1,720,957 research outputs found
A NOVEL BIORELEVANT IN VITRO SYSTEM TO PREDICT THE IN VIVO PERFORMANCE OF ORAL TRANSMUCOSAL PRODUCTS
Get PDFIn vitro dissolution, release and permeation testing is a common practice during drug product research and development. These in vitro tests, if predictive, are referred to as biorelevant tests and can play diverse roles to facilitate and expedite product development in a cost effective manner. Oral transmucosal products (OTPs) are currently tested using compendial and modified in vitro tests which may or may not be good predictors of in vivo performance due to a lack of biorelevance. A critical need for a broadly applicable and biorelevant in vitro system for OTPs has been expressed in the literature and the goal of this research was the development and validation of a biorelevant in vitro method that can facilitate accurate prediction of the in vivo behavior of OTPs. A combined strategy of appropriate apparatus design and relevant physiological and in vitro variable adjustment was investigated to incorporate biorelevance into evaluation of OTPs. A novel in vitro device, the bidirectional transmucosal apparatus (BTA), was designed and fabricated which allowed simulation of the oral cavity and its physiological variables to evaluate OTPs in a more realistic fashion. The BTA was tested using snus (a type of smokeless tobacco) as the OTP product. A simple and selective high performance liquid chromatographic (HPLC) method with photodiode array (PDA) detection was developed and validated to assess in vitro nicotine release and permeation (Linearity: 0.5 – 32 μg/mL; calibration curve accuracy (%recovery, n=5 ): 97.98-103.20%; calibration curve precision (%RSD, n=5): 0.15-3.14%). The performance of BTA was compared with the modified USP IV flow through apparatus (USP IV) and a commercially available vertical diffusion cell (VDC). The observed in vitro in vivo relationship (IVIVR) slopes with the USP IV, VDC and BTA were 0.27, 2.01 and 2.11 respectively. The BTA was selected over the VDC and USP IV devices because of better simulation and adjustment of variables to incorporate biorelevance in the test of OTPs. Additionally, the BTA allows study of permeation and release simultaneously unlike VDC and USP IV apparatuses. Further, the different BTA parameters were sequentially screened for their impact on in vitro rate of nicotine permeation that can be employed for the optimization of IVIVR for snus. Based on the results, stimulated saliva swallowing rate (SSSR) and media temperature were considered as significant factors affecting in vitro permeation of nicotine and used to further optimize IVIVR for snus. A 32 multifactorial experimental design integrating SSSR (0.32, 1.66 and 3 mL/min) and media temperature (25, 37 and 45 °C) was employed. Based on the response surface analysis, 0.55 mL/min SSSR and 43 °C media temperature were identified as optimal BTA conditions that would give perfect IVIVR (i.e. IVIVR slope close to one) for snus. The experimental value of IVIVR slope (0.92) at these optimal conditions indicated that the BTA is a valid in vitro system for evaluation of OTPs in a biorelevant manner. The applicability of BTA for predicting nicotine permeation from ‘Stonewall’, a dissolvable compressed tobacco was also evaluated. However, comparable in vitro nicotine permeation and in vivo nicotine absorption profiles were not obtained (ratio of in vitro permeation to in vivo absorption rate ranged from 0.04 to 0.14 at different in vitro conditions) either due to the unavailability of reliable clinical data or due to inherently different in vivo behavior of Stonewall compared to snus that would require further modification in the BTA. In conclusion, this research demonstrated the potential of the novel in vitro device to be a valuable tool for the prediction of in vivo performance of snus. The application of the novel bidirectional transmucosal apparatus for other types of OTPs will be an interesting subject for further investigation
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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