A clean‐up technology for the simultaneous determination of lysophosphatidic acid and sphingosine‐1‐phosphate by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry using a phosphate‐capture molecule,Phos‐tag

Lysophosphatidic acid (LPA) and sphingosine‐1‐phosphate (S1P) are growth factor‐like lipids having a phosphate group. The concentrations of these mediator lipids in blood are considered to be potential biomarkers for early detection of cancer or vascular diseases. Here, we report a method for simultaneous determination of LPA and S1P using Phos‐tag, a zinc complex that specifically binds to a phosphate‐monoester group. Although both LPA and S1P are hydrophilic compounds, we found that they acquire hydrophobic properties when they form complexes with Phos‐tag. Based on this finding, we developed a method for the enrichment of LPA and S1P from biological samples. The first partition in a two‐phase solvent system consisting of chloroform/methanol/water (1:1:0.9, v/v/v) is conducted for the removal of lipids. LPA and S1P are specifically extracted as Phos‐tag complexes at the second partition by adding Phos‐tag. The Phos‐tag complexes of LPA and S1P are detectable by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) and quantifiable based on the relative intensities of ions using 17:0 LPA and C17 S1P as internal standards. The protocol was validated by analyses of these mediator lipids in calf serum, a rat brain and a lung. The clean‐up protocol is rapid, requires neither thin‐layer chromatography (TLC) nor liquid chromatography (LC), and is applicable to both blood and solid tissue samples. We believe that our protocol will be useful for a routine analysis of LPA and S1P in many clinical samples. Copyright © 2010 John Wiley & Sons, Ltd.     

The Hukuhara–Kneser property for a nonlinear integral equation

Applying a structure theorem of Krasnosel’skii and Perov, we show that the solution set of a nonlinear integral equation satisfies the classical Hukuhara–Kneser property.     

Nachweis von Giften in der Asche feuerbestatteter Leichen

Ohne Zusammenfassung     

Lipschitzian stability of parametric variational inequalities over perturbed polyhedral convex sets

In this paper we investigate the Lipschitz-like property of the solution mapping of parametric variational inequalities over perturbed polyhedral convex sets. By establishing some lower and upper estimates for the coderivatives of the solution mapping, among other things, we prove that the solution mapping could not be Lipschitz-like around points where the positive linear independence condition is invalid. Our analysis is based heavily on the Mordukhovich criterion (Mordukhovich in Variational Analysis and Generalized Differentiation. vol. I: Basic Theory, vol. II: Applications. Springer, Berlin, 2006) of the Lipschitz-like property for set-valued mappings between Banach spaces and recent advances in variational analysis. The obtained result complements the corresponding ones of Nam (Nonlinear Anal 73:2271–2282, 2010) and Qui (Nonlinear Anal 74:1674–1689, 2011).     

Global existence of diffusive-dispersive traveling waves for general flux functions

We establish a global existence of traveling waves for diffusive-dispersive conservation laws for locally Lipschitz flux functions. Using Lyapunov stability techniques, we reduce the global problem of finding traveling waves to considering local behaviors of a stable trajectory of the saddle point.     

Simulation of stabilizing process of dielectric nanoparticle in optical trap using counter-propagating pulsed laser beams

<正>The stabilizing process of glass particle in water by optical trap using the pulsed counter-propagating Gaussian beams is investigated.The influence of the optical power and the particle dimension on the rate and time of the stabilizing process is simulated and discussed.     

Synthesis of the perovskite ceramic Li3xLa2/3–xTiO3 by a chemical solution route using a triblock copolymer surfactant

The synthesis of the perovskite Li_3xLa_2/3–x□_1/3–2xTiO₃ by a chemical solution route, using a triblock copolymer surfactant, PEO_n–PPO_m–PEO_n, is described. This titanate is a non-hygroscopic fast lithium conductor and therefore is a good candidate for electrochemical applications. It is generally prepared by a conventional solid-state reaction (SSR) method. However this synthesis method does not allow the preparation of nanopowders or the formation of thin films. For these special purposes, synthesis by a chemical solution route, with the formation of a polymeric precursor during synthesis, has been investigated. By using the above-mentioned non-ionic surfactant, the preparation of nanopowders of complex oxides can be done. Furthermore, this way of synthesis leads to the formation of an intermediate polymeric precursor which can be easily spread on substrates to obtain films. We show that the formation of a pure phase of the perovskite Li_3xLa_2/3–x□_1/3–2xTiO₃ is highly dependent on the synthesis conditions, namely the presence of water in the solvent, the EO/metal ratio, the Li⁺ content in the precursor and the calcination temperature. The influence of these parameters on the microstructure of the oxide is studied by X-ray diffraction, scanning electron microscopy and granulometry. A powder of Li_3xLa_2/3–x□_1/3–2xTiO₃ (x = 0.10), with an average particles size of 200 nm, has been obtained. The ionic conductivity of this oxide is the same as the one obtained with oxide prepared by SSR (a bulk conductivity of 1.4 × 10⁻³ S/cm at 37 °C). The ceramic obtained from this powder after sintering at 1,150 °C shows a good pH response. This material can then be used as a sensitive membrane in a potentiometric pH sensor. The presence of hydrophobic PPO groups in the polymer precursor allowed preparing films of Li_3xLa_2/3–x□_1/3–2xTiO₃ with a good adherence on Pt substrate. This kind of synthesis is then very promising to prepare micro pH sensors.     

Corrigendum to “Solution of a crack in an electrostrictive solid” [International Journal of Solids and Structures 47 (2010) 444–453]

In our previous work [Gao, C.F., Mai, Y.W., Zhang, N., 2010. Solution of a crack in an electrostrictive solid. International Journal of Solids and Structures 47, 444–453.] the intensity factor of the total stress for an impermeable crack is directly written by using the corresponding result of a permeable crack. This is based on the fact that an impermeable crack can be considered as a special case of a permeable crack where the electric field is not zero. However, the singularity of total stresses for the impermeable crack can also be analyzed directly from the complex potentials. In this Corrigendum, the singularity of the total stresses is further studied for the impermeable crack, and the intensity factors are re-derived by using the obtained complex potentials. It is shown that for an impermeable crack, the total stresses still have an inverse square-root singularity but their intensity factor is different from that obtained by the solution of a permeable crack. Therefore, it is concluded that solutions for impermeable cracks cannot be obtained directly from those of permeable cracks, since the assumption of the electric boundary condition has not only influenced the electric fields on the crack-faces but also on the electric body force inside the material.     

Morphology Dependence of Photocatalytic Activity of TiO2 Nanostructure Prepared through Microwave Hydrothermal Process

Five different morphologies selectively synthesized through a microwave hydrothermal route in order to determine the dependence of degradation efficiency on TiO₂ morphologies. These five morphologies include nanosphere, nanotube, hollow sphere, nanorod and granule‐like particle. Scanning electron microscopy, X‐ray diffraction and Brunauer‐Emment‐Teller methods were used to characterize the morphologies, crystalline structures, and specific surface area of these nanostructured TiO₂. Oxidants were used as sacrificial electron acceptor to accelerate the degradation. The degradation mechanism of oxalic acid on the surface of TiO₂ influenced by oxidants was discussed.