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991.
Edward Brainard 《Clearing house (Menasha, Wis.)》2013,86(4):207-210
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Nora Dickson M Tsinberg P Tang Z Bischoff FZ Wilson T Leonard EF 《Biomicrofluidics》2011,5(3):34119-3411915
Ability to perform cytogenetic interrogations on circulating tumor cells (CTCs) from the blood of cancer patients is vital for progressing toward targeted, individualized treatments. CTCs are rare compared to normal (bystander) blood cells, found in ratios as low as 1:109. The most successful isolation techniques have been immunocytochemical technologies that label CTCs for separation based on unique surface antigens that distinguish them from normal bystander cells. The method discussed here utilizes biotin-tagged antibodies that bind selectively to CTCs. The antibodies are introduced into a suspension of blood cells intending that only CTCs will display surface biotin molecules. Next, the cell suspension is passed through a microfluidic channel that contains about 9000 transverse, streptavidin coated posts. A CTC making contact with a post has the opportunity to engage in a biotin-streptavidin reaction that immobilizes the cell. Bystander blood cells remain in suspension and pass through the channel. The goal of the present study is to establish the technical performance of these channels as a function of antigen density and operating conditions, especially flow rate. At 18 μL/min, over 70% of cells are captured at antigen densities greater than 30 000 sites/cell while 50% of cells are captured at antigen densities greater than 10 000. It is found that lower flow rates lead to decreasing cell capture probabilities, indicating that some streamlines develop which are never close enough to a post to allow cell-post contact. Future modeling and streamline studies using computational fluid dynamics software could aid in optimization of channel performance for capture of rare cells. 相似文献
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Edward H. Spence 《Ethics and Information Technology》2011,13(3):261-275
This paper provides a general philosophical groundwork for the theoretical and applied normative evaluation of information
generally and digital information specifically in relation to the good life. The overall aim of the paper is to address the
question of how Information Ethics and computer ethics more generally can be expanded to include more centrally the issue
of how and to what extent information relates and contributes to the quality of life or the good life, for individuals and for society. To answer that question, the paper explores and provides by way of a theoretical groundwork
for further research, the concept of wisdom understood as a type of meta-knowledge as well as a type of meta-virtue, which can enable one to both know in principle what a good life is and how to successfully apply that knowledge in living
such a life in practice. This answer will be based on the main argument presented in this paper that the notion of wisdom understood as being at once a meta-epistemological, meta-axiological and meta-eudemonic concept, provides the essential conceptual link between information on the one hand and the good life on the other. If, as
we are told, this is the Age of Information, both the theoretical examination and analysis of the question of how information
relates to the good life and the provision of an adequate answer to that question are essential for developing a deeper understanding
of how to evaluate the theoretical and practical implications and ramifications of information for the good life, for individuals
and societies generally. 相似文献
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Brent Bridgeman Catherine Trapani Edward Curley 《Journal of Educational Measurement》2004,41(4):291-310
The impact of allowing more time for each question on the SAT I: Reasoning Test scores was estimated by embedding sections with a reduced number of questions into the standard 30-minute equating section of two national test administrations. Thus, for example, questions were deleted from a verbal section that contained 35 questions to produce forms that contained 27 or 23 questions. Scores on the 23-question section could then be compared to scores on the same 23 questions when they were embedded in a section that contained 27 or 35 questions. Similarly, questions were deleted from a 25-question math section to form sections of 20 and 17 questions. Allowing more time per question had a minimal impact on verbal scores, producing gains of less than 10 points on the 200–800 SAT scale. Gains for the math score were less than 30 points. High-scoring students tended to benefit more than lower-scoring students, with extra time creating no increase in scores for students with SAT scores of 400 or lower. Ethnic/racial and gender differences were neither increased nor reduced with extra time. 相似文献
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