Standardized Characterization of Electrocatalytic Electrodes

This paper investigates the utility of ‘cross–lab’ comparative analysis of electrocatalytic electrode performance using standardized modular stack cells and test protocols. Using poly(methylene green)‐modified glassy carbon electrodes as the model system, we characterized electrode fabrication and performance with respect to the catalytic oxidation of NADH at neutral pH and low overpotential. Three sets of experiments were duplicated across four independent laboratories and the experimental results from each set were analyzed and compared in terms of key electroanalytical parameters. Statistical analyses were performed at three distinct levels: 1) the standard deviation among repetitive cycles within an experiment; 2) the standard deviation among repetitive experiments in the same laboratory, and 3) the standard deviation among experiments performed across all four laboratories. Using predefined criteria of ‘reproducibility’ for each level, most parameters were found to be statistically reproducible at most levels. When a particular parameter was found to be irreproducible in a given level, commentary is given on how that information can be used diagnose what chemical/physical aspects of the process were uncontrolled or poorly understood and therefore candidates for future research. This exercise, which is presented as a ‘proof–of‐principle’ step towards the concept of standardizing electrocatalytic evaluation, illustrates the importance of executing electrochemical characterization protocols across several labs and using fixed geometry and dimensions, system configuration, and applied electrochemical conditions. Future work is under way to extend these principles to systems with fluid flow.     

An Oily Fish Diet Improves Subclinical Inflammation in People at High Cardiovascular Risk: A Randomized Controlled Study

Interest has arisen on the anti-inflammatory action of dietary components, including long-chain n-3 fatty acids (LCn3) and polyphenols (PP). The aim of this study was to evaluate the effects of diets rich in PP and oily fish (high-LCn3 diets) on markers of subclinical inflammation and growth factors in people at high cardiometabolic risk. Individuals with high waist circumference and one more component of metabolic syndrome were randomized to one of the following isoenergetic diets: low LCn3&PP, high LCn3, high PP, high LCn3&PP. Before and after 8 weeks, fasting and postprandial plasma concentrations of hs-CRP and fasting serum concentrations of IL-1β, IL-4, IL-6, IL-10, IL-17, INF-γ, TNF-α, FGF, VEGF, PDGF-ββ, G-CSF, and GM-CSF were determined. An oily fish diet reduced fasting plasma hs-CRP (1.28 ± 12.0, −12.5 ± 6.9, 22.5 ± 33.6, −12.2 ± 11.9; 8-week percent change, Mean ± SEM; low LCn3&PP, high LCn3, high PP, high LCn3&PP group, respectively), postprandial 6h-AUC hs-CRP (4.6 ± 16.3, −18.2 ± 7.2, 26.9 ± 35.1, −11.5 ± 11.8, 8-week percent change) and fasting IL-6 (20.8 ± 18.7, −2.44 ± 12.4, 28.1 ± 17.4, −9.6 ± 10.2), IL-17 (2.40 ± 4.9, −13.3 ± 4.9, 3.8 ± 4.43, −11.5 ± 4.7), and VEGF (−5.7 ± 5.8, −5.6 ± 7.5, 3.5 ± 5.8, −11.1 ± 5.5) (8-week percent change; p < 0.05 for LCn3 effect for all; no significant effect for PP; 2-factor ANOVA). An oily fish diet improved subclinical inflammation, while no significant effect was observed for dietary polyphenols.     

Synthesis and Immunostimulating Activity of A Thioglycolipopeptide Glycomimetic As A Potential Anticancer Vaccine Derived From Tn Antigen

ABSTRACT

The Tn epitope is one of the tumor associated O-linked cell surface glycopeptides. It is expressed in over 70% of human epithelial cancers such as lung, colon, stomach and breast carcinomas. The glycosidic linkage of the Tn antigen, between N-acetylgalactosamine and serine or threonine, can be cleaved either chemically or enzymatically in the presence of glycosidases. The latter case is particularly a problem in vivo. Therefore, it would be of great interest to obtain a metabolically stable analogue of the Tn antigen that maintains or improves the immunogenic activity of the latter. The purpose of this work was to synthesize a totally synthetic vaccine using a chemically and metabolically stable glycomimetic of the Tn antigen in which the interglycosidic oxygen was replaced by a sulphur atom (S-Tn). The S-Tn thioglycopeptide was linked to the P₃CS immunoadjuvant to obtain the potential S-Tn vaccine. Moreover, we synthesized the natural Tn antigen and derivatized it similarly to obtain the Tn vaccine. Last, we evaluated the immunostimulating activity of the two synthetic potential vaccines in vitro using cultured mouse splenocytes. The S-Tn construct showed immunostimulating activity comparable, in terms of maximal response, to the Tn analogue. Moreover, due to its higher stability the S-Tn construct reached its maximal effect at lower doses compared to the Tn analogue.     

Halogen bonding and pi...pi stacking control reactivity in the solid state

The halogen bonding and the pi...pi stacking interactions induce the noncovalent self-assembly of modules into photoreactive supramolecular architecture. The pi...pi interaction pre-organizes the template, and the halogen bonding aligns the olefins to conform to the topochemical principle for photoreaction. The UV irradiation of the crystal resulted in a cyclization product with quantitative yield and stereospecificity.     

Iron(III) complexes with benzoxazole derivatives

Summary Iron(III) complexes of the general formula Fe(L)_nX₃·mH₂O, where L=benzoxazole(benzox), 2-methylbenzoxazole(2-Mebenzox), 2, 5-dimethylbenzoxazole(2, 5-diMebenzox); n=2, 3, 4, 6; X=Cl, Br, NO₃ or ClO₄; m=0, 1, 2, 5, have been prepared and studied by chemical analysis, magnetic moments, i.r., electronic, Mössbauer spectra and molar conductivity values.The oxazoles are N_ring bonded and the complexes are hexacoordinate in the solid state with exception of the five-coordinate Fe(2, 5-diMebenzox)₂Br₃.     

Manganese(II) complexes with 3,5-diphynylisoxazole, 3-amino-5-methylisoxazole and 5-amino-3,4-dimethylisoxazole

Summary The complexes of manganese(II) halide and thiocyanate with 3.5-diphenylisoxazole (3,5-diPhisox), 3-amino-5-methyl-isoxazole(3-AMI) and 5-amino-3,4-dimethylisoxazole (5-ADI) have been prepeared and characterized by spectrocopic and magnetic methods and by conductivity measurements. The 3,5-diPhisox ligand is N-bonded, while the isoxazolamine ligands are bridging N(ring)- and O-bonded. All the compounds are nonelectrolytes, high-spin, with an octahedral stereochemistry.     

Dipyridinocalixcrown/diiodoperfluorocarbon binary host systems for CsI: structural studies and fluorous phase extraction of caesium

A mixture of partial cone 2,4-bis[(2-pyridylmethyl)oxy]-(1,3)-p-tert-butylcalix[4]crown-6, hexadecafluoro-1,8-diiodooctane and CsI in EtOH produces a crystalline ‘supramolecular salt’. In the solid state the caesium ion of the ‘supercation’ is encapsulated inside the cavity created by the crown ether loop, the picolyl and the inverted phenyl moieties, while the two iodide ions of the ‘superanion’ form a discrete five-component aggregate held together by co-existing hydrogen and halogen bonds. Similar calix/CsI/iodofluorocarbon adducts are shown to exist also in solution. In a prototypical study, a combination of this calixcrown and liquid octafluoro-1,4-diiodobutane acts as an effective ‘binary host’ system for the selective extraction of CsI from aqueous to fluorous phase.     

Secondary ion mass spectrometry and X-ray photoelectron spectroscopy investigation on chemical vapor deposited CeO(2-)ZrO(2)-TiO(2) thin films

Mixed CeO(2)-ZrO(2) systems have attracted widespread interest for their use in three-way catalyst (TWC) technology for automotive exhaust conversion to non-toxic products. In this work, CeO(2)-ZrO(2) thin films were deposited, via chemical vapor deposition, in order to obtain nanoscale materials with a high surface-to-volume ratio, with precise control of system properties. The addition of TiO(2) as buffer layer was also investigated. Cordierite was chosen as substrate, being the usual refractory material for catalytic mufflers. The multilayers were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). In particular, the combination of SIMS and XPS allowed us to investigate both surface and in-depth chemical composition, studying also film-intermixing phenomena induced by annealing processes.