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Edwards TL Harper JC Polsky R Lopez DM Wheeler DR Allen AC Brozik SM 《Biomicrofluidics》2011,5(4):44115-4411514
Herein is described the fabrication and use of a plastic multilayer 3-channel microfluidic fixture. Multilayer devices were produced by laser machining of plastic polymethylmethacrylate and polyethyleneterapthalate laminates by ablation. The fixture consisted of an array of nine individually addressable gold or gold/ITO working electrodes, and a resistive platinum heating element. Laser machining of both the fluidic pathways in the plastic laminates, and the stencil masks used for thermal evaporation to form electrode regions on the plastic laminates, enabled rapid and inexpensive implementation of design changes. Electrochemiluminescence reactions in the fixture were achieved and monitored through ITO electrodes. Electroaddressable aryl diazonium chemistry was employed to selectively pattern gold electrodes for electrochemical multianalyte DNA detection from double stranded DNA (dsDNA) samples. Electrochemical detection of dsDNA was achieved by melting of dsDNA molecules in solution with the integrated heater, allowing detection of DNA sequences specific to breast and colorectal cancers with a non-specific binding control. Following detection, the array surface could be renewed via high temperature (95 °C) stripping using the integrated heating element. This versatile and simple method for prototyping devices shows potential for further development of highly integrated, multi-functional bioanalytical devices. 相似文献
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Miller PR Gittard SD Edwards TL Lopez DM Xiao X Wheeler DR Monteiro-Riviere NA Brozik SM Polsky R Narayan RJ 《Biomicrofluidics》2011,5(1):13415
In this study, carbon fiber electrodes were incorporated within a hollow microneedle array, which was fabricated using a digital micromirror device-based stereolithography instrument. Cell proliferation on the acrylate-based polymer used in microneedle fabrication was examined with human dermal fibroblasts and neonatal human epidermal keratinocytes. Studies involving full-thickness cadaveric porcine skin and trypan blue dye demonstrated that the hollow microneedles remained intact after puncturing the outermost layer of cadaveric porcine skin. The carbon fibers underwent chemical modification in order to enable detection of hydrogen peroxide and ascorbic acid; electrochemical measurements were demonstrated using integrated electrode-hollow microneedle devices. 相似文献
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In an exploratory study, peer tutoring in higher education is examined for students with visual impairment and students with learning disability (LD). Data were collected by means of interviews and focus groups. Findings indicate both academic and social benefits for tutees and tutors. Difficulties encountered are discussed, and differences between the two populations are raised. It is suggested that the visibility and complexity of the student's disability affected the tutoring encounter. Professional guidance is suggested as a means of reducing tutoring problems and increasing benefits. 相似文献
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Modem technology offers powerful professional programs that were originally designed for scientific and practical engineering purposes. These programs are now easily operated by simple graphic interfaces. Even if they offer much more than we may need for instructional purposes, these tools can still be very useful as a support for teaching and learning both the subject matter domain and additional general skills from relatively early stages of scientific and technological education. This article describes the instructional approaches developed for using a professional electronic circuit analyzer program as a learning environment for students in basic electronics courses and discusses the general implications of using such programs for instruction. 相似文献
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Mirit Hen Maria Ronen Alex Deitch Efrat Barbiro-Michaely Ziv Oren Chaim N. Sukenik Doron Gerber 《Biomicrofluidics》2015,9(5)
Microfluidic-based protein arrays are promising tools for life sciences, with increased sensitivity and specificity. One of the drawbacks of this technology is the need to create fresh surface chemistry for protein immobilization at the beginning of each experiment. In this work, we attempted to include the process of surface functionalization as part of the fabrication of the device, which would substitute the time consuming step of surface functionalization at the beginning of each protein array experiment. To this end, we employed a novel surface modification using self-assembled monolayers (SAMs) to immobilize biomolecules within the channels of a polydimethylsiloxane (PDMS) integrated microfluidic device. As a model, we present a general method for depositing siloxane-anchored SAMs, with 1-undecyl-thioacetate-trichlorosilane (C11TA) on the silica surfaces. The process involved developing PDMS-compatible conditions for both SAM deposition and functional group activation. We successfully demonstrated the ability to produce, within an integrated microfluidic channel, a C11TA monolayer with a covalently conjugated antibody. The antibody could then bind its antigen with a high signal to background ratio. We further demonstrated that the antibody was still active after storage of the device for a week. Integration of the surface chemistry into the device as part of its fabrication process has potential to significantly simplify and shorten many experimental procedures involving microfluidic–based protein arrays. In turn, this will allow for broader dissemination of this important technology. 相似文献
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Education and Information Technologies - One-to-one laptop initiatives have become prevalent in schools aiming to enhance active learning and assist students in developing twenty-first-century... 相似文献
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Ronen Shay 《媒体管理杂志》2013,15(3):175-193
An audience-centric typology is conceptualized to assist media managers implementing windowed distribution strategies in an attempt to account for media consumption cannibalization. Diffusion theory identifies the demographics most likely to consume substitutive television content, while uses, gratifications, media habits, and consumption values are collaboratively used to re-segment the audiences based on platform selection motivators. Psychographic labels are then applied using the dominant characteristic of each audience type and then matched to a specific windowed distribution strategy. The strategies are based on existing windowing tactics used by ABC, CBS, FOX, and NBC or emerging strategies that are reflective of changing market trends. 相似文献
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A class activity developed as a framework for the introduction of the topic of ‘Ionizing radiation and its biological effects’ is described. A central component of the activity is a game in which students compare their own estimations of exposure levels in different situations, prior to and after the study. It was found that both students and their teachers had similar and mostly wrong, preconceptions. This activity is aimed at encouraging students to adopt an informed approach whenever dealing with issues of scientific content. 相似文献
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ABSTRACTThis study examined a moderated mediation model with 254 Israeli junior high school students, hypothesizing that students' environmental hope would simultaneously mediate the relationship between their engagement in school-based environmental activities (green engagement) and their environmental behavior as well as their positivity ratio, but that students' self-control skills would moderate these mediation processes. The results showed that engagement was linked to self-reported pro-environmental behavior, as well as experiencing more positive than negative emotions. Multigroup structural equation modeling indicated that the model provided a good fit to the data, and rigorous bootstrap analysis confirmed the simultaneous mediating role of environmental hope—but only for students with high self-control skills. The limitations and implications of the findings are discussed, and future directions are presented. 相似文献