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A quaternized polyvinylpyridine (Q‐PVP) polymer methanolic solution synthesized in a single step is used to covalently graft titanium surfaces. Q‐PVP is quaternized with varying N+/N ratios. 1 cm2 pure titanium plates are polished and activated. Treated samples are grafted by spin coating or dip‐coating (grafting‐to method). Surfaces are characterized by X‐ray photoelectron spectroscopy, polarization modulation reflection absorption IR spectroscopy, atomic force microscopy, scanning electron microscopy, and surface charge density calculation. Polymer leaching is assessed at 7 days. Biocompatibility is assessed on MC3T3 and L929 cells (MTT‐assay) and SEM. In vitro antibacterial activity is assessed on methicillin‐resistant Staphylococcus aureus (MRSA) at 1 and 24 h (37 °C in brain heart infusion) and at 7 days in a biofilm model. Polymers exceeding 31.3 ± 0.7% quaternization led to bactericidal surfaces. Bactericidal activity increased with surface cationic density. Surface cationic density and biocompatibility are inversely correlated. Polymers with 44.6 ± 1.2% quaternization are antibacterial and biocompatible. High‐density Q‐PVP inhibited MRSA biofilm formation. Q‐PVP is a promising candidate for antibacterial surface modification. Further in vivo studies are required. [ABSTRACT FROM AUTHOR]

The development of solid-state chemistry at the end of the 19th century offered a variety of routes to colour a glass matrix. Eight enamelled glass objects made by Philippe-Joseph Brocard and two representative objects made by Emile Gallé have been analysed using a mobile Raman instrument at the Musée des arts décoratifs (Paris) in order to compare their colouration technology. White, blue, yellow, green, orange, red, brown and black pigments have been identified. If most of the pigment palette is common to both craftsmen and typical of the second half of the 19th century, innovative uses are recognized for Gallé (wollastonite as an opacifier, manganese oxides in black mixtures) and Brocard (specific black and grey, pigment mixture, shade modification by small addition of white and red pigments). This preliminary work confirms the potential of Raman spectroscopy, not as a simple analytical method but as a way to document the ancient technology of fine art objects and to discriminate between different genuine productions and/or copies. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Raw sophorolipids, a variety of bioderived glycolipid biosurfactants produced by the yeast Candida bombicola, generally present themselves as a mixture of acetylated acidic and lactonic forms mixed with residual fatty acids. To recover the acidic form alone in large amounts, e.g., tens of grams, which is interesting for various applications in cleaning technologies, material science, medicine, one must either purify the mixture through column chromatography, thus tremendously reducing the final yield, or remove the fatty acids via hot hexane extraction followed by alkaline hydrolysis and a liquid-liquid extraction process; in the latter, pentanol, used as extraction medium, is a high boiling point solvent and, consequently, difficult to remove under standard vacuum extraction conditions. Here, we compare, quantify, and draw the positive and negative aspects of the typical hexane/pentanol extraction route compared to two additional ones, never reported for this system: a cold extraction from a pentanol/alkane mixture and a consecutive filtration on inverse C18-modified silica phase and silica gel in, respectively, water/acetonitrile and methanol/dichloromethane mixtures. The first one generates highly pure products but quantitative extraction is quite long (up to several days) while the second is an extremely handy and rapid (few hours) way but less quantitative as it provides a product with not less than 6% impurities. [ABSTRACT FROM AUTHOR]

The zoonotic pathogen Brucella abortus is part of the Rhizobiales, which are alpha‐proteobacteria displaying unipolar growth. Here, we show that this bacterium exhibits heterogeneity in its outer membrane composition, with clusters of rough lipopolysaccharide co‐localizing with the essential outer membrane porin Omp2b, which is proposed to allow facilitated diffusion of solutes through the porin. We also show that the major outer membrane protein Omp25 and peptidoglycan are incorporated at the new pole and the division site, the expected growth sites. Interestingly, lipopolysaccharide is also inserted at the same growth sites. The absence of long‐range diffusion of main components of the outer membrane could explain the apparent immobility of the Omp2b clusters, as well as unipolar and mid‐cell localizations of newly incorporated outer membrane proteins and lipopolysaccharide. Unipolar growth and limited mobility of surface structures also suggest that new surface variants could arise in a few generations without the need of diluting pre‐existing surface antigens. Synopsis: The outer membrane of Gram‐negative bacteria is an asymmetric bilayer. Single cell analysis reveals that cell envelope proteins and saccharides of Brucella abortus are targeted to active membrane growth sites and exhibit low mobility increasing surface antigen variability. The outer membrane composition of B. abortus is heterogeneous.The essential outer membrane porin Omp2b co‐localizes with LPS.Omp25 and peptidoglycan are selectively incorporated at the new growth pole and the division site.The cell envelope layers LPS, peptidoglycan and outer membrane proteins display limited mobility. Cell envelope proteins and saccharides of Brucella abortus are targeted to active membrane growth sites and exhibit low mobility increasing surface antigen variability. [ABSTRACT FROM AUTHOR]