1,720,965 research outputs found
Glycosylated liposomes: a potential tool for the detection and treatment of bacterial infections
No full textBacterial infections pose a huge concern for human health in terms of increased morbidity, mortality and healthcare costs. Two main issues contribute to render the treatment of some infectious diseases a difficult task: anti-microbial resistance (AMR) and the development of microbial biofilms.The aim of the work described in this thesis is the development of liposomes that, properly functionalized and loaded, could have a potential application in the diagnosis of bacterial infections and in the relative therapy. The chosen strategy to achieve the selective recognition of bacteria by liposomes is based on the decoration of vesicles surface with saccharide moieties that might ascribe to them specificity toward lectins and carbohydrate-receptors located on microbial cells. For what concerns the diagnosis, a further functionalization of the lipid bilayer capable of generating a specific optical response upon the interaction with pathogens is required; to achieve this goal, the chromo-responsive polydiacetylene (PDA) liposomes containing the π-conjugate “ene-yne” backbone were selected as suitable vesicular platform
Glucosylated liposomes as drug delivery systems of usnic acid to address bacterial infections
No full textBecause of the increased incidence of infections caused by resistant pathogens, due to the intensive use of antibiotics, there is an urgent need to develop new therapeutic strategies against bacteria, possibly based on non conventional drugs. (+)-Usnic acid is a natural compound that exerts a potent antibacterial activity, however its clinical application is hampered by its scarce solubility in water. Usnic acid was included, by both passive and active loading techniques, in liposomes containing structurally related glucosylated amphiphiles. Liposome formulations were characterized from the physicochemical point of view and their activity against biofilm associated Staphylococcus epidermidis was also evaluated. The inclusion of usnic acid in glucosylated cationic liposomes promotes its penetration in biofilm matrix with a consequent increase of its antimicrobial activity. The effect of both cationic charge and sugar residue seems to be synergistic
Glucosylated pH-sensitive liposomes as potential drug delivery systems
No full textThe inclusion of pH-sensitive components in liposome formulations can allow a more controlled and efficient release in response to low pH typical of some pathological tissues and/or subcellular compartments. On the other hand decorating the surface of liposomes with sugar moieties attributes to lipid vesicles specificity toward lectins, sugar-binding proteins overexpressed in many tumor tissues. A novel multifunctional pH-sensitive glucosylated amphiphile was synthesized and characterized as pure aggregate component and in mixtures with a natural phospholipid. The comparison of the properties of the new glucosylated amphiphile with respect to those of a previously described cationic structural analogue demonstrates that the pH-sensitivity can strongly affect drug release, lipid organization, as well as the exposure of the glucose residues on liposome surface and their ability to interact with Concanavalin A, a plant lectin used as model system
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
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