 + 2] are carried out by applying two types of one‐pot technique. In the first one‐pot technique, NMP of styrene (St), ROP of ε‐caprolactone (ε‐CL), and [3 + 2] click reaction (between azide end‐functionalized poly(ethylene glycol) (PEG‐N₃)/or azide end‐functionalized poly(methyl methacrylate) (PMMA‐N₃) and alkyne) are carried out in the presence of 2‐(hydroxymethyl)‐2‐methyl‐3‐oxo‐3‐(2‐phenyl‐2‐(2,2,6,6‐tetramethylpiperidin‐1‐yloxy)ethoxy) propyl pent‐4‐ynoate, 2 , as an initiator for 48 h at 125 °C (one‐pot/one‐step). As a second technique, NMP of St and ROP of ε‐CL were conducted using 2 as an initiator for 20 h at 125 °C, and subsequently PEG‐N₃ or azide end‐functionalized poly(tert‐butyl acrylate (PtBA‐N₃) was added to the polymerization mixture, followed by a click reaction [3 + 2] for 24 h at room temperature (one‐pot/two‐step). The 3‐miktoarm star terpolymers, PEG‐poly(ε‐caprolactone)(PCL)‐PS, PtBA‐PCL‐PS and PMMA‐PCL‐PS, were recovered by a simple precipitation in methanol without further purification. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3588–3598, 2007     

Electrochemical Determination and in silico Studies of Fludarabine on NH2 Functionalized Multiwalled Carbon Nanotube Modified Glassy Carbon Electrode

A sensitive voltammetric technique has been developed for the determination of Fludarabine using amine‐functionalized multi walled carbon nanotubes modified glassy carbon electrode (NH₂‐MWCNTs/GCE). Molecular dynamics simulations, an in silico technique, were employed to examine the properties including chemical differences of Fludarabine‐ functionalized MWCNT complexes. The redox behavior of Fludarabine was examined by cyclic, differential pulse and square wave voltammetry in a wide pH range. Cyclic voltammetric investigations emphasized that Fludarabine is irreversibly oxidized at the NH₂‐MWCNTs/GCE. The electrochemical behavior of Fludarabine was also studied by cyclic voltammetry to evaluate both the kinetic (k_s and E_a) and thermodynamic (ΔH, ΔG and ΔS) parameters on NH₂‐MWCNTs/GCE at several temperatures. The mixed diffusion‐adsorption controlled electrochemical oxidation of Fludarabine revealed by studies at different scan rates. The experimental parameters, such as pulse amplitude, frequency, deposition potential optimized for square‐wave voltammetry. Under optimum conditions in phosphate buffer (pH 2.0), a linear calibration curve was obtained in the range of 2×10^?7 M–4×10^?6 M solution using adsorptive stripping square wave voltammetry. The limit of detection and limit of quantification were calculated 2.9×10^?8 M and 9.68×10^?8 M, respectively. The developed method was applied to the simple and rapid determination of Fludarabine from pharmaceutical formulations.     

Purification of Peroxidase from Red Cabbage (Brassica oleracea var. capitata f. rubra) by Affinity Chromatography

Peroxidase was purified in a single step using 4-amino benzohydrazide affinity chromatography from red cabbage (Brassica oleracea var. capitata f. rubra), and some important biochemical characteristics of the purified enzyme were determined. The enzyme, with a specific activity of 3,550 EU/mg protein, was purified 120.6-fold with a yield of 2.9 % from the synthesized affinity matrix. The molecular weight of the enzyme was found to be 69.3 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme exhibited maximum activity at pH 7.0 and 30 °C. For guaiacol substrate, the K _m and V _max values were found as 0.048 mM and 1.46 EU/mL/min, respectively. Additionally, the IC₅₀ and K _i values for 4-amino benzohydrazide were calculated to be 1.047 and 0.702?±?0.05 mM, respectively, and 4-amino benzohydrazide showed noncompetitive inhibition.     

A probabilistic evolution approach trilogy, part 3: temporal variation of state variable expectation values from Liouville equation perspective

This is the third and therefore the final part of a trilogy on probabilistic evolution approach. The work presented here focuses on the probabilistic evolution determination for the state variables of a many particle system from classical mechanical point of view. Probabilistic evolution involves the expected value evolutions for all natural number Kronecker powers of the state variables, positions and momenta. We use the phase space distribution of the Liouville equation perspective to construct the expected values of the state variables’ Kronecker powers to define unknown temporal functions. The infinite number homogeneous linear ODEs with an infinite constant coefficient matrix are constructed by following the same steps as in the previous two works on quantum mechanics. The only difference is in the definitions of the expected values here. We also focus on a system of many harmonic oscillators to illustrate the block triangularity.     

Design of a hyperstable protein by rational consideration of unfolded state interactions

Stabilization of proteins is a long-sought objective. Targeting the unfolded state interactions of a protein is not a method used for this purpose, although many proteins are known to contain such interactions. The N-terminal domain of ribosomal protein L9 (NTL9) has a lysine residue at position 12, which makes strong non-native interactions in the unfolded state. Substitution of a d-alanine for G34 in NTL9 is known to stabilize the protein by reducing the entropy of the unfolded state. Here we combine these two mutations to design a hyperstable protein. The structure of the variant is the same as that of wild-type as judged by 2D NMR. The variant is hyperstable as judged by denaturation experiments, where complete thermal unfolding of the protein does not occur in native buffer.     

Iron(III) complex of a tridentate <Emphasis Type="Italic">NNN</Emphasis> type ligand: synthesis,X-ray structure,thermal analysis and voltammetric studies

A mononuclear iron(III) complex with 2,6-bis(3,4,5-trimethyl-N-pyrazolyl)pyridine (btmpp) has been synthesized, and characterized by X-ray crystallography, IR, UV–Vis and TGA–DTA methods. The Fe(III/II) couple was characterized by way of cyclic voltammetry using DMF solvent, where the complex was observed to have an irreversible behaviour.     

Normalizers of non-split Cartan subgroups, modular curves, and the class number one problem

Let be the open non-cuspidal locus of the modular curve associated to the normalizer of a non-split Cartan subgroup of level n. As Serre pointed out, an imaginary quadratic field of class number one gives rise to an integral point on for suitably chosen n. In this note, we give a genus formula for the modular curves and we give three new solutions to the class number one problem using the modular curves for n=16,20,21. These are the only such modular curves of genus ?2 that had not yet been exploited.     

A novel polyphosphazene with nitroxide radical side groups as cathode‐active material in Li‐ion batteries

A novel polyphosphazene carrying stable nitroxide aromatic radical groups as a pendant with four electrons involvement per repeating unit is synthesized. To do so, series of macromolecular substitution reactions of poly (dichlorophosphazene) with 3,5‐dibromophenol, 2‐methyl‐2‐nitrosopropane, and lead oxide, respectively, are performed. After characterization of the newly synthesized polymers by standard spectroscopic techniques (such as Fourier transform infrared [FT‐IR], nuclear magnetic resonance [NMR], or electron paramagnetic resonance [EPR]), the targeted polymer is further investigated as a cathode‐active material for rechargeable lithium‐ion batteries (LIBs). The cell delivered a good rate performance with a discharge capacity of 100 mAh/g at a C/2 current density over 500 cycles.