Spondylodiscitis and an aortic aneurysm due to Campylobacter coli

Campylobacter coli is a rare cause of bacteremia. We report here the first case of C.coli spondylodiscitis complicated by an aortic aneurysm. Outcome was favourable with surgery and antibiotic therapy

Photoluminescent lamellar bilayer mono-alkyl-urethanesils

A new family of lamellar bilayer hierarchically structured mono-urethane cross-linked alkyl/siloxanes designated as mono-alkyl-urethanesils and represented by the notation m-Ut(CY)-ac, with Y = 14, 16 and 22 (where Y is the number of carbon atoms of the pendant polymer chains and ac is acid catalyzed) was prepared by the sol-gel process and self-assembly routes. The compounds were obtained as solid powders and are thermally stable up to 250 A degrees C. The alkyl chains adopt essentially all-trans conformations and are interdigitated. The degree of interpenetration depends non-linearly on the chain length. The intrincate morphology of the samples mimicks cabbage leaves or the desert rose. The present system allowed us to conclude that the nature of the cross-link exerts a key role on the properties of this sort of silsesquioxanes. The hydrogen bonded array in the mono-alkyl-urethanesils is considerably weaker than that formed in the analogue mono-amidosil m-A(14) incorporating alkyl chains with 15 carbon atoms. The order/disorder phase transition temperatures of the mono-alkyl-urethanesils with Y = 14 and 16 are lower than that of m-A(14), making the former samples mechanically more resistant to consecutive heating/cooling cycles. The frequency of conformational-sensitive infrared modes of m-Ut(C16)-ac exhibit hysteresis behaviour during cooling after undergoing the order/disorder phase transition, but, unlike m-A(14), the latter transition, although reversible, is apparently time-independent. The hybrids display an efficient emission at room temperature in the blue-green spectral region with a maximum emission quantum yield value of 0.11 +/- A 0.01 (excited at 350-380 nm), which is of the same order of magnitude of that reported for m-A(14)

Luminescent coatings based on ethane tetracarboxamide containing Eu3+ and tta ligand: Application for Luminescent Solar Concentrators

International audienceDuring the past years, considerable interest has been focused on materials that exhibit potential applications as luminescent solar concentrators (LSCs). Indeed, the incorporation of trivalent lanthanide ion (Ln3+) complexes in organic-inorganic coatings enables the down-shifting of the UV radiationinto light that can be efficiently trapped inside the substrate and guided to the edges by total internal reflection where it can be efficiently collected by a solar cell [2]. In this communication, we will present two new precursors based on ethane tetracarboxamide and ethane dicarboxamide fragments P4 (Figure 1 (a)) and P2 (Figure 1 (b)), and their conversion into luminescent hybrid materials by the sol-gel process in the presence of Eu3+ salts (EuCl36H2O) and ligand 2-thienoyltrifluoracetone (tta) (Eu3+/tta molar ratio of 1:2). The organic-inorganic hybrid materials (P4(Eu3+/tta) and P2(Eu3+/tta)) were processed as free standing films by solvent casting. They display maximum emission quantum yield () values of 0.22 and 0.48, respectively, under excitation at 320 nm. In addition, P4(Eu3+/tta) was processed by spin-coating on glass substrates, yielding films (P4-F(Eu3+/tta) with controlled thickness of 75 nm. Under UV irradiation the films display a bright red emission ascribed to the intra-4f6 Eu3+ transitions, as illustrated in Figure 1(c) and a remarkable value of 0.60 under excitation at 345 nm

Luminescent coatings based on ethane tetracarboxamide containing Eu3+ and tta ligand: Application for Luminescent Solar Concentrators

International audienceDuring the past years, considerable interest has been focused on materials that exhibit potential applications as luminescent solar concentrators (LSCs). Indeed, the incorporation of trivalent lanthanide ion (Ln3+) complexes in organic-inorganic coatings enables the down-shifting of the UV radiationinto light that can be efficiently trapped inside the substrate and guided to the edges by total internal reflection where it can be efficiently collected by a solar cell [2]. In this communication, we will present two new precursors based on ethane tetracarboxamide and ethane dicarboxamide fragments P4 (Figure 1 (a)) and P2 (Figure 1 (b)), and their conversion into luminescent hybrid materials by the sol-gel process in the presence of Eu3+ salts (EuCl36H2O) and ligand 2-thienoyltrifluoracetone (tta) (Eu3+/tta molar ratio of 1:2). The organic-inorganic hybrid materials (P4(Eu3+/tta) and P2(Eu3+/tta)) were processed as free standing films by solvent casting. They display maximum emission quantum yield () values of 0.22 and 0.48, respectively, under excitation at 320 nm. In addition, P4(Eu3+/tta) was processed by spin-coating on glass substrates, yielding films (P4-F(Eu3+/tta) with controlled thickness of 75 nm. Under UV irradiation the films display a bright red emission ascribed to the intra-4f6 Eu3+ transitions, as illustrated in Figure 1(c) and a remarkable value of 0.60 under excitation at 345 nm

Luminescent coatings from bipyridine-based bridged silsesquioxanes containing Eu³⁺and Tb³⁺ salts

The sol-gel fabrication of bridged silsesquioxane thin films containing trivalent lanthanide ions (Ln³⁺) has been achieved from a 4,4'-diureido-2,2'-bipyridine bridged organosilane (P4) in the presence of Eu³⁺or Tb³⁺salts. Crack- and defect-free thin films (~50 nm) of optical quality were successfully deposited on glass substrates by spin-coating after optimizing the spinning rate and solvent system. Ellipsometry investigations revealed a significant decrease in the refractive index of the films with ageing of the corresponding precursor sols. In contrast, the photoluminescence properties of the films are independent of precursor ageing time, although significant differences are observed with respect to the corresponding bulk materials. Compared to the bulk materials, the films exhibit a significant blue-shift of the excitation spectra and an increase of the excited state lifetime. The optical conversion efficiencies (ɲopt) of the F4-Eu and F4-Tb-based collectors were also determined and potential applications of the coatings in such areas as luminescent solar concentrators are discussed