Oxidative fabrication of spherical polycarbazole-based microparticles

A straightforward oxidative liquid phase polymerization (LPP) method has been successfully developed for the fabrication of spherical functional (polyCOOH) polycarbazole-based microparticles from corresponding carbazole-containing monomers. The influence of the chemical structure of starting carbazole monomers on the LPP-based microparticle formation has been deeply examined using scanning electron microscopy (SEM).     

Electrical and mechanical percolation in graphene-latex nanocomposites

Conductive composites based on few layer graphene are of primary interests. In this work latex based composites were produced leading to a specific cellular morphology. Highly conductive graphene-based composite materials have been produced through a solvent-free procedure. Both the mechanical and conductivity behaviors were successfully described using a percolation approach that confirms the presence of a three dimensional filler network efficiently spread across the material. The influence of the aspect ratio between the conductive filler and the latex nanosphere drove the study. It was demonstrated experimentally that the tuning of the cell dimensions of the composite morphology influences the percolation threshold and the reachable maximum conductivity and reinforcement. These experimental results are consistent with phenomenological models based on the statistical percolation theory.     

Return flux budget of polychromatic laser guide stars

The polychromatic laser guide star (PLGS) is one of the solutions proposed to extend the sky coverage by large telescopes to 100% by enabling a complete knowledge of all perturbation orders of the wavefront. The knowledge of the tip-tilt is deduced from the monitoring of the chromatic components of the PLGS, from 330 nm to the visible or near infrared. Here we study the original scheme to create the PLGS by resonant excitation of the mesospheric sodium by two pulsed lasers (tens of kilohertz repetition rate, tens of watts average power, tens of nanoseconds pulse duration), at 589 and 569 nm, respectively. The efficiency of this process is investigated numerically by means of both Bloch equation and rate equation models. The influence of numerous laser parameters is studied. In the best case, having optimized all laser parameters, the return flux at 330 nm should not exceed 7x10(4) photons/s/m2 for 2x18 W laser average power at the mesosphere. This maximum is obtained for a modeless laser whose spot diameter corresponds to 4 times the diffraction limit. For a diffraction-limited spot, the return flux falls down to 4x10(4)photons/s/m2.     

First investigation on ultrasound-assisted preparation of food products: sensory and physicochemical characteristics

This paper presents a comparison between manufactured food products using conventional and ultrasound-assisted procedures. Three different foam-type products, chocolate Genoise, basic sponge cake, and chocolate mousse were prepared using both methods with subsequent evaluation of the samples using both sensory and physicochemical methods. Ultrasound-assisted preparations were considered superior according to the sensory analysis, and physicochemical data confirmed this finding. This approach of applying an emerging piece of equipment, with potential industrial application to assist food preparation, consists of a new technique that could be of great interest for the development of not only other food products created by molecular gastronomy but also for practical work carried out by students.     

Development of primers for detecting dominant yeasts in smear-ripened cheeses

PCR primers were developed for the specific detection of Clavispora lusitaniae, Debaryomyces hansenii var hansenii, Geotrichum candidum, Kluyveromyces lactis and K. marxianus and Yarrowia lipolytica, yeast species commonly found on the surface of smear cheese. Forty eight representative strains frequently found in smear cheeses or taxonomically related to the target yeasts were used as templates, to validate the designed primers. The specific and selective detection of these yeasts was effective in situ, in Livarot smear, without yeast isolation and culture and was comparable with data obtained with a conventional method. The primers described here have thus potential for PCR studies applied to cheese. It should also be possible to use some of these primers with other substrates.     

Approaches for the optimization of MR protocols in clinical hybrid PET/MRI studies

Magnetic resonance imaging (MRI) is the examination method of choice for the diagnosis of a variety of diseases. MRI allows us to obtain not only anatomical information but also identification of physiological and functional parameters such as networks in the brain and tumor cellularity, which plays an increasing role in oncologic imaging, as well as blood flow and tissue perfusion. However, in many cases such as in epilepsy, degenerative neurological diseases and oncological processes, additional metabolic and molecular information obtained by PET can provide essential complementary information for better diagnosis. The combined information obtained from MRI and PET acquired in a single imaging session allows a more accurate localization of pathological findings and better assessment of the underlying physiopathology, thus providing a more powerful diagnostic tool. Two hundred and twenty-one patients were scanned from April 2011 to January 2012 on a Philips Ingenuity TF PET/MRI system. The purpose of this review article is to provide an overview of the techniques used for the optimization of different protocols performed in our hospital by specialists in the following fields: neuroradiology, head and neck, breast, and prostate imaging. This paper also discusses the different problems encountered, such as the length of studies, motion artifacts, and accuracy of image fusion including physical and technical aspects, and the proposed solutions.     

On the Motion Planning Problem, Complexity, Entropy, and Nonholonomic Interpolation

We consider the sub-Riemannian motion planning problem defined by a sub-Riemannian metric (the robot and the cost to minimize) and a non-admissible curve to be ε-approximated in the sub-Riemannian sense by a trajectory of the robot. Several notions characterize the ε-optimality of the approximation: the “metric complexity” MC and the “entropy” E (Kolmogorov-Jean). In this paper, we extend our previous results. 1. For generic one-step bracketgenerating problems, when the corank is at most 3, the entropy is related to the complexity by E = 2πMC. 2. We compute the entropy in the special 2-step bracket-generating case, modelling the car plus a single trailer. The ε-minimizing trajectories (solutions of the “ε-nonholonomic interpolation problem”), in certain normal coordinates, are given by Euler's periodic inflexional elastica. 3. Finally, we show that the formula for entropy which is valid up to corank 3 changes in a wild case of corank 6: it has to be multiplied by a factor which is at most 3/2. 2000 Mathematics Subject Classification. 53C17, 49J15, 34H05. The second author is supported by grants RFBR 050100458 and UR 0401128.     

Fungal and Plant Xyloglucanases May Act in Concert During Liquefaction of Apples

Efficient enzymic degradation of cellulose in isolated cell wall material of apples requires prior removal of its xyloglucan coating. In this study, raw and blanched apple fruit tissues were treated with pectin lyase and various (combinations of purified) cellulases. These experiments confirmed that xyloglucanase activity is important for cellulose degradation in apple fruit tissue. Apart from this, it was observed that raw apple material disintegrated faster than blanched. Typically, the release of xyloglucan oligosaccharide XXXG from raw apple material was slower (relative to XXFG) when compared to that from blanched material. The endogenous enzyme, xyloglucan endotransglycosylase (XET), is probably responsible for these phenomena. It is hypothesised that XET activity accelerates disintegration of apple tissue once its depolymerising mode is triggered by xyloglucan oligosaccharides released by exogenous endoglucanases. © 1997 SCI.     

Pectin lyase is a key enzyme in the maceration of potato tuber

The maceration of potato tuber (Solanum tuberosum cv Bintje) by technical enzyme preparations was examined with the aid of fluorescence microscopy using fluorescein diacetate as a dye. Treatment with Pectinex Ultra-SP-L from Aspergillus aculeatus resulted in a higher release of single viable cells and smaller clumps of cells than treatment with Rohament P from Aspergillus niger. Fractions with high pectin lyase and low polygalacturonase activity obtained by anion exchange chromatography of Pectinex Ultra SP-L showed the highest degree of maceration. When two different cloned polygalacturonases (PG1 and PG2) and a cloned pectin lyase (PL1) from A aculeatus were examined, the highest degree of maceration was observed with PL1. In conclusion, pectin lyase is probably the main enzyme in Pectinex Ultra-SP-L responsible for the maceration of potato tuber. © 1997 SCI.     

Chemical Synthesis,Pharmacokinetic Properties and Biological Effects of JM-00266, a Putative Non-Brain Penetrant Cannabinoid Receptor 1 Inverse Agonist

Targeting cannabinoid 1 receptors (CB1R) with peripherally restricted antagonists (or inverse agonists) shows promise to improve metabolic disorders associated with obesity. In this context, we designed and synthetized JM-00266, a new CB1R blocker with limited blood–brain barrier (BBB) permeability. Pharmacokinetics were tested with SwissADME and in vivo in rodents after oral and intraperitoneal administration of JM-00266 in comparison with Rimonabant. In silico predictions indicated JM-00266 is a non-brain penetrant compound and this was confirmed by brain/plasma ratios and brain uptake index values. JM-00266 had no impact on food intake, anxiety-related behavior and body temperature suggesting an absence of central activity. cAMP assays performed in CB1R-transfected HEK293T/17 cells showed that the drug exhibited inverse agonist activity on CB1R. In addition, JM-00266 counteracted anandamide-induced gastroparesis indicating substantial peripheral activity. Acute administration of JM-00266 also improved glucose tolerance and insulin sensitivity in wild-type mice, but not in CB1R^−/− mice. Furthermore, the accumulation of JM-00266 in adipose tissue was associated with an increase in lipolysis. In conclusion, JM-00266 or derivatives can be predicted as a new candidate for modulating peripheral endocannabinoid activity and improving obesity-related metabolic disorders.