Fractional Conformal spin of pseudo differential operators and KP hierarchy

Given the importance of pseudo differential operators in physics, we present in this paper the useful background to study the algebraic structure of fractional pseudo differential operators. We present a brief account of basic properties of the space of higher conformal spin differential lax operators in the bosonic case and we give some applications through the fractional KP hierarchy Keywords: Lax operators, pseudo differential operators, fractional KP hierarch

Pt-Sn/C as a possible methanol-tolerant cathode catalyst for DMFC

An effective method was developed for preparing highly dispersed nano-sized Pt–Sn/C electrocatalyst synthesised by a modified polyol reduction method. From XRD patterns, the Pt–Sn/C peaks shifted slightly to lower 2θ angles when compared with commercial Pt/C catalyst, suggesting that Sn formed alloy with Pt. Based on HR-TEM images, the Pt–Sn/C nanoparticles showed small particle sizes and well dispersed onto the carbon support with a narrow particle distribution. The methanol oxidation reaction on the as-prepared Pt–Sn/C catalyst appeared at lower currents (+7.08 mA at +480 mV vs. Ag/AgCl) compared to the commercial Pt/C (+8.25 mA at +480 mV vs. Ag/AgCl) suggesting that the Pt–Sn/C catalyst has ‘methanol tolerance capabilities’. Pt–Sn/C HA Slurry pH3 catalysts showed better activity towards the oxygen-reduction reaction (ORR) than commercial Pt/C which could be attributed to smaller particle sizes. In our study, the Pt–Sn/C catalyst appears to be a promising methanol-tolerant catalyst with activity towards the ORR in the DMFC.Web of Scienc

An Adsorptive Transfer Technique Coupled with Brdicka Reaction to Reveal the Importance of Metallothionein in Chemotherapy with Platinum Based Cytostatics

The drugs based on platinum metals represent one of the oldest, but also one of the most effective groups of chemotherapeutic agents. Thanks to many clinical studies it is known that resistance of tumor cells to drugs is a frequent cause of chemotherapy failure. With regard to platinum based drugs, multidrug resistance can also be connected with increased expression of low-molecular weight protein metallothionein (MT). This study aimed at investigating the interactions of MT with cisplatin or carboplatin, using the adsorptive transfer technique coupled with differential pulse voltammetry Brdicka reaction (AdTS DPV Brdicka reaction), and a comparison of in vitro results with results obtained in vivo. The results obtained from the in vitro study show a strong affinity between platinum based drugs and MT. Further, we analyzed extracts of neuroblastoma cell lines treated with cisplatin or carboplatin. It is clear that neuroblastoma UKF-NB-4 cisplatin-resistant and cisplatin-sensitive cell lines unlikely respond to the presence of the platinum-based cytostatics cisplatin and carboplatin. Finally, we determined the level of MT in samples from rabbits treated with carboplatin and patients with retinoblastoma treated with the same drug

Optimisations des méthodes électrochimiques et spectroscopiques à l'aide de plan d'expériences dans l'étude des interactions métaux- biota (applications à diverses problématiques environnementales)

Dans l'environnement, les métaux à l'état de traces, sont impliqués comme micronutriments mais aussi comme inhibiteurs de croissance ou toxiques de l'écosystème. Leurs déterminations à de très faibles teneurs et leurs spéciations chimiques (formes ioniques, libres, engagés dans des complexes inorganiques ou organométalliques, chargés ou neutres ou encore intégrés dans des structures moléculaires) ont pour effet d'améliorer les connaissances des impacts toxiques L'écotoxicologie a besoin de données très précises sur la contamination environnementale. Nous avons donc mis au point et optimisé diverses méthodologies : Extraction sélective avec préconcentration de certains métaux. Dosages par des techniques électrochimiques et spectrométriques. Analyses qualitatives et quantitatives de la métallothionéine par une nouvelle méthode basée sur une technique électrochimique (voltampérométrie mode Square Wave). Les optimisations ont été réalisées à l'aide de plans d'expériences. Une étude sur les effets du cuivre en conditions expérimentales (mésocosmes) sur trois espèces de diatomées marines (Nitzchia closterium, Nitzschia gandersheimiensis et Skeletonema costatum), nous a permis de déterminer la spéciation du cuivre dans les différents compartiments du milieu en relation avec la croissance des cellules.In the environment, metals to the state of traces, are implied as micronutrients as well as inhibitories growth or toxic of the ecosystem. Their determination to very weak contents and their chemicals speciations (ionic forms, free, committed in inorganic complexs or organometalics, loaded or neutral or again integrated in molecular structures) have for effect to improve toxic impact knowledge The ecotox needs very precise data on the environmental contamination. We have therefore developed and optimized various methodologies : Selective Extraction and preconcentration of some metals Analysis by electrochimicals and spectrometricals technics Quantitative and qualitative Analysis of the metallothionein by a new method based on an electrochimical (Square Wave Voltammetry) technical Optimizations have been realized with the help experimental design. A study on the copper effects in experimental conditions (mesocosm) on three species of marine diatoms (Nitzchia closterium, Nitzschia gandersheimiensis and skeletonema costatum), has allowed us to determine of the copper speciation in the different compartments of the middle in connection with the growth of cells.NANTES-BU Médecine pharmacie (441092101) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Comparative study of the adsorptive removal of reactive yellow 14 azo dye from an aqueous solution on different synthetic materials

The purpose of this study is to investigate the adsorption behavior of the Reactive Yellow 14 (RY14) azo dye from an aqueous solution onto silica gel (SG), alumina (AO) and powdered activated carbon (PAC) via batch adsorption technique at room temperature (25 °C). Physicochemical properties of the adsorbents were characterized by means of scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The factors influencing the adsorption of SG, AO and PAC, such as adsorbent dosage, pH, ionic strength, contact time and initial concentration, were conducted to evaluate the adsorption performance. The kinetic studies indicated that the adsorption of RY14 on SG and PAC can be very well fitted by a pseudo-second-order kinetic model, and onto AO by a pseudo-first-order kinetic model. The equilibrium data were best described by a Langmuir model for all adsorbents. The maximum estimated adsorption capacity was 124.6, 116.2 and 200.7 mg·g−1, for SG, AO and PAC, respectively. HIGHLIGHTS Removal of RY14 azo dye from an aqueous solution onto SG, AO and PAC adsorbents.; The adsorption of RY14 on SG and PAC was well fitted by a pseudo-second-order kinetic model, whereas the adsorption was fittеd by a pseudo-first-order kinetic model on AO.; The maximum adsorption capacity was 124.6, 116.2 and 200.7 mg·g−1, for SG, AO and PAC, respectively.

An evaluation of the use of laminar C18 disks employed as part of the solid phase extraction process. Simultaneous capillary gas chromatography - mass spectrometry determination of triazines, organochlorine pesticides, and polyaromatic hydrocarbons

The combination of solid phase extraction and gas chromatography - mas s spectrometry enables fast and reliable analysis of pesticides residues in drin king water. The evaluation of analysis techniques is a priority for laboratories dealing with quality control. The ordinance 89-3 of the 1/3/89 fixes the maximu m acceptable concentrations of micro-pollutants in drinking water including pest icides and chemically related substances belonging to highly diversified chemica l families. This paper described a multiresidue analysis method of triazines, or ganochlorine pesticides and polyaromatic hydrocarbons, adapted from the method E .P.A. 525.2. This multiresidue method and especially the solid phase extraction process employing laminar C18 disks, is evaluated together with relevant statist ical tests as outlined in the NF XP T 90-210 procedure.

Zinc, copper and lead contents of wines. Comparison between the total concentrations by atomic absorption spectrometry and the concentrations of the free ions by polarography

In the introduction of this article, some examples of the use of trace element data in the characterisation of viticultural produce are reminded. This paper described the determination of zinc, copper and lead by two techniques based on radically different principles. The atomic absorption spectrometry, applied after the mineralisation of the samples by wet process, allows the determination of the total element contents in wine. The polarography allows the analysis of the concentrations of these elements that are under labile chemical forms, and which are dissolved under the ionic forms Zn++, Cu++ and Pb++. The wines analysed in this study were produced from three different parcels chosen in relation to their geological qualities. The vines implanted on these parcels are strictly identical, and three fermentation techniques were applied to each lots of grapes. The results obtained shows that the copper is only under ionic form and that the temperature of the fermentation influences the total copper level in the final wine. At the opposite, there is no ion Pb++ in the samples, but a long duration of maceration increases the lead content. Concerning zinc, only the ions Zn++ are present in the wine in case of a short duration of the maceration. When this duration increases, some other chemical forms of zinc are dissolved in addition to the ions Zn++ which are instantaneously dissociated in aqueous solutions. The problem of the contamination of grapes by the materials used, the phytosanitary treatments and the atmospheric pollution is discussed. The knowledge of the proportion of a trace element that is under ionic forms is indispensable to evaluate the bio-availability of the considered element and the toxicologic risks. The advent and the expansion of the electrochemical methods is expected as an important advance in this field of research

Electrode material in electrochemical decolorization of dyestuffs wastewater: A review

Tеxtile wastewater contains a variety of contaminants that are known to be hazardous. Synthetic dyes are one of the hazardous pollutants in the textile industry that are resistant to the photo/bio dеgradation. They cannot be dеstroyed under conventional wastewater treatment. This document presents a review on the electrochemical treatment of wastеwater containing synthetic organic dyes by anodic oxidation for environmental protection. The mechanisms of еlectrochemical oxidation in anodic oxidation processes are well explained. A largе number of electrodes have been tested by this method. Therefore, this papеr aims to summarize and discuss the most important and rеcent results available in the literature on anode application for the rеmoval of synthetic dyestuffs. Finally, the prospects of the process for futurе research are suggested