A New Access Control Solution for a Multi-Provider Wireless Environment

The fundamental goal in future 4G mobile multi-service networks is to provide an efficient mobile computing environment. We presume that future terminals will be equipped with multiple heterogeneous wireless interfaces. We want to enable each user to seamlessly move between different providers networks. Besides seamless roaming, a key consideration is also devoted to quality-of-service provision. In this article, we propose a model and an architectural framework for supporting quality of service in the context of interconnected multi-provider wireless systems. The proposed integrated COPS-based management and RADIUS-based access control architecture will allow providers to offer multimedia services while optimizing the use of the underlying network resources. We suggest new concepts and protocols to provide solutions to these challenges and describe the French national research project named MMQoS aiming on building such future networks.     

Tetrahydro anthraquinones disubstituees en - 1,5: etude de la regioselectivite de la reaction de diels-alder entre des naphtoquinones et des dienes attracteurs.

Diels-Alder reaction of - 2,4 pentadienoïc acid and its methyl ester (electron with-drawing) dienes with juglone and its derivatives is described. High regioselectivity is observed, the adducts have a “head-to-tail” geometry.     

Mutagenic, antimutagenic and antioxidant activities of a new polyphenolic and a flavonoid substances isolated from Anagallis monelli

A new polyphenolic natural substance: 2,5-dihydroxy-benzoic acid 3'-formyl-5'-hydroxy-phenyl ester (1), Anamighrinal and 3-(O-alpha-L-rhamnosyl) quercetin (2) have been isolated from the methanolic aerial part extract of the plant Anagallis monelli by chromatographic separation. Their structures have been deduced essentially by one and two NMR spectroscopic procedures and mass spectrometry. Antioxidant, mutagenic, antimutagenic activities, of the natural products were realised and positive results were recorded.     

Validation of a confirmatory method for the determination of macrolides in liver and kidney animal tissues in accordance with the European Union regulation 2002/657/EC

This study proposes a simple multiresidue liquid chromatography-diode array detector (LC-DAD) method capable of determining seven macrolide antibiotics in samples of liver and kidney animals at concentrations lower than those allowed by current legislation. Samples were prepared by homogenizing the tissue with EDTA-McIlvaine's buffer and extracted with an Oasis HLB cartridge. The consumption of organic solvent during extraction was minimum. The analytes were detected by LC-DAD and also by liquid chromatography-mass spectrometry with electrospray ionization (LC-(ESI)MS). The method was specific, stable and robust enough for the required purposes. The DAD method was validated in accordance with the European Commission Decision 657/2002. Recovery data were also satisfactory with values higher than 67% for most macrolide antibiotics extracted from liver and kidney samples spiked at 200 microg/kg, the lowest MRL established for the macrolides studied. The relative standard deviations (RSD (%), (n=3)) were lower than 13% and 15% for intra-day and inter-day assays. The method was applied to investigate the occurrence of the studied macrolides in 31 beef and kidney animal samples. The results obtained by LC-DAD for positive samples were compared to those obtained by LC-(ESI)MS. Therefore, the method with simpler instrumentation than a LC-(ESI)MS can be used as a control method and the results of the validation process demonstrate that this method is suitable for application in a European Union program for monitoring residues of veterinary drugs.     

Synthesis, crystal structure, and spectroscopic study of K0.92(2) Zn0.08(2) H1.92(2) (PO4) (Zn-KDP)

The structure of K0.92₍₂₎ Zn_0.08(2) H_1.92(2) (PO₄) was determined using single-crystal X-ray diffraction. The crystal structure of the Zn-KDP belonged to the tetragonal space group $ \mathrm{I}\overline{4}2\mathrm{d} $ , with cell parameters of a?=?b?=?7.4487(5)?Å and c?=?6.9703(5)?Å, 386.73(5) Å3, Z?=?4, and R?=?0.023. Zn²⁺ ions were used as substitutes for K⁺ ions with hydrogen vacancy. The Zn-KDP single crystals were submitted to further Raman, infrared, and ¹H NMR studies to investigate chemical group functionalisation, possible bonding between the organic and inorganic materials, and partial substitution of K⁺ by Zn²⁺. The latter partial substitution was confirmed by the deviation of IR frequencies for O–H stretching, the variation of IR and Raman frequencies for stretching and bending vibrations ν(PO₄) of H₂PO₄, and the appearance of additional Raman (147, 386 and 481 cm^?1) vibrational bands. Electrical conductivity measurements were performed on polycrystalline pellets of Zn-KDP and pure KDP at room temperatures (RT) of up to 473K. In both cases, a conductivity jump close to 453K was observed, and a stronger increase of conductivity was measured.     

Molecularly Imprinted Electrochemical Sensor Based on Modified Reduced Graphene Oxide‐gold Nanoparticles‐polyaniline Nanocomposites Matrix for Dapsone Determination

This work was designed to develop an electrochemical sensor based on molecular imprinted polyaniline membranes onto reduced graphene oxide (RGO) and gold nanoparticles (AuNPs) modified glassy carbon (GC) electrode for dapsone (DDS) determination. The prepared RGO/AuNPs/PANI‐MIPs nanocomposite was characterized by Ultra‐Violet‐Visible (UV‐Vis), Fourier transform infrared spectroscopy (FT‐IR) and scanning electronic microscopy (SEM) images. The feature of the imprinted electrode was evaluated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and impedance spectroscopy (IS). Throughout this study several analytical parameters, such as incubation time, pH value, concentration of monomer/template molecules and electro‐polymerization cycles were investigated. Under the optimized conditions, the experimental results showed best analytical performances for DDS detection with a sensitivity of 0.188 Ω/mol L^?1, a linear range from 1.0×10^?7 M to 1.0×10^?3 M and a detection limit of 6.8×10^?7 M. The bioanalytical sensor was applied to the determination of dapsone in real samples with high selectivity and recovery.     

基于H.263视频解码的误码掩盖技术研究

本文提出了一种基于接收端像素域的误码掩盖算法,包括误码检测、重同步、误码定位和估计误码数据等四个环节。计算机模拟结果显示,经误码掩盖之后的图像质量有显著的改善