Common tea formulations modulate in vitro digestive recovery of green tea catechins

Epidemiological evidence suggests a role for tea catechins in reduction of chronic disease risk. However, stability of catechins under digestive conditions is poorly understood. The objective of this study was to characterize the effect of common food additives on digestive recovery of tea catechins. Green tea water extracts were formulated in beverages providing 4.5, 18, 23, and 3.5 mg per 100 mL epicatechin (EC), epigallocatechin (EGC), epigallocatechin-gallate (EGCG), and epicatechin-gallate (ECG), respectively. Common commercial beverage additives; citric acid (CA), BHT, EDTA, ascorbic acid (AA), milk (bovine, soy, and rice), and citrus juice (orange, grapefruit, lemon, and lime) were formulated into finished tea beverages at incremental dosages. Samples were then subjected to in vitro digestion simulating gastric and small intestinal conditions with pre- and post-digestion catechin profiles assessed by HPLC. Catechin stability in green tea was poor with <20% total catechins remaining post-digestion. EGC and EGCG were most sensitive with less, not double equals 10% recovery. Teas formulated with 50% bovine, soy, and rice milk increased total catechin recovery significantly to 52, 55, and 69% respectively. Including 30 mg AA in 250 mL of tea beverage significantly (p<0.05) increased catechin recovery of EGC, EGCG, EC, and ECG to 74, 54, 82, and 45% respectively. Juice preparation resulted in the highest recovery of any formulation for EGC (81-98%), EGCG (56-76%), EC (86-95%), and ECG (30-55%). These data provide evidence that tea consumption practices and formulation factors likely impact catechin digestive recovery and may result in diverse physiological profiles.     

Multiposture leg tracking for temporarily vision restricted environments based on fusion of laser and radar sensor data

Leg tracking is an established field in mobile robotics and machine vision in general. These algorithms, however, only distinguish the scene between leg and nonleg detections. In application fields like firefighting, where people tend to choose squatting or crouching over standing postures, those methods will inevitably fail. Further, tracking based on a single sensor system may reduce the overall reliability if brought to outdoor or complex environments with limited vision on the target objectives. Therefore, we extend our recent work to a multiposture detection system based on laser and radar sensors, that are fused to allow for maximal reliability and accuracy in scenarios as complex as indoor firefighting with vastly limited vision. The proposed tracking pipeline is trained and extensively validated on a new data set. We show that the radar tracker reaches state-of-the-art performance, and that laser and fusion tracker outperform recent methods.     

Synthesen 3-substituierter 7,8-Dimethyl-1,5-dihydro-2,4-benzdithiepine

Synthesis of 3-Substituted 7,8-Dimethyl-1,5-dihydro-2,4-benzdithiepines 7,8-Dimethyl-1,5-dihydro-2,4-benzdithiepines substituted in 3-position are available from the dithiol 1 and aldehydes or acetales. By chlorination of the dithiepin 6 the 3-chloro-dithiepin 3 is formed, which was not available in pure state, but can be transformed in situ with N- or C-nucleophiles into the respective 2 -derivatives. By oxidation of 6 using chloramin T and subsequent reaction with methanol the 3-methoxy derivative 4 is formed via the S-tosyliminocompound 5 .     

Comparison of p-n junction and inversion-layer silicon solar cells by means of experiment and simulation

Inversion-layer solar cells can be fabricated on crystalline silicon in a time- and energy-efficient way. In this article we experimentally investigate inversion layer cells of the type developed in the 1980s at the University of Erlangen. The best cell has an independently confirmed one-sun efficiency of 15.7%, the highest reported to date for this simple cell technology. In order to gain insight into the performance-limiting mechanisms, these cells are compared to p-n junction cells fabricated on identical substrates. Subsequently, the impact of the most important emitter parameters on the performance of both cell types is determined by means of two-dimensional numerical modelling. These simulations reveal that inversion-layer cells can principally produce the same efficiencies (> 23%) as p-n junction cells, provided the emitter parameters are properly adjusted and the front contact is of a sufficiently high quality. Therefore, a research project is presently under way at ISFH aiming at an improvement of inversion-layer cell efficiency above 18%. The basis for these new cells is the fact that silicon nitride films deposited at higher temperatures (∼400°C) demonstrate strongly improved passivation properties compared to the present 250° C silicon nitride films.     

Quantitative Element-Sensitive Analysis of Individual Nanoobjects

A reliable and quantitative material analysis is crucial for assessing new technological processes, especially to facilitate a quantitative understanding of advanced material properties at the nanoscale. To this end, X-ray fluorescence microscopy techniques can offer an element-sensitive and non-destructive tool for the investigation of a wide range of nanotechnological materials. Since X-ray radiation provides information depths of up to the microscale, even stratified or buried arrangements are easily accessible without invasive sample preparation. However, in terms of the quantification capabilities, these approaches are usually restricted to a qualitative or semi-quantitative analysis at the nanoscale. Relying on comparable reference nanomaterials is often not straightforward or impossible because the development of innovative nanomaterials has proven to be more fast-paced than any development process for appropriate reference materials. The present work corroborates that a traceable quantification of individual nanoobjects can be realized by means of an X-ray fluorescence microscope when utilizing rather conventional but well-calibrated instrumentation instead of reference materials. As a proof of concept, the total number of atoms forming a germanium nanoobject is quantified using soft X-ray radiation. Furthermore, complementary dimensional parameters of such objects are reconstructed.