Hemifluorinated and fluorinated surfactants are lipophobic and, as such, non-detergent. Although they do not solubilize biological membranes, they can, after conventional solubilization, substitute for detergents to keep membrane proteins soluble, which generally improves their stability [Breyton, Chabaud, Chaudier, Pucci and Popot (2004) FEBS Lett. 564, 312-318]. In the present study, we show ...

The cycloaddition reaction of acylketenes with vinyl ethers affords an extremely direct route to 2,6-dideoxysugars and their methyl ethers. The lithium enolate of commercial 2,6,6-trimethyldioxinone 3 was fluorinated in good yield to afford fluorinated dioxinone 8. An illustrative range of fluorinated 2,6-dideoxysugar derivatives was prepared via the acetyl ketene-vinyl ether cycloadduct. Elect...

BACKGROUND AND AIMS This experimental study mainly aims at comparing the most important mechanical properties of the new orthodontic archwires, those immersed in fluorinated solution, the as-retrieved ones and the intra-oral used ones. METHODS A total of 270 arch wires were tested, using tensile testing and three-point bending tests. The tested archwires were made of Stainless Steel, Nickel T...

Perfluorinated surfactants are demonstrated to dramatically enhance desorption/ionization on fluorinated silicon (DIOS) mass spectrometry. Perfluorooctanesulfonic acid improved the signal-to-noise ratio of tryptic digests and gave a 3-fold increase in the number of peptides identified. Similar results were also obtained using perfluoroundecanoic acid; yet among the seven different surfactants t...

Because of small surface area to volume ratios nanoscale devices can exhibit dominant surface forces that can quickly degrade unlubricated contacting surfaces. While fluorinated materials have been widely used as lubricants, because of their low critical surface tension and high thermal and mechanical stability, fluorinated monolayer coatings, which are suitable for lubricating nanoscale device...

Methods for selective oxidation of aliphatic C-H bonds are called on to revolutionize organic synthesis by providing novel and more efficient paths. Realization of this goal requires the discovery of mechanisms that can alter in a predictable manner the innate reactivity of these bonds. Ideally, these mechanisms need to make oxidation of aliphatic C-H bonds, which are recognized as relatively i...

Oxygen is known to partition with an increasing concentration gradient toward the hydrophobic membrane interior. At partial pressures (P(O2)) of 100 Atm or more, this concentration gradient is sufficient to induce paramagnetic effects that depend sensitively on membrane immersion depth. This effect is demonstrated for the fluorine nucleus by depth-dependent paramagnetic shifts and spin-lattice ...

An analytical method was elaborated for simultaneous extraction and determination of fluorinated anionic and non-ionic surfactants in sewage sludge. Surfactant compounds were determined by liquid chromatography-mass spectrometry (LC-MS) after Soxhlet extraction, hot steam extraction and pressurised liquid extraction (PLE) using spiked sludge samples. PLE in a multiple-step procedure consisting ...

Little is known of the potential for biodegradation of fluorinated sulfonates. To evaluate this potential, the following model compounds were selected: difluoromethane sulfonate (DFMS), trifluoromethane sulfonate (TFMS), 2,2,2trifluoroethane sulfonate (TES), perfluorooctane sulfonate (PFOS), and 1H,1H,2H,2H-perfluorooctane sulfonate (H-PFOS). A laboratory isolate designated Pseudomonas sp. stra...