Matrix-assisted laser desorption ionization--time of flight mass spectrometry: an emerging tool for the rapid identification of mosquito vectors.

BACKGROUND: The identification of mosquito vectors is typically based on morphological characteristics using morphological keys of determination, which requires entomological expertise and training. The use of protein profiling by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), which is increasingly being used for the routine identification of bacteria, has recently emerged for arthropod identification. METHODS: To investigate the usefulness of MALDI-TOF-MS as a mosquito identification tool, we tested protein extracts made from mosquito legs to create a database of reference spectra. The database included a total of 129 laboratory-reared and field-caught mosquito specimens consisting of 20 species, including 4 Aedes spp., 9 Anopheles spp., 4 Culex spp., Lutzia tigripes, Orthopodomyia reunionensis and Mansonia uniformis. For the validation study, blind tests were performed with 76 specimens consisting of 1 to 4 individuals per species. A cluster analysis was carried out using the MALDI-Biotyper and some spectra from all mosquito species tested. RESULTS: Biomarker mass sets containing 22 and 43 masses have been detected from 100 specimens of the Anopheles, Aedes and Culex species. By carrying out 3 blind tests, we achieved the identification of mosquito vectors at the species level, including the differentiation of An. gambiae complex, which is possible using MALDI-TOF-MS with 1.8 as the cut-off identification score. A cluster analysis performed with all available mosquito species showed that MALDI-Biotyper can distinguish between specimens at the subspecies level, as demonstrated for An gambiae M and S, but this method cannot yet be considered a reliable tool for the phylogenetic study of mosquito species. CONCLUSIONS: We confirmed that even without any specific expertise, MALDI-TOF-MS profiling of mosquito leg protein extracts can be used for the rapid identification of mosquito vectors. Therefore, MALDI-TOF-MS is an alternative, efficient and inexpensive tool that can accurately identify mosquitoes collected in the field during entomological surveys

Cu-Zn metallic coatings elaboration : electrolytes formulation, structural characterization and brass corrosion behavior

Résumé : Les laitons sont les alliages de cuivre les plus produits car ils offrent une large gamme de propriétés qui dépendent essentiellement de leurs fractions massiques en zinc. Bien que les travaux relatifs à l’électrodéposition des revêtements du laiton soient très nombreux, ces alliages sont habituellement produits par la méthode de fusion qui se caractérise par une forte consommation d'énergie. L’électrodéposition avec des bains non-cyanurés présente un procédé alternatif mais l’industrialisation de ces procédés n’existe pas encore. Ainsi, la littérature est très pauvre concernant l’étude des propriétés physico-chimique et de la corrosion des électrodépots du laiton. Cette étude a permis d’accroître les connaissances des conditions de formulation d’un bain non cyanuré de codéposition CuZn fonctionnel selon le titre de l’élément d’alliage souhaité. Les résultats obtenus ont permis, d’une part, l’élaboration d’un panel de dépôts d’alliage CuZn avec une teneur de zinc qui varie entre 33% et 45% sous régime continu et pulsé, et d’une autre part, la caractérisation cristalline de ce panel (quantification des phases, orientation préférentielle, taille des cristallites…) par voie spectroscopique (l’affinement de Rietveld des diffractogrammes DRX) et également par déconvolution des courbes d’oxydation potentiodynamique couplées à des analyses complémentaires par DRX. La stabilité thermique des différentes phases a été également évaluée et quantifiée. Enfin l’investigation du comportement électrochimique et analytique des alliages CuZn α et αβ’, issus de la fonderie et de l’électrodéposition, dans une solution de 3% NaCl, a été accompli au niveau du mécanisme de corrosion et l’évolution des surfaces attaquées.Abstract : Brass is a copper and zinc alloy that plays an important role in a large range of industrial applications. According to the zinc ratio, this alloy exhibits several valuable properties such as hardness, excellent deformability, adhesion of rubber to steel, good mechanical and corrosion resistance, as well as serving several decorative purposes. On a commercial scale, brass coating is ordinary produced by successive depositions of zinc and copper, followed by a thermal diffusion step, despite its high energy consumption. Thus, the literature is rare when it concerns the physicochemical properties and the corrosion of electrodeposits of brass. The present work consists of an extensive study of the formulation conditions of a functional non-cyanide CuZn bath with a control of alloy composition. Electrochemical and spectroscopic studies have been conducted to understand the main parameters that controls CuZn codeposition. Then, two panels of CuZn alloy deposits with a zinc content varies between 33% and 45% were elaborated under continuous and pulsed current. Afterwards, the crystalline structure of the two panels were characterized (quantification of phases, preferential orientation, size of crystals…) by spectroscopy (Rietveld refinement of XRD diffractograms) and by oxidation curves deconvolution coupled with XRD. Different phases thermal stability was also evaluated and quantified. Finally, the investigation of the electrochemical and analytical behavior of CuZn α and CuZn αβ 'alloys, produced by the foundry and electrodeposition, in 3 % NaCl solution has been accomplished, the focus was made on the corrosion mechanism and the evolution of the attacked surfaces

Élaboration des revêtements métalliques Cu-Zn : formulation d’électrolytes, caractérisation structurale et comportement à la corrosion du laiton

Abstract : Brass is a copper and zinc alloy that plays an important role in a large range of industrial applications. According to the zinc ratio, this alloy exhibits several valuable properties such as hardness, excellent deformability, adhesion of rubber to steel, good mechanical and corrosion resistance, as well as serving several decorative purposes. On a commercial scale, brass coating is ordinary produced by successive depositions of zinc and copper, followed by a thermal diffusion step, despite its high energy consumption. Thus, the literature is rare when it concerns the physicochemical properties and the corrosion of electrodeposits of brass. The present work consists of an extensive study of the formulation conditions of a functional non-cyanide CuZn bath with a control of alloy composition. Electrochemical and spectroscopic studies have been conducted to understand the main parameters that controls CuZn codeposition. Then, two panels of CuZn alloy deposits with a zinc content varies between 33% and 45% were elaborated under continuous and pulsed current. Afterwards, the crystalline structure of the two panels were characterized (quantification of phases, preferential orientation, size of crystals…) by spectroscopy (Rietveld refinement of XRD diffractograms) and by oxidation curves deconvolution coupled with XRD. Different phases thermal stability was also evaluated and quantified. Finally, the investigation of the electrochemical and analytical behavior of CuZn α and CuZn αβ 'alloys, produced by the foundry and electrodeposition, in 3 % NaCl solution has been accomplished, the focus was made on the corrosion mechanism and the evolution of the attacked surfaces.Résumé : Les laitons sont les alliages de cuivre les plus produits car ils offrent une large gamme de propriétés qui dépendent essentiellement de leurs fractions massiques en zinc. Bien que les travaux relatifs à l’électrodéposition des revêtements du laiton soient très nombreux, ces alliages sont habituellement produits par la méthode de fusion qui se caractérise par une forte consommation d'énergie. L’électrodéposition avec des bains non-cyanurés présente un procédé alternatif mais l’industrialisation de ces procédés n’existe pas encore. Ainsi, la littérature est très pauvre concernant l’étude des propriétés physico-chimique et de la corrosion des électrodépots du laiton. Cette étude a permis d’accroître les connaissances des conditions de formulation d’un bain non cyanuré de codéposition CuZn fonctionnel selon le titre de l’élément d’alliage souhaité. Les résultats obtenus ont permis, d’une part, l’élaboration d’un panel de dépôts d’alliage CuZn avec une teneur de zinc qui varie entre 33% et 45% sous régime continu et pulsé, et d’une autre part, la caractérisation cristalline de ce panel (quantification des phases, orientation préférentielle, taille des cristallites…) par voie spectroscopique (l’affinement de Rietveld des diffractogrammes DRX) et également par déconvolution des courbes d’oxydation potentiodynamique couplées à des analyses complémentaires par DRX. La stabilité thermique des différentes phases a été également évaluée et quantifiée. Enfin l’investigation du comportement électrochimique et analytique des alliages CuZn α et αβ’, issus de la fonderie et de l’électrodéposition, dans une solution de 3% NaCl, a été accompli au niveau du mécanisme de corrosion et l’évolution des surfaces attaquées

Characteristics of the bitter and sweet honey from Algeria Mediterranean coast

Aim: This study aimed to compare the physicochemical, the biochemical, and the antioxidant characteristics of unifloral bitter honey and polyfloral sweet honey. Materials and Methods: Unifloral bitter and polyfloral sweet honey samples were, respectively, harvested in January and July, and then, they were extracted by the traditional method. The markers of refractive index, pH, free acidity, Brix index, density, reducing sugars, total polyphenols, flavonoids, tannins, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing/ antioxidant power (FRAP) were evaluated. Results: The obtained results showed that the physicochemical parameters are within the normal ranges, in which they meet the international standards (Codex Alimentarius). For biochemical constituents, matching concentrations of reducing sugars (glucose+fructose) were observed in both samples, while that of sucrose were very low in unifloral than polyfloral honey. The levels of the active ingredients showed a difference in total polyphenols and tannins of the two types of honey studied, whereas that of flavonoids were almost similar. The antioxidant activity of various samples evaluated by DPPH and FRAP indicated that unifloral has a superior activity. Conclusion: Compared to polyfloral honey, unifloral bitter honey has lower sucrose, high total polyphenols, and tannins levels, in addition to higher antioxidant potential

CuZn Electrodeposition in Cyanide-Free Electrolytes: Influence of Citrate/Metal ratio and pH on Simultaneous Copper and Zinc Reduction Kinetics and Alloy Composition Control

International audienc

Analytical Study of CuZn 30 and CuZn 39 Brass Surfaces in 3% NaCl Solution Under Polarization

International audienceThe main objective of the investigation is to identify the role of beta phase on the corrosion behavior of CuZn alloys in chloride solution. The experimental study was based on the characterization and identification of the anodized brass films formed on the surface of two alloys: CuZn30 and CuZn39, abbreviated by CuZnα and CuZnαβ. Oxidation was carried out at different potentials chosen from the anodic polarization curves recorded beforehand with the two alloys. The main analysis techniques are AFM, SEM, EDS and XRD. Results indicate that the corrosion mechanism is similar for both alpha and alpha beta brasses and followed the same succession of steps. Nevertheless, the rate of dezincification is higher in the case of CuZnαβ: the surface of the attack is larger, and different plugs could be created at the same potential. Therefore, the composition of the protective layer is more diverse than that of CuZnα, while much more varied oxide and hydroxide species are likely to be formed

Engineering of Bio-Adhesive Ligand Containing Recombinant RGD and PHSRN Fibronectin Cell-Binding Domains in Fusion with a Colored Multi Affinity Tag: Simple Approach for Fragment Study from Expression to Adsorption

Engineering of biomimetic motives have emerged as promising approaches to improving cells’ binding properties of biomaterials for tissue engineering and regenerative medicine. In this study, a bio-adhesive ligand including cell-binding domains of human fibronectin (FN) was engineered using recombinant protein technology, a major extracellular matrix (ECM) protein that interacts with a variety of integrins cell-surface’s receptors and other ECM proteins through specific binding domains. 9th and 10th fibronectin type III repeat containing Arginine-Glycine-Aspartic acid (RGD) and Pro-His-Ser-Arg-Asn (PHSRN) synergic site (FNIII9-10) were expressed in fusion with a Colored Multi Affinity Tag (CMAT) to develop a simplified production and characterization process. A recombinant fragment was produced in the bacterial system using E. coli with high yield purified protein by double affinity chromatography. Bio-adhesive surfaces were developed by passive coating of produced fragment onto non adhesive surfaces model. The recombinant fusion protein (CMAT-FNIII9/10) demonstrated an accurate monitoring capability during expression purification and adsorption assay. Finally, biological activity of recombinant FNIII9/10 was validated by cellular adhesion assay. Binding to α5β1 integrins were successfully validated using a produced fragment as a ligand. These results are robust supports to the rational development of bioactivation strategies for biomedical and biotechnological applications

Granulosa Cell Tumor of the Ovary: A Retrospective Study of 31 Cases and a Review of the Literature

Background. Adult granulosa cell tumors (AGCTs) are the most common sex cord-stromal tumors. Unlike epithelial ovarian tumors, they occur in young women and are usually detected at an early stage. The aim of this study was to report the clinical and pathological characteristics of AGCT patients and to identify the prognostic factors. Methods. All cases of AGCTs, treated at Salah Azaïz Institute between 1995 and 2010, were retrospectively included. Kaplan-Meier’s statistical method was used to assess the relapse-free survival and the overall survival. Results. The final cohort included 31 patients with AGCT. The mean age was 53 years (35–73 years). Patients mainly presented with abdominal mass and/or pain (61%, n=19). Mean tumor size was 20 cm. The majority of patients had a stage I disease (61%,  n=19). Two among 3 patients with stage IV disease had liver metastasis. Mitotic index was low in 45% of cases (n=14). Surgical treatment was optimal in almost all cases (90%, n=28). The median follow-up time was 14 years (1–184 months). Ten patients relapsed (32%) with a median RFS of 8.4 years (6.8–9.9 years). Mean overall survival was 13 years (11–15 years). Stage I disease and low-to-intermediate mitotic index were associated with a better prognosis in univariate analysis (resp., p=0.05 and p=0.02) but were not independent prognostic factors. Conclusion. GCTs have a long natural history with common late relapses. Hence, long active follow-up is recommended. In Tunisian patients, hepatic metastases were more frequent than occidental series. The prognosis remains good and initial staging at diagnosis is an important prognostic factor

Comet assay with gill cells of Mytilus galloprovincialis end point tools for biomonitoring of water antibiotic contamination

International audienc