Simple method to identify the spatial location better than the pulse length with high strain accuracy

The second-order partial derivative of the Stokes signal with respect to frequency and position shows a maximum or minimum at the boundary between two different strained sections. This idea is used to locate the boundary of different stress regions. Knowing the boundaries, we then fit the Brillouin spectrum at the middle between them to get the strain value. This allows a location accuracy of between 5 and 10 cm, which is shorter than the pulse length of 20 cm used in the experiment. The lowest detectable Brillouin frequency difference between two strain sections is 1.2 MHz.     

Sur les puissances de l’idéal fondamental de l’anneau de Witt

We reformulate a recent result of Arason and Elman by giving a very simple presentation of the powers of the fundamental ideal of the Witt ring of a field of characteristic 2.

---

Sur les puissances de lidéal fondamental de lanneau de Witt

Nous reformulons un résultat récent de Arason et Elman en donnant une présentation très simple des puissances de lidéal fondamental de lanneau de Witt dun corps de caractéristique 2.

     

Power-law spatial correlations in arrays of locally coupled lasers

We investigate correlations of the intensity fluctuations of two-dimensional arrays of nonidentical, locally coupled lasers, numerically and experimentally. We find evidence of a power-law dependence of spatial correlations as a function of laser pair distance (or coupling strength) near the phase-locking threshold.     

Easy and effective method to produce functionalized particles for cellular uptake

In this contribution, a versatile approach for the synthesis of functionalized particles for drug delivery is presented, using two nonaggressive standardized procedures. The first procedure considered is the functionalization of an azido‐terminated α‐norbornenyl poly(ethylene oxide) (PEO) macromonomer with an alkyne‐containing active molecule via the copper catalyzed azide alkyne cycloaddition, click type reaction. The functionalized macromonomer is then polymerized by Ring‐Opening Metathesis Polymerization (ROMP) in dispersion to form functionalized particles. The second procedure consists in synthesizing particles by ROMP in dispersed media of norbornene with azido‐terminated α‐norbornenyl PEO macromonomer. The ROMP was initiated by the first generation Grubbs catalyst. Such functionalized core‐shell particles have stealthy properties due to their PEO shell and can be viewed as universal nanocarriers on which any alkyne‐modified active molecule can be grafted by click chemistry. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Computation of the invariant measure for a Lévy driven SDE: Rate of convergence

We study the rate of convergence of some recursive procedures based on some “exact” or “approximate” Euler schemes which converge to the invariant measure of an ergodic SDE driven by a Lévy process. The main interest of this work is to compare the rates induced by “exact” and “approximate” Euler schemes. In our main result, we show that replacing the small jumps by a Brownian component in the approximate case preserves the rate induced by the exact Euler scheme for a large class of Lévy processes.     

Measurement of Total and Unbound Mycophenolic Acid and Its Glucuronide by LC Coupled with MS. Application to a Pharmacokinetic Study of Mycophenolate Mofetil in Patients with Autoimmune Diseases

Liquid chromatography coupled with mass spectrometry for the determination of total and unbound mycophenolic acid and its major metabolite in human plasma has been developed. Sample preparations were based on a fully automated solid-phase extraction process and ultrafiltration. Mass spectrometric data were acquired in a single-ion monitoring method. The analytes and nevirapine (internal standard) were well separated in an isocratic mode over 8 min. Validation study exhibited excellent linearity, with intra- and inter-day precision and accuracy of less than 12%. The assay was successfully applied to the pharmacokinetic study of mycophenolic acid in patients with autoimmune diseases.     

A vibrational study of the nature of hydroxyl groups chemical bonding in two aluminium hydroxides

Lengths, strengths and valences of OH bonds in the two aluminium hydroxides gibbsite and bayerite were determined on the basis of vibrational spectral data. The uncoupled OD stretching modes in the range 2400–2800 cm⁻¹ were recorded by means of infrared diffuse reflectance, thereby avoiding effects of surface, vibrational coupling or particle shape. The assignment of the corresponding Raman spectra resulted in the determination of harmonic wavenumbers, force constants and anharmonicity coefficients of bulk OH groups in the two minerals. OH bond lengths deduced from these data varied from 0.964 Å to 0.975 Å in gibbsite and 0.962 Å to 0.973 Å in bayerite. These lengths appear to correspond to weak H-bonds contrary to previously recognized data from X-ray diffraction and neutron diffraction studies. Finally, bond valences were calculated on the basis of these new bond lengths and discussed as a function of crystallographic structures and the nature of hydrogen bonding in these two structures.