Shrink-film microfluidic education modules: Complete devices within minutes     

Nguyen D  McLane J  Lew V  Pegan J  Khine M 《Biomicrofluidics》2011,5(2):22209

As advances in microfluidics continue to make contributions to diagnostics and life sciences, broader awareness of this expanding field becomes necessary. By leveraging low-cost microfabrication techniques that require no capital equipment or infrastructure, simple, accessible, and effective educational modules can be made available for a broad range of educational needs from middle school demonstrations to college laboratory classes. These modules demonstrate key microfluidic concepts such as diffusion and separation as well as "laboratory on-chip" applications including chemical reactions and biological assays. These modules are intended to provide an interdisciplinary hands-on experience, including chip design, fabrication of functional devices, and experiments at the microscale. Consequently, students will be able to conceptualize physics at small scales, gain experience in computer-aided design and microfabrication, and perform experiments-all in the context of addressing real-world challenges by making their own lab-on-chip devices.  相似文献   

Bandpass sorting of heterogeneous cells using a single surface acoustic wave transducer pair     

Gergely Simon  Caroline Busch  Marco A. B. Andrade  Julien Reboud  Jonathan M. Cooper  Marc P. Y. Desmulliez  Mathis O. Riehle  Anne L. Bernassau 《Biomicrofluidics》2021,15(1)

Separation and sorting of biological entities (viruses, bacteria, and cells) is a critical step in any microfluidic lab-on-a-chip device. Acoustofluidics platforms have demonstrated their ability to use physical characteristics of cells to perform label-free separation. Bandpass-type sorting methods of medium-sized entities from a mixture have been presented using acoustic techniques; however, they require multiple transducers, lack support for various target populations, can be sensitive to flow variations, or have not been verified for continuous flow sorting of biological cells. To our knowledge, this paper presents the first acoustic bandpass method that overcomes all these limitations and presents an inherently reconfigurable technique with a single transducer pair for stable continuous flow sorting of blood cells. The sorting method is first demonstrated for polystyrene particles of sizes 6, 10, and 14.5 μm in diameter with measured purity and efficiency coefficients above 75 ± 6% and 85 ± 9%, respectively. The sorting strategy was further validated in the separation of red blood cells from white blood cells and 1 μm polystyrene particles with 78 ± 8% efficiency and 74 ± 6% purity, respectively, at a flow rate of at least 1 μl/min, enabling to process finger prick blood samples within minutes.  相似文献   

Designing Reading Comprehension Assessments for Reading Interventions: How a Theoretically Motivated Assessment Can Serve as an Outcome Measure     

Tenaha O’Reilly  Jonathan Weeks  John Sabatini  Laura Halderman  Jonathan Steinberg 《Educational Psychology Review》2014,26(3):403-424

When designing a reading intervention, researchers and educators face a number of challenges related to the focus, intensity, and duration of the intervention. In this paper, we argue there is another fundamental challenge—the nature of the reading outcome measures used to evaluate the intervention. Many interventions fail to demonstrate significant improvements on standardized measures of reading comprehension. Although there are a number of reasons to explain this phenomenon, an important one to consider is misalignment between the nature of the outcome assessment and the targets of the intervention. In this study, we present data on three theoretically driven summative reading assessments that were developed in consultation with a research and evaluation team conducting an intervention study. The reading intervention, Reading Apprenticeship, involved instructing teachers to use disciplinary strategies in three domains: literature, history, and science. Factor analyses and other psychometric analyses on data from over 12,000 high school students revealed the assessments had adequate reliability, moderate correlations with state reading test scores and measures of background knowledge, a large general reading factor, and some preliminary evidence for separate, smaller factors specific to each form. In this paper, we describe the empirical work that motivated the assessments, the aims of the intervention, and the process used to develop the new assessments. Implications for intervention and assessment are discussed.  相似文献   

On electrets     

Adams Edwin P. 《Journal of The Franklin Institute》1927,204(4):469-486

(I) Evidence has been given that the so-called permanent electrets of Eguchi are not permanent, but that their polarization decays with the time. At room temperatures this decay is too slow to be observed directly; but it is the decay of the polarization that, at least in part, accounts for the presence of the free charges that are always observed. At higher temperatures the results that have been obtained are consistent with the view that the rate of decay of the polarization increases very rapidly with the temperature; so much so that the polarization may be almost completely destroyed at a temperature which is not high enough to cause any appreciable softening of the waxes that form the substance of the electrets.(2) As is to be expected from Lord Kelvin's hypothesis as to the cause of pyro-electricity, these electrets have been shown to possess the pyro-electric property.(3) The piezo-electric effect, which always accompanies the pyro-electric property, has been shown to be exhibited by these electrets.  相似文献   

Book reviews     

Eric Marshall White  Natalee Rosenstein  Trysh Travis  Peter W. Adams  Robert E. Baensch 《Publishing Research Quarterly》2003,19(2):65-72

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Freedom and the Individual     

Ruth Jonathan 《Journal of Philosophy of Education》1997,31(1):109-141

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More Misuses of Evolutionary Psychology     

Jonathan Michael Kaplan 《Metascience》2006,15(1):177-181

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Online Distance Education Pedagogy: Emulating the practice of global business     

Jonathan Mark Hochberg 《Distance Education》2006,27(1):129-133

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Re-ordering Society: Re-forming Education     

Ruth Jonathan 《Journal of Philosophy of Education》1997,31(1):13-29

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The relationship between bilingual proficiency and self-esteem     

Jonathan W. Pesner  Frank Auld 《Int J Intercult Relat》1980,4(3-4)

Proposing that bilingual proficiency should produce a more favorable attitude toward bilingualism and should enhance one's self-esteem, the authors compared 57 bilingual and 67 unilingual students from grades 9, 10, and 11, measuring their opinions about bilingualism and their self-esteem. The bilingual students are substantially more favorably disposed toward bilingualism than the unilingual students are. On the Janis-Field scale of self-esteem, the bilingual students show greater self-esteem than the unilingual students. The largest differences between the groups are on questions that measure self-confidence and social ease; differences are less pronounced on questions about self-worth and about shyness. We speculate that bilingual proficiency offers some psychological advantages to students who achieve it.  相似文献