1,721,335 research outputs found
An investigation into the use of zinc oxide nanowiresensors in the detection of micro-RNA cancer biomarkers
No full textCancer is a complex disease characterised by genes which encode oncogenic and tumour-suppressor proteins. microRNAs (miRNA), a group of small noncoding RNAs that regulate gene expression, have been shown to participate in a number of essential biological process including cell proliferation control, hematopoietic B-cell lineage fate, B-cell survival, brain patterning, pancreatic cell insulin secretion and adipocyte development [1]. Abnormal expression, that is, the loss, amplification and mutations of miRNA genes has been identified in a wide variety of cancers including B-Cell Chronic Lymphocytic Leukemia (B-CLL) [2], breast carcinoma [3], primary glioblastoma [4], hepatocellular carcinoma [5], papillary thyroid carcinoma [6], lung cancer [7], colon carcinoma [8], and pancreatic tumours [9]. Presently, medical diagnostic tests, by and large, are performed in laboratories equipped with benchtop analyzers and operated by trained lab technicians. Although these systems have a high throughput, in most cases patients wait a number of days to receive their test results [10]. Being able to perform diagnostic tests at or near the site where patients encounter the health care system; and receiving the results within the time frame of a consultation with a healthcare professional (approximately 15 minutes [11]), would be extremely beneficial. It would provide actionable information that can lead to several changes in patient management. With respect to cancer diagnostics and treatment, this would reduce the need for multiple patient visits; enabling the prompt treatment of the illness in a more targeted fashion. Point of Care (PoC) devices are diagnostic devices which rapidly provide actionable information for patient care at the time and location of an encounter with the health care system. They are becoming more prevalent. The most commonly found type of PoC device is the Lateral Flow Immunoassays (LFIA) [12] [13]. However, LFIA conventionally provide qualitative results (i.e., yes or no) which are of little use when trying to gauge changes in concentration as would be needed in detecting the loss or amplification miRNA strands. Furthermore, LFIA suffers from difficulties due to varying consistency of the flow rate and from non-uniform dispersion of the sample to label [10]. Field Effect Transistor (FET) biosensors, a promising class of PoC devices, have been shown to able to distinguish between iv different concentrations of molecular analyte [14]. This function would be vital in cancer diagnosis revolving around detection of the abnormal expression of miRNA. This is because cancerous cells typically manifest a deviation in miRNA concentration from the normal range. These FETs are made with established semiconductor techniques and technologies meaning that, they can be readily integrated with other electronic systems. This would enable on chip signal processing and the instantaneous electronic transmission of results from remote areas to a centralised hub. The goal is to leverage the advantages in semiconductor technologies to develop a PoC device for cancer diagnostics. This is to enable cancers to be caught and treated earlier thus reducing the need for invasive or debilitating treatments like surgery or chemotherapy. In pursuit of this goal, the preliminary step was to fabricate FETs capable of detecting changes in miRNA concentration. The FETs fabricated for this purpose were Zinc Oxide Nanowire Field Effect Transistors (NWFETs) arrays. ZnO is an ideal material with which to fabricate these NWFETs because it is naturally a n-type semiconductor [15], thus eliminating the need for a high temperature doping process steps. ZnO has a large and direct band-gap (3.37 eV [16]) which enables it to sustain large electric fields; withstand higher breakdown voltages; generate lower levels of noise; and operate at high temperatures and levels of power [17]. The ZnO NWFETs were passivated with stack high-κ dielectrics. The stack layer consists of a layer of Hafnium dioxide sandwiched between two Aluminium oxide layers which has been shown to diminish threshold voltage drift effectively [18]. Once fabricated, the ZnO NWFETs were first tested to observe how well they functioned as transducers of ionic charge. The ZnO NWFETs were seen to be excellent transducers of ionic charge with a shift in gate voltage per pH of 117 mV/pH. This shift in gate voltage per pH is comparable to largest known value of 220 mV/pH recorded by Knopfmacher’s single Silicon NWFET with a Dual Gate [19]. It is also twice as large as the Nernst limit (59 mV/pH). Following the pH-sensing experiment, a microDNA(miDNA) detection investigation was conducted. miDNA are the stable biological equivalent of miRNA and thus can serve as proxy of miRNA detection. The result of the investigation was compelling. The ZnO NWFETs were found to have a 43.88% Sensitivity to one order of magnitude changes in miDNA concentration (10 nM, 100 nM and 1 µM). Subsequently, the same investigation was carried out with miRNA as the analyte. In this instance the ZnO NWFETs were found to have a 5.07% Sensitivity to one order of magnitude changes in miRNA concentration of (10 nM, 100 nM and 1 µM). These results irrevocably demonstrate that ZnO NWFETs are capable of detecting changes in miRNA concentration. Thus, making ZnO NWFETs a suitable candidate for the development of a PoC device with which to conduct cancer diagnostics
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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