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41.
We previously characterized a Na+/H+ exchange activity in rat pancreatic zymogen granules [Anderie, I., and Thévenod, F. (1996) J. Membrane Biol, 152, 195-205]. Here we have identified the Na+/H+ exchanger (NHE) isoforms present in zymogen granules by functional studies with NHE inhibitors. The NHE1 specific blocker HOE 694 [3-(methylsulfonyl-4-piperidino-benzoyl)-guanidine methanesulfonate] inhibited zymogen granule Na+/H+ exchange in a concentration dependent manner, maximally to 53 +/- 5% of controls at 100nM. The remaining Na+/H+ exchange activity was inhibitable by EIPA [5-(N-ethyl-N-isopropyl)amiloride] (EC50 approximately 25 microM) or benzamil (EC50 approximately 100 microM). Amiloride inhibited weakly suggesting that "amiloride-resistant" and "amiloride-sensitive" NHE are expressed in zymogen granules. cDNA sequences encoding NHE1- and NHE4-specific transmembrane domains were detected by RT-PCR in rat pancreatic tissue and in the rat pancreatic acinar cell line AR4-2J. The presence of NHE1 and NHE4 in zymogen granule membranes was confirmed by immunoblots of zymogen granule membranes and by pre-embedding immunogold labeling of purified rat pancreatic zymogen granules with polyclonal NHE1 and NHE4 antibodies. Therefore, we propose that NHE1 and NHE4 are expressed in zymogen granule membranes of rat exocrine pancreas.  相似文献   
42.
For the effective alignment of ontologies, the subsumption mappings between the elements of the source and target ontologies play a crucial role, as much as equivalence mappings do. This paper presents the “Classification-Based Learning of Subsumption Relations” (CSR) method for the alignment of ontologies. Given a pair of two ontologies, the objective of CSR is to learn patterns of features that provide evidence for the subsumption relation among concepts, and thus, decide whether a pair of concepts from these ontologies is related via a subsumption relation. This is achieved by means of a classification task, using state of the art supervised machine learning methods. The paper describes thoroughly the method, provides experimental results over an extended version of benchmarking series of both artificially created and real world cases, and discusses the potential of the method.  相似文献   
43.
A process for deep trench filling by BenzoCycloButene (BCB) polymer is explored. Deep trenches with 100-μm depth and different aspect ratios from 1.4 to 20 have been successfully filled by BCB. Besides, chemical mechanical polishing (CMP) of BCB is studied with the main goals of smoothing surface topography of substrate after BCB filling and removing excess BCB coating which may be necessary in some applications. Removal rate for BCB, V RR, of about 0.24 μm/min has been achieved for hard cured BCB films using acid slurry. After CMP, the BCB layer showed a roughness of about 1.36 nm (Rq, measured by atomic force microscopy, AFM).  相似文献   
44.
OBJECTIVE: An evaluation study was conducted to answer the question of which system properties of night vision enhancement systems (NVESs) provide a benefit for drivers without increasing their workload. BACKGROUND: Different infrared sensor, image processing, and display technologies can be integrated into an NVES to support nighttime driving. Because each of these components has its specific strengths and weaknesses, careful testing is required to determine their best combination. METHOD: Six prototypical systems were assessed in two steps. First, a heuristic evaluation with experts from ergonomics, perception, and traffic psychology was conducted. It produced a broad overview of possible effects of system properties on driving. Based on these results, an experimental field study with 15 experienced drivers was performed. Criteria used to evaluate the development potential of the six prototypes were the usability dimensions of effectiveness, efficiency, and user satisfaction (International Organization for Standardization, 1998). RESULTS: Results showed that the intelligibility of information, the easiness with which obstacles could be located in the environment, and the position of the display presenting the output of the system were of crucial importance for the usability of the NVES and its acceptance. Conclusion: All relevant requirements are met best by NVESs that are positioned at an unobtrusive location and are equipped with functions for the automatic identification of objects and for event-based warnings. APPLICATION: These design recommendations and the presented approach to evaluate the systems can be directly incorporated into the development process of future NVESs.  相似文献   
45.
The broad range of capabilities exhibited by humans and animals is achieved through a large set of heterogeneous, tightly integrated cognitive mechanisms. To move artificial systems closer to such general-purpose intelligence we cannot avoid replicating some subset—quite possibly a substantial portion—of this large set. Progress in this direction requires that systems integration be taken more seriously as a fundamental research problem. In this paper I make the argument that intelligence must be studied holistically. I present key issues that must be addressed in the area of integration and propose solutions for speeding up rate of progress towards more powerful, integrated A.I. systems, including (a) tools for building large, complex architectures, (b) a design methodology for building realtime A.I. systems and (c) methods for facilitating code sharing at the community level.
Kristinn R. ThórissonEmail:
  相似文献   
46.
Mobile communications beyond 3G will integrate different (but complementary) access technologies into a common platform to deliver value-added services and multimedia content in an optimum way. However, the numerous possible configurations of mobile networks complicated the dynamic deployment of mobile applications. Therefore, research is intensely seeking a service provisioning framework that is technology-independent, supports multiple wireless network technologies, and can interwork high-level service management tasks to network management operations. This paper presents an open value chain paradigm, a model for downloadable applications and a mediating platform for service provisioning in beyond 3G mobile settings. Furthermore, we introduce mechanisms that support a coupled interaction between service deployment and network configuration operations, focusing on the dynamic provisioning of QoS state to data path devices according to the requirements of dynamically downloadable mobile value-added services (VAS).
Vangelis GazisEmail:
  相似文献   
47.
Mechanische Sensoren zur Drehzahl- und Lageerfassung bei elektrischen Antrieben verursachen Kosten, vergrößern das Bauvolumen des Antriebs, bedingen die Datenübertragung zwischen Regler und Sensor und schränken das Einsatzgebiet des Antriebs ein. Daher wurden verschiedene Konzepte zum Ersatz dieser mechanischen Sensoren entwickelt. Sie unterscheiden sich durch den Aufwand, die benötigte Genauigkeit (Pumpenantrieb Servoantrieb) und dem gewünschten Betriebsbereich.In diesem Beitrag wird die Realisierung des sensorlosen Betriebs einer permanenterregten Synchronmaschine durch ein Kalman-Filter beschrieben. Durch Simulation und durch praktische Untersuchungen konnte gezeigt werden, daß die Schätzung von Lage und Drehzahl die Genauigkeitsanforderungen für eine indirekte Lageregelung erfüllt. Eine solche Lageregelung besitzt keinen mechanischen Sensor mehr.  相似文献   
48.
49.
UHV-fracture surfaces of different (B, C)- and (Al, C)-doped pressureless sintered SiC materials are investigated by using high resolution Auger electron spectroscopy (HRAES). The grain boundaries at intergranular fractured regions of (B, C)-doped materials are evidently free of any enrichment of impurity elements or sintering additives. In contrast, the (Al, C)-doped materials reveal the existence of thin Al-containing grain boundary films. Sputtering indicates their thickness to be less than 1 nm. The concentrations of the elements segregated in the grain boundary films are determined.  相似文献   
50.
In the off-gases of internal combustion engines running with oxygen excess, non-thermal plasmas (NTPs) have an oxidative potential, which results in an effective conversion of NO to NO2. In combination with appropriate catalysts and ammonia (NH3-SCR) or hydrocarbons (HC-SCR) as a reducing agent, this can be utilized to reduce nitric oxides (NO and NO2) synergistically to molecular nitrogen.

The combination of SCR and cold plasma enhanced the overall reaction rate and allowed an effective removal of NOX at low temperatures. Using NH3 as a reducing agent, NOX was converted to N2 on zeolites or NH3-SCR catalysts like V2O5–WO3/TiO2 at temperatures as low as 100–200 °C. Significant synergetic effects of plasma and catalyst treatment were observed both for NH3 stored by ion exchange on the zeolite and for continuous NH3 supply.

Certain modifications of Al2O3 and ZrO2 have been found to be effective as catalysts in the plasma-assisted HC-SCR in oxygen excess. With an energy supply of about 30 eV/NO-molecule, 500 ppm NO was reduced by more than half at a temperature of 300 °C and a space velocity of 20 000 h−1 at the catalyst. The synergistic combinations of NTP and both NH3- and HC-SCR have been verified under real diesel engine exhaust conditions.  相似文献   

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