1,720,957 research outputs found

    Formulation and investigation of Self-Emulsifying Drug Delivery System (SEDDS) containing natural herb extract or different antitumor agents

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    Approximately 70-75% of medications marketed worldwide are administrated per os and are proven to be less effective than desired. The majority of newly developed drugs represent poor aqueous solubility and stability. Drug instability results in lack of dose appropriateness after oral administration. Many different methods have been found to enhance drug dissolution rate and improve the physicochemical stability of drugs by applying surface-active agents, Cyclodextrins, nanoparticles or liposomes. Lipid-based drug delivery systems represent one of the most popular technologies for improving oral bioavailability and solubility. Micro- and nanoemulsions are lipid-based formulations that have a significant potential for drug delivery applications and self-micro/nanoemulsifying drug delivery systems (SM/NEDDS) considered as the best of these systems. Many studies suggested that SM/NEDDS are suitable carrier systems drugs which are very sensitive to hydrolysis. SM/NEDDS are characterized as isotropic mixtures of synthetic or natural oil and solid or liquid surface active agents or, alternatively, a single or several hydrophilic solvents and co-solvents and a drug which spontaneously forms oil-in-water (o/w) nanoemulsion/microemulsion droplets with water following a gentle stirring. In gastrointestinal fluid, this system spreads readily in the GI lumen and the agitation necessary for self-emulsification is provided by the gastric and intestinal digestive motility. After dilution with aqueous media, the oil droplets keep the drug inside of them or they form a micellar solution due to the very high surface-active agent concentration of such formulations. The drug will be delivered to the GI mucosa in dissolved state by these fine droplets; therefore, it will be readily available for absorption and its efficacy and bioavailability will also be increased. Micro/nanoemulsions improve oral bioavailability, protect drugs from enymatic hydrolysis and have high drug solubilization capacity and outstanding thermodynamic stability. The phenomenon of self-emulsification occurs only when specific combinations of pharmaceutical excipients are present. Several chemotherapeutic agents are used in the treatment of cervical cancer. Cisplatin is considered to be among the most effective drugs that treat advanced uterine and cervical cancer. Bleomycin sulfate is a mixture of glycopeptide antitumor antibiotics that has a unique mechanism of antitumor activity in cervical cancer. Ifosfamide is an anti-cancer drug and is widely used in the treatment of cervical, ovarian and testicular malignancies. In recent chemotherapy, cisplatin, bleomycin and ifosfamide (BIP) in combination has also been applied against inoperable cervical cancer. To decrease the serious side effects resulted from use of cytostatic medications it is necessary to formulate modern drug delivery systems which can reduce toxicity by decreasing the dose of potent therapeutic agent. SMEDDS are frequently used to increase the bioavailability of poorly soluble drugs by presenting and maintaining API in a dissolved state, in small droplets of oil with a ability to penetrate through various biological barriers. Plantago lanceolata has been widely used for medical purposes, such as the treatment of bleeding and tissue damage, antioxidant, anti-inflammatory, antibacterial antiviral and hepatoprotective. Some prominent pharmacological studies are outlined in the following section. Iridoid glucoside aucubin and its derivatives have been identified as important biologically active compounds in plantain by several studies. The main bioactive component of Plantago lanceolata is verbascoside (acteoside), which is a phenylpropanoid glycoside. However the high capability of its bioactive components for hydrolysis resulted in poor stability of this natural extract. SNEDDS is frequently used for the stabilization of natural products and these carrier systems may also increase the bioavailability of natural bioactive materials.N

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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 Under Sail The Imagination of Jack London, 1893-1902

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    In 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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