Packaged hybrid soliton pulse source results 70 terabit.km/secsoliton transmission

A packaged hybrid soliton pulse source is used in a soliton transmission experiment employing sliding-frequency guiding filters. The source shows excellent stability and very clean tuning characteristics. Control of the operating frequency and wavelength are described. Error free transmission at 10 GBit/s is achieved over a distance of 27000 km     

Saponification of oils rich in polyunsaturated fatty acids: Optimization of conditions by response surface methodology

A methodological approach was used to optimize experimental conditions leading to complete saponification of cod liver oil without loss of polyunsaturated fatty acids. Each experiment, using conditions imposed by a Doehlert design, was analyzed for the percentages of fatty acids with different chain lengths and degrees of unsaturation: Y1=%C22:6ω3, Y2=%C20:5ω3, Y3=%C18:4ω3, Y4=%C18:1ω9+ω7, Y5=%C16:0. The difference between values obtained in each experiment and values obtained by transesterification allowed the extent of fatty acid degradation to be quantified. The experimental results were expressed by response surfaces allowing the choice of saponification conditions for each type of fatty acid. An optimum zone for saponification was observed which was larger when carried out under nitrogen. Nitrogen did not eliminate degradation, but degradation was less marked under nitrogen than under air. The fatty acid having the greatest degree of unsaturation in this study, C22:6ω3, was the first to be degraded. The extension of the Doehlert design to four factors showed that under air, alkali concentration and reaction time were the major factors governing loss of polyunsaturated fatty acids.     

Transjugular intrahepatic portosystemic shunt in an infant

BACKGROUND: Merkel cell (neuroendocrine) carcinoma (MCC) is a very aggressive primary cutaneous neoplasm most often occurring on the head and neck of the elderly. Spontaneous regression of MCC was first described in this journal in 1986. Since then, other such cases have been reported. This case represents the sixth case of spontaneous regression of MCC. OBJECTIVE: To describe to clinical course in a patient with MCC who underwent spontaneous regression of metastatic disease. METHODS: Clinical records including detailed history and frequent follow-up examination made this observation possible. RESULTS: Complete clinically evident regression of metastatic MCC was observed in this case. However, the patient received no treatment known to be effective for MCC. CONCLUSIONS: Spontaneous regression of MCC has been documented. The reason for regression is unknown. Further study of these rare cases may in the future provide more answers than questions.     

An electron-phonon contribution to the stoner enhancement in GaMo4X8 compounds

Using the Stoner-Wohlfarth model of itinerant ferromagnetism for GaMo₄X₈ compounds, we determine the electron-phonon enhancement from their electronic specific heats. These compounds have unstable structures due to strong electron-phonon coupling. The room-temperature structure can be stabilized by doping with nonmagnetic isoelectronic impurities. The Curie temperature is decreased by a factor of three as a consequence of itinerant-electron parallel-spin scattering on nonmagnetic impurities. This property demonstrates that a long-range ferromagnetic interaction contributes to the Stoner enhancement. We speculate that the amplitude of this extra contribution is governed by the electron-phonon coupling, which depends on the mass. We are able to predict the experimental values of and the amplitude of the possible isotope effect.     

The Multivalent Effect in Glycosidase Inhibition: Probing the Influence of Valency,Peripheral Ligand Structure,and Topology with Cyclodextrin‐Based Iminosugar Click Clusters

In view of recent reports of a strong multivalent effect in glycosidase inhibition, a library of β‐CD‐based multivalent iminosugars has been efficiently synthesized by way of Cu^I‐catalyzed azide–alkyne cycloaddition (CuAAC). In combination with the first application of isothermal titration calorimetry (ITC) experiments to the study of multivalent iminosugar–enzyme interactions, the inhibition properties of these click clusters were evaluated on a panel of glycosidases. The structural parameters that were varied include valency, peripheral ligand structure, and topology. The inhibition results obtained with the iminosugar clusters further highlight the importance of multivalency in the inhibition of α‐mannosidase. Generally, the evaluated multivalent iminosugars displayed comparable thermodynamic signatures of binding towards α‐mannosidase (Jack bean): that is, large negative enthalpies of complexation coupled with small entropies of either sign. In addition, the enthalpy–entropy compensation observed in all tested cases may be attributed to a common mechanism of dissociation for the enzyme–multivalent iminosugar interactions. The measured binding stoichiometries indicated that each iminosugar cluster interacts with no more than one protein molecule.     

Multivariate optimization of fecal bioindicator inactivation by coupling UV-A and UV-C LEDs

The development of new technologies for water recycling is a priority for arid and semi-arid countries such as those of the Mediterranean basin. The aim of this study was to test the efficiency of UV-A and UV-C light emitting diodes (UV-LEDs) on bacteria inactivation. We used Escherichia coli and Enterococcus faecalis, bioindicators of fecal pollution typically found in urban wastewaters. An experimental design was performed to discriminate weight of factors influencing bacteria inactivation yields and reactivation phenomena. Four parameters were tested on simple bacterial cultures: pH, bacterial density, exposure time and wavelength. It appears that the exposure time and wavelength used have a significant effect on the response. The 280/365 nm or 280/405 nm coupled wavelengths, have the most important bactericidal effect, and we also note the absence of bacterial reactivation after 60 s of exposure to UV.     

Determination of the Most Bioactive Phenolic Compounds from Rosemary Against Listeria Monocytogenes: Influence of Concentration, pH, and NaCl

ABSTRACT: The anti-Listeria monocytogenes effects of 8 phenolic compounds, carnosol, carnosic acid, 12-methoxy carnosic, ferulic and caffeic acid, rosmarinic acid, luteolin and luteolin-7-glucoside were evaluated with a Plackett and Burman design in mixtures mimicking the phenolic composition of rosemary extract without essential oils. At 30°C carnosic acid was the most efficient compound during 24 h, whereas luteolin became more active after 72 h. The antibacterial effect of pure carnosic acid was modeled under a range of different pH and NaCl concentration, using a Doehlert design. Under moderately acidified conditions, carnosic acid displayed a bactericidal effect at low concentration (5.5 μg/ml). Its activity was not greatly influenced by NaCl.     

Surface-plasmon quantum cascade microlasers with highly deformed resonators

We report the demonstration of surface-plasmon microcylinder quantum cascade lasers with circular and deformed resonators. An improved self-alignment fabrication technique was developed that allows the use of wet etching, necessary to achieve smooth and clean surfaces, in combination with the deposition of the surface-plasmon-carrying metal layer up to the very edge of the resonator, where the optical mode is mostly located. The diameter of the microcylinders ranges from 75 to 180 /spl mu/m while their deformation coefficient /spl epsiv/ ranges from /spl epsiv/=0 to /spl epsiv/=0.32. Circular microcylinder lasers show a reduction of /spl sim/50% of the threshold current density with respect to devices with standard ridge-waveguide resonators. On the other hand, highly deformed microcylinder lasers exhibit a complex mode structure, suggesting the onset of chaotic behavior.     

Role of the input in visual hemispheric asymmetries.

Because the nature of the input is one of the most important variables in determining how the brain will process information, findings from tachistoscopic studies aimed at assessing hemispheric lateralization of functions are examined in terms of the characteristics of the incoming information either available or required for processing. The basic features of tachistoscopic experiments are analyzed with a special emphasis on methodology. Variables determining the quality of the input are investigated as a function of the properties of the human visual system. Exposure duration, luminance, retinal eccentricity, and stimulus size all contribute to the efficiency of the hemispheres and interact in complex ways in the emergence of visual-field superiorities. Task demands are also examined in terms of the information necessary for efficient processing. The present review suggests that in tachistoscopic experiments, the factors determining the quality of the input must be controlled if this technique is to prove a reliable source of information for assessing hemispheric asymmetries. (5 p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)