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Experimental granulomas were induced in lepromatous volunteers, rabbits and guinea pigs, by the intradermal injection of incomplete Freund's adjuvant. Experimental hypercholesterolemic xanthomatosis was produced in rabbits by cholesterol feeding. Despite histological and histochemical similarities between such lesions and lepromata, and the fact that chloroform-methanol extracts of experimental lesions bound methylene blue, no coloring could be seen after parenteral administration of this dye at doses far above those needed to stain lepromata. The blueing phenomenon, then, is one of relative specificity. We suggest that it is due to some metabolic derangement induced by Mycobacterium leprae in a susceptible parasitized macrophage. This might involve oxidation-reduction processes and/or some unusual lipid from cells or bacilli, that were able to hind methylene blue in a stable complex. [ABSTRACT FROM AUTHOR]

Abstract: From ethanolic, water extracts and their fractions of mature fruits of wild black-berry Aristotelia chilensis (Mol) Stuntz (Elaeocarpaceae), different phenolic compounds were identified by chromatographic (HPLC) and unequivocally assignments by spectroscopic (UV, NMR) data analysis. Anthocyanidins, flavonoids and phenolic acids fractions were obtained using flash and open column chromatography. The main compounds gentisic acid, ferulic acid, gallic acid, p-coumaric acid, sinapic acid, 4-hydroxybenzoic acid, delphinidin, cyanidin, vanillic acid, delphinidin gallate, gallocatechin gallate, quercetin, rutin, myricetin, catechin and epi-catechin as mixture 1:1, and several glycosides of anthocyanidins (delphinidin-3-sambubioside-5-glucoside, delphinidin-3,5-diglucoside, cyanidin-3-sambubioside-5-glucoside, cyanidin-3,5-diglucoside, delphinidin-3-sambubioside, delphinidin-3-glucoside, cyanidin-3-sambubioside, and cyanidin-3-glucoside), and proanthocyanidin B were detected. In addition to phytochemical analysis the antioxidant activities of extracts, partitions and fractions were strongly correlated with the highest polyphenol contents. The most active samples were the ethanolic and acetone extracts in all bioassays used and all samples were compared for activity against butylated hydroxy toluene (BHT), quercetin and tocopherol used as pattern samples. The juice (E), EtOH extract (A) and acetone partition (B) were found to have IC50 values of 4.7, 1.7 and 7.4ppm, respectively against DPPH and 5.9, 2.1 and 3.9ppm, respectively against TBARS formation. Additionally, the fraction F-4 showed a strong activity with IC50 of 4.9 and 6.5ppm, against DPPH and TBARS respectively. Consistent with this finding, EtOH extract had the greatest ORAC and FRAP values as percentage of activity. On the other hand the IC50 values for the inhibitory activity against of extract B, F-3 and F-4 were 9.7, 13.2 and 10.7ppm, respectively and against OH − were 29.1, 7.0 and 6.3ppm, respectively. The EtOH extract protects against stress oxidative reducing the concentration of the MDA a lipid peroxidation index. These results shows that this fruit could be useful as antioxidant and nutraceutical sources. [Copyright &y& Elsevier]

We report on a spatial mapping of the electronic and vibrational structure of three-dimensional (3D) nanoporous graphene architectures, which have a hierarchical pore structure. We demonstrate that the topology, curvature, and pores lead to local changes in the electronic and vibrational structure and in the hybridization states of the carbon atoms (sp 2 vs. sp 3 -like). Nitrogen substitutions in pyrrolic bonding configurations also contribute to local distortions of the planar geometry of graphene. The distortions influence the electronic density of states at the Fermi level by shifting the Dirac cone apex, opening potential avenues for applications of two-dimensional graphene in 3D devices. [ABSTRACT FROM AUTHOR]

Modifications of graphene's electronic band structure can be achieved through periodic bending strain and related potential in samples grown on stepped substrates, opening a viable route to implement the periodicity effects in this ultimate two-dimensional (2D) material. We studied graphene grown on stepped Ir(332), which can be benchmarked to a well-known graphene on flat Ir(111) recognized for a weak van der Waals (vdW) interaction. The structural characterization indicated that graphene growth induces reversible, well defined faceting of iridium surface into alternating terraces and step bunches, while spectroscopy techniques revealed substantial changes of graphene's electronic structure. Crucially, highly concentrated Ir step edges, resulting in locally strong chemical bonding of graphene, introduce a dominant energy parameter which overwhelms the induced strain and presents a driving force for the surface faceting. This sets a general framework for the understanding of graphene mediated faceting of stepped substrates whenever the corresponding low index surface exhibits dominantly vdW interaction with graphene, which can be also supplemented to other 2D materials. Interestingly, the graphene π band becomes pronouncedly anisotropic due to the presence of a periodic potential originating from steps, and lateral variation of the charge carrier concentration enabling a straightforward electronic band engineering in graphene. [ABSTRACT FROM AUTHOR]