Lactic Acid Bacteria as a Cell Factory for the Delivery of Functional Biomolecules and Ingredients in Cereal-Based Beverages: A Review

In this review, we aim to describe the mechanisms by which LAB can fulfil the novel role of efficient cell factory for the production of functional biomolecules and food ingredients to enhance the quality of cereal-based beverages. LAB fermentation is a safe, economical, and traditional method of food preservation foremost, as well as having the additional benefits of flavor, texture, and nutrition amelioration. Additionally, LAB fermentation in known to render cereal-based foods and beverages safe, in a chemical-free, consumer-friendly manner, from an antinutrient and toxigenic perspective.

Huge market opportunities and potential exist for food manufacturers who can provide the ideal functional beverage fulfilling consumer needs. Newly developed fermented cereal-based beverages must address markets globally including, high-nutrition markets (developing countries), lifestyle choice consumers (vegetarian, vegan, low-fat, low-salt, low-calorie), food-related non-communicable disease sufferers (cardiovascular disease, diabetes), and green label consumers (Western countries). To fulfil these recommendations, a suitable LAB starter culture and cereal-based raw materials must be developed. These strains would be suitable for the biopreservation of cereal beverages and, ideally, would be highly antifungal, anti-mycotoxigenic, mycotoxin-binding and proteolytic (neutralize toxic peptides and release flavor-contributing amino acids) with an ability to ferment cereals, whilst synthesizing oligosaccharides, thus presenting a major opportunity for the development of safe cereal-based prebiotic functional beverages to compete with and replace the existing dairy versions.     

Effects of hydrophobicity of the cathode catalyst layer on the performance of a PEM fuel cell

The effects of hydrophobicity of the cathode catalyst layer on the performance of a PEM fuel cell are studied. The surface contact angle is measured to understand the changes of the hydrophobicity of the cathode catalyst layer upon the addition of hydrophobic dimethyl silicone oil (DSO). The results show that the contact angle increases with the DSO loadings in the cathode catalyst layer ranging from 0 to 0.65 mg/cm². The subsequent electrochemical measurements of the fuel cells with various cathodes reveal that the addition of DSO in the cathode catalyst layer can effectively prevent the cathode flooding at high current density, thus leading to a much higher limiting current density and the maximum power density when compared to the fuel cell with a normal cathode. An optimal DSO loading in the cathode catalyst layer is found to be around 0.5 mg/cm² under the testing conditions in this work. The fuel cell with cathode loaded with 0.5 mg/cm² can reach the maximum power density of 356 mW/cm² in H₂/air (or 709 mW/cm² in H₂/O₂) at room temperature, which is around 2.5 times in H₂/air (or 1.8 times in H₂/O₂) of that with normal cathode. All of the results indicate that the hydrophobicity of the cathode catalyst layer plays a crucial role in the water management of the fuel cell. The possible function of the DSO on improved oxygen solubility for the oxygen starved cathode during flooding warrants some further investigation.     

Blast testing of ultra-high performance fibre and FRP-retrofitted concrete slabs

A series of tests was conducted to investigate the blast resistances of slabs constructed with both plain ultra-high performance fibre concrete (UHPFC) and reinforced ultra-high performance fibre concrete (RUHPFC), and slabs reinforced with externally bonded (EB) fibre reinforced polymer (FRP) plates. Normal reinforced concrete (NRC) slabs were tested as control specimens. LVDTs and pressure transducers were used to record deflection histories, and pressure sensors located at the centre and one edge of the slabs measured airblast pressure histories. The measured pressures at the centre and edge of the slabs were significantly different from those estimated using traditional procedures such as those in TM5-1300. Tests indicated that the plain UHPFC slab had a similar blast resistance to the NRC slab and that the RUHPFC slab was superior to both. The addition of EB carbon FRP plates to the compression face of a reinforced concrete slab increased its ductility and blast resistance. Test results were compared with the maximum energy absorptions predicted from layered capacity analyses of the NRC, retrofitted, plain UHPFC, and RUHPFC specimens.     

Critical variables in the alignment of electrospun PLLA nanofibers

Electrospun polymer nanofibers show promise as components of scaffolds for tissue engineering because of their ability to orient regenerating cells. Our research focuses on aligned electrospun fiber scaffolds for nerve regeneration. Critical to this are highly aligned fibers, which are frequently difficult to manufacture reproducibly. Here we show that three variables: the distance between the spinneret tip and collector, the addition of DMF to the solvent, and placement of an aluminum sheet on the spinneret together greatly improve the alignment of electrospun poly-L-lactide (PLLA) nanofibers. We identified the most important variable as tip-to-collector distance. Nanofiber alignment was maximal at 30 cm compared to shorter distances. DMF:chloroform (1:9) improved nanofiber uniformity and was integral to maintaining a uniform stream over the 30 cm tip-to-collector distance. Other ratios caused splattering of the solution or flattening or beading of the fibers and non-uniform fiber diameter. The aluminum sheet helped to stabilize the electric field and improve fiber alignment provided that it was placed at 1 cm behind the tip, while other distances destabilized the stream and worsened alignment. This study demonstrates that control of these variables produces dramatic improvement in reproducibly obtaining high alignment and uniform morphology of electrospun PLLA nanofibers.     

A REBIC and CL study of interfaces in a zinc oxide based varistor

Conductive mode (CM) and cathodoluminescence (CL) microscopy techniques were used to study grain boundary structures in a zinc oxide based varistor, doped with 0.5 mol % Bi₂O₃ and 0.5 mol % Sb₂O₃. By combining these two techniques specific details of the electrical and luminescence properties of individual interfaces could be characterised. CM imaging clearly showed the presence of potential barriers at the grain boundaries. The same grain boundaries were regions of strong CL emission. It is suggested that the dominant CL emission at grain boundaries in this material originates from self-excitation centres at impurities and/or defects within the structure rather than the direct recombination of electron-hole pairs across the forbidden band gap.     

Service profiling and outcomes benchmarking using the CORE-OM: Toward practice-based evidence in the psychological therapies.

To complement the evidence-based practice paradigm, the authors argued for a core outcome measure to provide practice-based evidence for the psychological therapies. Utility requires instruments that are acceptable scientifically, as well as to service users, and a coordinated implementation of the measure at a national level. The development of the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) is summarized. Data are presented across 39 secondary-care services (n?=?2,710) and within an intensively evaluated single service (n?=?1,455). Results suggest that the CORE-OM is a valid and reliable measure for multiple settings and is acceptable to users and clinicians as well as policy makers. Baseline data levels of patient presenting problem severity, including risk, are reported in addition to outcome benchmarks that use the concept of reliable and clinically significant change. Basic quality improvement in outcomes for a single service is considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

THE ADSORPTION OF HOP SUBSTANCES ON THE YEAST CELL WALL

The adsorption of hop substances on to the yeast cell wall, as distinct from the total loss during fermentation, followed the classical pattern of the Freundlich adsorption isotherm with both top and bottom fermentation yeasts. In order to avoid adventitious contamination of the yeasts by hop compounds during head formation, the fermentations were not fully attenuated. The three yeasts adsorbed closely similar proportions of hop substances from fermenting worts of the same composition, but the actual amount differed from one series of fermentations to another. The losses of bitter compounds during the fermentations were only partly accounted for by adsorption on the yeast.     

Local variability in PTC thermistor grain boundary structures

Scanning electron microscopy-based conductive mode (CM) microscopy, using the remote electron beam-induced current configuration, was carried out on a positive temperature coefficient of resistance thermistor at temperatures below and above the Curie temperature, T(C). Below T(C), when the thermistor is in a low resistance state, no strong CM contrast was observed. Above T(C) the thermistor grain boundaries become highly resistive and significant CM contrast formed owing to three mechanisms: all of the areas that were studied showed resistive contrast, but in addition some grain boundaries showed additional contrast due to electron beam-induced current, the origin of which was consistent with the presence of a back-to-back Schottky barrier structure at the grain boundary. Other grain boundaries exhibited additional contrast owing to beta-conductivity, which suggests a slightly different n-i-n grain boundary structure at these interfaces. These results suggest that electrically active grain boundaries with different structures coexist within the thermistor.