Concise Multigram‐Scale Synthesis of Push–Pull Tricyanofuran‐Based Hemicyanines with Giant Second‐Order Nonlinearity: An Alternative for Electro‐optic Materials

Highly stable and highly soluble push–pull heptamethine hemicyanines based on the tricyanofuran electron‐accepting group can be prepared on a 15 g scale. The compounds display giant second‐order nonlinear figure of merit, μβ of up to 31 000×10^?48 esu, and lead to a poled material with a second‐order nonlinear response, r₃₃ of 90 pm V^?1 at 1.06 μm     

Direct access to 1-aryl-5-amino-1,2,4-triazoles and [1,2,4]triazolo[1,5-a]pyridines by two new single-step reactions from 1,3,4-thiadiazol-2-amines

Two new single-step reactions allowing the construction of two heterocyclic motifs are reported. Both processes involve 5-substituted 1,3,4-thiadiazol-2-amines as starting materials. Reaction with 1-fluoro-2-nitrobenzenes in presence of Hünig's base permitted the convenient synthesis of various 3-substituted 1-aryl-5-amino-1,2,4-triazoles. Reaction with 2-chloro-3-nitropyridines and 2-chloro-5-nitropyridines in similar conditions readily gave access to a number of [1,2,4]triazolo[1,5-a]pyridines. In absence of base, adducts composed by one aromatic unit and two thiadiazole units were formed. This observation and previous work by Anders and co-workers led to the suggestion of plausible mechanisms for these reactions.     

A benchmark for cooperative coevolution

Cooperative co-evolution algorithms (CCEA) are a thriving sub-field of evolutionary computation. This class of algorithms makes it possible to exploit more efficiently the artificial Darwinist scheme, as soon as an optimisation problem can be turned into a co-evolution of interdependent sub-parts of the searched solution. Testing the efficiency of new CCEA concepts, however, it is not straightforward: while there is a rich literature of benchmarks for more traditional evolutionary techniques, the same does not hold true for this relatively new paradigm. We present a benchmark problem designed to study the behavior and performance of CCEAs, modeling a search for the optimal placement of a set of lamps inside a room. The relative complexity of the problem can be adjusted by operating on a single parameter. The fitness function is a trade-off between conflicting objectives, so the performance of an algorithm can be examined by making use of different metrics. We show how three different cooperative strategies, Parisian Evolution, Group Evolution and Allopatric Group Evolution, can be applied to the problem. Using a Classical Evolution approach as comparison, we analyse the behavior of each algorithm in detail, with respect to the size of the problem.     

Determination of ciprofloxacin in plasma by micro‐liquid chromatography–mass spectrometry: An adapted method for neonates

There are many limitations to conducting pharmacokinetic studies in neonates, both ethical and technical. Regarding technical aspects, the number and volume of samples are limited, and the analytical method to measure drug concentration should be both specific and highly sensitive. In the present report, an analytical method adapted to neonates was developed for the determination of ciprofloxacin plasma concentration. After a simple protein precipitation, analytes were separated on a micro‐liquid chromatography and quantified by mass spectrometry, with D8‐ciprofloxacin as internal standard. The calibration range was linear from 25 to 3000 ng/mL. Intra‐ and inter‐day precision was less than 2.4 and 4.1%, respectively. The acceptance criteria of accuracy (between 85 and 115%) were met in all cases. A plasma volume of 150 µL was required to achieve the limit of quantification of 25 ng/mL. The method was successfully applied to routine monitoring of ciprofloxacin in pediatric patients and also used in preclinical studies. It will be used to determine the population pharmacokinetic parameters of ciprofloxacin in neonates. Copyright © 2010 John Wiley & Sons, Ltd.     

Isomérisation de 2,3‐époxypinanes fonctionnels en présence d'acides de Lewis

Isomerization of Functionalized 2,3‐Epoxypinanes in the Presence of Lewis Acids The functionalized 2,3‐epoxypinanes 1b – i were submitted to isomerization in the presence of ZnBr₂ at 110° (Table 1) or of BF₃⋅Et₂O at different temperatures (Table 2), and their behavior was compared with that of the non‐functionalized parent 1a and with similar known transpositions. The produced campholenals 2 , pinocamphones 3 , and in some cases, fencholenals 4 were isolated and characterized. A mechanism involving a concerted oxirane ring opening is proposed (Scheme 4).     

Nanoparticles from vesicles polymerization. II. Evaluation of their encapsulation capacity

The polymerization of isodecyl acrylate (ISODAC) in vesicles of sodium di-2-ethylhexyl phosphate (SEHP) loaded with dyes or tyrosine was achieved. The study of the polymerization rate–conversion curve of the monomer confirmed that this polymerization was different from other polymerizations known, as it was proposed previously. Then the entrapment of hydrophilic molecules such as tyrosine or brilliant cresyl blue and lipophilic molecules such as sudan III into the nanoparticles was evaluated and confirmed by different methods. While tyrosine was not retained, brilliant cresyl blue and sudan III were entrapped inside nanoparticles. The size and the polarity of the molecules to be encapsulated, which are related to their diffusion coefficients and partition coefficients between water and the nanoparticle, seem to be the parameters responsible of the entrapment. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3035–3043, 1998     

A consistent correction for Redlich-Kwong-Soave volumes

If the volumetric and phase behaviour of a fluid mixture is calculated by means of an equation of state, certain translations along the volume axis may be effected that leave the predicted phase equilibrium conditions unchanged. This property may be exploited in the form at a consistent correction to improve volume estimations by the Redlich-Kwong-Soave method. Applications of this improved method to pure liquids, mixtures of liquids or gases, and petroleum fluids show that markedly superior volume estimations are obtained, except in the neighbourhood of the pure-component critical points; nonetheless, critical volumes for mixtures can be estimated correctly.