Characterization of microstructured optical fibers for wideband dispersion compensation

Microstructured optical fibers (MOFs) with small hole-to-hole spacing and large airholes are designed to compensate the anomalous dispersion and the dispersion slope of single-mode fibers. The geometrical parameters that characterize triangular MOFs are chosen to optimize the fiber length and the compensation over a wide wavelength range. A proper design of the photonic crystal fiber geometry allows us to achieve dispersion values of approximately -1700 ps nm(-1) km(-1) at 1550 nm and to compensate the dispersion of standard fibers within +/- 0.5 ps nm(-1) km(-1) over a 100-nm range. The MOF dispersion properties have been studied by means of a numerical simulator for modal analysis based on the finite-element method.     

Characterization of the long time oxidation protection of fluorine implanted technical TiAl-alloys using ion beam methods

In the present work the oxidation resistance of fluorine treated technical TiAl-alloys was investigated. Single and double fluorine beam line implantation was found to improve the high temperature oxidation resistance of this class of materials with Al-contents higher than 40 at.%. Calculated and measured fluorine depth profiles were compared. It was shown that the alloying elements do not modify significantly the fluorine profile and do not disturb the halogen effect. After single and double fluorine implantation and for different oxidation stages (isothermal/thermocyclic conditions) the maximum of the fluorine profile was measured by PIGE (Proton Induced Gamma Emission). The fluorine maximum was found to be located at the metal/oxide interface. The time dependence of the fluorine profile was determined as well. Double implantation led to a slower growing alumina layer. In this case a F-reservoir is obtained and improves the long term oxidation resistance of TiAl-based alloys.     

Mono and Bifunctional Catalysts for Styrene Oxide Isomerization or Hydrogenation

Abstract  

Styrene oxide can be effectively isomerized to phenyl-acetaldehyde (98%) over amorphous silica alumina catalysts under very mild liquid phase conditions. On the other hand, a copper catalyst prepared using a silica zirconia support gave up to 80% yield in the hydrogenation of styrene oxide to 2-phenyl-ethanol.     

Room-Temperature Degradation of t-Zr(Pr)O2 in an Aqueous Suspension Revealed by Perturbed Angular Correlations

This paper deals with the phase stability of an aqueous suspension of tetragonal Zr_0.9Pr_0.1O₂ (20 wt%/vol%) at room temperature as a function of the aging time. The suspension is investigated in situ using the highly localized Perturbed Angular Correlations technique. The results indicate that an almost fully reversible degradation process toward monoclinic zirconia takes place through a first-order reaction of rate constant k =0.7 day⁻¹. Two successive diffusion mechanisms are observed that are interpreted as OH⁻ ions' migration in the grain surface and then, as proton defects' diffusion into the bulk.     

The International Energy Agency photovoltaic power systems implementing agreement

Motivations, objectives, and specific achievements and progress of the first five years of activities of the IEA Photovoltaic Power Systems Co-operation Programme are summarized. A brief input of the activities starting now or planned for the future is also given.     

Influence of the suspension media on the thermal treatment of mesophilic lactococcal bacteriophages

The thermal resistances of the Lactococcus lactis phages P008 (a heat-sensitive wide-spread phage) and P680 (a heat-resistant phage) suspended in milk and in solutions supplemented with milk components were studied to elucidate the protective role of milk on phage inactivation. For both phages a decrease of inactivation was observed in casein solution. Furthermore, the inactivation kinetics of the phages in whey, in whey cream (3.5%, 20%, 30% fat) and in whey protein concentrate (0.7%, 5%, 10% protein) were tested. The inactivation experiments in whey cream and in whey protein concentrate having different concentrations of fat and protein revealed that fat had no influence on the inactivation, while, in contrast, the presence of protein had a protective effect.     

Understanding the Selectivity Mechanism of the Human Asialoglycoprotein Receptor (ASGP-R) toward Gal- and Man-type Ligands for Predicting Interactions with Exogenous Sugars

A practical approach for addressing the computer simulation of protein-carbohydrate interactions is described here. An articulated computational protocol was set up and validated by checking its ability to predict experimental data, available in the literature, and concerning the selectivity shown by the Carbohydrate Recognition Domain (CRD) of the human asialoglycoprotein receptor (ASGP-R) toward Gal-type ligands. Some required features responsible for the interactions were identified. Subsequently the same protocol was applied to monomer sugar molecules that constitute the building blocks for alginates and ulvans. Such sugar polymers may supply a low-cost source of rare sugars with a potential impact on several industrial applications, from pharmaceutical to fine chemical industry. An example of their applicative exploitation could be given by their use in developing biomaterial with adhesion properties toward hepatocytes, through interaction with the ASGP-R. Such a receptor has been already proposed as a target for exogenous molecules, specifically in the case of hepatocytes, for diagnostic and therapeutic purposes. The DOCK5.2 program was used to search optimal locations of the above ligands of interest into CRD binding site and to roughly estimate interaction energies. Finally, the binding ΔG of theoretical protein-ligand complexes was estimated by using the DelPhi program in which the solvation free energy is accounted for with a continuum solvent model, by solving the Poisson-Boltzmann equation. The structure analysis of the obtained complexes and their ΔG values suggest that one of the sugar monomers of interest shows the desired characteristics.     

Synthesis and Antiplasmodial Activity of Novel Chloroquine Analogues with Bulky Basic Side Chains

Chloroquine is commonly used in the treatment and prevention of malaria, but Plasmodium falciparum, the main species responsible for malaria‐related deaths, has developed resistance against this drug. Twenty‐seven novel chloroquine (CQ) analogues characterized by a side chain terminated with a bulky basic head group, i.e., octahydro‐2H‐quinolizine and 1,2,3,4,5,6‐hexahydro‐1,5‐methano‐8H‐pyrido[1,2‐a][1,5]diazocin‐8‐one, were synthesized and tested for activity against D‐10 (CQ‐susceptible) and W‐2 (CQ‐resistant) strains of P. falciparum. Most compounds were found to be active against both strains with nanomolar or sub‐micromolar IC₅₀ values. Eleven compounds were found to be 2.7‐ to 13.4‐fold more potent than CQ against the W‐2 strain; among them, four cytisine derivatives appear to be of particular interest, as they combine high potency with low cytotoxicity against two human cell lines (HMEC‐1 and HepG2) along with easier synthetic accessibility. Replacement of the 4‐NH group with a sulfur bridge maintained antiplasmodial activity at a lower level, but produced an improvement in the resistance factor. These compounds warrant further investigation as potential drugs for use in the fight against malaria.     

Potent,Metabolically Stable 2‐Alkyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐adenines as Adenosine A2A Receptor Ligands

Inhibition of adenosine A_2A receptors has been shown to elicit a therapeutic response in preclinical animal models of Parkinson’s disease (PD). We previously identified the triazolo‐9H‐purine, ST1535, as a potent A_2AR antagonist. Studies revealed that ST1535 is extensively hydroxylated at the ω‐1 position of the butyl side chain. Here, we describe the synthesis and evaluation of derivatives in which the ω‐1 position has been substituted (F, Me, OH) in order to block metabolism. The stability of the compounds was evaluated in human liver microsomes (HLM), and the affinity for A_2AR was determined. Two compounds, (2‐(3,3‐dimethylbutyl)‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐6‐amine ( 3 b ) and 4‐(6‐amino‐9‐methyl‐8‐(2H‐1,2,3‐triazol‐2‐yl)‐9H‐purin‐2‐yl)‐2‐methylbutan‐2‐ol ( 3 c ), exhibited good affinity against A_2AR (K_i=0.4 nM and 2 nM , respectively) and high in vitro metabolic stability (89.5 % and 95.3 % recovery, respectively, after incubation with HLM for two hours).     

Next-Generation Sequencing Workflow for NSCLC Critical Samples Using a Targeted Sequencing Approach by Ion Torrent PGM? Platform

Next-generation sequencing (NGS) is a cost-effective technology capable of screening several genes simultaneously; however, its application in a clinical context requires an established workflow to acquire reliable sequencing results. Here, we report an optimized NGS workflow analyzing 22 lung cancer-related genes to sequence critical samples such as DNA from formalin-fixed paraffin-embedded (FFPE) blocks and circulating free DNA (cfDNA). Snap frozen and matched FFPE gDNA from 12 non-small cell lung cancer (NSCLC) patients, whose gDNA fragmentation status was previously evaluated using a multiplex PCR-based quality control, were successfully sequenced with Ion Torrent PGM™. The robust bioinformatic pipeline allowed us to correctly call both Single Nucleotide Variants (SNVs) and indels with a detection limit of 5%, achieving 100% specificity and 96% sensitivity. This workflow was also validated in 13 FFPE NSCLC biopsies. Furthermore, a specific protocol for low input gDNA capable of producing good sequencing data with high coverage, high uniformity, and a low error rate was also optimized. In conclusion, we demonstrate the feasibility of obtaining gDNA from FFPE samples suitable for NGS by performing appropriate quality controls. The optimized workflow, capable of screening low input gDNA, highlights NGS as a potential tool in the detection, disease monitoring, and treatment of NSCLC.