1,721,159 research outputs found
Načrtovanje mehanskih lastnosti elastomerov polimlečne kisline s kemijskim premreževanjem
No full textHistologic Assessment of Drug-Eluting Grafts Related to Implantation Site
No full textDrug-eluting vascular prostheses represent a new direction in vascular surgery to reduce
early thrombosis and late intimal hyperplasia for small calibre grafts. Subcutaneous implantation in
rats is a rapid and cost-effective screening model to assess the drug-elution effect and could, to some
extent, be useful to forecast results for vascular prostheses. We compared biological and histological
responses to scaffolds in different implantation sites. Polycaprolactone (PCL), paclitaxel-loaded
PCL (PCL-PTX) and dexamethasone-loaded PCL (PCL-DXM) electrospun scaffolds were implanted
subcutaneously and in an infrarenal abdominal aortic model in rats for up to 12 weeks. At the
conclusion of the study, a histological analysis was performed. Cellular graft invasion revealed
differences in the progression of cellular infiltration between PCL-PTX and PCL/PCL-DXM groups in
both models. Cell infiltration increased over time in the aortic model compared to the subcutaneous
model for all groups. Cell counting revealed major differences in fibroblast, macrophage and
giant cell graft colonisation in all groups and models over time. Macrophages and giant cells
increased in the PCL aortic model; whereas in the subcutaneous model these cell types increased
only after three weeks or even decreased in the drug-eluting PCL groups. Other major findings were
observed only in the aortic replacement such as extracellular matrix deposition and neo-angiogenesis.
The subcutaneous implant model can be used for screening, especially when drug-eluting effects are
studied. However, major histological differences were observed in cell type reaction and depth of
cell penetration compared to the aortic model. Our results demonstrate that the implantation site is
a critical determinant of the biological response
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
New copolymers based on poly(dopamine) for the sustained delivery of active pharmaceutical ingredient to the eye by intravitreal administration
No full textLes maladies oculaires sont un problème de santé publique majeur. Actuellement, la recherche se focalise sur l’élaboration de formulations à base de polymère permettant la libération prolongée de principe actifs par administration intravitréenne pour le traitement des pathologies rétiniennes. A ce jour, un seul implant dégradable contenant une petite molécule est commercialisé, et aucune formulation polymère viable pour la libération de protéine n’est disponible sur le marché. L’objectif est de créer des implants solides et des solutions gélifiantes in-situ à base de poly(éthylène glycol) (PEG) et/ou poly(ε-caprolactone) (PCL) (approuvés par la Food and Drug Administration) fonctionnalisée par de la poly(dopamine) (PDA) (utilisé dans les traitements du cancer) en exploitant les interactions PDA – principe actif. Les implants à base de PCL et de PCL-g-PDA sont obtenus par compression à chaud. Les études in vitro montrent que les implants sont dégradables et sont non-cytotoxiques. Les cinétiques de libération sont modulées en ajustant le ratio entre la PCL et la PCL-g-PDA et en fonction de la nature de la molécule chargée. Les implants de PCL-g-PDA permettent une libération prolongée pendant plus de 5 mois sans retardement. Les solutions gélifiantes à base de PCL-b-PEG-b-PCL et/ou (PCL-g-PDA)-b-PEG-b-(PCL-g-PDA) sont formulées dans du PEG de faible masse molaire et de l’eau afin de solubiliser les copolymères et l’anticorps. Elles permettent l’injectabilité à travers une fine aiguille, la stabilité des composés. Les études de libération in vitro montrent une libération de l’anticorps en 3 jours. Ces deux stratégies ouvrent des perspectives quant à la poursuite du développement industriel de systèmes polymère novateur d’administration oculaire pour la libération des principes actifs.The ocular diseases are a major public health issue. More than 216 million people are visually impaired and another 36 million people are estimated to be blind worldwide. Currently, research is focusing on formulations providing sustained delivery of active pharmaceutical ingredient (APIs) using intravitreal administration for the treatment of retinal pathologies. At present, only one biodegradable implant loaded with small API is commercially available (Ozurdex™), and no commercial polymeric formulation is found for the delivery of large API. Consequently, this project focuses on the development of new solid implants or in-situ gelling formulations based on poly(ethylene glycol) (PEG) and/or poly(ε-caprolactone) (PCL) (approved by the Food and Drug Administration) functionalized with poly(dopamine) (PDA) (already used in cancer treatment) by exploiting PDA-API interactions. The PCL and PCL-g-PDA implants are obtained by hot compression. The in vitro studies show the degradability and the non-cytotoxicity (L929 and ARP19 cells lines) of the implants. To modulate the release kinetics, the PCL and PCL-g-PDA proportion and the nature of the small molecule are adjusted. The PCL-g-PDA implants allow the release over 5 months without lag time. The liquid formulations based on PCL-b-PEG-b-PCL and/or (PCL-g-PDA)-b-PEG-b-(PCL-g-PDA) are formulated in small molecular weight PEG and water to enhance the solubility of the components. They allow injectability through small 30G needle and stability of the antibody. The in vitro release studies show the release of the antibody within 3 days. The two strategies open perspectives for the development of innovative ocular drug delivery copolymer systems
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
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