Heat treatment effects on the corrosion resistance of some HVOF-sprayed metal alloy coatings

The present study evaluates the effects of a 600 °C, 1 h heat treatment on the corrosion resistance of three High Velocity Oxygen Fuel (HVOF) flame-sprayed alloy coatings: a Co-28Mo-17Cr-3Si (similar to Tribaloy-800) coating, a Ni-20Cr-10W-9Mo-4Cu-1C-1B-1Fe (Diamalloy-4006) coating and a Ni-32Mo-16Cr-3Si-2Co (similar to Tribaloy-700) coating. Electrochemical polarization tests and free corrosion tests were performed in 0.1 M HCl aqueous solution. The corrodkote test (ASTM B380-97R02) was also performed, to evaluate the coatings qualitatively. The heat treatment improves the corrosion resistance of the Co-28Mo-17Cr-3Si coating and of the Ni-20Cr-10W-9Mo-4Cu-1C-1B-1Fe coating by enhancing their passivation ability. The precipitation of sub-micron sized secondary phases after the treatment may produce galvanic microcells at intralamellar scale, but the beneficial contribution provided by the healing of the very small but dangerous interlamellar defects (normally present in thermal spray coatings but not detectable using ordinary scanning electron microscopy) prevails. The effect on Ni-32Mo-16Cr-3Si-2Co coatings is more ambiguous: its sensitivity to crevice corrosion is worsened by the heat treatment.     

Selective catalytic reduction (SCR) of NO by NH3 over TiO2-supported V2O5–WO3 and V2O5–MoO3 catalysts

A comparison between commercial and model WO₃–V₂O₅/TiO₂ and MoO₃–V₂O₅/TiO₂ SCR catalysts is considered in this study. The data indicate that WO₃ and MoO₃ behave as “structural” and “chemical” promoters for the catalysts. MoO₃-based catalysts are more active but less selective than WO₃–V₂O₅/TiO₂ catalysts in the SCR reaction, although in the presence of water the catalytic performances of the investigated samples are comparable. This revised version was published online in August 2006 with corrections to the Cover Date.     

New Mixed Esters with a Complex Alkyl‐Aryl Structure Considered as Tribological Fluids

This paper presents the results of a study carried out to produce synthetic ester oils of mixed structure and based on phthalic anhydride with beneficial tribological properties. Three series of unsymmetric diesters were synthesised using aliphatic alcohols such as n‐propanol, n‐butanol, n‐hexanol, 2‐ethylhexanol, isodecanol, and isotridecanol, along with special alcohols of a complex alkyl‐aryl structure, namely 2‐phenoxyethanol, 2‐((o‐sec‐butyl)phenoxylethanol, and 2‐ftp‐nonyl)phenoxylethanol. Also synthesised were symmetric esters based on these special aliphatic‐aromatic alcohols. The variation in the principal properties as a function of both the length of the aliphatic chain introduced by the aliphatic alcohol and the length and position of the aliphatic pendant chain on the aromatic nucleus of the complex alkyl‐aryl alcohol was assessed. Based on this, it has been possible to obtain fluid products with variable properties. The introduction of the aromatic function in the structure of these diesters leads to interesting features, and the wide range of viscosity values demonstrates their versatility.     

V2V protocols for traffic congestion discovery along routes of interest in VANETs: a quantitative study

One of the most interesting and promising challenges for Intelligent Transportation Systems (ITSs) relates to the traffic congestion problem. Congestion is a relevant issue for transportation because it reduces the efficiency of infrastructure and increases travel time, air pollution, and fuel consumption. Nowadays, the most promising technology in support of ITSs is found in the domain of Vehicular Ad Hoc Networks (VANETs). In this paper, we propose three protocols that are able to transmit traffic information for routes of interest on VANETs without any Road Side Unit (RSU) support. The proposed protocols adopt strategies to improve the performance of packet routing based on the density and location of vehicles; moreover, they enable an interesting comparison of the performance achievable with either reactive or proactive approaches. The extensive performance results reported show how it is possible to limit the congestion monitoring overhead along Routes of Interest (ROIs), while maintaining a sufficiently high performance in terms of traffic reporting. This may be done by employing context‐aware data delivery techniques that autonomously adapt to runtime conditions. Copyright © 2016 John Wiley & Sons, Ltd.     

Cryo‐scanning electron microscopy investigation of the Octopus Vulgaris arm structures for the design of an octopus‐like arm artefact

Octopus vulgaris is a cephalopod of the Octopodidae family. It has four pairs of arms and two rows of suckers which perform many functions, including bending and elongation. For this reason the octopus was chosen as model to develop a new generation of soft‐body robots. In order to explain some of the fine structures of the octopus arm in relation to its specific ability, we examined the external and internal structures of O. vulgaris arms in a frozen‐hydrated state using cryo‐scanning electron microscopy. The arms showed skin with a very complex design that is useful to elongation, and a pore pattern distribution on their surface which is functional to cutaneous oxygen uptake. The analysis of freeze‐fractured frozen‐hydrated arm samples allowed us to describe the developmental differences in the relative proportion of the areas of axial nerve cord, intrinsic and extrinsic musculature, in relation to the growth of the arms and of the increase in functional capability. In the suckers, we analyzed the shedding mechanisms in the outer part of the infundibulum and described the outer and inner characteristics of the denticles, showing in detail their pore system, which is fundamental for their ability to explore the environment. These results are discussed by considering their possible application in the design of new octopus‐like artefacts, which will be able to take advantage of some of these ultrastructure characteristics and achieve advanced bioinspired functionalities. Microsc. Res. Tech. 78:1133–1145, 2015. © 2015 Wiley Periodicals, Inc.     

Antiproliferative,Antibacterial and Antifungal Activity of the Lichen Xanthoria parietina and Its Secondary Metabolite Parietin

Lichens are valuable natural resources used for centuries throughout the world as medicine, food, fodder, perfume, spices and dyes, as well as for other miscellaneous purposes. This study investigates the antiproliferative, antibacterial and antifungal activity of the acetone extract of the lichen Xanthoria parietina (Linnaeus) Theodor Fries and its major secondary metabolite, parietin. The extract and parietin were tested for antimicrobial activity against nine American Type Culture Collection standard and clinically isolated bacterial strains, and three fungal strains. Both showed strong antibacterial activity against all bacterial strains and matched clinical isolates, particularly against Staphylococcus aureus from standard and clinical sources. Among the fungi tested, Rhizoctonia solani was the most sensitive. The antiproliferative effects of the extract and parietin were also investigated in human breast cancer cells. The extract inhibited proliferation and induced apoptosis, both effects being accompanied by modulation of expression of cell cycle regulating genes such as p16, p27, cyclin D1 and cyclin A. It also mediated apoptosis by activating extrinsic and intrinsic cell death pathways, modulating Tumor Necrosis Factor-related apoptosis-inducing ligand (TRAIL) and B-cell lymphoma 2 (Bcl-2), and inducing Bcl-2-associated agonist of cell death (BAD) phosphorylation. Our results indicate that Xanthoria parietina is a major potential source of antimicrobial and anticancer substances.     

Optimization of Diarylthiazole B‐Raf Inhibitors: Identification of a Compound Endowed with High Oral Antitumor Activity,Mitigated hERG Inhibition,and Low Paradoxical Effect

Aberrant activation of the mitogen‐activated protein kinase (MAPK)‐mediated pathway components, RAF‐MEK‐ERK, is frequently observed in human cancers and clearly contributes to oncogenesis. As part of a project aimed at finding inhibitors of B‐Raf, a key player in the MAPK cascade, we originally identified a thiazole derivative endowed with high potency and selectivity, optimal in vitro ADME properties, and good pharmacokinetic profiles in rodents, but that suffers from elevated hERG inhibitory activity. An optimization program was thus undertaken, focused mainly on the elaboration of the R¹ and R² groups of the scaffold. This effort ultimately led to N‐(4‐{2‐(1‐cyclopropylpiperidin‐4‐yl)‐4‐[3‐(2,5‐difluorobenzenesulfonylamino)‐2‐fluorophenyl]thiazol‐5‐yl}‐pyridin‐2‐yl)acetamide ( 20 ), which maintains favorable in vitro and in vivo properties, but lacks hERG liability. Besides exhibiting potent antiproliferative activity against only cell lines bearing B‐Raf V600E or V600D mutations, compound 20 also intriguingly shows a weaker “paradoxical” activation of MEK in non‐mutant B‐Raf cells than other known B‐Raf inhibitors. It also demonstrates very good efficacy in vivo against the A375 xenograft melanoma model (tumor volume inhibition >90 % at 10 mg kg^?1); it is therefore a suitable candidate for preclinical development.     

Biodiversity and dynamics of meat fermentations: the contribution of molecular methods for a better comprehension of a complex ecosystem

The ecology of fermented sausages is complex and includes different species and strains of bacteria, yeasts and molds. The developments in the field of molecular biology, allowed for new methods to become available, which could be applied to better understand dynamics and diversity of the microorganisms involved in the production of sausages. Methods, such as denaturing gradient gel electrophoresis (DGGE), employed as a culture-independent approach, allow to define the microbial dynamics during the fermentation and ripening. Such approach has highlighted that two main species of lactic acid bacteria, namely Lactobacillus sakei and Lb. curvatus, are involved in the transformation process and that they are accompanied by Staphylococcus xylosus, as representative of the coagulase-negative cocci. These findings were repeatedly confirmed in different regions of the world, mainly in the Mediterranean countries where dry fermented sausages have a long tradition and history. The application of molecular methods for the identification and characterization of isolated strains from fermentations highlighted a high degree of diversity within the species mentioned above, underlining the need to better follow strain dynamics during the transformation process. While there is an important number of papers dealing with bacterial ecology by using molecular methods, studies on mycobiota of fermented sausages are just a few. This review reports on how the application of molecular methods made possible a better comprehension of the sausage fermentations, opening up new fields of research that in the near future will allow to unravel the connection between sensory properties and co-presence of multiple strains of the same species.     

Storage and Baking Stability of Encapsulated Sour Cherry Phenolic Compounds Prepared from Micro- and Nano-Suspensions

The objective of this study was to investigate storage and baking stability and in vitro digestibility of encapsulated phenolic powders obtained from micro- and nano-suspensions. In addition, it was aimed to study the influence of the incorporation of phenolic capsules into cakes on their quality and sensory attributes. Extraction of phenolic compounds from sour cherry pomace and concentration steps were used to obtain phenolic powders. Half of the concentrate was then freeze dried to produce extracted phenolic powder (EPP) and the rest was centrifuged at 10,000 rpm for 2 min before freeze drying to obtain purified extracted phenolic powder (PEPP). Phenolic powders were mixed with coating material containing 8 % maltodextrin and 2 % gum arabic at a core-to-coating ratio of 1:20 and homogenized by using ultrasound (160 W, 50 % pulse, 20 min). Micro-suspensions and nano-suspensions were prepared using EPP and PEPP, respectively. Suspensions were freeze dried to obtain capsules. Encapsulation had a positive effect on the hygroscopicity, in vitro digestibility and storage and baking stability of phenolic compounds. Loss of total phenolic content (TPC) of encapsulated EPP and PEPP was 10 % and 15 %, respectively, during storage at 43 % relative humidity (RH). Under the same conditions, uncoated EPP and PEPP lost TPC by 37 % and 43 %, respectively. There was no significant difference (p?>?0.05) between encapsulated EPP and PEPP in terms of baking stability. Encapsulation was also effective in the masking of the flavor of the phenolic powders when capsules were incorporated into cakes. In addition, incorporation of capsules did not change quality parameters of cakes adversely.