A rhenium tris-carbonyl derivative as a single core multimodal probe for imaging (SCoMPI) combining infrared and luminescent properties

A rhenium tris-carbonyl derivative has been designed to couple infrared and luminescent detection in cells. Both spectroscopies are consistent with one another; they point out the reliability of the present SCoMPI (for Single Core Multimodal Probe for Imaging) for bimodal imaging and unambiguously indicate a localization at the Golgi apparatus in MDA-MB-231 breast cancer cells.     

Time-resolved ultraviolet laser-induced breakdown spectroscopy for organic material analysis

Ultraviolet pulses (266 nm) delivered by a quadrupled Nd:YAG laser were used to analyze organic samples with laser-induced breakdown spectroscopy (LIBS). We present characteristics of the spectra obtained from organic samples with special attentions on the emissions of organic elements, O and N, and molecular bonds CN. The choice of these atomic or molecular species is justified on one hand, by the importance of these species to specify organic or biological materials; and on the other hand by the possible interferences with ambient air when laser ablation takes place in the atmosphere. Time-resolved LIBS was used to determine the time-evolution of line intensity emitted from these species. We demonstrate different kinetic behaviors corresponding to different origins of emitters: native atomic or molecular species directly vaporized from the sample or those generated through dissociation or recombination due to interaction between laser-induced plasma and air molecules. Our results show the ability of time-resolved UV-LIBS for detection and identification of native atomic or molecular species from an organic sample.     

Highly enantioselective and regioselective copper-catalyzed 1,4 addition of grignard reagents to cyclic enynones

In this letter we describe an unusual result in terms of regioselectivity with respect to copper-catalyzed conjugate additions of various Grignard reagents to cyclic enynones. The use of Cu(OTf)(2) and NHC ligand L1 as the catalyst combination in CH(2)Cl(2) led to the unique formation of the 1,4 adduct. This selectivity does not follow the general trend previously observed in the literature using extended Michael acceptors. Moreover these reactions allowed for the creation of a quarternary stereogenic center with enantioselectivities up to 97% ee.     

Supersymmetry and its spontaneous breaking in the random field Ising model

We provide a resolution of one of the long-standing puzzles in the theory of disordered systems. By reformulating the functional renormalization group for the critical behavior of the random field Ising model in a superfield formalism, we are able to follow the associated supersymmetry and its spontaneous breaking along the functional renormalization group flow. Breaking is shown to occur below a critical dimension d(DR) ? 5.1 and leads to a breakdown of the "dimensional reduction" property. We compute the critical exponents as a function of dimension and give evidence that scaling is described by three independent exponents.     

Regularity Issues in the Problem of Fluid Structure Interaction

We investigate the evolution of rigid bodies in a viscous incompressible fluid. The flow is governed by the 2D Navier–Stokes equations, set in a bounded domain with Dirichlet boundary conditions. The boundaries of the solids and the domain have Hölder regularity C ^1,α , 0 < α ≦ 1. First, we show the existence and uniqueness of strong solutions up to the collision. A key ingredient is a BMO bound on the velocity gradient, which substitutes to the standard H ² estimate for smoother domains. Then, we study the asymptotic behaviour of one C ^1,α body falling over a flat surface. We show that a collision is possible in finite time if and only if α < 1/2.     

(−)‐Englerin A is a Potent and Selective Activator of TRPC4 and TRPC5 Calcium Channels

Current therapies for common types of cancer such as renal cell cancer are often ineffective and unspecific, and novel pharmacological targets and approaches are in high demand. Here we show the unexpected possibility for the rapid and selective killing of renal cancer cells through activation of calcium‐permeable nonselective transient receptor potential canonical (TRPC) calcium channels by the sesquiterpene (?)‐englerin A. This compound was found to be a highly efficient, fast‐acting, potent, selective, and direct stimulator of TRPC4 and TRPC5 channels. TRPC4/5 activation through a high‐affinity extracellular (?)‐englerin A binding site may open up novel opportunities for drug discovery aimed at renal cancer.     

Trapping Nanostructures on Surfaces through Weak Interactions

The assembly of imidazole‐functionalized phenanthroline‐strapped zinc porphyrins (ZnPorphen) with alkyl or polyethylene glycol (PEG) side chains was studied in solution and by AFM after casting on highly oriented pyrolytic graphite (HOPG) or mica. The nature of the solvent and its evaporation time influenced the morphology of the objects observed. On HOPG, short rods of about 100 nm were observed after fast evaporation of solutions of the alkyl derivatives in CHCl₃, THF, or pyridine, whereas islands of aligned rows of longer wires were obtained from methylcyclohexane (MCH). Slow evaporation of MCH led to a three‐dimensional assembly. The PEG porphyrin assembled into short wires on HOPG or fibers on mica after slow evaporation of solutions in THF. This study shows the role of surface–molecule interactions in the interfacial assembly of ZnPorphen derivatives and contributes to understanding the parameters that control their noncovalent assembly into molecular wires on a surface.     

Enhanced UV photosensing properties of ZnO nanowires prepared by electrodeposition and atomic layer deposition

A new process enabling the synthesis of zinc oxide (ZnO) and Al-doped ZnO nanowires (NWs) for photosensing applications is reported. By combining atomic layer deposition (ALD) for the seed layer preparation and electrodeposition for the NW growth, high-quality ZnO nanomaterials were prepared and tested as ultraviolet (UV) sensors. The obtained NWs are grown as arrays perpendicular to the substrate surface and present diameters between 70 and 130 nm depending on the Al doping, as seen from scanning electron microscopy (SEM) studies. Their hexagonal microstructure has been determined using X-ray diffraction and Raman spectroscopy. An excellent performance in UV sensing has been observed for the ZnO NWs with low Al doping, and a maximal photoresponse current of 11.1 mA has been measured. In addition, initial studies on the stability have shown that the NW photoresponse currents are stable, even after ten UV on/off cycles.