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111.
Which kind of instruction helps children aged 9–14 years interact efficiently with a mobile phone? Due to analogies between navigation in menu structures and the natural environment, three instructions providing different forms of spatial knowledge were under study: A step-by-step instruction featuring landmark knowledge of the menu functions to be selected, a diagram of the menu structure providing survey knowledge and a free exploration of the menu, also giving the children the opportunity to develop survey knowledge. Results show a superiority of the two instructions that provide survey knowledge, except for the youngest children aged 9–10 years. This group showed to have lower spatial abilities and is therefore presumably not able to understand and integrate this type of knowledge. For those very young children, the landmark information given in traditional step-by-step instructions is more helpful. It is concluded, that simple diagrams of the menu structure can help children from 11 years on to significantly ease their interaction with small menu driven devices. 相似文献
112.
Red wine contains a diversity of polyphenolic compounds that exert beneficial health effects including anti-cancer effects. This trial evaluated the anti-proliferative potential of red muscadine (Vitis rotundifolia) and red cabernet sauvignon (Vitis vinifera) wines in cell culture. Chemical properties of wines were determined by HPLC-PDA analysis and concentrated extracts of each wine were evaluated before and after glycosidic hydrolysis in MOLT-4 leukemia cells. Cell growth and the induction of apoptosis were evaluated after exposure to various extract dilutions. Wine extracts reduced cell viability up to 68% and cell numbers up to 50% after 48 h with muscadine extracts being more effective than cabernet sauvignon. Caspase-3 activity was induced similarly by all extracts in a dose dependent manner. Cell cycle arrest in the G2/M phase was observed for both muscadine and the non-hydrolyzed cabernet sauvignon extract. Collectively, extracts from both wines exerted anti-cancer effects in leukemia cells. 相似文献
113.
Natalia Schiefermeier-Mach Violetta Moresco Stephan Geley Lea Heinrich Lukas Lechner Heidi Oberhauser Susanne Perkhofer 《International journal of molecular sciences》2021,22(11)
Inhaled Aspergillus fumigatus spores can be internalized by alveolar type II cells. Cell lines stably expressing fluorescently labeled components of endocytic pathway enable investigations of intracellular organization during conidia internalization and measurement of the process kinetics. The goal of this report was to evaluate the methodological appliance of cell lines for studying fungal conidia internalization. We have generated A549 cell lines stably expressing fluorescently labeled actin (LifeAct-mRuby2) and late endosomal protein (LAMP1-NeonGreen) following an evaluation of cell-pathogen interactions in live and fixed cells. Our data show that the LAMP1-NeonGreen cell line can be used to visualize conidia co-localization with LAMP1 in live and fixed cells. However, caution is necessary when using LifeAct-mRuby2-cell lines as it may affect the conidia internalization dynamics. 相似文献
114.
This study examines the impact of university spillovers on the locational choice of firm formation. Based on a unique and hand-collected data set of high-technology start-ups publicly listed in Germany, this paper tests the propositions that geographic proximity to the university is influenced by the kind of science and type of knowledge spillover. The results provide evidence that younger high technology start-ups (less than eight years old) settle near universities with a high academic output and a high number of students in both natural and social science. Thus, spillover of tacit knowledge has an impact on the firms' geographic decision. Older firms, however, only locate closer to technical universities in order to satisfy demand for traditional German industries such as engineering and machinery. 相似文献
115.
116.
Andrea Nolte Susanne Hossfeld Marcell Post Jan Niederlaender Tobias Walker Christian Schlensak Hans Peter Wendel 《Journal of materials science. Materials in medicine》2014,25(9):2121-2130
Chitosan is used in several pharmaceutical and medical applications, owing to its good cytocompatibility and hemocompatibility. However, there are conflicting reports regarding the biological activities of chitosan with some studies reporting anti-inflammatory properties while others report pro-inflammatory properties. In this regards we analyzed the endotoxin content in five different chitosans and examined these chitosans with their different deacetylation degrees for their hemocompatibility and cytocompatibility. Therefore, we incubated primary human endothelial cells or whole blood with different chitosan concentrations and studied the protein and mRNA expression of different inflammatory markers or cytokines. Our data indicate a correlation of the endotoxin content and cytokine up-regulation in whole blood for Poly-Morpho-Nuclear (PMN)-Elastase, soluble terminal complement complex SC5b-9, complement component C5/C5a, granulocyte colony-stimulating factor, Interleukin-8 (IL), IL-10, IL-13, IL-17E, Il-32α and monocyte chemotactic protein-1. In contrast, the incubation of low endotoxin containing chitosans with primary endothelial cells resulted in increased expression of E-selectin, intercellular adhesion molecule-1, vascular cell adhesion protein-1, IL-1β, IL-6 and IL-8 in endothelial cells. We suggest that the endotoxin content in chitosan plays a major role in the biological activity of chitosan. Therefore, we strongly recommend analysis of the endotoxin concentration in chitosan, before further determining if it has pro- or anti-inflammatory properties or if it is applicable for pharmaceutical and medical fields. 相似文献
117.
Dirk Oliver Schmidt Susanne Hoffmann‐Eifert Hehe Zhang Camilla La Torre Astrid Besmehn Michael Noyong Rainer Waser Ulrich Simon 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(48):6444-6456
Resistively switching devices are considered promising for next‐generation nonvolatile random‐access memories. Today, such memories are fabricated by means of “top–down approaches” applying thin films sandwiched between nanoscaled electrodes. In contrast, this work presents a “bottom–up approach” disclosing for the first time the resistive switching (RS) of individual TiO2 nanoparticles (NPs). The NPs, which have sizes of 80 and 350 nm, respectively, are obtained by wet chemical synthesis and thermally treated under oxidizing or vacuum conditions for crystallization, respectively. These NPs are deposited on a Pt/Ir bottom electrode and individual NPs are electrically characterized by means of a nanomanipulator system in situ, in a scanning electron microscope. While amorphous NPs and calcined NPs reveal no switching hysteresis, a very interesting behavior is found for the vacuum‐annealed, crystalline TiO2–x NPs. These NPs reveal forming‐free RS behavior, dominantly complementary switching (CS) and, to a small degree, bipolar switching (BS) characteristics. In contrast, similarly vacuum‐annealed TiO2 thin films grown by atomic layer deposition show standard BS behavior under the same conditions. The interesting CS behavior of the TiO2–x NPs is attributed to the formation of a core–shell‐like structure by re‐oxidation of the reduced NPs as a unique feature. 相似文献
118.
Ralf Rettig Susanne Steuer Robert F. Singer 《Journal of Phase Equilibria and Diffusion》2011,32(3):198-205
Interdiffusion and impurity diffusion of Ge is studied in Ni and multicomponent alloys over the temperature range of 1150-1250 °C.
The diffusion is investigated using diffusion couples, which are evaluated using microprobe measurements. The interdiffusion
coefficients are calculated with the den Broeder method, while the impurity diffusion coefficients are determined with the
Hall method. A model for the diffusion simulation software DICTRA is developed by mobility assessments. Further on, the diffusion
of Ge in the multicomponent superalloys PWA1483 and René N5 is investigated. The Ge diffusion coefficient in René N5 is 4.5 × 10−14 m2/s at 1180 °C which is similar to other alloying elements such as Co, Cr, Mo or Ta. 相似文献
119.
Scope: Structural‐based recognition of foreign molecules is essential for activation of dendritic cells (DCs) that play a key role in regulation of gut mucosal immunity. Orally ingested non‐starch polysaccharides (NSP) are ascribed many health‐promoting properties, but currently we lack insight into the impact of structure and size for their capacity to affect immune responses. Methods and results: This study addresses the importance of chemical structure, size, origin and presence of contaminants for the capacity of both dietary and non‐food NSP to modulate DC. Of 28 NSP products, β‐glucans of microbial and plant origin and the galactomannan guar gum were found to modulate the DC cytokine pattern induced by the Toll‐like receptor 4‐ligand LPS giving rise to reduced IL‐12p70 and increased IL‐10 levels, whereas IL‐6 production was unaffected. A large proportion of the tested NSP were able to down‐regulate LPS‐induced IL‐12p70 production. The most potent NSP induced up‐regulation of CD86 on DC independently of LPS stimulation. Cereal‐based β‐glucans showed less potency than β‐glucans of microbial origin, but proper molecular weight composition and preparation may improve effectiveness. Conclusions: Collectively, this comparative study revealed that some plant‐derived NSP besides those of microbial origin exert modulation of the DC phenotype, with the exact structure being important for the activity. 相似文献
120.
The degradation of the enantiomers of α-, β-, and γ-hexabromocyclododecane (HBCD) by phase I metabolism was investigated using induced rat liver microsomes. HBCD isomers were quantified using HPLC-MS/MS (ESI(-)) after separation on a combination of a reversed phase and a chiral analytical column. The degradation of all six isomers followed first-order kinetics and the estimated half-lives ranged from 6.3 min for both β-HBCD enantiomers to 32.3 min in case of (+)-γ-HBCD. (+)-α- and (-)-γ-HBCD displayed significantly shorter half-lives than their corresponding antipodes. It could be shown that this degradation led to a significant enrichment of the first eluting enantiomers (-)-α- and (+)-γ-HBCD. Individual patterns of mono- and dihydroxylated derivatives obtained from each α- and γ-HBCD enantiomer were seen to be distinctly characteristic. The patterns of monohydroxylated HBCD derivatives detected in liver and muscle tissues of pollack, mackerel and in herring gull eggs were largely similar to those observed in the in vitro experiments with rat liver microsomes. This enabled individual hydroxy-HBCDs to be assigned to their respective parent HBCD enantiomers. 相似文献