Computed transient solution for the m.s.m. diode with traps

A numerical technique has been developed to simulate a 1-carrier model of the m.s.m. diode with traps. The distributions of free and trapped carriers, and consequently the terminal current, are predicted as functions of time following a step change in the voltage across the device.     

Bovine milk oligosaccharides decrease gut permeability and improve inflammation and microbial dysbiosis in diet-induced obese mice

Obesity is characterized by altered gut homeostasis, including dysbiosis and increased gut permeability closely linked to the development of metabolic disorders. Milk oligosaccharides are complex sugars that selectively enhance the growth of specific beneficial bacteria in the gastrointestinal tract and could be used as prebiotics. The aim of the study was to demonstrate the effects of bovine milk oligosaccharides (BMO) and Bifidobacterium longum ssp. infantis (B. infantis) on restoring diet-induced obesity intestinal microbiota and barrier function defects in mice. Male C57/BL6 mice were fed a Western diet (WD, 40% fat/kcal) or normal chow (C, 14% fat/kcal) for 7 wk. During the final 2 wk of the study, the diet of a subgroup of WD-fed mice was supplemented with BMO (7% wt/wt). Weekly gavage of B. infantis was performed in all mice starting at wk 3, yet B. infantis could not be detected in any luminal contents when mice were killed. Supplementation of the WD with BMO normalized the cecal and colonic microbiota with increased abundance of Lactobacillus compared with both WD and C mice and restoration of Allobaculum and Ruminococcus levels to that of C mice. The BMO supplementation reduced WD-induced increase in paracellular and transcellular flux in the large intestine as well as mRNA levels of the inflammatory marker tumor necrosis factor α. In conclusion, BMO are promising prebiotics to modulate gut microbiota and intestinal barrier function for enhanced health.     

The first dairy product exclusively fermented by Propionibacterium freudenreichii: A new vector to study probiotic potentialities in vivo

Dairy propionibacteria display probiotic properties which require high populations of live and metabolically active propionibacteria in the colon. In this context, the probiotic vector determines probiotic efficiency. Fermented dairy products protect propionibacteria against digestive stresses and generally contain a complex mixture of lactic and propionic acid bacteria. This does not allow the identification of dairy propionibacteria specific beneficial effects. The aim of this study was to develop a dairy product exclusively fermented by dairy propionibacteria. As they grow poorly in milk, we determined their nutritional requirements concerning carbon and nitrogen by supplementing milk ultrafiltrate (UF) with different concentrations of lactate and casein hydrolysate. Milk or UF supplemented with 50 mM lactate and 5 g L⁻¹ casein hydrolysate allowed growth of all dairy propionibacteria studied. In these new fermented dairy products, dairy propionibacteria remained viable and stress-tolerant in vitro during minimum 15 days at 4 °C. The efficiency of milk fermented by the most tolerant Propionibacterium freudenreichii strain was evaluated in piglets. Viability and SCFA content in the colon evidenced survival and metabolic activity of P. freudenreichii. This work results in the design of a new food grade vector, which will allow preclinical and clinical trials.     

Thin-film, flat-panel, composite imagers for projection and tomographic imaging

The recent development of large-area, flat-panel a-Si:H imaging arrays is generally expected to lead to real-time diagnostic and megavoltage X-ray projection imagers with film-cassette-like profiles. While such flat-panel imagers offer numerous advantages over existing fluoroscopic and radiographic imaging devices, the unique properties of the arrays also offer the prospect of detector configurations not previously possible with other real-time technologies. The thin, highly uniform profile of the arrays allows the creation of composite imaging devices in which a flat-panel detector overlies a second imaging detector. A dual-energy (diagnostic and megavoltage) composite imager consisting of a pair of stacked, flat-panel imagers would provide unique information helping to resolve the patient localization and verification problem in megavoltage radiotherapy. In PET or SPECT, attenuation corrections could be obtained by placing a flat-panel array for transmission measurements directly in front of the main emission detector. In this article, the concept of such real-time flat-panel composite imagers is proposed. Specific embodiments of this concept applied toward the resolution of outstanding problems in radiotherapy, PET and SPECT are outlined and calculations and data supporting the feasibility of the concept are presented.     

“It’s the services,stupid!”: Identifying killer applications for next-generation networks

Cities and countries all over the world are currently in the process of developing large-scale broadband projects in order to upgrade their Internet access infrastructure. They justify this costly endeavor of rolling out fiber to the home (FTTH) networks in believing that state-of-the-art ICT infrastructure will function as a growth engine, bridge the digital divide and increase quality of living. In the meantime, they believe it to be simply indispensable because an ever increasing demand for bandwidth-intensive applications is anticipated. The former goals, however, can only be achieved if citizens and companies alike migrate to this new technology. Hence, it is essential to consider the utility of fiber networks for future users and to explore applications that can convince end-users to migrate from their current connections to high-bandwidth networks. By means of an international expert survey, this paper tries to identify value-added services that benefit from fiber’s network potential and that can stimulate users to switch to fiber. Health monitoring, online content storage and management services, and desktop sharing were identified as the most promising fiber applications in the short term based on a combination of technological feasibility, time to reach the mass market and overall persuasiveness. Augmented video applications such as health monitoring and virtual classrooms on the other hand were deemed very persuasive but long-term oriented.