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111.
Leukemic cells isolated from most patients with acute myelogenous leukemia (AML) have higher low density lipoprotein (LDL) uptake than normal mononuclear blood cells. Little is known, however, about the mechanism behind the elevated LDL uptake. We investigated if AML cells secrete factors that stimulate cellular LDL uptake. Mononuclear blood cells were isolated from peripheral blood from 42 patients with AML at diagnosis. Cellular LDL uptake was determined from the degradation rate of 125I-labelled LDL. Conditioned media from AML cells stimulated the LDL degradation in the leukemic cell lines KG1 and HL60, and in isolated AML cells. The stimulatory effect correlated with the LDL degradation in the AML cells directly after isolation from blood. Conditioned media also autostimulated LDL degradation in the AML cells themselves. Concentrations of IL-6 and IL-8 in AML cell conditioned media correlated with the LDL degradation in AML cells directly after isolation from blood. Addition of R-TNF-α, but not IL-6 or IL-8, stimulated LDL degradation in HL60, KG1, and AML cells. The LDL degradation in AML cells could be inhibited by a LDL receptor blocking antibody. AML cells secrete factors that stimulate LDL uptake in a paracrine and autocrine pattern which open up therapeutic possibilities to inhibit the uptake of LDL by administration of antibodies to these factors.  相似文献   
112.
Das ,,Curriculum für ein Basismodul zur Mensch-Computer-Interaktion (MCI)“ wurde im Sommer 2006 von der Fachgruppe ,,Software-Ergonomie“ in der Gesellschaft für Informatik (GI) vorgestellt und anschlie?end vom Pr?sidium der GI als Empfehlung für Studieng?nge der Informatik angenommen und verabschiedet. Mit diesem Curriculum werden die notwendigen Grundlagen für eine erfolgreiche Ausbildung von Informatikern/-innen und anderen Berufsgruppen im Themenfeld der Software-Ergonomie geschaffen und vereinheitlicht. Des Weiteren soll es zur Konkretisierung der Anforderungen an Bachelor- und Masterstudieng?nge der Informatik dienen. Zudem soll die Akkreditierung von Informatikstudieng?ngen durch dieses Curriculum unterstützt werden.  相似文献   
113.
The emergence of highly interactive media and the increased connectivity among people call for an investigation of usage behaviour of those media. People tend to rely heavily on peer-to-peer interaction influencing the adoption of new media formats that enhance this interactivity. The first explorative phase of this research consists of interviews with experts and focus groups and builds the basis of the proposed framework and measurement model. Then, a Structural Equation Modelling approach is used to assess the relative importance and the strength between different constructs, including perceived enjoyment, social norm, usefulness, ease of use and intention to use. The results indicate that perceived enjoyment and social norm are important antecedents for the adoption of technology with network externalities.  相似文献   
114.
Recognizing the growing importance of scientific benchmarking in water distribution, we provide a comprehensive survey of the available literature. We begin with a discussion about the (limited) use of benchmarking in the regulation of UK water utilities, and then extend the analysis to regulated water sectors in other countries. We find no clear impact of public or private ownership; instead, the institutional settings appear to be a dominant driver of efficiency. Quality and structural variables are significant parameters; and water losses and population density are also important drivers. Analysis reveals that economies of scale only exist in fragmented water industries, whereas economies of density are omnipresent. We find evidence suggesting important economies of scope (e.g. between water and sewerage). Finally, we summarize the tensions that exist in attempting to measure efficiency in the water industry and draw conclusions about how to improve efficiency analysis in the future.  相似文献   
115.
Although there are numerous potential benefits to diversity in work groups, converging dimensions of diversity often prevent groups from exploiting this potential. In a study of heterogeneous decision-making groups, the authors examined whether the disruptive effects of diversity faultlines can be overcome by convincing groups of the value of diversity. Groups were persuaded either of the value of diversity or the value of similarity for group performance, and they were provided with either homogeneous or heterogeneous information. As expected, informationally diverse groups performed better when they held pro-diversity rather than pro-similarity beliefs, whereas the performance of informationally homogeneous groups was unaffected by diversity beliefs. This effect was mediated by group-level information elaboration. Implications for diversity management in organizations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
116.
Cod liver oil (CLO) with no added antioxidants (REF), 200 mg/kg ascorbyl palmitate (AP), and/or 800 mg/kg tocopherol concentrate (TOH) were stored in sealed bottles with a small headspace of air at 25°C in the dark. A binary mix of TOH +AP affected the sensory perception of CLO by leading to a more grass/cucumber-like and less herring oil-like impression, whereas TOH alone had no effect. This was caused by the different influence of the antioxidants with regard to formation of volatile oxidation products. TOH+AP promoted formation of, e.g., hexanal, 2-hexenal, and 2,6-nonadienal and inhibited formation of, e.g., 2,4-heptadienal. TOH affected the proportions of trans, cis-and trans,trans-2,4-heptadienal that were formed and inhibited formation of, e.g., 1-penten-3-ol, whereas formation of acetic acid and some other volatiles was inhibited by both antioxidants. The total amount of volatiles increased during the experiment, and with REF were significantly higher (P<0.05) than with TOH. The PV increased during the first 2 wk of storage. PV levels were in the order of TOH>REF>TOH+AP. The observed effects could partly be explained by hydrogen donation from TOH to peroxyl radicals, but the mode of action for AP was unclear.  相似文献   
117.
118.
There is relatively little guidance on the situated ergonomic assessment of medical devices, and few case studies that detail this type of evaluation. This paper reports results of a detailed case study that focuses on the design and use of a modern blood glucose meter on an oncology ward. We spent approximately 150 h in-situ, over 11 days and 4 nights, performing observations and interviews with users. This was complemented by interviews with two staff with oversight and management responsibility related to the device. We identified 19 issues with the design and use of this device. These issues were grouped into 7 themes which can help guide the situated study of medical devices: usability, knowledge gaps and mental models, workarounds, wider tasks and equipment, the patient, connection between services, and policy.  相似文献   
119.
International Journal of Control, Automation and Systems - Accurate underwater navigation systems are required for closed-loop guidance and control of unmanned underwater vehicles (UUV). This paper...  相似文献   
120.
Presence is usually assessed via a variety of subjective and objective measures. However, constraints often result in subjective measurements using questionnaires as a key method of data collection. In this paper we present a study of 44 participants of a collaborative augmented reality game known as TimeWarp which used both subjective and objective behavioral measures. Behavior as coded from video recordings of one scene of the game and self-reports about feelings of presence were compared. Our findings indicate that pointing behavior and verbal responses to the virtual content are correlated negatively to sense of presence. We further investigated the influence of subjectively perceived interactivity on perceived presence. We found that the interaction possibilities perceived by the participants predicted their experience of social presence with the virtual characters in the game. Furthermore, playing together with another person did not result in decreased social presence of the virtual characters. Implications for presence research are discussed.  相似文献   
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