1,721,035 research outputs found
Hybrid membrane containing cyclodextrin nanosponges for innovative active packaging
Full text linkFood packaging has multiple scopes i.e.: protection, communication, containement etc. but more recently other performances were requires such as to reduce preservatives and increase food safety. Actually active packaging can be intended as an innovative packaging that allows the extention of the shelf life of the products ameliorating or preserving their original qualities. Organic polymers are often the material of choice for these applications. Nevertheless, their properties not always meet the requirement of the industries. More recently, the incorporation of certain components in the packaging films can favour the release or the adsorption of the desired substances from or into the packaged food so prolong the shelf life and sustain the quality, the safety and sensory characteristics of the food
Cyclodextrin nanosponge for the GSH-mediated delivery of Resveratrol in human cancer cells
No full textSmart drug delivery systems are required for the site-specific drug targeting to enhance the therapeutic efficiency of a drug. Resveratrol (RV) is a polyphenolic compound with anti-cancer activity. However, its poor aqueous solubility and non-selectivity are the major challenges for its employment in cancer therapy. In this work, we present the synthesis of RV-loaded glutathione responsive cyclodextrin nanosponges (RV-GSH-NSs) to improve the therapeutic efficiency and selective delivery of RV. The drug loading and encapsulation efficiency were 16.12% and 80.64%, respectively. The in vitro release profile confirmed that RV release was enhanced in response to external glutathione (GSH). Nude NSs were not toxic per se to human fibroblasts when administered for up to 72 h at the highest dose. Cell internalization studies confirmed that RV-GSH-NSs were preferentially up-taken by tumor cells compared to non-tumorigenic cells. Accordingly, RV showed selective toxicity to cancer cells compared to normal cells. GSH depletion by buthionine sulfoximine, a potent inhibitor of its synthesis, reflected in a significant decrease of the NSs accumulation, and consequently resulted in a drastic reduction of RV-mediated toxic effects in cancer cells. These findings demonstrate that GSH- responsive NSs represent an effective delivery system for targeting cancer cells by harnessing the differential tumor characteristics in terms of redox status in parallel with the limitation of side effects toward normal cells
PREPARATION OF FUNCTIONALIZED COTTON FABRICS BY MEANS OF MELATONIN LOADED β-CYCLODEXTRIN NANOSPONGES
No full textBiofunctional textiles are a new category of advanced materials which combine conventional textiles with advanced drug delivery systems to obtain fabrics able to release active principles through skin. The work presents the synthesis of hyper cross-linked β-cyclodextrins nanosponges with the carbonyl group acting as bridge between cyclodextrin molecules. The result of the synthesis is a 3-D porous structure, where melatonin molecules have been complexed. The complex has been characterized by elemental analysis, DSC, SEM, XRD and FT-IR spectroscopy and the results confirm that melatonin interacts with the synthesized nanosponge at molecular level. Melatonin loaded nanosponges has been dispersed on cotton fibres, which have proved to be a suitable substrate for durable nanosponge adsorption. The in-vitro release tests from the funtionalized fabrics have shown a zero order kinetics, which is typical of a reservoir diffusion controlled system
Sustainable N-containing biochars obtained at low temperatures as sorbing materials for environmental application: Municipal biowaste-derived substances and nanosponges case studies
Full text linkBio-based substances (BBS) obtained from composted urban biowaste and nanosponges obtained from β-cyclodextrins (βCD) were used as green source to produce biochar via pyrolysis performed under mild conditions. Pyrolysis conditions were optimized by means of TGA analysis, and different temperatures of pyrolysis were investigated. The resulting carbonaceous materials were characterized with several physicochemical techniques (elemental analysis, FTIR spectroscopy, XRD, SEM, surface area analysis, and zeta potential measurements). Additionally, the adsorption capacity of such materials was tested toward the removal of charged dyes from aqueous environment. Isothermal experiments carried out at circumneutral pH indicated an important charge-selectivity, which encourages their use as sustainable alternative materials in wastewater purification treatments. Moreover, the analysis of the adsorption capacity as a function of specific surface area of materials suggests the strategy to obtain carbonaceous solids with enhanced capacity in capture of polar molecules
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
- …
