1,720,964 research outputs found
INNOVATIVE ANTIBACTERIAL SYSTEMS FOR ORTHOPEDIC AND TRAUMATOLOGY APPLICATIONS
No full textLe infezioni ortopediche sono una problematica devastante che colpisce il 2% dei pazienti che si sottopongono ad interventi di sostituzione articolari. Il lavoro di ricerca di questo dottorato ha come scopo l'individuazione di sistemi tecnologicamente innovativi per la profilassi e la cura di tali infezioni
EFFECT OF COMPOSITION ON THE RELEASE FROM MELT EXTRUDED LAMINAR SYSTEMS BY APPLICATION OF MIXTURE EXPERIMENTAL DESIGN
No full textEFFECT OF COMPOSITION ON THE RELEASE FROM MELT EXTRUDED LAMINAR SYSTEMS BY APPLICATION OF MIXTURE
EXPERIMENTAL DESIG
Synthesis and receptor binding studies of some new arylcarboxamide derivatives as sigma-1 ligands
No full textWe describe here the synthesis and the binding interaction with simga1 and sigma2 receptors of a series of new arylcarboxamide derivatives variously substituted on the aromatic portions. Maintaining a partial scaffold of a series of compounds previously synthesized by us, we evaluate the effect of the substitution on sigma binding. The synthesized compounds have been tested to estimate their affinity and selectivity toward sigma1 and sigma2 receptors. Two out of 16 derivatives showed an interesting sigma1 affinity (21.2 and 13.6 nM - compounds 2m and 2p) and a good selectivity (Ki(sigma2) / Ki(sigma1) >140 and >40 respectively)
Thermo-responsive hydrogels from cellulose-based polyelectrolytes and catanionic vesicles for biomedical application
No full textIn this study, negatively charged catanionic vesicles/hydrophobically modified hydroxyethylcellulose polymers thermo-responsive hydrogels have been fabricated. Vesicular aggregates were found to act as multifunctional junctions for networking of modified-cellulose water solutions. The contributions of the electrostatic and hydrophobic interactions were evaluated by changing either vesicles composition or the polymer hydrophobic substitution. Thermal-induced size and lamellarity of hydrogelenclosed vesicles were detected, with further polygonal shape changes induced by cellulose-based polymer addition. The thermal transition was also found to tune hydrogel mechanical behaviour. The network formation was further assessed through molecular insights, which allow to determine the arrangement of the polymer chains on the vesicles’ surface. The examined systems exhibited interesting thermo-responsive characteristics. Thus, vesicularly crosslinked hydrogels herein presented can offer a wide variety of applications, i.e. in biomedical field, as multi-drug delivery systems, thanks to their ability to provide for different environments to guest molecules, comprising bulk water, vesicles’ interior and bilayers, sites on polymeric chains
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
Development and preclinical pharmacokinetics of a novel subcutaneous thermoresponsive system for prolonged delivery of heparin
Full text linkHeparin is still widely used for treatment and prevention of thromboembolic diseases. Due to specific physicochemical properties, it requires frequent parenteral injections. In this study we present the development and in vitro evaluation of an advanced delivery system for prolonged subcutaneous release of heparin. The delivery system consisted of an in situ forming thermoresponsive poloxamer-based platform combined with pH-responsive polyelectrolyte heparin/chitosan nanocomplexes. Thermoresponsive hydrogels were tested for gelation temperature, gel dissolution and in vitro heparin release, whereas polyelectrolyte nanocomplexes were physico-chemically characterized, as well as tested for in vitro cytotoxicity and in vitro heparin release. Hydrogel combined of two poloxamers demonstrated the highest gelation temperature (28.6 C), while the addition of hydroxypropyl methylcellulose prolonged gel dissolution. On the other hand, nanocomplexes’ dispersions, prepared at 1:1 heparin/chitosan mass ratio and in the concentration range 0.375–1.875 mg/mL, demonstrated mean diameter 34 mV. Pharmacokinetics of selected formulations (thermoresponsive hydrogel, nanocomplexes and a dual system consisting of nanocomplexes incorporated into thermoresponsive
hydrogel) were studied in rats. Heparin plasma concentration-time profiles revealed a double-peak phenomenon, probably due to heparin diffusion inside the polymer matrix and gel dissolution. Pharmacokinetic parameters were determined by a non-linear mixed effects modeling approach. It was
demonstrated that thermoresponsive hydrogel with heparin/chitosan nanocomplexes enabled the lowest absorption rate of heparin into systemic circulation and provided heparin concentration above the prophylaxis threshold for 5 days. In situ gelling thermoresponsive matrix combined with chitosan nanocomplexes present a promising delivery system for heparin, requiring less frequent administration during long-term treatment
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
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