The impact of blood on liver metabolite profiling – a combined metabolomic and proteomic approach

Metabolomics has entered the well‐established omic sciences as it is an indispensable information resource to achieve a global picture of biological systems. The aim of the present study was to estimate the influence of blood removal from mice liver as part of sample preparation for metabolomic and proteomic studies. For this purpose, perfused mice liver tissue (i.e. with blood removed) and unperfused mice liver tissue (i.e. containing blood) were compared by two‐dimensional gas chromatography time of flight mass spectrometry (GC × GC‐TOFMS) for the metabolomic part, and by liquid chromatography tandem mass spectrometry (LC‐MS/MS) for the proteomic part. Our data showed significant differences between the unperfused and perfused liver tissue samples. Furthermore, we also observed an overlap of blood and tissue metabolite profiles in our data, suggesting that the perfusion of liver tissue prior to analysis is beneficial for an accurate metabolic profile of this organ. Copyright © 2013 John Wiley & Sons, Ltd.     

Study of the retention behavior of iodinated X‐ray contrast agents in hydrophilic interaction liquid chromatography,comparing bare silica and zwitterionic stationary phases

Iodinated X‐ray contrast media are the most widely used pharmaceuticals for intravascular administration in X‐ray diagnostic procedures. The increasing concern of the fate of these compounds into the environment has led to the development of analytical methods to determine them. However, these methods present problems due to the polar character of these analytes. In this paper, hydrophilic interaction LC is presented as an alternative technique. The retention of iodinated X‐ray contrast media was studied in two bare silica phases with different particle designs (i.e. porous and Fused Core?) and a zwitterionic sulfoalkylbetaine phase. The effect of the most important parameters of the mobile phase was studied for each stationary phase. It was observed that optimal mobile phase conditions included buffers with a high buffering capacity. Additionally, the retention mechanisms involved were studied in order to provide some insight into the possible occurring interactions. The contributions of partition and adsorption and the effect of the temperature on the retention of analytes were evaluated on all of the stationary phases.     

Noise effect on Grover algorithm

The decoherence effect on Grover algorithm has been studied numerically through a noise modelled by a depolarizing channel. Two types of error are introduced characterizing the qubit time evolution and gate application, so the noise is directly related to the quantum network construction. The numerical simulation concludes an exponential damping law for the successive probability of the maxima as time increases. We have obtained an allowed-error law for the algorithm: the error threshold for the allowed noise behaves as ε_th(N) ∼1/N^1.1 (N being the size of the data set). As the power of N is almost one, we consider the Grover algorithm as robust to a certain extent against decoherence. This law also provides an absolute threshold: if the free evolution error is greater than 0.043, Grover algorithm does not work for any number of qubits affected by the present error model. The improvement in the probability of success, in the case of two qubits has been illustrated by using a fault-tolerant encoding of the initial state by means of the [[7,1,3]] quantum code.     

Exact Potts Model Partition Functions for Strips of the Square Lattice

We present exact calculations of the Potts model partition function Z(G, q, v) for arbitrary q and temperature-like variable v on n-vertex square-lattice strip graphs G for a variety of transverse widths L _t and for arbitrarily great length L , with free longitudinal boundary conditions and free and periodic transverse boundary conditions. These have the form Z(G, q, v)= . We give general formulas for N _{Z, G, j} and its specialization to v=–1 for arbitrary L _t for both types of boundary conditions, as well as other general structural results on Z. The free energy is calculated exactly for the infinite-length limit of the graphs, and the thermodynamics is discussed. It is shown how the internal energy calculated for the case of cylindrical boundary conditions is connected with critical quantities for the Potts model on the infinite square lattice. Considering the full generalization to arbitrary complex q and v, we determine the singular locus , arising as the accumulation set of partition function zeros as L , in the q plane for fixed v and in the v plane for fixed q.     

Transfer Matrices and Partition-Function Zeros for Antiferromagnetic Potts Models. II. Extended Results for Square-Lattice Chromatic Polynomial

We study the chromatic polynomials for m×n square-lattice strips, of width 9m13 (with periodic boundary conditions) and arbitrary length n (with free boundary conditions). We have used a transfer matrix approach that allowed us also to extract the limiting curves when n. In this limit we have also obtained the isolated limiting points for these square-lattice strips and checked some conjectures related to the Beraha numbers.     

A new approach for modelling the damped Helmholtz oscillator:applications to plasma physics and electronic circuits

In this paper,a new approach is devoted to find novel analytical and approximate solutions to the damped quadratic nonlinear Helmholtz equation(HE)in terms of the Weiersrtrass elliptic function.The exact solution for undamped HE(integrable case)and approximate/semi-analytical solution to the damped HE(non-integrable case)are given for any arbitrary initial conditions.As a special case,the necessary and sufficient condition for the integrability of the damped HE using an elementary approach is reported.In general,a new ansatz is suggested to find a semi-analytical solution to the non-integrable case in the form of Weierstrass elliptic function.In addition,the relation between the Weierstrass and Jacobian elliptic functions solutions to the integrable case will be derived in details.Also,we will make a comparison between the semi-analytical solution and the approximate numerical solutions via using Runge-Kutta fourth-order method,finite difference method,and homotopy perturbation method for the first-two approximations.Furthermore,the maximum distance errors between the approximate/semi-analytical solution and the approximate numerical solutions will be estimated.As real applications,the obtained solutions will be devoted to describe the characteristics behavior of the oscillations in RLC series circuits and in various plasma models such as electronegative complex plasma model.     

Finite-temperature phase transition in a class of four-state Potts antiferromagnets

We argue that the four-state Potts antiferromagnet has a finite-temperature phase transition on any Eulerian plane triangulation in which one sublattice consists of vertices of degree 4. We furthermore predict the universality class of this transition. We then present transfer-matrix and Monte?Carlo data confirming these predictions for the cases of the Union Jack and bisected hexagonal lattices.     

Solvent and surfactant effect on the self-assembly and luminescence properties of ZrO2:Eu3+ nanoparticles

ZrO₂:Eu³⁺ nanocrystals ranging from 17 to 43 nm were prepared by the facile precipitation method with a hydrothermal process. The crystallite size was strongly influenced by the solvent composition and enhanced with the presence of surfactant. The use of ethanol combined with surfactant stabilizes 50 wt% of the monoclinic phase, while the use of water only results in 100 wt% tetragonal phase. 80% of nanobelts were obtained preparing the sample with ethanol and surfactant as a results of the self-assembly of nanoparticles. The photoluminescence emission peak centered at 606 nm dominates the emission band for nanobelts, while for nanoparticles it is dominated by a peak centered at 612 nm. Such differences were explained in terms of the site symmetry occupying Eu³⁺ in the host that in turn depends on the crystalline phase. Changes in the intensity ratio I(612 nm)/I(606 nm) is proposed as a tool to analyzing changes in the monoclinic/tetragonal phase composition. The calculated asymmetry ratio R=⁷F₂/⁷F₁～1.2 suggest a high degree of crystallinity of the prepared samples.