Antimicrobial peptide-based array for Escherichia coli and Salmonella screening

A method based on solid-phase microextraction (SPME) followed by gas chromatography with microwave-induced plasma atomic emission detection for determining 16 pesticides of different chemical families (organochlorines, organophosphorus compounds and pyrethrins) in honey is proposed. Parameters affecting the sample enrichment step, such as sample mass, ionic strength, absorption and desorption times and temperatures, were carefully optimized in the direct immersion mode. Element-specific detection and quantification was carried out by monitoring the chlorine (479 nm), bromine (478 nm) and sulphur (181 nm) emission lines, which provided nearly specific chromatograms. The matrix effect was evaluated for samples of different floral origin, it being concluded that standard addition calibration was required for quantification purposes. The detection limits ranged from 0.02 to 10 ng g⁻¹, depending on the compound and the honey sample under analysis. The method is reliable and can be considered useful for routine monitoring. None of the honey samples analyzed contained the studied compounds at concentrations above the corresponding detection limits.     

1-Soliton solution and conservation laws for the Jaulent-Miodekequation with power law nonlinearity

This paper obtains the 1-soliton solution of the Jaulent-Miodek equation with power law nonlinearity. The solitary wave ansatz is used to obtain the soliton solution to this equation. Subsequently, the conserved quantities are computed using the invariance and multiplier approach based on the well known result that the Euler-Lagrange operator annihilates the total divergence.     

Parameter estimation in geometric process with Weibull distribution

We consider geometric process (GP) when the distribution of the first occurrence time of an event is assumed to be Weibull. Explicit estimators of the parameters in GP are derived by using the method of modified maximum likelihood (MML) proposed by Tiku [24]. Asymptotic distributions and consistency properties of these estimators are obtained. We show that our estimators are more efficient than the widely used modified moment (MM) estimators via Monte Carlo simulation study. Further, two real life examples are given at the end of the paper.     

Conservation laws of a nonlinear (1+1) wave equation

In this paper, further study of the conservation laws of the nonlinear (1+1) wave equation involving two arbitrary functions of the dependent variable is performed. This equation is not derivable from a variational principle. By writing the equation, admitting a partial Lagrangian, in the partial Euler–Lagrange   form, partial Noether operators associated with the partial Lagrangian are obtained for all possible cases of the functions. These partial Noether operators do not form a Lie algebra in general. Partial Noether operators aid via a formula in the construction of the conservation laws of the equation. We obtain new conservation laws for the equation which have not been presented in the earlier literature.     

Generalization of the double reduction theory

In a recent work Sjöberg (2007, 2008) [1], [2] remarked that generalization of the double reduction theory to partial differential equations of higher dimensions is still an open problem. In this note we have attempted to provide this generalization to find invariant solution for a non linear system of $q$th order partial differential equations with $n$ independent and $m$ dependent variables provided that the non linear system of partial differential equations admits a nontrivial conserved form which has at least one associated symmetry in every reduction. In order to give an application of the procedure we apply it to the nonlinear (2+1) wave equation for arbitrary function $f\left(u\right)$ and $g\left(u\right)$.     

The application of (Z)-3-aryl-3-haloenoic acids to the synthesis of (Z)-5-benzylidene-4-arylpyrrol-2(5H)-ones

Studies directed at the synthesis of (Z)-5-benzylidene-4-arylpyrrol-2(5H)-ones from (Z)-3-aryl-3-haloenoic acids are described. The successful strategy relies on the preparation of (Z)-3-aryl-3-haloenoic acids from acetophenones through the corresponding (Z)-3-aryl-3-haloenals and the conversion of the (Z)-3-aryl-3-haloenoic acids to (Z)-5-benzylidene-4-aryl-5H-furan-2-ones. The furanones were subsequently treated with primary amines and dehydrated to the corresponding (Z)-5-benzylidene-4-arylpyrrol-2(5H)-ones.     

Properties of the promotion Markov chain on linear extensions

The Tsetlin library is a very well-studied model for the way an arrangement of books on a library shelf evolves over time. One of the most interesting properties of this Markov chain is that its spectrum can be computed exactly and that the eigenvalues are linear in the transition probabilities. This result has been generalized in different ways by various people. In this work, we investigate one of the generalizations given by the extended promotion Markov chain on linear extensions of a poset P introduced by Ayyer et al. (J Algebr Comb 39(4):853–881, 2014). They showed that if the poset P is a rooted forest, the transition matrix of this Markov chain has eigenvalues that are linear in the transition probabilities and described their multiplicities. We show that the same property holds for a larger class of posets for which we also derive convergence to stationarity results.     

When some complement of a z-closed submodule is a summand

In this article we study modules with the condition that every z-closed submodule has a complement which is a direct summand. This new class of modules properly contains the class of extending modules. It is well known that the class of extending modules is closed under direct summands, but not under direct sums. In contrast to extending (or CS) modules, it is shown that the class of modules with former property is closed under direct sums. However we provide number of algebraic topological examples which show that this new class of modules is not closed under direct summands. To this end we obtain several results on the inheritance of the latter closure property.     

A photon transmission study for film formation from poly(vinyl acetate) latex particles with different molecular weights

The photon transmission technique was used to monitor the temperature evolution of film formation from poly(vinyl acetate) (PVAc) latex particles with two different molecular weights. Two sets of latex films were prepared below the glass transition temperature (T_g) of PVAc, which are named as low (LM) and high molecular weight (HM) films. These films were annealed at elevated temperatures above the T_g of PVAc for various time intervals. It is observed that transmitted photon intensity (I_tr) from these films increased as the annealing temperature was increased. Onset temperatures (T_H) at given times (τ_H) for starting the optical clarity of LM and HM films were measured and used to calculate the healing activation energies (ΔH) for the PVAc minor chains, and found to be as 28.1 kcal/mol and 27.7 kcal/mol, respectively. The increase in the transmitted photon intensity, I_tr above T_H was attributed to the increase in the number of disappeared interfaces between the deformed latex particles. Prager–Tirrell (PT) model was employed to interpret the increase in the crossing density of chains at the junction surfaces. The interdiffusion (backbone) activation energies (ΔE) were measured and found to be 177.5 kcal/mol and 210.7 kcal/mol for a diffusing PVAc chains across the junction surface of LM and HM latex films, respectively. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2918–2925, 2007     

Resolution of indobufen enantiomers by capillary zone electrophoresis. Pharmacokinetic studies of human serum

A direct and stereospecific method was worked out to quantify indobufen enantiomers in human serum using capillary zone electrophoresis (CZE). The indobufen enantiomers and (+)-S-ketoprofen (internal standard, IS) were separated in a fused silica capillary, filled with heptakis 2,3,6-tri-O-methyl-beta-cyclodextrin as a chiral selector in a buffer of pH 5.0. Indobufen enantiomers and other non-steroidal anti-inflammatory drugs: flurbiprofen, ketoprofen and (+)-S-naproxen were also separated during one analytical run. UV absorbances of indobufen enantiomers were measured at 282 nm. Influence of temperature on resolution of the enantiomers, and the electrophoretic parameters: electrophoretic (muep) and electroosmotic (muEOF) mobilities were also determined. Validation of the method was carried out. Calibration curves of indobufen enantiomers were linear in the range of 0.2-20.0 microg/ml. Percent recovery of both enantiomers from acidified serum was calculated after extraction with methylene chloride. Intra- and inter-day measurement precision and accuracy were below 15.0%. Limits of quantitation and detection were also estimated. The elaborated method was tested in vivo after administration of a single dose of 200 mg rac-indobufen tablets to healthy volunteers. Calculated parameters confirmed usefulness of the method in human pharmacokinetic studies on indobufen enantiomers. The direct CZE method can provide an alternative to HPLC, where enantiomers used to be derivatised before determination.