Adherence measurements and corrosion resistance in primer/hot-dip galvanized steel systems

This paper focuses on the adherence during ageing of a primer (made of polyester resins crosslinked with melamine) applied onto hot-dip galvanized (HDG) steel for coil coating application and its influence on corrosion protection. A chromium-free surface treatment, composed of fluorotitanic acid, phosphoric acid, manganese phosphate, and vinylphenol was applied on the HDG steel to obtain high corrosion resistance and high adherence of a polyester and melamine primer. The influence of the manganese phosphate on the corrosion and adherence was investigated. To measure the adherence between the metal and the primer, a three-point flexure test was set up. The adherence was then linked with corrosion resistance during ageing, using electrochemical impedance spectroscopy

Species diversity of Trichoderma in Poland

In the present study, we reinvestigate the diversity of Trichoderma in Poland utilizing a combination of morphological and molecular/phylogenetic methods. A total of 170 isolates were collected from six different substrata at 49 sites in Poland. These were divided among 14 taxa as follows: 110 of 170 Trichoderma isolates were identified to the species level by the analysis of their ITS1, ITS2 rDNA sequences as: T. harzianum (43 isolates), T. aggressivum (35), T. citrinoviride (11), T. hamatum (9), T. virens (6), T. longibrachiatum (4), T. polysporum (1), and T. tomentosum (1); 60 isolates belonging to the Viride clade were identified based on a fragment of the translation-elongation factor 1-alpha (tef1) gene as: T. atroviride (20 isolates), T. gamsii (2), T. koningii (17), T. viridescens (13), T. viride (7), and T. koningiopsis (1). Identifications were made using the BLAST interface in TrichOKEY and TrichoBLAST (http://www.isth.info). The most diverse substrata were soil (nine species per 22 isolates) and decaying wood (nine species per 75 isolates). The most abundant species (25%) isolated from all substrata was T. harzianum

Human gut Bacteroidetes can utilize yeast mannan through a selfish mechanism

Yeasts, which have been a component of the human diet for at least 7,000 years, possess an elaborate cell wall α-mannan. The influence of yeast mannan on the ecology of the human microbiota is unknown. Here we show that yeast α-mannan is a viable food source for the Gram-negative bacterium Bacteroides thetaiotaomicron, a dominant member of the microbiota. Detailed biochemical analysis and targeted gene disruption studies support a model whereby limited cleavage of α-mannan on the surface generates large oligosaccharides that are subsequently depolymerized to mannose by the action of periplasmic enzymes. Co-culturing studies showed that metabolism of yeast mannan by B. thetaiotaomicron presents a ‘selfish’ model for the catabolism of this difficult to breakdown polysaccharide. Genomic comparison with B. thetaiotaomicron in conjunction with cell culture studies show that a cohort of highly successful members of the microbiota has evolved to consume sterically-restricted yeast glycans, an adaptation that may reflect the incorporation of eukaryotic microorganisms into the human diet

Biochimie du liquide hydatique

Onze métabolites ont été dosés dans le liquide hydatique de 19 kystes humains ainsi que dans le plasma des patients avant l’intervention chirurgicale. Le dosage des anticorps spécifiques, associés à chacun de ces kystes de localisation et de taille variables, a été assuré par immunofluorescence indirecte sur coupe en congélation de protoscolex. Les résultats montrent que le sodium (132 ± 5,2 mmol/1), le chlore (92,9 ± 6,5 mmol/1) et les bicarbonates (22,1 ± 1,5 mmol/1) représentent les 3 ions principaux et qu’ils sont en équiconcentration avec le plasma. Le potassium (5,4 ± 0,3 mmol/1) et le calcium (4,7 ± 0,9 mmol/1) sont plus concentrés qu’au niveau plasmatique. Le phosphore (0,1 ± 0,03 mmol/1) l’est 10 fois moins. Le glucose (3,4 ± 0,8 mmol/1), la créatinine (39,3 ± 7,2 µmol/l) et l’urée (4,6 ± 0,8 mmol/1) subissent des variations importantes. Le cholestérol (0,06 ± 0,03 mmol/1) est environ 100 fois moins concentré qu’au niveau plasmatique. Les protéines totales (0,34 ± 0,09 g/l) sont en très faible quantité. Les kystes extra-pulmonaires sont associés aux réponses immunes les plus fortes, et aucune corrélation n’est observée entre la taille des kystes et l’intensité des réponses immunes associées.Une différence significative des concentrations relatives en cholestérol (concentration kystique / concentration plasmatique) est observée entre les kystes pulmonaires et extra-pulmonaires (respectivement 0,0048 ± 0,0032 et 0,018 ± 0,01 — p < 0.05). Ces derniers sont environ 4 fois plus riches en cholestérol. La taille des kystes et l’intensité des réponses immunes associées n’ont pas d’influence sur ce phénomène. L’hypothèse d’une perméabilité plus importante des kystes extra-pulmonaires est avancée

Results Obtained with Various Antifungal Susceptibility Testing Methods Do Not Predict Early Clinical Outcome in Patients with Cryptococcosis

The in vitro susceptibilities of Cryptococcus neoformans isolates from consecutive human immunodeficiency virus-positive and -negative patients to the antifungal agents fluconazole, amphotericin B, and flucytosine were determined by different techniques, including the CLSI method, Etest, and broth microdilution in yeast nitrogen base (YNB) medium, during a multicenter prospective study in France. The relationship between the in vitro data and the clinical outcome 2 weeks after the initiation of antifungal therapy was assessed. In addition, the correlation between the strain serotype and the in vitro activities of the antifungals was determined, and the susceptibility results obtained with the different techniques were also compared. Thirty-seven patients received a combination of amphotericin B with flucytosine as first-line therapy, 22 were treated with amphotericin B alone, and 15 received fluconazole alone. Whatever the antifungal tested, there was no trend toward higher MICs for strains isolated from patients who failed to respond to a given therapy compared to those from patients who did not with either the CLSI method, Etest, or broth microdilution in YNB medium. The MICs obtained by the CLSI or Etest method were significantly lower for serotype D strains than for serotype A strains for both fluconazole and amphotericin B, while flucytosine MICs were not different according to serotype. These findings suggest that the in vitro antifungal susceptibility of C. neoformans, as determined with the techniques used, is not able to predict the early clinical outcome in patients with cryptococcosis