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31.
ML Heijnen JW Dorigo-Zetsma JW de Jong MJ Sprenger 《Canadian Metallurgical Quarterly》1998,123(3):86-87
The folate receptor, bound to the plasma membrane through a glycosylphosphatidylinositol anchor, requires both sphingolipids and cholesterol in the membrane for full activity. In recent studies, treatment of cells in culture with the mycotoxin fumonisin B1, which inhibits sphingolipid synthesis, virtually abolished uptake of 5-methyltetrahydrofolate. 相似文献
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Balancing of an inverted pendulum with a SCARA robot 总被引:1,自引:0,他引:1
The balancing act of an inverted pendulum with a robotic manipulator is a classical benchmark for testing modern control strategies in conjunction with fast sensor-guided movements. From the control design perspective, it presents a challenging and difficult problem, as the system is open-loop instable and includes nonlinear effects in the actuators, such as friction, backlash, and elasticity. In addition, the necessity of a sensor system that can measure the inclination angles of the pendulum contributes to the complexity of the balancing problem. The pendulum is projected onto the xz and yz planes of the inertial coordinate system. These projections are treated independently from each other and are controlled individually by a state-space controller in the x and y axes, respectively. The nonlinearities of the robot are compensated by using inverse dynamics and inverse kinematics. A specially developed sensor system allows the contactless measurement of the inclination angles of the pendulum. This system consists of a small magnet, placed at the bottom of the pendulum, and Hall-effect sensors placed inside the end effector 相似文献
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Tobias?MettlerEmail authorView authors OrcID profile Michaela?Sprenger Robert?Winter 《欧洲信息系统杂志》2017,26(5):451-468
Changing demands in society and the limited capabilities of health systems have paved the way for robots to move out of industrial contexts and enter more human-centered environments such as health care. We explore the shared beliefs and concerns of health workers on the introduction of autonomously operating service robots in hospitals or professional care facilities. By means of Q-methodology, a mixed research approach specifically designed for studying subjective thought patterns, we identify five potential end-user niches, each of which perceives different affordances and outcomes from using service robots in their working environment. Our findings allow for better understanding resistance and susceptibility of different users in a hospital and encourage managerial awareness of varying demands, needs, and surrounding conditions that a service robot must contend with. We also discuss general insights into presenting the Q-methodology results and how an affordance-based view could inform the adoption, appropriation, and adaptation of emerging technologies. 相似文献
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A novel disk-shaped packed bed micro-reactor containing Rh/ceria/zirconia nanoparticles is investigated with respect to catalytic butane-to-syngas processing at moderate temperatures of 550 °C. The main goal of this study is the development of an efficient butane processor which can be integrated into a micro solid oxide fuel cell system due to its small size, easily packaged geometry in layered microdevices, high compactness, low pressure drop, and low reaction temperature. It is shown that Rh/ceria/zirconia has an excellent long-term stability and achieves very high C4H10 conversion and syngas selectivity, considering the relatively low operating temperature. The yields of H2 and CO can be increased up to 71% and 57%, respectively, by optimizing operational parameters such as the C/O ratio and the total inlet flow rate. The introduced disk-shaped packed bed reactor shows significant advantages in catalytic behavior, at a 6.5 times lower pressure drop compared to an equivalent tubular packed bed reactor. This increased catalytic performance is pursued extensively by investigating possible reaction pathways in three regions of the radial-flow reactor, leading to the significant discovery of a threefold pathway of syngas production on a single catalyst. To this end, it is shown that the excellent selectivities to H2 and CO for high flow rates are due to the combination of partial oxidation, steam reforming, and dry reforming of C4H10, indicating one direct and two indirect reaction paths. 相似文献
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Synthesis of the Human Milk Oligosaccharide Lacto‐N‐Tetraose in Metabolically Engineered,Plasmid‐Free E. coli 下载免费PDF全文
Florian Baumgärtner Dr. Jürgen Conrad Prof. Dr. Georg A. Sprenger Dr. Christoph Albermann 《Chembiochem : a European journal of chemical biology》2014,15(13):1896-1900
Human milk oligosaccharides (HMOs) constitute the third most abundant solid component of human milk. HMOs have been demonstrated to show positive effects on the infant’s well‐being. Despite numerous studies, more physiological analyses of single compounds are needed to fully elucidate these effects. Although being one of the most abundant core structures in human milk, the HMO lacto‐N‐tetraose (LNT) is not available at reasonable prices. In this study, we demonstrate the construction of the first E. coli strain capable of producing LNT in vivo. The strain was constructed by chromosomally integrating the genes lgtA and wbgO, encoding β‐1,3‐N‐acetylglucosaminyltransferase and β‐1,3‐galactosyltransferase. In shake‐flask cultivations, the strain yielded a total concentration of 219.1±3.5 mg L?1 LNT (LNT in culture broth and the cell pellet). After recovery of LNT, structural analysis by NMR spectroscopy confirmed the molecule structure. 相似文献
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Membranes are designed to bridge a precise separation process at the nanoscale with industrial applications running at cubic meters per hour. This review outlines materials applied in membrane production with a particular focus on polymers. Membrane performance and created value are directly linked to controlled pore formation. Their economic relevance has created a number of large companies and associated academic research at top institutions. The authors review, therefore, starts from well‐established techniques applied in products and then moves on to evolving concepts from academia. Pore formation through hard templating is a versatile field for separation processes. A more detailed view is given on the two known concepts for nanopore formation, namely colloidal templates and random hard salt templating. A comparison between these two concepts underlines their relevance to combine a process specific separation with large scale manufacturing requirements (i.e., upscale possibility, flexible process control and environmental impact). 相似文献
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The present study evaluates the effect of heat treatment on electrospun poly(lactide‐co‐glycolide) fibrous membranes. Both a temperature (75–150 °C) and a treatment time range (5–40 min) are tested. The effect on the fibrous structure is investigated in terms of morphology, showing that with increasing temperature or longer treatment time the fusion of fibres progresses continuously. Additionally, the tensile properties of the various scaffolds deliver results on the effect of increasing fibre‐to‐fibre linkages. Both modulus and yield increase within the heat treatment procedures. The elevated stiffness of the membranes accompanies a loss in porosity. These findings deliver insights into the tailoring of membranes that might be used in the fabrication of customised scaffolds intended for cell culture in tissue engineering.