Evaluation of <Emphasis Type="Italic">flaA</Emphasis> Short Variable Region Sequencing,Multilocus Sequence Typing,and Fourier Transform Infrared Spectroscopy for Discrimination between <Emphasis Type="Italic">Campylobacter jejuni</Emphasis> Strains

Discriminatory and robust typing methods are needed to improve the understanding of the dynamics of food-borne Campylobacter infections and epidemiology in primary animal production. To evaluate the strain discriminatory potential of typing methods, flaA short variable region (SVR) sequencing and Fourier transform infrared (FTIR) spectroscopy were applied on a collection of 102 epidemiologically related and unrelated Campylobacter jejuni strains. Previous application of FTIR spectroscopy for subtyping of Campylobacter has been limited. A subset of isolates, initially discriminated by flaA SVR sequencing, were further subjected to multilocus sequence typing (MLST). It was found that flaA SVR sequencing had a slightly higher discriminatory power than FTIR spectroscopy, based on the Simpson diversity index. The clustering of strains indicated that FTIR spectroscopy is indeed a suitable method for discrimination of Campylobacter. The isolates were assigned to six clusters based on flaA SVR sequences and nine clusters based on the FTIR spectroscopy profiles. Furthermore, the cluster analysis of flaA SVR sequences, MLST, and FTIR spectroscopy profiles showed a high degree of congruence, assigning the isolates to similar cluster structures. In conclusion, FTIR spectroscopy can be applied for subtyping of Campylobacter, and the high discriminatory potential of both flaA SVR sequencing and FTIR spectroscopy render them suitable screening methods for large numbers of strains.     

Geranylgeraniol and Neurological Impairment: Involvement of Apoptosis and Mitochondrial Morphology

Deregulation of the cholesterol pathway is an anomaly observed in human diseases, many of which have in common neurological involvement and unknown pathogenesis. In this study we have used Mevalonate Kinase Deficiency (MKD) as a disease-model in order to investigate the link between the deregulation of the mevalonate pathway and the consequent neurodegeneration. The blocking of the mevalonate pathway in a neuronal cell line (Daoy), using statins or mevalonate, induced an increase in the expression of the inflammasome gene (NLRP3) and programmed cell death related to mitochondrial dysfunction. The morphology of the mitochondria changed, clearly showing the damage induced by oxidative stress and the decreased membrane potential associated with the alterations of the mitochondrial function. The co-administration of geranylgeraniol (GGOH) reduced the inflammatory marker and the damage of the mitochondria, maintaining its shape and components. Our data allow us to speculate about the mechanism by which isoprenoids are able to rescue the inflammatory marker in neuronal cells, independently from the block of the mevalonate pathway, and about the fact that cell death is mitochondria-related.     

Matter Timed

At best, the ageing of materials is regarded as lending a patina to historic buildings. In reality, however, materials often age disgracefully and unevenly, requiring a high level of maintenance and refurbishment. What if materials could be engineered and integrated into buildings not only to enhance but to heal? Martina Decker , Assistant Professor in the College of Architecture and Design at the New Jersey Institute of Technology (NJIT), looks at pioneering research that is being undertaken into performative, time-dependent materials.     

Lake extent changes in Basotu,Tanzania: a mixed-methods approach to understanding the impacts of anthropogenic influence and climate variability

Incompatible land use is a major contributor to ecosystem degradation, and is often exacerbated by climate change impacts. We investigate Lake Basotu, Tanzania as a case study where natural lake variability has been affected by agricultural land use. Comparisons between a satellite-derived history of lake surface area, local precipitation records, and corresponding anthropogenic activity show the impacts of agricultural and historical practices. We argue that insufficient consideration to the wider ecological impacts of large agricultural projects has lasting implications. This is particularly true in semi-arid environments where food production demands need to be continuously met. In the future, major conservation strategies should be investigated to maintain the environmental integrity and sustainability of freshwater resources.     

Preceramic polymer‐derived SiOC fibers by electrospinning

Silicon oxycarbide (SiOC) fibers with different chemical compositions were successfully fabricated by electrospinning a mixture of polyvinylpyrrolidone (PVP) and commercially available polymethylsilsesquioxane (MK) or polymethylphenylsilsesquioxane (H44) preceramic polymers, followed by cross‐linking and pyrolysis at 1000°C in Argon. The influence of the processing procedure (solvent selection, cross‐linking catalyst and additives) on the morphology of the produced fibers was investigated. For the MK/isopropanol system, the introduction of 20 vol% N,N‐dimethylformamide (DMF) enabled to decrease the diameter of the as‐spun fibers from 2.72 ± 0.12 μm to 1.65 ± 0.09 μm. For the H44/DMF systems, beads‐free fibers were obtained by adding 50 vol% choloroform. After pyrolysis, the resultant SiOC fibers derived from MK and H44 resins possessed uniform morphology, with an average diameter of 0.97 ± 0.07 μm and 1.07 ± 0.08 μm, respectively. Due to their different chemical compositions, the MK‐derived and H44‐derived SiOC ceramic fibers could find different potential applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39836.     

How Different Characterization Techniques Elucidate the Nature of the Gold Species in a Polycrystalline Au/TiO2 Catalyst

TiO₂‐supported gold species were prepared via the deposition‐precipitation route, with conservation of the initial speciation by freeze‐drying. The structural and electronic properties of the Au species were investigated by X‐ray absorption spectroscopy, electron microscopy, and IR spectroscopy of adsorbed CO in four states. Exclusively Au^III was deposited on the TiO₂ surface in patches ranging from isolated Au ions to three‐dimensional clusters. This paper illustrates in detail the unique contributions of all characterization techniques to this structural model.     

Functional mesoporous poly(ionic liquid)-based copolymer monoliths: From synthesis to catalysis and microporous carbon production

Ionic liquid-functionalized mesoporous polymeric networks with specific surface area up to 935 m²/g have been successfully synthesized one pot by solvothermal copolymerization of divinylbenzene and monomeric ionic liquids. The as-obtained polymers exhibit a monolithic structure featuring large pore volumes, an abundant mesoporosity and an adjustable content of ionic liquids. The effect of the reaction conditions on the pore structure has been studied in detail. These poly(ionic liquid)-based porous networks (PILPNs) have then been employed as precursors in two distinct applications, namely organocatalysis and production of microporous carbon monoliths. Selected organocatalyzed reactions, including carbonatation of propylene oxide by cycloaddition with carbon dioxide, benzoin condensation, and cyanosilylation of benzaldehyde have been readily triggered by PILPNs acting as crosslinked polymer-supported (pre)catalysts. The two latter reactions required the prior deprotonation of the imidazolium salt units with a strong base to successfully generate polymer-supported N-heterocyclic carbenes, referred to as poly(NHC)s. Facile recycling and reuse of polymer-supported (pre)catalysts was achieved by simple filtration owing to the heterogeneous reaction conditions. Furthermore, PILPNs could be easily converted into microporous carbon monoliths via CO₂ activation.     

Particle Size of Whole Meal Rye Bread does not Affect the Digestibility of Macro-Nutrients and Non-Starch Polysaccharides and the Energy Value of Dietary Fibre in Humans

The effect of particle size of whole meal rye bread on the apparent digestibility of macro-nutrients, non-starch polysaccharides (NSP) and energy, the energy value of rye NSP and on faecal weight was studied in balance experiments in seven young women. The whole meal breads were prepared from one single batch of rye milled to two different particle sizes (coarse bread: 50% of particles >2 mm, 90% >1 mm; fine bread: 86% of particles <0·5 mm, 58% <0·2 mm). Two diets containing either coarse (350 g day⁻¹) or fine (377 g day⁻¹) whole meal bread and a low fibre control diet were consumed for 3 weeks each in a 3×3 cross-over design. Relative to the low fibre control diet, digestibility of protein, NSP and energy was significantly lower for the diets containing the whole meal breads. Digestibility of fat was the same for all diets. Partial digestible energy value for each g of NSP from coarse and fine whole meal rye bread was calculated to be −3±7 and 1±5 kJ, respectively. There were no differences between coarse and fine whole meal rye bread in the effects on the parameters measured with the exception on faecal wet weight, which was higher for the coarse bread diet.     

Sustainable Bioactive Packaging Based on Thermoplastic Starch and Microalgae

This study combines the use of corn starch and Tetradesmus obliquus microalgae for the production of antioxidant starch films as flexible packaging material. Starch was plasticized with glycerol and blended with 1 w% polyallylamine chosen as an agent to modify the film physical properties. The addition of polyallylamine improved film water stability and water vapor transmission rate as well as mechanical stiffness and tenacity. The dried Tetradesmus obliquus microalgae, which showed an EC₅₀ value of 2.8 mg/mg DPPH (2.2-Diphenyl-1-picrylhydrazyl radical), was then used as antioxidant filler. The addition of microalgae provided the films with good antioxidant activity, which increased with microalgae content increasing. To our knowledge, this is the first study reporting the development of sustainable bioactive packaging films composed of almost 100% starch, and follows the European union’s goals on plastics strategy concerning the promotion of bio-based, compostable plastics and the setting up of approaches to prevent food waste with a simple plastic packaging.