1,720,966 research outputs found
Development of High-Throughput Microfluidic Impedance Spectroscopy Platform for Analyzing Microdroplets in Droplet Microfluidic System
Full text linkThis thesis presents the development of a high-throughput microfluidic impedance spectroscopy platform for electrically detecting analyzing impedance measurements of non-contact and label free microdroplets. This microfluidic impedance spectroscopy platform gives valuable information of the size and contents of the microdroplets in general and particularly of cells encapsulated within droplets.
Impedance spectroscopy is a common method for analyzing dielectric properties of particles with respect to the stimulating frequency. Microfluidic based impedance spectroscopy can analyze up to micro size particles. However, droplets based microfluidic impedance spectroscopy systems for analyzing cells encapsulated within droplets have been rarely developed.
However, to develop a high-throughput system, a novel sensitive high-throughput droplets based microfluidic impedance spectroscopy platform for analyzing cells encapsulated with droplets at different levels concentrations at throughput of 140 Hz which has not been reported in the literature yet.
The device sensitivity was demonstrated using chlamydomonas reinhardtii cells. Two throughputs (17 and 140 droplets/s) for four level of cells concentrations were discriminating and compared. The maximum deviation in the acquired data for both cases was 6.9%. At 10% difference of cells encapsulated within droplets, the device was capable of discriminating and distinguishing different between the encapsulated microdroplets
DEVELOPMENT OF HIGH-THROUGHPUT IMPEDANCE SPECTROSCOPY-BASED MICROFLUIDIC PLATFORM FOR DETECTING AND ANALYZING CELLS AND PARTICLES
Full text linkImpedance spectroscopy based microfluidics have the capability to characterize the dielectric properties of mediums, particles, cellular and sub-cellular contents in response to stimulating voltage signals over a frequency range. This label-free technology has broad ranges of applications in life sciences where there is a need for high-throughput, label-free, non-contact, and low-cost microsystems. To address these limitations, three innovative impedance spectroscopy microfluidic platforms have been developed and presented in this dissertation. The first platform was developed for detecting and characterizing the transverse position of a single cell flowing within a microfluidic channel using a single impedance spectroscopy electrode pair. Regardless of the cell separation methods used, identifying and quantifying the position of cells and particles within a microchannel are important, as these information indicate both the degree of separation as well as how many cells are separated into each position. Using a single pair of non-parallel surface microelectrodes, five different transverse positions of single cells flowing through a microfluidic channel were successfully identified at a throughput of more than 400 particles/s using the detected impedance peak height and width.
The second platform utilizes the above technology to count and quantify cells flowing through multiple outlets of microfluidic cell separation systems. A single pair of step-shaped electrodes was developed by integrating five different electrode-to-electrode gaps within a single pair of electrodes. Using this platform, an overall misclassification error rate of only 1.85% was achieved. The result shows the technology’s capability in
achieving efficient on-chip cell counting and quantification, regardless of the cell separation methods used, making it a promising on-chip, low-cost and label-free quantification method for cell and particle sorting and separation applications.
The third platform was developed for counting cells and particles encapsulated in water-in-oil emulsion droplets using microfluidic based impedance spectroscopy systems. Impedance signal peak height and width were utilized to successfully quantify the number of cells encapsulated within a droplet, and was successfully applied for various cell types and growth media. In addition, the developed platform has been also successfully tested for identifying and discriminating filamentous fungal cell growth, where single fungal spores and filamentous fungi of different lengths could be discriminated inside droplets.
Overall in this research, several impedance spectroscopy based microfluidic systems have been successfully developed to solve current limitations in technologies that need high-throughput, low-cost and label-free detection and characterization method for a broad range of cell/particle screening applications
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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