Microorganisms and Cellulose Digestion in the Gut of the Woodlouse Porcellio scaber

In the common woodlouse Porcellio scaber different parts of the gut were observed with respect to microbial counts, cellulose activity, and degradation of cellulose. Cellulose is mainly digested in the anterior part of the hindgut, as was indicated by the distribution of cellulolytic activity and the decrease of cellulose content inside the gut. The cellulases woodlice utilize for the degradation of litter are mainly produced by endosymbiotic bacteria in the hepatopancreas rather than by microorganisms ingested with the food. Microorganisms ingested with the litter are digested in the anterior part of the hindgut and may provide an important food source. In the posterior hindgut, bacterial proliferation ensures microbial colonization of feces.     

Specific Inhibitors of the Breast Cancer Resistance Protein (BCRP)

A new class of specific breast cancer resistance protein (BCRP) inhibitors was identified, showing no inhibition of the ATP binding cassette (ABC) transporters P‐gp and MRP1. Some of these modulators inhibit BCRP with high potency; they are only slightly less potent than Ko143 and could serve as promising lead structures for the design of novel effective BCRP inhibitors. These inhibitors are structurally related to tariquidar (XR9576) and belong to a library of multidrug‐resistance modulators synthesized by our research group. The absence of the tetrahydroisoquinoline substructure appears to play a crucial role for specificity; we found that the presence of this substructure is not essential for interaction with BCRP. To determine the type of interaction between pheophorbide A and compounds with and without the tetrahydroisoquinoline substructure, various substrate pheophorbide A concentrations were used in enzyme kinetics assays. The resulting data show that these compounds share a noncompetitive‐type interaction with pheophorbide A. Experiments with imatinib and pheophorbide A revealed a mixed‐type interaction. The combination of imatinib and compounds with and without the tetrahydroisoquinoline substructure resulted in a positive cooperative effect, indicating that imatinib engages a binding site distinct from that of the new compounds on one side and distinct from that of pheophorbide A on the other side as well. The results of this study suggest that the category of BCRP‐specific inhibitors, which includes only fumitremorgin C, Ko143 and analogues, and novobiocin needs to be extended by this new class of inhibitors, which possess three key characteristics: specificity, potency, and low toxicity.     

Verfahrenstechnische und wirtschaftliche Vorteile der Kochextrusion im Vergleich zu herkömmlichen Verfahren der Lebensmittel-Industrie

Economic and process engineering advantages of extrusion cooking in comparison with conventional processes in the food industry . Extrusion cooking is introduced as a modern high-temperature short-time process. Possible process steps in extruder machine systems, such as continuous conveying, mixing, homogenizing and reactions, mechanical and thermal energy dissipation for plasticizing and modifying biopolymers, are explained. This process creates new products with completely new textures, for example in the snack and breakfast cereal sector, while on the other hand the extrusion process competes with long-standing conventional processes. The latter work slowly with low pressures, low temperatures and energy dissipation with high water contents in large batch-operated machines. The quality of extruder-cooked products depends on the extrusion system. The self-cleaning corotating twin-screw extruder with its narrow residence time spectrum is the optimum system. However, the counter-rotating intermeshing machine has certain advantages for products of low viscosity. The cooking time at high temperature is a matter of seconds, which serves to maintain the properties of the ingredients and active substances, while ensuring fast destruction of microorganisms. The end-products have a long shelf-life on account of their low process moisture content. Continuous extrusion cooking has economic advantages mainly because it replaces many batch processes and because extrusion is carried out entirely or almost entirely with the final moisture content, thus avoiding the necessity to evaporate huge quantities of water.     

High-Temperature Hall Measurements on Cerium Dioxide Thin Films

Simultaneous Hall and conductivity measurements have been performed on sputtered polycrystalline thin films and on bulk ceramic specimens of nearly stoichiometric CeO₂ in the temperature range between 900° and 1040°C. The measurements have been performed in air using low-frequency alternating current. In the case of the bulk ceramic specimens, an upper limit for the carrier mobility of ≤0.2 cm²/(V·s) has been obtained, which is in accordance with data from the literature for bulk samples. The conductivity of the thin films (l/1Ω·m) at 1000°C) is in accordance with data from the literature for bulk ceramics. The carrier density derived from the Hall measurements (3 × 10¹⁶/cm³ at 1000°C) increases with increasing temperature, whereas the Hall mobility (4 cm²(V·s) at 1000°C) decreases with increasing temperature. These values differ from literature data for bulk ceramic specimens. The difference may be duelo the small grain diameters (∼200 nm) in the 1-μm-thick thin films.     

A disaggregate Box-Cox Logit mode choice model of intercity passenger travel in Germany and its implications for high-speed rail demand forecasts

We show that enriching logit mode choice model specification by mode attributes, socio economic variables and trip purpose characteristics significantly improves model quality, and that Box-Cox transformations applied to model attributes imply an asymmetry of the reaction curve, as well as more reasonable properties (diminishing marginal values of time savings, elasticities and values of time that differ among the modes) than those of the linear logit model. Moreover, the model yielded very different high speed rail market shares for Germany than results obtained with the usual linear utility functions. Received: December 1996 / Accepted: April 1997     

Far-off and close-up dry matter intake modulate indicators of immunometabolic adaptations to lactation in subcutaneous adipose tissue of pasture-based transition dairy cows

The common practice of increasing dietary energy density during the close-up dry period (last ～3 wk prepartum) has been recently associated with a higher incidence of metabolic disorders after calving. Despite these reports, over-feeding of metabolizable energy (ME) during the far-off, nonlactating period is a common management policy aimed at achieving optimum calving body condition score (BCS) in pasture-based systems, as cows are generally thinner than total mixed ration cows at the end of lactation. Our hypothesis was that both far-off and close-up overfeeding influence the peripartum adipose tissue changes associated with energy balance and inflammatory state. Sixty mid-lactation, grazing dairy cows of mixed age and breed were randomly allocated to 1 of 2 groups that were managed through late lactation to achieve a low and high BCS (approximately 4.25 and 5.0 on a 10-point scale) at dry-off. The low BCS cows were then overfed ME to ensure that they achieved the same BCS as the higher BCS group by calving. Within each rate of BCS gain treatment, cows were offered 65, 90, or 120% of their pre-calving ME requirements for 3 wk pre-calving in a 2 × 3 factorial arrangement of treatments (i.e., 10 cows/treatment). Subcutaneous adipose tissue was collected via biopsy at ?1, 1, and 4 wk relative to parturition. Quantitative PCR was used to measure mRNA and microRNA expression of targets related to adipogenesis and inflammation. Cows overfed in the far-off period had increased expression of miR-143 and miR-378 prepartum (?1 wk) indicating greater adipogenesis, consistent with their rapid gain in BCS following dry-off. Furthermore, the lower postpartum expression of IL6, TNF, TLR4, TLR9, and miR-145, and a higher abundance of miR-99a indicated lower body fat mobilization in early lactation in the same group. In the close-up period, feeding either 65 or 120% of ME requirements caused changes in FASN, IL1B, IL6R, TLR9, and the microRNA miR-143, miR-155, and miR-378. Their respective expression patterns indicate a tentative negative-feedback mechanism in metabolically compromised, feed-restricted cows, and a possible immune-related stimulation of lipolysis in apparently static adipocytes in overfed cows. Data from cows fed 90% of ME requirements indicate the existence of a balance between lipolytic (inflammatory-related) and anti-lipolytic signals, to prime the mobilization machinery in light of imminent lactation. Overall, results indicate that far-off dry cow nutrition influences peripartum adipose tissue metabolism, with neither strategy negatively affecting the physiological adaptation to lactation. Furthermore, to ensure a favorable transition, cows should be subjected to a small feed restriction in the close-up period, irrespective of far-off nutritional management.     

Graphene oxide covalently functionalized with zinc phthalocyanine for broadband optical limiting

A soluble graphene oxide (GO) covalently functionalized with zinc phthalocyanine (PcZn), GO–PcZn, was synthesized by an amidation reaction. The formation of an amido bond between PcZn and GO has been confirmed by X-ray photoelectron and Fourier transform infrared spectroscopy. At the same level of linear extinction coefficient, GO–PcZn exhibited much larger nonlinear optical extinction coefficients and broadband optical limiting performance than GO at both 532 and 1064 nm, indicating a remarkable accumulation effect as a result of the covalent link between GO and PcZn.     

Wein

Ohne Zusammenfassung