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排序方式: 共有536条查询结果,搜索用时 15 毫秒
491.
Verena C. Stimberg Johan G. Bomer Iris van Uitert Albert van den Berg Séverine Le Gac 《Small (Weinheim an der Bergstrasse, Germany)》2013,9(7):1076-1085
A microfluidic platform is reported for various experimentation schemes on cell membrane models and membrane proteins using a combination of electrical and optical measurements, including confocal microscopy. Bilayer lipid membranes (BLMs) are prepared in the device upon spontaneous and instantaneous thinning of the lipid solution in a 100‐μm dry‐etched aperture in a 12.5‐μm thick Teflon foil. Using this quasi‐automated approach, a remarkable 100% membrane formation yield is reached (including reflushing in 4% of the cases), and BLMs are stable for up to 36 h. Furthermore, the potential of this platform is demonstrated for (i) the in‐depth characterization of BLMs comprising both synthetic and natural lipids (1,2‐diphytanoyl‐sn‐glycero‐3‐phosphocholine (DPhPC) and L ‐α‐phosphatidylcholine (L ‐α‐PC)/cholesterol, respectively) in terms of seal resistance, capacitance, surface area, specific capacitance, and membrane hydrophobic thickness; (ii) confocal microscopy imaging of phase separation in sphingomyelin/L‐α‐PC/cholesterol ternary membranes; (iii) electrical measurements of individual nanopores (α‐hemolysin, gramicidin); and (iv) indirect assessment of the alteration of membrane properties upon exposure to chemical stimuli using the natural nanopore gramicidin as a sensor. 相似文献
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Peter Frach Dr. Daniel Glöß Dr. Michael Vergöhl Dr. Kerstin Hund-Rinke Dr. Iris Trick Dr. 《真空研究与实践》2007,19(6):20-27
Crystalline TiO2 layers show interesting properties for different applications. Rutile layers can be used as optical layers with high refractive index and as transparent protective layers with good mechanical properties. Both, anatase and rutile are photo-semiconductors and exhibit in a different degree photocatalytic, photo-induced hydrophilic and antifogging properties. For a better control of the TiO2 deposition and thin film properties a special deposition system has been developed: a reactive pulse magnetron sputtering (PMS) system. Layers with different content of crystalline phases were deposited at dynamic deposition rates of about 45 nm·m/min (corresponding to about 160 nm/min in a stationary coating system). Moreover, the anionic doping of the layers succeeded by nitrogen as well as the cationic doping by different metals. The layer structure was determined by XRD. Furthermore, the following properties connected with photo-induced hydrophilicity or photocatalysis were studied: the photo-induced decrease of the water contact angle, the decomposition of methylene blue and lumogen orange as well as the inhibition of algae and bacteria. By doping the layers some of these properties can be improved significantly in comparison to undoped titanium oxide. Some doped layers showed a high activity also under visible irradiation only without UV. 相似文献
494.
This research analyzes the effect on measurement accuracy when taking X-ray diffraction (XRD) measurements on spherical rather than flat surfaces in the assessment of the proportion of retained austenite and martensite phases. By calculating the difference in X-ray absorption paths between a flat surface and spherical surface, this study demonstrates that only in spherical surfaces of small diameter (0.381 cm) will the difference in X-ray absorption path affect the accuracy of measurements derived from XRD. To improve the accuracy of such measurements, the research presents a model for quantifying the absorption path that X-rays follow when measuring spherical surfaces. 相似文献
495.
Modern lifestyles, new demographic trends, and the expansion of the European Community are changing the European countryside. At stake are cultural landscapes, their richness in wildlife, historical interest, scenic beauty, and the recreational opportunities they provide. Visible phenomena of change are symptoms of a growing socio-economic and ecological disparity between different regions. Agreements on AGENDA 2000 European policy provide a new platform for regional and agricultural development. The paper explores which landscape dynamics are in store. Employing examples from rural Germany, the paper presents corridors of possible futures for unique, and at the same time, dynamic places. Modern strategies of landscape and urban planning are discussed which aim at closer co-operation between a multitude of stakeholders, policy makers, planners, and other agents of change. Methods and tools are needed to build consensus among ever increasing numbers of participants representing potentially wide ranges of values. 相似文献
496.
This paper reports on halal credence quality coordination and Muslim consumers' willingness to buy and pay for certified halal labelled meat at the supermarket and the Islamic butcher. Cross-sectional data were collected through a survey with 202 Muslim consumers in Belgium. Findings indicate that more acculturated and female consumers are more in favour of purchasing certified halal labelled meat in a supermarket. Important conditions are that supermarkets can provide a guarantee of separating halal from non-halal meat and of the organisation of adequate verification and control. Results further show that more Muslim consumers are willing to pay a price premium (of 13% on average) for halal labelled meat at the Islamic butcher shop than at the supermarket. The higher the importance attached to a certified halal label and the more distrust in the actual halal meat status, the higher the likelihood that a Muslim consumer is willing to pay a higher price for certified halal labelled meat at the Islamic butcher shop. Gender and generation determine the actual premium Muslim consumers are willing to pay. 相似文献
497.
Chang Chen;Mauricio Espinal-Ruiz;Alyssa Francavilla;Iris J. Joye;Maria G. Corradini; 《Journal of food science》2024,89(7):4331-4344
Color and shape are important quality attributes in baked goods, particularly cookies. Composition and processing conditions determine and influence color development and morphological changes in these baked goods. The objective of this study was to systematically evaluate the evolution of color and shape during baking to determine useful correlations that can be implemented during the assessment and modeling of the baking process. Cookies (AACC-I standard protocol 10-53.01) were baked at 185, 205, and 225°C. Moisture content, water activity, surface temperature, characteristic dimensions (radius and thickness), and color indexes (lightness, redness, blueness, and browning index [BI]) were monitored at different locations on the cookie surface and baking times. Relationships among the tested conditions were explored using correlation analysis. The cookies’ dimensions and color indexes were strongly correlated with changes in moisture content over time, and those relationships were characterized using empirical models. The temperature dependence of the kinetic parameters of the changes in lightness and BI was also described and deemed independent of the location on the cookie surface. This study provides insights into the influence of heat and mass transfer on the physical and physicochemical changes of cookies during baking. The kinetic and secondary models developed in this study can serve as important components for establishing a comprehensive approach for coupling heat transfer, mass transfer, and reaction kinetics to estimate and optimize cookie-baking processes. 相似文献
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ABSTRACTJewish colonies were established in rural areas of Ottoman Palestine in the late nineteenth century; a period full of radical changes, including the industrial revolution, political and cultural shifts in the Ottoman Empire, and social transformations wrought by World War I. These global and local events had a significant impact on everyday life in the colonies, challenging the resilience of the built-up and open public spaces. According to urban space research, the ability of public spaces to withstand change depends on how these spaces are created and defined and the extent to which they evoke a communal sense of ownership and belonging. In light of the above, this paper combines archival and theoretical research in order to examine and characterize the resilience of public spaces in the Jewish colonies in Ottoman Palestine over four decades – from 1878, the foundation of the first colony, to 1918, the end of World War I. Planned and designed by mostly European-educated designers and entrepreneurs, the colonies’ public spaces demonstrated modernity, accommodated change, and created vibrant centres geared to serve a diverse ethnic local population. 相似文献