1,720,954 research outputs found
Investigation of the Effect of Different Emulsifiers on the Transdermal Delivery of EGCG Entrapped in a Polymeric Micelle System
No full textEpigallocatechin gallate, one of the most active antioxidant compounds, has a low chemical stability and ability to permeate the human epidermis. The encapsulation in polymeric micelles would be beneficial to improve both stability and permeation of epigallocatechin gallate and, therefore, to facilitate the pharmacological effects. Polymeric micelles containing epigallocatechin gallate were incorporated in O/W emulsions prepared by using different types of emulsifying systems. All emulsions were uniform in colour and aspect, without evidences of phase separation after centrifugation at the preparation time and over a 6-month period of storage at room temperature. Emulsions containing epigallocatechin gallate incorporated in polymeric micelles showed a colour variation, probably due to epigallocatechin gallate degradation, over the stability period. The skin permeability study evidenced a significant increase in epigallocatechin gallate permeation after encapsulation in micelles. Pure epigallocatechin gallate was not able to permeate the skin and only limited amounts were retained in the epidermis, while both permeated and retained amounts after 24 h were measured in the case of polymeric micelles containing epigallocatechin gallate. Moreover, the epigallocatechin gallate release and human skin permeability were affected by the type of emulsifier. The epigallocatechin gallate release in the presence of an emulsifier system based on cereal and fruit fibres never occurred. The best results in terms of release and skin permeability were obtained using glycerides of synthetic or semisynthetic origin or esters
Influence of SLN Matrix on "in vitro" and "in vivo" nanoparticle performances
No full textThis study focuses on the production of solid lipid nanoparticles (SLN) loaded with the hydrophilic carbonyl quencher N-acetylcarnosine (NAC) in order to develop topical formulations useful in several skin diseases and in the photoageing prevention and treatment. The addition of amphiphilic substances into lipid matrix, such as phosphatidylcholine (PC), polyglyceryl-3-diisostearate and sorbitan monooleate, was evaluated. The influence of additives on "in vitro" SLN performances was investigated by Differential Scanning Calorimetry, size and zeta potential, active content analyses, release and occlusion tests. Preliminary "in vivo" investigations of cutaneous tolerability and short-term effect of SLN application were also carried out using non-invasive skin bioengineering techniques. Results obtained from this work allowed to conclude that the incorporation of these additives, in concentration of 15% with respect to lipid mass, strongly affects colloidal systems physical properties leading to a very different in in vitro and in vivo performances. In particular, encapsulation efficiency can be very good reaching the 65.75% by addition of PC into lipid matrix. In vivo evaluation evidenced good cutaneous tolerability for all batches produced. The presence of PC can significantly modify the short-term effect of SLN application on the skin with respect to both vehicle alone and unmodified SLN
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
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