Secure quantum sealed-bid auction

A new experimentally feasible and secure quantum sealed-bid auction protocol using quantum secure direct communication based on GHZ states is proposed. In this scheme all bidders Bob, Charlie, … , and Zach use M groups n-particle GHZ states to represent their bids. Here, an auctioneer gives the auction outcome by performing a sequence of n-particle GHZ-basis measurements on the final quantum states. It has been shown that using this method guarantees the honesty of the protocol, and malicious bidders can not collude with the auctioneers.     

A frictional molecular model for the viscoelasticity of entangled polymer nanocomposites

The dynamics of polymer melts and concentrated solutions reinforced with nanoscale rigid spherical particles is analyzed. Nanocomposites with low filler volume fraction and strong polymer-filler interactions are considered. Entanglement effects are represented by requiring the diffusion in the chain contour direction to be more pronounced than in the direction transverse to the chain primitive path. Filler particles are treated as material points. They reduce the polymer mobility in both longitudinal and transverse tube directions due to short-range energetic filler-polymer interactions. Hence, the contribution to chain dynamics and stress production of both filler-polymer and polymer-polymer interactions is considered to be purely frictional in nature. In the model, the strain rate sensitivity is associated with the thermal motion of chains, with the convective relaxation of entanglement constrains and with the polymer-filler attachment/detachment process. The effect of model parameters is discussed and the predictions are compared with experimental data.     

Microextraction by packed sorbent and liquid chromatography–tandem mass spectrometry as a tool for quantification of peptides in plasma samples: determination of sensory neuron‐specific receptors agonist BAM8‐22 and antagonist BAM22‐8 in plasma samples

Microextraction by packed sorbent (MEPS) is a miniaturized, solid‐phase extraction (SPE) technique that works online with gas chromatography (GC) and liquid chromatography (LC). Not only is the automation process with MEPS advantageous, but the much smaller volumes of the samples, solvents and dead space in the system also provide other significant advantages such as the speed and the simplicity of the sample preparation process. In this study MEPS has been evaluated for quantification of sensory neuron‐specific receptors agonist (BAM8‐22). Owing to the instability of BAMs, the focus was on fast extraction and determination of the peptide online using LC‐MS/MS. Sorbents such as C2, C8 and ENV+ (hydroxylated polystyrene–divinylbenzene copolymer) were investigated in the present study. MEPS‐C8 gave the best results compared with C2 and ENV and it was used for the method validation. The calibration curve was obtained within the concentration range of 20.0–3045 nmol/L in plasma. The regression correlation coefficients for plasma samples were ≥0.99 for all runs (n = 6). The between‐batch accuracy and precision for BAM8‐22 ranged from ?13 to ?2.0% and from 4.0 to 14%, respectively. Additionally, the accuracy and precision for BAM22‐8 ranged from ?13 to 7.0% and from 3.0 to 12%, respectively. The present method was used for pharmacokinetic studies for BAMs in plasma samples. Copyright © 2012 John Wiley & Sons, Ltd.     

A thermodynamic study on the binding of theophylline with human serum albumin

The thermodynamic parameters of interaction between theophylline and Human Serum Albumin (HSA) in buffer solution (30 mM) of pH = 7 at 27 °C was investigated by isothermal titration calorimetry (ITC). The thermodynamic quantities of the binding mechanism, the number of binding sites (g), the dissociation binding constant (K _d), the molar enthalpy of binding (ΔΗ) and other thermodynamic parameters can be obtained by the extended solvation theory.     

Improved secure quantum sealed-bid auction

The security of a secure quantum sealed-bid auction protocol using quantum secure direct communication based on GHZ states [M. Naseri, Opt. Commun. 282 (2009) 1939] is reexamined. It is shown that the protocol does not complete the task of a sealed-bid auction fairly. It is shown that a dishonest bidder can obtain all the other one’s secret bids by two special types of attack, i.e., double Controlled NOT attack or using fake entangled particles. Furthermore, a simple possible improvement of the protocol is proposed.     

Multipartite non-locality and entanglement signatures of a field-induced quantum phase transition

Quantum correlation measures are limited in practice to a few number of parties, since no general theory is still capable of reaching the thermodynamic limit. In the present work we study entanglement and non-locality for a cluster of spins belonging to a compound that displays a magnetocaloric effect. A quantum phase transition (QPT) is induced by an external magnetic field B, in such a way that the corresponding quantum fluctuations are reproduced at a much smaller scale than the experimental outcomes, and then described by means of the aforementioned quantum measures.     

VT and VF classification using trajectory analysis

Visual classification of Ventricular Fibrillation (VF) and Ventricular Tachycardia (VT) patterns is a hard task for cardiologists. VT and VF signals are apparently similar in the time domain but their underlying information is totally different. In this paper, an image-based technique is presented which extracts discriminative information from the trajectories of VT and VF signals in the state space. In this way, first, signals are sketched in the state space by the delay time method. Then, the state space is considered as an image and trajectories of VT and VF signals are considered as two different images. The purpose is to design some masks, apply them on the images, and finally classify these masked images by a box counting method. These masks are designed to remove the common information between the two patterns and just discriminative pixels are flagged. After applying the masks, flagged pixels are counted and a threshold is determined through the cross validation phase under the receiver operator curve (ROC) criterion to classify the VT and VF trajectory images. The signals are selected from two different data sets include MIT/BIH and CCU of the Royal Infirmary of Edinburgh. Our experiments show brilliant results which provide 100% classification rate on the training and testing phases. Even, through the cross validation phase, the results remained the same also, so thep value is determined as less than 0.0001, that experimentally shows no over-fitting is occurred.     

Thermodynamic study on the interaction of cyanide ion and jack bean urease at different temperatures

A method based on Isothermal Titration Calorimety (ITC) is described for the thermodynamic assay of jack bean urease. Inhibitory activity of cyanide ion was examined against jack bean urease (JBU), at 27 and 37 ^oC in 30 mM Tris buffer of pH = 7. The binding parameters of the CN^? + JBU complexation have been calculated. It was found that in the low and high concentrations of the cyanide ions, the JBU structure was destabilized, resulting in a decrease in its biological activity.     

Effective oxidation of 1,2-cyclooctene by oxo-vanadium(IV) tetradentate Schiff base complexes under 1 atmosphere of molecular oxygen

Development of methods for the understanding of chemical reactivity of high-valent metal-oxo species with respect to organic substrates is important. Here we report a high yield, high TON conversion of cyclooctene using VO (Schiff base) complexes (Figure 1) as catalyst and O₂ as oxidant in MeCN under mild conditions. The results show that catalytic activity increases with a decrease in the number of electron-donating groups. At higher concentration of catalyst and shorter reaction time, a low yield but high selectivity of epoxide was observed.