Potential Antigenic Candidates for the Development of Peptide-Based Vaccines to Induce Immunization against Helicobacter pylori Infection in BALB/c Mice

Helicobacter pylori (H. pylori) has been identified as a group-1 definite carcinogen. As of yet, there is no available vaccine for this microorganism. Our study aimed to identify antigenic peptides in H. pylori using an in silico proteomic approach, and to evaluate their effectiveness as potential vaccine candidates. Four different peptide sequences were prioritized using the reverse vaccinology, namely, CagA¹, CagA², VacA, and SabA. Peptides emulsified with Freunde’s adjuvant were used to immunize BALB/C mice. Subcutaneously immunized mice were challenged by oral administration of H. pylori. IgG, IgA, IL4, and IL17 were detected in mice sera. Histopathology of the dissected stomach of vaccinated and control mice were assessed using H&E stain. IgG was significantly higher in mice vaccinated with SabA. IL-4 was significantly increased in CagA¹, CagA², VacA, and SabA vaccinated mice compared to the adjuvant group. Additionally, histopathological examination of gastric tissue showed a protective effect in the vaccinated groups compared to adjuvant and PBS groups. Our findings indicate a promising effect of the tested epitopes, particularly the SabA antigen, to induce an immune response against H. pylori.     

Alterations to Cerebral Perfusion,Metabolite Profiles,and Neuronal Morphology in the Hippocampus and Cortex of Male and Female Mice during Chronic Exposure to a High-Salt Diet

Excess dietary salt reduces resting cerebral blood flow (CBF) and vascular reactivity, which can limit the fueling of neuronal metabolism. It is hitherto unknown whether metabolic derangements induced by high-salt-diet (HSD) exposure during adulthood are reversed by reducing salt intake. In this study, male and female mice were fed an HSD from 9 to 16 months of age, followed by a normal-salt diet (ND) thereafter until 23 months of age. Controls were continuously fed either ND or HSD. CBF and metabolite profiles were determined longitudinally by arterial spin labeling magnetic resonance imaging and magnetic resonance spectroscopy, respectively. HSD reduced cortical and hippocampal CBF, which recovered after dietary salt normalization, and affected hippocampal but not cortical metabolite profiles. Compared to ND, HSD increased hippocampal glutamine and phosphocreatine levels and decreased creatine and choline levels. Dietary reversal only allowed recovery of glutamine levels. Histology analyses revealed that HSD reduced the dendritic arborization and spine density of cortical and hippocampal neurons, which were not recovered after dietary salt normalization. We conclude that sustained HSD exposure throughout adulthood causes permanent structural and metabolic alterations to the mouse brain that are not fully normalized by lowering dietary salt during aging.     

Assessment of reservoir heterogeneity by using produced water chemistry in SAGD

The key challenge of extracting oil from oil sand reservoirs is the viscosity of the oil which is typically between 100 000 and several million cP. To reduce the viscosity of the oil, high pressure, high temperature steam, typically between about 185 and 250 °C, is injected into the reservoir by using recovery processes such as the steam‐assisted gravity drainage (SAGD) process. In this process, steam heats the bitumen and as a consequence, its viscosity drops to about 5 cP and it readily flows under gravity within the reservoir. One key issue that has not gained much attention with respect to SAGD process evolution are steam–rock reactions, water geochemistry, and how the produced water composition varies as the process evolves. Here, we examine how the produced water composition varies in SAGD operations. For the first time, we show that the produced water composition can be used to detect shale barriers and contact of the steam chamber with the overburden. As yet, the produced water composition is not used to understand in situ process development but as we show here, this could be a rich data source for understanding process dynamics. Copyright © 2016 John Wiley & Sons, Ltd.     

Rye secalin characterisation and use to improve zein-based film performance

Rye prolamins (secalin) were extracted, characterised and used as biopolymer source to produce plasticised films, as well as composite films in the presence of corn zein. Secalin film showed lower contact angle values and higher moisture content, solubility and swelling index than zein film, whereas the water vapour permeability of the two films was not different. Also, secalin film exhibited lower tensile strength and Young’s modulus and higher elongation at break. The average functional properties of the secalin/zein blend were morphologically confirmed by SEM analysis of the composite film surface that showed a good miscibility and compatibility of the two different biopolymers. These results indicated that secalin films were less hydrophobic and more flexible than those previously prepared by using other prolamins, whereas a material with hydrophobic features similar to those of zein films and a flexibility comparable to that exhibited by secalin films was obtained by preparing a secalin/zein blend.     

One-factor-at-a-time (OFAT) optimization of hemicellulases production from Fusarium moniliforme in submerged fermentation

Hemicellulose degrading enzymes play an important role in bioconversion of lignocellulosic and agro-industrial wastes. In this study, production of hemicellulase by six fungal isolates was determined under submerged culture using corn cobs xylan as a carbon source and enzyme inducer at different incubation periods. The results indicated that Alternaria tenuis showed the lowest enzyme productivity (156.95 ± 2.07U/l) while the highest enzyme production (2,594.44 ± 62.25 U/l) was obtained by Fusarium moniliforme. One-factor-at-a-time revealed maximum enzyme productivity of 10,950.11 ± 98.45 U/l at corn cobs xylan (6 g/l), yeast extract (4 g/l), inorganic salts (1.5 g/l KH₂PO₄, 1.0 g/l MgSO₄.7H₂O, 0.2 g/l CaCl₂, 0.4 g/l FeSO₄.7H₂O, and 0.3 g/l MnSO₄.5H₂O), initial pH (5), initial inoculum size (4%), 150 rpm, and temperature (30°C) in a submerged fermentation process.     

An efficient,clean synthesis of 3,3′-(arylmethylene)bis(2-hydroxynaphthalene-1,4-dione) derivatives

A clean, simple and efficient method for the synthesis of 3,3′-(arylmethylene)bis(2-hydroxynaphthalene-1,4-dione) derivatives has been developed which uses the reaction of 2-hydroxynaphthalene-1,4-dione and aromatic aldehydes in the presence of a catalytic amount of LiCl in aqueous media. To the best of our knowledge, this is the first report on such a synthesis of 3,3′-(arylmethylene)bis(2-hydroxynaphthalene-1,4-dione).     

A novel symmetrical 4H–SiC MESFET: an effective way to improve the breakdown voltage

In this paper, a novel symmetrical structure (SS) of 4H–SiC metal semiconductor field effect transistor (MESFET) as an effective way to improve the breakdown voltage is presented. The key idea in this work is to improve the breakdown voltage, maximum output power density, and frequency parameters of the device using a symmetrical structure with recessed gate. The SS-MESFET modifies the electric field in the drift layer significantly. The influence of the SS-MESFET on the saturation current, breakdown voltage \((\hbox {V}_{\mathrm{BR}})\), and small-signal characteristics of the SS-MESFET are studied by numerical device simulation. Using two-dimensional device simulation, we demonstrate that the breakdown voltage \((\hbox {V}_{\mathrm{BR}})\) improved by factors 2.5 and 3.3 in comparison with an asymmetrical conventional MESFET structure (AC-MESFET) and a symmetrical conventional MESFET structure (SC-MESFET), respectively. Also, the maximum output power density \((\hbox {P}_{\mathrm{max}})\) improved about by 93 and 250 % in comparison with the AC-MESFET and SC-MESFET structures, respectively. So, the SS-MESFET shows the superior maximum available gain (MAG), unilateral power gain (U), and current gain \((\hbox {h}_{12})\) which is presenting the proposed structure is more suitable device for high power microwave applications.     

An efficient fully bio‐based reactive diluent for epoxy thermosets: 2‐[(Oxiran‐2‐ylmethoxy) methyl] furan versus a petroleum‐based counterpart

Furfuryl alcohol and bio‐based epichlorohydrin were used to prepare a fully bio‐based reactive diluent, 2‐[(oxiran‐2‐ylmethoxy) methyl] furan (FOM). After spectral characterization, FOM was blended with epoxy resin, diglycidylether bisphenol A (DGEBA), at different ratios for reducing the viscosity. For a comparison, Cardura (one of the most common commercial reactive diluents), was separately incorporated to DGEBA. Amine‐curing process of the blends was recorded by FTIR and DSC. Similar trends of curing progression for DGEBA containing the reactive diluents were observed. Thermogravimetric analysis and dynamic mechanical thermal analysis, mechanical (hardness, adhesion, and stress–strain) and morphological properties were also investigated to study characteristics of the epoxy matrices formulated with FOM or Cardura. It was concluded that FOM could be considered as an efficient reactive diluent in formulations of polymer composites, structural adhesives and surface coatings based on epoxy resins. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44957.